Why does my Mercedes C class run rough off-idle?

21 people found this helpful. Hmmm, so what you’re saying is it idles ruff but passed that part of the test and runs smooth off-idle but fails that part because it’s running too rich ( too much fuel). If you had a vacuum leak at the throttle body you’ll be running lean not rich as you are now.

What to do if your car has rough idle?

12 people found this helpful. For rough idle problem check the fuel pressure regulator (on injection system @ front top of motor) it has a small rubber vacuum line on it, with the engine running; gently pull off the vacuum hose and hold it about 1/4 inch away from nipple.

Why is my Mercedes C class engine not working?

One Mercedes specialist told be that my cars engine is a gonner and the timing chain and gears were also damaged. Another one told us that our ECU was faulty and then suddenly there was no pressure on the one valve and so the so-called list of difference diagnosis started.

What kind of engine does a Mercedes C180 have?

Hi everyone – I am driving a Mercedes C180 2004 model, at first it only occasionally started misfiring when low revs or stopped at a stop street. The idling sounded very erratic as well. It only got worse during the past year. One Mercedes specialist told be that my cars engine is a gonner and the timing chain and gears were also damaged.

What causes a car to have rough idling?

Rough idling can be cause by a couple of things, vacuum leak somewhere in the intake, a dirty throttle body.

What makes a Mercedes C class run Ruff?

Dirty injectors ( irregular spray pattern, fuel comes out in a stream instead of a fine atomized spray) that will sure to make the car run ruff and run rich 4.

Rough idling can be cause by a couple of things, vacuum leak somewhere in the intake, a dirty throttle body.

Dirty injectors ( irregular spray pattern, fuel comes out in a stream instead of a fine atomized spray) that will sure to make the car run ruff and run rich 4.

Why is my Mercedes Benz W210 running rough?

Many times, a lean running condition can be traced back to a cracked or torn boot in the system. A good quick way to check the overall health of the system is to take the oil filler cap off with the engine running. If the system is in good shape, the idle of the engine should drop and the car will run rougher.

Why does my Mercedes Benz have a vacuum leak?

This is due to the extra unmetered air flowing through the oil filler port. If there is no change in the vehicle’s idle, then you probably have a vacuum leak somewhere in the system. Don’t forget to check places where vacuum leaks may not be as obvious, such as the oil filler cap, the dipstick and also the valve cover.

Where does air leak in Mercedes Benz W210?

Just be sure to check all possible places air can leak in between the cylinders and the ICV. This also includes the oil dipstick O-ring, the oil filler cap, valve cover gasket, PCV valve and also the intake manifold gaskets. Sometimes, the process of eliminating all of the leaks can be quite frustrating.

What are the common problems with Mercedes diesels?

Here are some common problems that affect many Mercedes-Benz diesel models including E350, ML350, GL350, R350, Sprinter, R320 CDI and BlueTec models. Common problems Diesel Particulate Filter. As Mercedes DPF traps and holds soot, with time it reaches a point when it needs to be ‘emptied out’. This is done by regeneration.

Is there a problem with the throttle sensor on a Mercedes?

Mercedes-Benz throttle body or throttle position sensor found on C-Class, E-Class, S-Class, CLK-Class, SLK-Class may fail causing idle issues, no idle or poor acceleration. Symptoms of defective Mercedes throttle body or throttle position sensor include:

What should I do about my Mercedes slk230 low idle problem?

Solutions will vary from vehicle to vehicle. This just happens to be a Mercedes SLK230 and the problem was the gas pedal position sensor, but other vehicles or even this vehicle may have the same symptoms but have a different solution. 1. Ignition coils 2. Coil wires and connectors 3. Egr vacuum switching solenoid valve 4.

Why does my Mercedes Benz engine misfire so often?

Engine misfires are one of the most common problems we see in many Mercedes-Benz cars. To be honest, it is not because MB cars are weak in this area, but because most owners forget that spark plugs are wear items and need to be replaced at the recommended intervals.

