compression test results please help

watchunglava

watchunglava

New member
ok i have been consuming a lot of oil latley .

around 10 qts since my last oil change 3 months ago.

all my spark plug gaskets are leaking but i doubt that its whats causeing so much loss.

no other visable leaks or oil in the coolant.

i ran a vaccum test and a dry compression test .

compression checked out at

cyl#1 160

cyl#2 170

cyl#3 170

cyl#4 168

and here is the vaccum test



everything looks good so im at a loss. an advise , input or help?

 
Your wrx seems to have much higher compression then what sti's typically have. If those numbers are correct your compression should be fine since all the cylinders are within 10% of each other. that's interesting.

 
if it's an NA motor pull a few of your vac lines and see if they are wet

how many miles?

 
is there a wet residue on the exhaust tip?

and are you filling this yourself?

that is a hell of a lot of oil to be burning..

 
27k !! Good idea with the vac lines. I went outside to check them out and they are dry.
Click to expand...
With 27k its under warranty. Bring it to the dealer, let them deal with it. 1qt per 1000 miles is considered acceptable, but even that's a little high.

Your car should not be burning oil at 27k.

 
Your compression is nice! You are withing 10 of each other. You numbers look really good.

Have you drained out your checked your cooling system? Just amazing you are loosing so much oil and there is no trace of it. Not to many placed it can go.

Exhaust, vacuum lines, or cooling system. Or just leaking out of the motor which would be obvious. The oil would be obvious if it was coming from exhaust also.

You said you checked all the vacuum lines and its not there.

Let me call my dad he is an ASE certifed tech in like everything mybe he will have some ideas for you.

 
is there a wet residue on the exhaust tip?
and are you filling this yourself?

that is a hell of a lot of oil to be burning..
Click to expand...
Yea it really is. Too much!

the tail pipe does have a ring of black gunk coating the tip. But its not like any more gooey than normal. Just a layer of black carbon soot.

 
Change your PCV valve. Change the Valve cover gaskets and tube seals.
Click to expand...
Funny I was about to tell him to change his PCV valve.

Dad said you could be still getting some blow by the valve. also could be blowing back into the breather filter.

 
I've seen some PCVs cause 1qt/day oil loss. Generally something like that only happens on a higher mileage car, and a very old PCV.

On NA cars its wicked easy simple to change. Next to the coil there is a tube that comes off the intake and goes down below to the coil. The tube is connected directly to the PCV in the block. You'll need a deep 19mm and a long extention. Its part of the 30k service.

 
A PCV would be. imho

An oil consumption might not be. There would be a lot of riff raff and red tape to jump thru to verify that. I've never had to go thru it with Subarus, but many times with Saturns. My guess would be the customer would have to get an oil change at the dealer and oil level exactified, inspected for leaks internally and externally. Then the owner would have to come in once a week for a few weeks to have the level checked and recorded, and the car inspected for leaks. Then the regional service rep would have to be consulted. Then repairs begin if deemed necessary.

In this case it should be easy to confirm the excessive consumption, if it was not the PCV, which it most likely is. If a PCV replacement did not fix it, then the most likely route would be replacing the rings and/or valves and valve seals. And a thorough investigation to find out the cause of valve seal or ring failure on a NA engine would go on..and on and on. It just doesn't happen very much if at all on the NA cars and the alarms would go off at headquarters.

-----Added 4/29/2009 at 07:56:19-----

so did anyone else watch that vacuum gauge video? The needle looks like something straight out of a cartoon. Its all wiggly and floppy and *****. Is that from the video or a silly guage?
default_additional_iam.gif


 
so did anyone else watch that vacuum gauge video? The needle looks like something straight out of a cartoon. Its all wiggly and floppy and *****. Is that from the video or a silly guage?
default_additional_iam.gif
Click to expand...
default_biggrin.png
I did now! It's like the rubber pencil trick!

 
A PCV would be. imho
An oil consumption might not be. There would be a lot of riff raff and red tape to jump thru to verify that. I've never had to go thru it with Subarus, but many times with Saturns. My guess would be the customer would have to get an oil change at the dealer and oil level exactified, inspected for leaks internally and externally. Then the owner would have to come in once a week for a few weeks to have the level checked and recorded, and the car inspected for leaks. Then the regional service rep would have to be consulted. Then repairs begin if deemed necessary.

In this case it should be easy to confirm the excessive consumption, if it was not the PCV, which it most likely is. If a PCV replacement did not fix it, then the most likely route would be replacing the rings and/or valves and valve seals. And a thorough investigation to find out the cause of valve seal or ring failure on a NA engine would go on..and on and on. It just doesn't happen very much if at all on the NA cars and the alarms would go off at headquarters.
Click to expand...
Sounds like a lot of work to get the PCV replaced for free... especially when it is like a $5 part.

 
Yeah, the PCV would be done first, then if customer still believes oil is disappearing we'd start consumption monitoring.

A very inconvienent process, which might result in having the car in a million pieces all over my bay for 2 weeks.

 
You must log in or register to reply here.
Back
Top