Author Topic: Here they are...Compression test results! NEW FIGURES PG 5!  (Read 10052 times)

Offline AudiA8Quattro

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Re: Here they are...Compression test results!
« Reply #20 on: 18 February 2010, 21:55 »
I was going to suggest this, do the test again when the engine is hot.
Get someone to hold the throttle wide open and crank the engine, while you watch how quickly the pressure increases.
The pressure should build up quickly, and there should be no more than 1 bar(about 13.5 psi) between cylinders.
You do not need to do a wet test unless there is a problem with the dry test.
Let me know the results.
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Offline Khare

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Re: Here they are...Compression test results!
« Reply #21 on: 18 February 2010, 22:02 »
will do dude. I remember it did take a while for the pressure to build. About 4 or 5 cranks.

Offline AudiA8Quattro

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Re: Here they are...Compression test results!
« Reply #22 on: 18 February 2010, 22:08 »
Yes, but you did the test cold, and a well worn in engine will take longer when cold.
When the engine is hot the readings will be accurate.
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Offline Khare

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Re: Here they are...Compression test results!
« Reply #23 on: 19 February 2010, 10:55 »
got my compression tester today, so will do the test again with engine warm and see what happens. I'll report back this afternoon.

Offline richandhazel

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Re: Here they are...Compression test results!
« Reply #24 on: 19 February 2010, 11:06 »
Those compressions don't look bad and the difference between dry and wet seems to indicate good rings. You would see a much more noticeable imbalance if there was a problem.

Not having read your previous posts, what makes you think your crankcase pressure is high?

Offline Khare

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Re: Here they are...Compression test results!
« Reply #25 on: 19 February 2010, 11:16 »
Those compressions don't look bad and the difference between dry and wet seems to indicate good rings. You would see a much more noticeable imbalance if there was a problem.

Not having read your previous posts, what makes you think your crankcase pressure is high?
Blow by. It's the only thing the RAC guy said when he came to fix my leak. He said at idle alone there was huge amounts of pressure being forced out, and he said only to imagine how much pressure is coming out at higher revs.

Offline richandhazel

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Re: Here they are...Compression test results!
« Reply #26 on: 19 February 2010, 11:37 »
Are you losing oil?

I've experienced worn rings twice on Golfs and on both occasions yes it was breathing very heavily and I was getting a lot of oil in the breather area of the air filter housing (older Golfs).
One was so bad I disconnected the breather from the air filter housing and routed it into a an old washer bottle to collect the oil. Car was also lumpy in running due to uneven compressions.

It is possible that the breathing is normal and that the RAC guy is comparing it with newer vehicles or different marques :undecided:

If the car is running fine and you're not losing oil then I would be inclined to leave well alone and 'not fix what ain't broke' :smiley:

Offline Khare

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Re: Here they are...Compression test results!
« Reply #27 on: 19 February 2010, 11:43 »
Are you losing oil?

I've experienced worn rings twice on Golfs and on both occasions yes it was breathing very heavily and I was getting a lot of oil in the breather area of the air filter housing (older Golfs).
One was so bad I disconnected the breather from the air filter housing and routed it into a an old washer bottle to collect the oil. Car was also lumpy in running due to uneven compressions.

It is possible that the breathing is normal and that the RAC guy is comparing it with newer vehicles or different marques :undecided:

If the car is running fine and you're not losing oil then I would be inclined to leave well alone and 'not fix what ain't broke' :smiley:
I did think that maybe the bloke was comparing it to newer cars, but I asked him about his car experience and he had a huge car garage in Bournemouth were they tuned Ford Capri's, Fiesta XR2's and Escort XR3's and lods of other now classic cars. He even had a mk1 escort mexico, so I'm pretty sure he knew what was what.
Not burning oil, although I do get a fair bit of some coming from the pipes when cold. It used to last anything between 1 or 2 minutes but now it's about 5 or so minutes, and quite an amount too.

Offline Adam

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Re: Here they are...Compression test results!
« Reply #28 on: 19 February 2010, 11:51 »
Sounds like you don't have worn piston rings then.

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Offline Khare

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Re: Here they are...Compression test results!
« Reply #29 on: 19 February 2010, 12:35 »
Well I'm bout to go off to do the test again so I'll report back in half an hour.