How many spark plugs does a Mercedes Benz have?

Rember that Mercedes-Benz V6 and V8 engines utilize two spark plugs per cylinder. That is typical in Mercedes-Benz engines such as M112 M113 M272 M273 found on E, C, S, CL, CLK, ML, GL, G, R, SLK Class. For example, if you have an E320 (M112 engine) or E350 (M272) your car has six cylinders but requires 12 spark plugs.

What to do if Mercedes check engine light is on?

1. Turn ignition to position II. All dash lights should be on. Don’t start the car. 2. Locate the OBD-II port under the dashboard. Location of OBD II port used to retrieve Mercedes-Benz fault codes. 3. Plug your OBD II scanner and let it turn on. Use an OBD II scanner to check why the Check Engine Light is ON.

What happens when catalytic converter is clogged in Mercedes?

If your catalytic converter is clogged you will notice a drastic drop in fuel efficiency and real struggle getting your Mercedes to accelerate. If the cat is completely clogged your car won’t even start.

What causes a Mercedes to go into lime home mode?

If you are reading a P0301 through P0312 code plus another code, let say P0100. It is very likely that the P0100 fault code which refers to a malfunction in the mass air flow sensor circuit is also causing the misfire codes and even a limp home mode. Lime home mode means the transmission gets stuck in gear, typically in second gear.

What causes a car to stall while idling?

STALLING DUE TO LOW FUEL PRESSURE If the engine stalls while idling or driving, the engine may be running out of fuel or not receiving enough fuel pressure to keep it running. The most likely cause of this kind of stalling would be a fuel pump that is not spinning fast enough or is intermittently cutting out.

When does a car have a rough idle?

November 27, 2017. It’s easy to tell when your car has a rough idle: When you start the engine, it won’t run at a steady rate. It may almost stall, or it may run at varying RPMs without your putting your foot on the gas, or it may do both.

Why does my engine stall when the EGR is open?

This is because the temperature is lower so fuel does not burn at the optimal temperature and as a result is less efficient. Stalling when the engine idles like a rough idle is usually caused when the EGR valve is permanently open and is constantly letting exhaust gases into the EGR system.

When does the engine stall in a Mercedes?

There are never any notifications on the dash or any signs of it beginning to fail. This typically happens when I’m slowing down at an intersection or just driving slower in traffic.

What causes random engine stall, decreasing idle too?

Disconnecting the MAF will set several ECU parameters to a default mode, so it’s effectively bypassing lots of inputs. Thus, even if it runs better it might be one of the other sensors that it is bypassing that is the real issue. So, check codes.

Why does my car engine run rough while idling?

When your car engine runs as it should, everything should be smooth without any noise. When any number of things goes wrong, the engine can start running rough, especially while idling. By understanding the causes of a car engine that has a rough idle, you can resolve the issue easily.

What happens to the engine when left in idling position?

When the engine is left in idling position, it maintains a steady but low rate of revolution approximately 1,000 RPM. The RPM needle stays constant, and this indicates that the vehicle’s engine is receiving the correct amount of air and fuel.

What causes a rough idle on an air conditioner?

A clogged air filter will not allow clean air to pass through causing a rough idle. To remedy the situation, have your air filter replaced with a new one and also have the housing serviced to clean any dirt buildup. 7. Dirty Oxygen Sensor

What causes fuel injectors to get clogged with carbon?

Your fuel injectors operate in a very hostile environment, with high temperatures and fuel pressures. The injectors’ spray nozzles have tiny openings, which can get clogged from the carbon that is a byproduct of the combustion process.

How to troubleshoot Mercedes Benz air suspension problems?

Learn how to troubleshoot Mercedes-Benz Air Suspension Problems. You decide to buy a Mercedes-Benz, maybe an S-Class, CLS-Class, R-Class, CL-Class or E-Class. One day you hear of other Mercedes-Benz owners having suspension problems. The next day you start having air suspension problems yourself.

Is it normal to have a rough engine idle?

