At what engine state is vacuum test done?
More About, Engine Vacuum Testing Remember that engine vacuum is just air pressure, lower than atmospheric pressure. So, the starting point to evaluate engine vacuum is, at the intake manifold. When you connect a gauge to a port on the intake; you’re measuring manifold vacuum.
What should my vacuum gauge read?
Idle vacuum for most engines is about 18 to 22 in. -Hg, but some may produce only 15 to 17 inches at idle. (Remember what we said about experience.) If vacuum is steady and within these ranges, the engine and fuel and ignition systems are operating normally.
Does vacuum increase with rpm?
Vacuum decreases with load, plain and simple. RPM has little or no effect.
How does the timing chain work on a GM engine?
On most GM vehicles with V-8 or V-6 engines, a metal timing chain is used to connect the camshaft to the crankshaft. This causes the camshaft to move in synchronization with the crank, causing the camshaft to open and close the valves in the proper sequence and duration for the intake, power stroke and exhaust cycle. …
What does GM’s variable valve timing do to the engine?
Twisting pretty much describes what GM is doing with its camshafts today. Valve timing improvements used to be accomplished via camshaft lift, duration and lobe separation. Those values were set in stone once the engine was assembled and were strictly the province of engine designers and performance enthusiasts. Not so with variable cam timing.
How did GM change the timing of the camshaft?
Twisting pretty much describes what GM is doing with its camshafts today. Valve timing improvements used to be accomplished via camshaft lift, duration and lobe separation. Those values were set in stone once the engine was assembled and were strictly the province of engine designers and performance enthusiasts.
Why is the timing chain on my GMC Canyon going south?
I am suspecting the stumbling behavior is probably both the IAC sensor on the throttlebody and the oil level sensor in the engine going south and also need replacement, hence my desire to totally replace the engine at this point with a newer 2007 2.9L I-4 I’ve found here locally.
Twisting pretty much describes what GM is doing with its camshafts today. Valve timing improvements used to be accomplished via camshaft lift, duration and lobe separation. Those values were set in stone once the engine was assembled and were strictly the province of engine designers and performance enthusiasts. Not so with variable cam timing.
Can a GMC Canyon timing chain be replaced?
The scoring on the cams is common but too much scoring is bad and theres actually a TSB or PI (can’t remember) that talks about replacing the cams and valve cover with an updated cover and PCV to not allow moisture into the head. Oh and I doubt the chain has stretched enough to reach the limitations of the tensioner, its pretty long.
Is there a timing drive replacement for GM Ecotec?
This video covers the timing drive system replacement for GM’s Ecotec platform which includes 2.0L, 2.2L, & 2.4L displacement engines.
Twisting pretty much describes what GM is doing with its camshafts today. Valve timing improvements used to be accomplished via camshaft lift, duration and lobe separation. Those values were set in stone once the engine was assembled and were strictly the province of engine designers and performance enthusiasts.