Compression..........

[97f150]

Okay guys, back to the problem I posted about here:

http://www.bobistheoilguy.com/forums/ubb...rue#Post2374883

This thread will give the back story. Anyhow, a week ago I thought it was the coil as it firing on the #2 cylinder, which is the dead cylinder. New coil came in a few days ago and I changed it out today. We now have fire for all cylinders from the coil but #2 is still dead. I went out and rented a compression gauge from AZ and checked the compression as follows:

Warm car up to operating temp
Remove all plugs
Screw gauge into plug hole, open throttle all the way and crank. Took down highest reading.

I repeated this 2x and came up with the same numbers. Could someone decipher this for me?

#1: 120 psi
#2: 90 psi
#3: 120 psi
#4: 110 psi

I have no clue and no luck looking around online on what the numbers are supposed to be. As always any help is very much appreciated.

 

[snapcrackle12]

I have seen valve issues with these, not seating properly. The cel would only come on while cruising down the highway. They were still under factory warranty when this happened so we sent them to the dealer. The dealer would replace the head and that would fix the issue. I would recommend to due some research on this one, and if it get to be to much to take it to a good diagnostic tech.

 

[QuOk]

Valves are known to stick on Aveos.
Probably just enough to leak compression.

 

[97f150]

My step dad told me only tonight, I forgot to add this to my original post, that when the car started running bad he head a banging type noise. He said its a noise he has never heard before, not even when the timing belt broke and all the valves were grenaded. Dont know if that helps any. What can be done about a sticking valve, and would it kill a cylinder like that? I already told him I have done just about all I can, but if there is something to try, even a silly trick while holding my mouth a certain way, I will.

 

[snapcrackle12]

Is it a popping noise like combustion coming back through the intake?

 

[97f150]

Not really. Does not make any noise now to speak of, just runs like, well....like its missing. Nothing outstanding though.

 

[cmf]

I would pour a little 30 or higher weight motor oil into the 90 PSI cylinder and take it again. If it improves then it's the rings, if it doesn't improve then it's most likely a valve. The motor oil acts to help seal the rings.

On a side note, I'm surprised it ending up being the coil pack in your other post. That's a really early failure point for a coil pack. 35k is really early for a timing belt as well. I hope they don't have any more issues after the compression problem is solved!

 

[snapcrackle12]

I would do the wet compression test, and the go from there. Don't use too much oil though.

 

[97f150]

I will give that a shot when I can get back down to their house if they don't have it in a shop by then. CMF, I hope they sell or trade the sucker in once this mess is sorted out.

 

[mechtech2]

A leak down test is needed.
That is the air pressure type of test.
You need different equipment.
This will show a tech either/or/both rings or valve problems.

 

[97f150]

I appreciate all the advice and info guys. Mechtech is absolutely correct, and this problem is out of my league. I have narrowed it down to an internal problem, and the car being an hour away from where I live makes it an impossible job to do in an apartment parking lot without proper tools in hand. I have told my them this last night and they are making plans to have it towed to a shop nearby to have the actual problem found out and fixed. Thanks again.