Consequently, rough engine idle, is not a normal operating condition. As a result, there can be a variety of reasons for a, rough engine idle. It is best to try to diagnose and fix a rough engine idle; before it gets worse and before it gets expensive!

What does it mean when your car Idles smooth?

Smooth idling indicates that your engine’s fuel and air are mixing just right. What is rough idling? If your vehicle’s idle is rough, possibly rising and falling, or having difficulty maintaining a steady rate of rotation, you may have a problem that needs fixing.

Why does my car idle at a higher RPM?

This also creates a vacuum within the intake manifold. These hoses can wear out over time and a leak may develop. If too much air gets mixed in with the fuel, it will cause your engine to misfire. This will result in a rough idle, usually at a higher RPM.

What’s the problem with my Mercedes C class?

21 people found this helpful. its the same problem in my 2002 c200,it caused by the nuetral pooly and the engine fountdation……. 78 people found this helpful. Is that an easy fix?, 25 people found this helpful. you have to put arround 12-15 grands for the fix and have to order parts from company. 14 people found this helpful.

How can I tell if my idle control motor is working?

Look for a difference in idle speed. Allow the engine to run for a minute so it settles to a consistent idle, then take note of any difference in the idle RPMs versus the idle you observed earlier. If the idle has not changed at all, it’s likely because your idle control motor has not been functioning.

Why does my 07 C230 not start in cold weather?

The fuel pump could be weak or you could have a fuel line leak due to shrinking seals in cold weather. have you ever found the source to your cold starts problem? I have 07 c230 flex with 62k miles as well and my car started having exactly the same symptoms just like yours.

Is the 07 C230 flex hard to start?

I have 07 c230 flex with 62k miles as well and my car started having exactly the same symptoms just like yours. When my car sits for longer period of time and especially when it sits outside in cold weather, it is very hard to start.

Why does my Mercedes not start in cold weather?

When I park it in my heated garage over night, it starts a little easier in the morning, but still hesitates a little. When I leave it over night outside in cold weather, the car keeps cranking in the morning with no sign of firing up.

What are the symptoms of a bad throttle / accelerator pedal?

Symptoms of a Bad or Failing Throttle/Accelerator Pedal Position Sensor. $79.99 – $89.99. Average rating from 4,829 customers who received a Check Engine Light is on Inspection. The days of having to constantly adjust the throttle cable due to a loose nut on the carburetor are long gone.

Why was the C230 Kompressor made in 1999?

Because adding a supercharger means a big power increase. Something that the entry level 4-cylinder Mercedes-Benz C-Class sedan definitely needed. And in the 1999 C230 Kompressor, Kompressor being German for supercharger, the difference is immediately apparent. But first, the numbers.

What kind of mileage does a 1999 C230 get?

EPA estimates are 21 city/29 highway, while we managed 24 miles per gallon in every-day driving. But while the drivetrain sees big changes for 1999, the C230’s double-wishbone front and 5-arm multi-link rear suspension remains the same.

How to know if your Mercedes C class is idle?

Check for vacuum leaks with a smoke generator injecting smoke into any vacuum line and see where the smoke comes out. That’s a leak that needs to be plugged. Other than that, there is the Idle Control Unit computer and the Idle Control Adjustment Valve, all which control the idle.

What’s the price of a 1999 Mercedes Kompressor?

With more power and extra equipment, the Mercedes-Benz C230 Kompressor still carries a very reasonable base price of $31,795. With premium paint, sunroof, and CD changer, our test car carries a final price of $34,255. Now ask yourself this question: For the same money, would you rather have this car or a Lexus ES300?

Why does my Mercedes have a low idle?

This video shows several different solutions to the low and/or rough idle that many vehicles have. Solutions will vary from vehicle to vehicle. This just happens to be a Mercedes SLK230 and the problem was the gas pedal position sensor, but other vehicles or even this vehicle may have the same symptoms but have a different solution. 1.

Why does my Mercedes C class run lean?

