Knackered Piston Rings?

[Moys1.9 0]

If you read my other posts over the past few weeks you'll see I've had a lot of problemss since getting my pug back nearly ten weeks ago from having the head gasket done. (still isn't running )

 

Compression test results:

 

No 1 gave a reading of 10

No 2 gave a reading of 6

No 3 also gave a reading of 6

No 4 gave areading of 0

 

We re-torqued the head following the haynes guide, Lossened off in the reverse order then followed guide lines for stages 1 and 2. It said to turn an extra 300 degrees but we couldn't get them round that far so we turned them an extra 90 degrees (which we struggled to do). All the bolts where new when the head was done. We also checked that all the pistons where moving by turning by hand.

 

Does this sound like the piston rings are knackered (also brand new ten weeks ago)? Is there anything I can do to check before I start stripping it all down?

[Moys1.9 0]

I forgot to mention that we re-did the timing as it was a couple of teeth out. Now ir sounds like a bag of new spanners instead of old ones.

[GLPoomobile 958]

Did you try the comp test again?

 

I thought it sounded like a leaking head gasket untill I saw that the last cylinder was 0!

 

Have you tried putting a spoonful of oil in the cylinder and seeing if the compression increases?

[Moys1.9 0]

Yeah we did the comp test first then re-torqued it then did another comp test. Somebody mentioned the mehtod of putting a tea spoon of oil in and checking if compression increases. TBH I wasn't to sure about that at first but seeing has 2 people have now suggested it I think I'll give it a whirl. Why does the compression go up if its the piston rings?

[Guest BrainFluid]

I imagine that the oil helps to seal around the piston and the bore.

 

Man I'm really out of my depth when I start answering question coz I'm but a humble learner, but after taking my head of to do the gasket I'm learning bits and bobs...

 

So, I'll throw this into the mix...wrong as it may be...What if the valves on the head are not closing properly? More so the one thats reading 0 on the compression test?

 

Nate.

[jonah 1]

Yeah it could be the valves not closing properly... they could have been bent / damaged by the timing being a couple of teeth out (resulting in valve / piston contact).

 

I'd say there's no point doing any more checks, whatever's wrong the head will need to come off anyway, and with a compression reading of 0 the cause should be immediately visible!

 

Maybe your best bet now is to get your money back for the botched job and start looking for a working second hand engine...

[simonb 0]

Does the car smoke? If the rings are that bad I would have thought it would use more oil than petrol. AM very supprised it runs at all with figures like that.

 

If no smoke then I would look at the valve train. Could be a badly fitted head gasket, valves not seating correctly, worn guides or just the fatc that either the timing is still way out of that the compression tester is no good.

[Guest BrainFluid]

Yeh but if it sounds like a bag of spanners were talking piston and valve contact are we not?

 

Like jonah says best to whip the head off and all will be reveiled.

 

Come to think of it, you mentioned that it was like this after getting the car back from ahaving the head done? Did you not get mad with the peeps who did the head and start demaning compensation?

 

Nate.

[Anthony 1,003]

If you've got no compression at all on one cylinder, and a second compression check gives the same figure, then it's almost certainly valve related - knackered rings or a blown head gasket would typically show some compression.

[Moys1.9 0]

Thanks for the advice guys. We've started stripping the head down now. Someone suggested the wetliners could be cracked? Think we'll have a good look at the valves as you guys suggested. Really peeved off cause the guy who did it was a good friend who's bloody let me down. Guess I've learnt summat there .

[Moys1.9 0]

With the head off what is the correct way of checking valve clearances?

[Guest BrainFluid]

Bit too long to quote the Haynes manual, basicly you use feeler blades to measure the gap.

 

I suggest you pick up a Haynes Manual for next to nothing on Ebay

 

Nate.

[Moys1.9 0]

I've got a haynes but always check on here first because I usually learn more. Even the index is pants in the haynes .

[Banjo 1]

Did you clamp the liners down when you turned the engine over?

[Guest Cartooner]

Did you clamp the liners down when you turned the engine over?

 

This is my guess too. You did clamp the liners did You, otherwise You could have lifted them and in doing so have disturbed the o-rings at the base of the liners. Thus causing unequal linerheight and therewith a leaking headgasket. The fact that You could not do the additional 300 degrees could be an indication of this also.

Edited April 2, 2006 by Cartooner

[Moys1.9 0]

Here I am asking questions nearly a month later . Clamping the liners down? How do you do this whilst the head is on? I ask this now because we're rebuilding the head from the liners upwards and found whilst looking at the liners that the o-rings are knackered. Don't wanna make the same mistakes as the guy who botched it up in the first place after all. Getting the head back from a place in Blackburn next week where its been fully refurbished.

 

Also it turns out the shims weren't replaced correctly .

[saml666 0]

Here I am asking questions nearly a month later . Clamping the liners down? How do you do this whilst the head is on? I ask this now because we're rebuilding the head from the liners upwards and found whilst looking at the liners that the o-rings are knackered. Don't wanna make the same mistakes as the guy who botched it up in the first place after all. Getting the head back from a place in Blackburn next week where its been fully refurbished.

 

Also it turns out the shims weren't replaced correctly .

 

When the head is on, it clamps the liners down, when you remove it you have to use the head bolts and some thick washers / collars to clamp the liners down instead (lots of pics in manuals etc). If you don't and you turn the crank, a piston rising will push the liner up, the seal at the bottom is bound to break / not seat properly again and hey-presto theres your problem.

 

Its very tempting when you remove a head to turn the engine over and watch the little pistons go up and down...

 

up and down... up and

 

DOH!

 

Its that easy, you only have to do it a little bit and you could cause big problems. Unfortunately thats very likely what happened to yours - proper bummer that

 

Hope you get sorted soon

 

Sam

[Moys1.9 0]

Cheers for the info. Gonna do everything by the book. Scared to death of putting it all back together and it not being right. After all this time I'll just be happy to hear the pistons moving up and down. And i want all the chavs near my house to hear them to so they can keep they're rep mobiles outta my way .

Hopefully I should have it running in a couple of weeks. the guy whose helping me has just bought a mk2 16v golf gti so it'll be cool to get em runnin together.