Where is the idler pulley on a Mercedes?
Pull the hood release under the dashboard on the driver’s side. Remove the engine cover by lifting it. Locate the idler pulley at the front of the engine. Remove the serpentine belt. Use a 17mm socket and ratchet on the tensioner nut to unload the tensioner.
Can a bad idler pulley cause a belt to come off?
A bad idler pulley can cause the serpentine belt to come off. Once the belt comes off you will experience multiple problems if you continue to operate the vehicle. At the early stage indicating that the idler pulley is failing, you will only hear a squeaky noise coming from the front of the engine.
Do you need a Torx socket for a Mercedes idler pulley?
This is common on M112 and M113 engines from 1997 to 2007. Newer Mercedes-Benz idler pulleys (on M272 and M273 and newer models) require a Female Torx socket. Always verify by inspecting the bolt on the center of your idler pulley. Park your Mercedes-Benz in an area where you can work.
Pull the hood release under the dashboard on the driver’s side. Remove the engine cover by lifting it. Locate the idler pulley at the front of the engine. Remove the serpentine belt. Use a 17mm socket and ratchet on the tensioner nut to unload the tensioner.
What do you use to loosen a Mercedes crankshaft pulley?
You will need to use Mercedes harmonic balancer tool to hold the crankshaft pulley in place as you loosen up the 27 mm bolt. You will use the harmonic balancer tool to keep the crankshaft from turning. Next, use a 27 mm socket on the bolt to loosen it up.
What kind of breaker bar do I need for a Mercedes pulley?
You will need to use a breaker bar such as Neiko 00206A 1/2 Inch Drive Premium Breaker Bar, 24″ Length | Cr-V Steel to get this bolt loose. If you can’t get it loose you can add a cheater pipe to your breaker bar. You will be applying over 200 Nm of force to the bolt which requires is a considerable amount of energy.
Can a Mercedes-Benz radiator fan be removed?
The radiator fan can be easily removed. There are clips on the side of the fan that you need to press and pull out the fan. Before you pull the radiator fan upwards unplug the electrical connector. If you have a pre-2000 Mercedes-Benz equipped with a viscous fan, it will need to be removed as well.
You will need to use Mercedes harmonic balancer tool to hold the crankshaft pulley in place as you loosen up the 27 mm bolt. You will use the harmonic balancer tool to keep the crankshaft from turning. Next, use a 27 mm socket on the bolt to loosen it up.
You will need to use a breaker bar such as Neiko 00206A 1/2 Inch Drive Premium Breaker Bar, 24″ Length | Cr-V Steel to get this bolt loose. If you can’t get it loose you can add a cheater pipe to your breaker bar. You will be applying over 200 Nm of force to the bolt which requires is a considerable amount of energy.
The radiator fan can be easily removed. There are clips on the side of the fan that you need to press and pull out the fan. Before you pull the radiator fan upwards unplug the electrical connector. If you have a pre-2000 Mercedes-Benz equipped with a viscous fan, it will need to be removed as well.
What’s the best way to replace an idler pulley?
You can use a nail or a 5mm Allen wrench as a pin. Slide the serpentine belt off the idler pulley. It is not necessary to remove the serpentine belt completely unless you are replacing it. Use a flathead screwdriver to remove the dust cap on the center of the idler pulley.
What happens if you have a bad idler pulley?
A bad idler pulley can cause the serpentine belt to come off. Once the belt comes off, you will experience multiple problems if you continue to operate the vehicle. Power steering is difficult to turn. The alternator stops working and no longer charges the battery. Air Conditioner stops working. Engine stalls once the battery is drained.
This is common on M112 and M113 engines from 1997 to 2007. Newer Mercedes-Benz idler pulleys (on M272 and M273 and newer models) require a Female Torx socket. Always verify by inspecting the bolt on the center of your idler pulley. Park your Mercedes-Benz in an area where you can work.
You can use a nail or a 5mm Allen wrench as a pin. Slide the serpentine belt off the idler pulley. It is not necessary to remove the serpentine belt completely unless you are replacing it. Use a flathead screwdriver to remove the dust cap on the center of the idler pulley.
What’s the best way to unload a tensioner?
Use a 17mm socket and ratchet on the tensioner nut to unload the tensioner. Use a pin to lock the tensioner in the pre-loaded position. You can use a nail or a 5mm Allen wrench as a pin.
Do you need to replace the Mercedes belt tensioner?
In this guide, you will find step-by-step instructions on how to replace the Mercedes-Benz belt tensioner. While it is not required to replace the drive belt, it makes sense to replace it simultaneously as the tensioner. It is ok to reuse the old belt if it does not show wear, cracking, degradation, or drying.
What should the torque be on a Mercedes tensioner?
Torque the tensioner bolts to the recommended manufacturer specifications. Typical torque for the tensioner bolts ranges between 25Nm to 35 Nm. Check with your dealer. Install the drive belt. Make sure it is routed on all the pulleys properly. If the belt does not reach, make sure it is not sitting on top of one of the pulleys.
A bad idler pulley can cause the serpentine belt to come off. Once the belt comes off you will experience multiple problems if you continue to operate the vehicle. At the early stage indicating that the idler pulley is failing, you will only hear a squeaky noise coming from the front of the engine.
How big is the bolt on an idler pulley?
The bolt size is 10mm 1.5 thread pitch here is a video of an idler pulley being replaced on a similar car the process is the same. helpful? Bad idler pulley–Bearing actually fell apart when I was investigating a noise under the hood. Removed the bolt holding the pulley to the block bracket and got a Dayco replacement.
Do you need a Torx socket for a idler pulley?
Newer Mercedes-Benz idler pulleys (on M272 and M273 and newer models) require a Female Torx socket. Always verify by inspecting the bolt on the center of your idler pulley. Park your Mercedes-Benz in an area where you can work.
Why does my idler pulley squeal when I Turn on the engine?
Another common symptom of a possible issue with the idler pulley is squealing from the engine belts. If the surface of the idler pulley wears, or the pulley seizes or binds it may cause the engine belt to squeal as a result of it rubbing against the surface of the pulley.
When does an idler pulley need to be replaced?
Most engines use one idler pulley, and one tensioner pulley, though some designs do use more than one idler. Over time, idler pulleys will eventually wear out and need to be replaced. Usually a bad or failing idler pulley will produce a few symptoms that can notify the driver of an issue. 1. Visibly worn pulleys
What does it mean when your idler pulley rattles?
Average rating from 138 customers who received a Loud squealing or rattling is coming from engine Inspection. Idler pulleys are engine pulleys that are responsible for guiding and tensioning the engine drive belts.