You see with a vacuum leak, unmetered air is getting into the engine without passing through the air mass sensor, therefore the computer can’t account for that unmetered air and can’t calculate the correct fuel trim hence more air than fuel and the car runs lean.

Can a mercury motor have a smooth idle?

You were told right,these motors do not have a smooth idle.There’s even a warning in the mercury service manuel which states (DO NOT ADJUST CARBORATORS TO ACHIVE A SMOOTH IDLE)This is because the engine will be running to lean at this point.

What’s the root cause of mercury 2-strokes’rough idle?

I’ve been told rough idle is the nature of the beast and is common for all Mercury 2-strokes as they are optimized for riding. Fair enough but what’s the root cause of rough idle? (assuming all components work as designed)

Why does my 90 elpto stall at idle?

My 90 ELPTO is quite rough at idle, even stalling occasionally. I’ve been told rough idle is the nature of the beast and is common for all Mercury 2-strokes as they are optimized for riding. Fair enough but what’s the root cause of rough idle? (assuming all components work as designed)

Is there a problem with rough idle when warm up?

So, once there’re visible signs of rough idling, trouableshoot the problem without causing any further delay. As reported by Car From Japan experts, most Makes getting this engine rough idle after warm up are: Though the problem is not common but drivers of the Makes had their car serviced at garages for Rough Idle When Warm.

What causes engine to run rough after warm up?

Most likely, the causes of rough engine idle crops from the basic functional components like direct fuel injectors, PCV valve, EGR valve, Oxygen sensors, vacuum leaks, air filter, and spark plugs or wire. Now, let’s fix the issue when engine runs rough after warm up in sequence and later troubleshoot the actual cause of it. 1.

Why does my Mercedes C220 have a rough idle?

While there are a variety of reasons your Mercedes-Benz C220 has a rough idle, the most common 3 are a vacuum leak, an issue with the spark plugs, or a problem with the ignition coil.

Is there an issue with my 2002 C240?

I have a 2002 C240 and I’ve recently had an issue while driving. I’ve read similar posts to this one but someone always writes their own issues that are different from this matter.

Why does my Mercedes engine misfire when I change the spark plug?

Keep this in mind especially if you change the spark plugs in your Mercedes and you are still getting an engine misfire. Fuel pressure can cause engine misfire as well.

How to diagnose an engine misfire on a Mercedes?

To diagnose an engine misfire on a Mercedes all you need is a generic OBD II code reader that can be bought in some cases for under 20 at your local auto parts store or on Amazon’s Best Selling OBD II scanners list.

What are the downsides of a rough idle?

The downsides of a rough idle can be reduced fuel economy, poor performance, starting issues, or potential major engine problems in the near future. It is best to try to diagnose and fix a rough idle before it gets worse and before it gets expensive! What Is idling? Let’s start with a definition of idling.

The injectors’ spray nozzles have tiny openings, which can get clogged from the carbon that is a byproduct of the combustion process. This leads to less fuel going through the injectors, leading to noticeably poor performance and possibly rough idling.

How many miles does a Mercedes spark plug last?

They are wear and tear items. Standard copper spark plugs last up to 30k miles while iridium and platinum spark plugs can last over 60,000 miles. If your Mercedes-Benz has over 80,000 miles and still has the original spark plugs, it makes sense to change the spark plugs before you pour money on any other repair.

What happens when a Mercedes engine misfire occurs?

As soon as an engine misfire occurs on a Mercedes-Benz, you will notice poor engine performance and strange vibrations that in some cases can be felt even in the driver cabin. The first thing that comes to mind when you get an engine misfire is: “This is going to be expensive.” Take a deep breath because in most cases it doesn’t have to be.

What causes the throttle body on a Mercedes to fail?

When there are throttle body malfunctions the wrong amount of air enters into the engine causing problems with air/fuel mixture ratio. Here is a close up picture of a Mercedes throttle body. Mercedes throttle bodies made by Bosch and VDO may fail. Luckily these units are repairable.

