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badassbaldie
01-05-2006, 04:05 PM
Did a compression tests with the following results:

Piston #1 - 180
Piston #2 - 165*
Piston #3 - 180
Piston #4 - 175

Piston #2 seems a little low. What is the normal range? I looked through my manual and I can't seem to find it.

I did the test because I've been burning some oil and I wanted to try and isolate the problem. Maybe 1/3 of a quart every 600-800 miles. Not a huge deal but burning oil, nevertheless.

I notice a decent cloud of smoke after waiting at stop light, but not all the time. Also seems to be less during the cold months.

TheQuattro
01-05-2006, 04:40 PM
How much miles are on the car?

SeanF
01-05-2006, 04:52 PM
if i recall correctly, thats within what is acceptable...

what year is your car?

tontod
01-05-2006, 04:52 PM
I have a 99.5, and the expected range is from 145-188 psi from what I can remember. Mine were between 185 and 200, so I'm good.

badassbaldie
01-05-2006, 06:27 PM
How much miles are on the car?

My A4 is a '98.5 with 99k miles.

mike-2ptzero
01-05-2006, 07:14 PM
Originally posted by badassbaldie
Did a compression tests with the following results:

Piston #1 - 180
Piston #2 - 165*
Piston #3 - 180
Piston #4 - 175

Piston #2 seems a little low. What is the normal range? I looked through my manual and I can't seem to find it.

I did the test because I've been burning some oil and I wanted to try and isolate the problem. Maybe 1/3 of a quart every 600-800 miles. Not a huge deal but burning oil, nevertheless.

I notice a decent cloud of smoke after waiting at stop light, but not all the time. Also seems to be less during the cold months.


Well its seems you have 2 good cylinders, 1 that is starting to wear and 1 that has even more wear. Might want to look into having a "leak down test" done. If it is rings you will have to figure out the cost of how much it will be to replace them. Dont wait too long if it is the rings, because as they go they will do damage to the cylinder walls.


SeanF- Only time you consider anything within the acceptable range, is when they are all equal. Anytime they are not equal is when you want to start doing some tests to figure out what the problem is.

turbojunkie
01-05-2006, 07:19 PM
To check if its the rings in cyl #2, squirt a SMALL amount of oil into the cylinder and re-test.......if the compression # go up its bad rings.

ceas
01-05-2006, 07:20 PM
I think acceptable is between 160-180, my car was compression checked a couple days ago. I think mine was 170, 165, 175, 165.

Cactus00S4
01-05-2006, 07:21 PM
who cares about compression cheks,hahaha, if ur goin stg3 jus go for it, i had 138k on my 98.5 and wen i put mine on, got 141k on it now with the turbo on it, still running strong

badassbaldie
01-05-2006, 07:22 PM
To check if its the rings in cyl #2, squirt a SMALL amount of oil into the cylinder and re-test.......if the compression # go up its bad rings.

Yes, I knew to do this but I didn't have any oil in the garage, believe it or not. I usually keep a 5 quart jug of Mobil 1 but I was out.


Well its seems you have 2 good cylinders, 1 that is starting to wear and 1 that has even more wear. Might want to look into having a "leak down test" done. If it is rings you will have to figure out the cost of how much it will be to replace them. Dont wait too long if it is the rings, because as they go they will do damage to the cylinder walls.

Yes, I figured that much. Leak down test is next on the list. Friend of mine is a former GM mechanic so I'll probably have him assist me with it. Thanks for the help.

mike-2ptzero
01-05-2006, 07:35 PM
Originally posted by BSaudiA4
who cares about compression cheks,hahaha, if ur goin stg3 jus go for it, i had 138k on my 98.5 and wen i put mine on, got 141k on it now with the turbo on it, still running strong


Well compression checks are important, they tell you how the car is wearing and when it might need some work.


ceas- that word "acceptable" is just something the dealer uses so they wont have to do warranty work on your slightly worn engine. To me the only thing that is "acceptable" is having 4 cylinders that are equal. Your readings just mean that you have 2 cylinders that have a slight compression leak.

tontod
01-05-2006, 07:39 PM
I think a slight variation in the cylinders is acceptable. Piston #2 is a bit low, but still in the acceptable range.

SeanF
01-05-2006, 09:48 PM
Originally posted by mike-2ptzero
SeanF- Only time you consider anything within the acceptable range, is when they are all equal. Anytime they are not equal is when you want to start doing some tests to figure out what the problem is.

thanks, good to know.... i think im gonna test mine sometime soon...

onemoremile
01-06-2006, 08:48 AM
Originally posted by badassbaldie
Yes, I knew to do this but I didn't have any oil in the garage, believe it or not. I usually keep a 5 quart jug of Mobil 1 but I was out.


your car does have a dipstick doesn't it? betcha there's oil at the other end of it.[:p]

badassbaldie
01-06-2006, 08:58 AM
your car does have a dipstick doesn't it? betcha there's oil at the other end of it.

You're right...but that would have been too easy.[rolleyes]

Cactus00S4
01-06-2006, 09:12 AM
[QUOTE]Originally posted by mike-2ptzero
[B]Well compression checks are important, they tell you how the car is wearing and when it might need some work.

i know mike, i was jus kidding