Possible piston rings... decision time

[tony_ack]

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?

[tshirt2k]

ABF it. Job done. 

[X4MGS]

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...

[clipperjay]

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?

[Mr Blue]

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.

[tony_ack]

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.

[X4MGS]

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...

[danny_p]

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     cheep engine to rebuild tho

[Wayne]

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

[tony_ack]

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.