Can a clogged catalytic converter cause a misfire?

A catalytic converter that is clogged and is restricting the exhaust gasses from leaving the engine can also trigger multiple cylinder misfire. If your catalytic converter is clogged you will notice a drastic drop in fuel efficiency and real struggle getting your Mercedes to accelerate. If the cat is completely clogged your car won’t even start.

What kind of harness do Mercedes cars have?

We all know that all 1992 to 1995 S-class and SL-class, 1993-1996 E-class, 1994-1996 C-class Mercedes cars have major problem: biodegradable wiring harness insulation. Plastic insulation flakes off on main engine harness, throttle body harness, starter/alternator harness, Mass Air Flow meter harness ( V12 engines) .

How long does it take to rewire a Mercedes harness?

Some harnesses have around 400’ of wires to replace. Given that I replace one wire at the time to eliminate possible errors and maintain original wire length for all plugs to reach their destinations repair takes very long time. Some harnesses take me one day to rewire while others take few days depending on the model.

When do I need to replace my wiring harness?

If your car engine stalls, runs rough, misfires, “check engine” light comes on, lots of trouble codes stored in computer memory, wiring harness insulation falling apart, your mechanic tells you to replace wiring harness-rewire or replace it.

What kind of wiring does Mercedes 92 500SEL use?

On 92 500SEL I used heat resistant wiring, heat shrink tubing, friction tape, epoxy. The job was very labor extensive and took me around 8 hours. Some plugs could no be saved as plastic was very brittle. Metal contacts were reused and new wires soldered directly to them. Finished harness looked close to factory and worked without any flaws.

Why does my Mercedes Benz hesitate to accelerate?

-Air filter and throttle body are clean. -I haven’t changed the MAF in the 2 years that I’ve owned the car, and i tried running the car with the MAF unplugged; the problem was the same except now the idle was constantly low and rough. The problem is slowly getting worse. I’m contemplating ordering a new MAF or maybe a set of new coils..

What causes a cylinder to misfire in a Mercedes?

In most cases, a cylinder misfire is caused either due to old spark plugs that need to be replaced. A failed ignition coil or a bad spark plug wires. If none of the above fixes your misfire problem carefully analyze the fault codes, it is possible that misfire may be indirectly caused by another problem in the engine.

Why are the spark plugs on my car not working?

The spark plug delivers electric current from the ignition system to the combustion chamber and creates a spark to ignite the fuel/air mixture. Over time, the spark plugs get damaged due to the carbon deposit or other waste product from the combustion process. This reduces the amount of power generated after the spark plug ignites.

Why does my car idle at rough idle?

Is the EGR valve supposed to run during idle?

However, this EGR valve isn’t supposed to operate during idle, at wide open throttle or before the engine is warmed up. If it runs at any of these times, the performance of the engine is affected.

Why do we need Mercedes genuine spark plugs?

When you drive a luxury vehicle, your parts should function as such. That’s why Mercedes Genuine Parts makes sure that our OEM spark plugs are crafted with only the utmost care and quality to give your Benz the power it deserves.

What causes idle surges on a car ECM?

Idle surging can be caused due to other issues in the car, but if it happens in conjunction with other throttle position sensor symptoms, the culprit is often the TPS. At idle, the ECM will not get the correct information and the throttle will variate randomly causing idle surges.

Why does my car stall at low rpm?

The will likely force your computer to stall the engine and only allow it to run at low RPMs, which means the car will only move at slow speeds. This is a safety feature enforced by the computer so that your engine doesn’t get too damaged.

What to do if your fuel injector is clogged?

Once the injectors are clogged or restricted, an injectable solution will need to be introduced into the system. Fuel injectors do often contain a small filter which is easy to replace if the injectors have become clogged, which is much cheaper than replacing them.

Keep this in mind especially if you change the spark plugs in your Mercedes and you are still getting an engine misfire. Fuel pressure can cause engine misfire as well.

What causes a spark plug to get filled with gasoline?

