Finding TDC on 3100v6

[rich_e777]

Going to be doing a compression test on my 3100 v6 and I`m not %100 sure on finding TDC to get an accurate reading. What is the best way to go about finding TDC and might there be any indication marks on the crank pulley? I don't have access to someone who has done this before which would e ideal.

[Crazy K]

You don't need TDC to do a compression test.

 

rather than explaining too much. here you go:

http://www.dummies.com/how-to/content/how-to-check-an-engines-cylinder-compression.html

You can unplug the connectors that go to the Ignition control Module under the coils, and disable fuel by removing the relay in the electric box and the front right of the engine bay.

[rich_e777]

I think I might have gotten another test mixed up with this one. Thanks though. Its the leak down test that requires TDC right?

[RobertISaar]

leakdown does require TDC.

 

also, if you unplug the crank sensor alone from the ICM, that should disable fuel and spark.

[rich_e777]

Good to know, Took it out for a bit today and don't even think either are necessary anymore but I would like to know how to do both personally. I`ve been thru a few cans of brake cleaner/ starting fluid looking for any vacuum leaks and also tried a makeshift smoke test from a few vids I saw and neither showed any evidence. Trying to figure out that sound from the plenum and thought maybe an intake valve, but the sound is constant. The compression test is to rule out a bad piston ring.

[RobertISaar]

depending on the type of noise you're hearing, could be normal. stock airbox/tubing with the donkey dong?

[Crazy K]

The more you know!

 

TDC for each cylinder can be found with a dowel rod sticking into the spark plug hole and finding the point when it is the highest... It works best on an LQ1, but with a little care you could do the same even with a 3100.