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Model specific boards => Golf mk2 => Topic started by: tony_ack on 06 March 2012, 19:16

Title: Possible piston rings... decision time
Post by: tony_ack on 06 March 2012, 19:16
Right, I swapped my old Audi A4 diesel barge for this in the classifieds:

http://www.golfgtiforum.co.uk/index.php?topic=221254.0

The idea is to use it as a daily, but that's not to put it down as I look after my dailys (especially the VW-shaped ones)

I figured that the 'headgasket' problem mentioned in the ad is unlikely to be the headgasket, as the oil and water are fine aside from a little oil in the water due to a leaky oil cooler, and more likely to be a blocked breather or worn piston rings (I bought it taking into account that it might be the rings). The engine has done 213k.

I've spent some time cleaning the breather (gauze, flying saucer), and replaced the bung, so I've hopefully ruled that out, but there is still a fair bit of crank pressure - enough so if I remove the oil filler cap and rest it over the hole, it bounces about quite a lot (only at idle, once I rev it is fine). There's also oil on the air filter which suggests there's a fair bit of oil entering the intake (I put on a clean filter yesterday, and there were already oil stains on it today). So now I'm thinking piston rings... I've got a compression test kit but I don't have the right attachment for the Golf, but I am thinking that once I do the test it will confirm this.

The thing is that aside from running a bit rich, the engine doesn't smoke, and it still pulls quite well, and returns about 35 mpg. Although there is blow-by through the dipstick when you pull it out, it is just gas and no oil. I was thinking about whether to do an engine rebuild, or just get a replacement second hand engine, but now I'm thinking... why not just keep running it as it is? How long is the engine likely to last? Or is the amount of blow-by I'm seeing actually normal, and I'm fretting over nothing?

Is there something else it could be other than the rings?
Title: Re: Possible piston rings... decision time
Post by: tshirt2k on 06 March 2012, 19:24
ABF it. Job done.  :wink:
Title: Re: Possible piston rings... decision time
Post by: X4MGS on 06 March 2012, 19:26
Ahhhh.... So you bought that one in the end....

Nice looking car - even with space mileage!!!

Could it be that someone has over filled it with oil at some time and you are just seeing the end results??

I thought if piston rings had worn the car would smoke but don't hold me to that as I'm no mechanic...
Title: Re: Possible piston rings... decision time
Post by: clipperjay on 06 March 2012, 19:26
Tony consider dropping a secondhand block as a full rebuild bottom and top could be needed?
Valves
stems
seats tappits
honing
new rings,
possible new pistons?
Not sure how confident you are in stripping a block?
If you keep driving it when the headgasket goes it will really be hard to get the oil and water out properly (sluge)
But not sure why you think the rings need doing? Its not smoking is it?
Title: Re: Possible piston rings... decision time
Post by: Mr Blue on 06 March 2012, 21:38
Smokes on cold and when you boot it? - valve stems most likely.


tbh it sounds like every other mk2. I would leave it till it blows properly.
Title: Re: Possible piston rings... decision time
Post by: tony_ack on 06 March 2012, 23:04
Okay, I think I'm worried about nothing (or very little). There's no smoke as far as I can see - hot or cold, idle or driving, booting it or overrun. The only thing that makes me think the rings are worn is because I thought there was quite a lot of gas coming up from the crankcase, with a fair bit of pressure behind it.

I'm just going to keep driving it and see how it does. I do fancy an 8v rebuild as a project but it doesn't make much sense economically when second hand engines can be had for peanuts, and will probably go on forever.

Ken - it's a very very good looking car but there are a few issues underneath, including a rotten battery tray and some jacking point welding, but it was a straight swap for the Audi, which cost me £720 a few months back, so I can't complain.
Title: Re: Possible piston rings... decision time
Post by: X4MGS on 06 March 2012, 23:11
Ken - it's a very very good looking car but there are a few issues underneath, including a rotten battery tray and some jacking point welding, but it was a straight swap for the Audi, which cost me £720 a few months back, so I can't complain.

Good price then, seen as he wanted 1200.00 for it....

Thought it looked better than the average car from the pics....

Need to get that rust sorted thoo... Battery tray especially make sure it aint done the front chassis leg...
Title: Re: Possible piston rings... decision time
Post by: danny_p on 06 March 2012, 23:30
been rebuilding a LOT of 8 valves recently

more people are wanting to keep original cars original and to be fair good 1.8 8valve lumps re becomeing a bit  thin on the ground,  i got heap of motors that were soposed to be good but are actualy rather worn  :sad:   cheep engine to rebuild tho
Title: Re: Possible piston rings... decision time
Post by: Wayne on 06 March 2012, 23:52

I'm just going to keep driving it and see how it does. I do fancy an 8v rebuild as a project but it doesn't make much sense economically when second hand engines can be had for peanuts, and will probably go on forever.