Then, when the spark plug enters the carburetor to provide the spark that will ignite the mixture of gasoline and air, it can dip into the excessively high level of gasoline. If a spark plug gets gasoline in it, the significant problem is that the moisture created by the gasoline makes it impossible for the spark plug to generate sparks.

Can a clogged fuel injector cause engine trouble?

There are many ways clogging can affect the injectors. Click to enlarge. The importance of cleaning clogged fuel injectors cannot be overstated. But how to tell if your fuel injectors are clogged? Or faulty? Engine trouble is rarely easily identified, but there are symptoms for every issue, symptoms that everyone can learn to notice.

Can a fuel injector be blocked by a spark plug?

Blocked diesel injector symptoms are similar. And in many cases can lead to an easier diagnosis of the issue, as the lack of spark plugs in diesel engines mean that there’s one less potential cause for the problems.

Why does my fuel injector make a bad sound?

Rough idling/engine stalling – uneven supply of fuel during idling can cause RPM to fall too low and result in stalling. For example have a listen to this bad fuel injector sound: In addition to performance issues, you will also have to deal with:

There are never any notifications on the dash or any signs of it beginning to fail. This typically happens when I’m slowing down at an intersection or just driving slower in traffic.

What should I do if my Mercedes Benz won’t start?

Start the car and you should be able to get around 60 psi. When the engine is running and when you turn off the engine the pressure should stay steady. Always perform this test on a cold engine. Next, make sure that the fuel injector connections are secure and not loose. Check the fuel pump and the fuel pump relay.

What are the problems with a Mercedes Benz?

Top 5 Mercedes-Benz no start problems 1 Engine Click, No Start 2 Engine Dies Right After It Starts 3 Car turns over, but it won’t start 4 The car makes a clicking noise but won’t start. Hint: Starter Problem or Low Battery 5 Key will not turn the ignition More …

What causes a Mercedes Benz to not start?

In most cases you will get a fault code related to one of the following: 1 ECM / PCM computer failure 2 Camshaft position sensor 3 Shifter Selector module 4 Fault codes related to driver authorization or immobilizer 5 Electrical problems

What should the RPM be on an idling car?

When you start your engine, and just let it run without pressing on the accelerator or putting it into gear, that’s idling. A properly idling engine should be able to maintain a steady but low rate of revolutions, somewhere in the vicinity of 1,000 RPM.

Are there any problems with the Mercedes C320?

Common Problems The most common problem with the Mercedes C320 concerns its 3.2-liter 215-horsepower V-6 engine. Affecting all model years apart from the 2006 version–and most severe with the 2001 and 2002 years–the problem lies specifically with its mass air flow sensor, which the engine uses to measure the amount of air it consumes.

How much does a 1999 Mercedes E Class E 320 cost?

Used 1999 Mercedes-Benz E-Class E 320 Sedan 4D Prices | Kelley Blue Book See pricing for the Used 1999 Mercedes-Benz E-Class E 320 Sedan 4D. Get KBB Fair Purchase Price, MSRP, and dealer invoice price for the 1999 Mercedes-Benz E-Class E 320 Sedan 4D. View local inventory and get a quote from a dealer in your area.

How much does a 1999 Mercedes Benz cost?

For Sale Near You 11 Mercedes-Benz E-Class vehicles in your area. Used 1999 Mercedes-Benz E 320 Sedan $2,000 Private Seller Used 2001 Mercedes-Benz E 320 4MATIC Wagon $3,000 Private owner via Tred.com Used 2000 Mercedes-Benz E 320 Sedan $3,495 Selected Motors Used 1999 Mercedes-Benz E 430 Sedan $4,500 Private Seller Used 1998

What causes a Harley Davidson engine to stall?

A: Bob, the most common reason a m/c will act this way is because of an intake leak. Start the bike cold. Mist the intake flanges with brake cleaner. If your bike’s idle drops, or the engine stalls, you have an intake leak.

What causes a car to run at a rough idle?

A PCV valve leak can cause the air-fuel mixture to run too lean, and this will cause a rough idle. Proper periodic servicing of the PCV valve will prevent this situation from occurring.

What happens when the engine is running at low rpm?

When the engine is running at low RPM, lower temperatures in the combustion chambers prevent all the fuel from burning, so the flow of unburned hydrocarbon gases coming out of the tailpipe increases significantly. The Check Engine light (or Malfunction Indicator Light, MIL, depending on your model) illuminates on your dashboard.

Why does my vacuum have a rough idle?

Leaks in these hoses and in other parts of the vacuum system can be another cause of a rough idle, often because of a lean air-fuel mixture from excess air entering the system.

Why does my check engine light keep coming on?

If you have a OBD II scanner such as the one mentioned above then you can know for sure if this is your problem. Oxygen Sensor O2 You car has a few oxygen sensors typically between 2 to 4. They measure the unburned oxygen. If your Check Engien Light is on because of O2 sensor you may be getting poor fuel economy as well.

Why does my car rough idle but no check engine light?

This issue is normally caused by low fuel pressure or a faulty injector, but since you have just replaced the fuel pump, this may also be a sign of a failing idle air control (IAC) valve. This is a unit that is located on or near your intake manifold that monitors the air intake as it is mixed…

What causes a car to rough idle and stall?

My car has an automatic transmission. This issue is normally caused by low fuel pressure or a faulty injector, but since you have just replaced the fuel pump, this may also be a sign of a failing idle air control (IAC) valve.

What kind of problem does a Mercedes C230 have?

21 people found this helpful. Folks I have a 1997 C230 Mercedes, This seems to be having the same problem, but when it Idles it runs rough and when driving it is stalling out but will re-start. I had the codes checked, came up with bad cam sensor.

Why is my 2005 C180 shaking at idle?

Had codes p0306 and p0300, replaced mass air flow sensor, no help.Car runs fine at idle, but when almost hits rev limiter starts skipping and cutting back.Fuel pressure holds,chang … read more I have a 2005 C180 – I just took the vehicle out to the shops and noticed the engine was shaking the car at idle and the revs were not totally steady.

What does it mean when your engine idle is too low?

If your idle is too low, it could be the IAC not talking to the computer correctly. Disconnect the IAC connector for a couple seconds while your engine is idling. If your engine idle didn’t change, you can suspect it to be the IAC. If it is working properly, unplugging it would cause your idle to freak out.

Is the warm engine undriveable when cold?

This time it started with an idle around 1500rpm, slowly dropped to 1k, then quickly cycled back up to 1500. It did this for a minute or two, then dropped down to the rough idle, which seems to run between 500-800, kind of hunting around. Is there a key sequence that is used to help it learn? The car is undriveable when warm.

How long does a warm engine idle for?

With a steady throttle, it fluctuated between 3 and 3.5 for a couple mins, then bogged out and stalled. Next time I started it, it went to 2k intially then started hunting between 1k and 1500, with about a two sec interval. After a couple mins, fluctuated around 750, but not steady.

What causes a car to have a rough idle?

The engine can run too rich or too lean. A too-rich mixture will result in poor fuel economy. A too-lean mixture will cause a rough idle. Solution: Since the oxygen sensor is part of the emissions system, its failure will usually trip a trouble code in the engine computer.

What causes the idle speed to go up or down?

The idle air control valve is programmed to regulate and maintain the engine idle speed at a constant rate. If the valve fails or has any issues it can cause the idle speed to be thrown off. This may result in an unusually high or low idle speed, or in some cases a surging idle speed that repeatedly climbs and falls. 2. Check Engine Light comes on

What are the symptoms of a bad idle control valve?

$0.00 1 Irregular idle speed One of the most common symptoms commonly associated with a problematic idle air control valve is irregular idle speed. 2 Check Engine Light comes on Another symptom of a potential issue with the idle control valve is an illuminated Check Engine Light. 3 Engine stalling

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