That is a good idea, looks a clean and tidy car btw
Title: Re: Possible piston rings... decision time
Post by: tony_ack on 13 April 2012, 21:46
Finally got a compression test done and got 150psi (just over 10 bar) on all cylinders (did a wet test just for a larf and got 210-215 psi across all cylinders)

Pretty convinced the car is burning a bit of oil now too. Blow-by is just as bad, there's white-grey smoke on start up and to be honest when up to temp as well now, and a bit of smoke visible in the rear view mirror under hard acceleration. Smells quite rich so may get the CO set just to rule that out first.
Title: Re: Possible piston rings... decision time
Post by: clipperjay on 13 April 2012, 21:59
Did you test the coolant for hydrocarbons?
Sometimes a good compression doesnt mean a head gasket is not leaking water into the down stroke of the piston
Title: Re: Possible piston rings... decision time
Post by: danny_p on 14 April 2012, 01:05
sounds to me like an old worn engine.   
Title: Re: Possible piston rings... decision time
Post by: tony_ack on 14 April 2012, 10:18
Nope, not done a test for hydrocarbons, but I'm pretty sure the smoke out of the back is oil, not water. What confirmed it for me was after the wet compression test, there was a lot more smoke out of the back as the engine burned off the oil in the bores, but the colour and smell of the smoke didn't change compared to what it was normally like.

I think the engine is well past its best like Danny says. Going to start looking at replacement options and put some money aside, though the car still runs okay for now despite being a bit smelly so no rush as long as I keep an eye on oil and water levels
Title: Re: Possible piston rings... decision time
Post by: leigh_harty on 14 April 2012, 10:29
Im in the same boat as you but with a vr6, doing my compression tests today

Not thought about getting a replacement engine and rebuild it yourself, its not that hard when you get going.

Good luck anyway  :smiley: :smiley:

Leigh
Title: Re: Possible piston rings... decision time
Post by: Sam on 14 April 2012, 13:14
Where abouts are you based buddy out of interest.

Anyhow, your compression sounds about right (12bar as standard no?) and chances are that on such a well driven engine the bores may simply need re-honing to remove the glaze and put new rings on the pistons to seal them. If you catch it early the head wont even need re-building. I wouldn't describe it as a simple job but its a case of taking the head off and the sump and popping the pistons out. You could do it in a couple of days, this way you would also be able to remove and replace the head gasket.
Title: Re: Possible piston rings... decision time
Post by: search on 02 April 2013, 01:58
I know this is a year old but check my user name and you'll understand.

that aside I'm curious to know what you did in the end? as it sounds like the problems I'm having although mine's not smoking but is breathing heavily with the oil build up behind it.
Title: Re: Possible piston rings... decision time
Post by: mush on 02 April 2013, 14:58
just to throw a spanner in the works i have a 16v engine if you want it.

has everything apart from the engine loom and was running fine before i removed which was for my vr6 project.

mileage on engine was 165,000

yours for £50.00 - you'd have to collect

sorry to high jack but its for a good cause  :wink:
Title: Re: Possible piston rings... decision time
Post by: search on 02 April 2013, 21:18
did a compression test came out as 175/ 145/ 140/ 180
Title: Re: Possible piston rings... decision time
Post by: Sgt_Lemon on 02 April 2013, 22:29
just to throw a spanner in the works i have a 16v engine if you want it.

has everything apart from the engine loom and was running fine before i removed which was for my vr6 project.

mileage on engine was 165,000

yours for £50.00 - you'd have to collect

sorry to high jack but its for a good cause  :wink:
Where are you located, I don't need an engine but for that price why the f**k not haha
Title: Re: Possible piston rings... decision time
Post by: danny_p on 02 April 2013, 23:41
did a compression test came out as 175/ 145/ 140/ 180

thats not healthy,   something is leacking,  drop the sump, pull and rebuild the head then push the pistons up time i think
Title: Re: Possible piston rings... decision time
Post by: clipperjay on 02 April 2013, 23:43
1.3's have higher compression don't they being smaller head and crown? If so 2 and 3 are buggered!
Title: Re: Possible piston rings... decision time
Post by: danny_p on 03 April 2013, 20:44
in general anywhere between 180 and 220 iswhat you expect to see but all cyls want to be failrly even.

184, 188, 182,186  for example would be a set of very healthy readings

genral rule of thumb upto  15 psi between any two cyls is expected on an older engine

but when your getting differances of upto 30 psi between any two cyls  it's not healthy something will be developing but should be managable and not cause big problems for the moment but performance and economy will be suffering

40 + PSI  differance means something is broken and is going to start developing ever more rapidly much more loss of compression will cause running problems more than likely that the engine is lame and thirsty