'90 2l 16v(ABF) mk2 (restoration page9, going megasquirt), mk5 ed30

could be oil control rings glazing the bores.

 

right, just been out to get some petrol and i had a bit of a play on the way back.

i don't think there is any smoke during normal driving. not that i can easily see.

however i then did some engine breaking followed by giving it some accelration and the result was blue smoke screen galore.

just off to do a search as to possible answers.

 

Sounds like a Broken ring/rings you may even find the ring landings on a
pistion have broke, after reading your topic, I would say it will be a broken piston

 

after not being able to find out what is wrong wih the car.

the time has come to rip the engines head off to do find the culprit of the problem.

will report back later with pics once finished.

 

Only thinking out loud here, but did you check the bore for ovality before you put it all back together.
I know you had it honed, but it doesn't mean they are round anymore, which could lead to oil passing the rings.
Also found this from page 2 I think


If this has happened in the past, I'd be re-checking all the pipework and breather before you rip the head off.

I have to ask as well, but are you sure the flywheel and crank are balanced? There's no evidence of it at all on the pics in the post.

 

checked that breather and it's clear (block to airbox). maybe a tiny bit soft.

didn't check for ovality but can do once the head is off.

got to do something as the car is struggling to start now, might be the plugs are fouled.

 

Would it oval bores with good compression test? The oil smoke after decel does point to a ring problem though.

 

pics
exhaust ports look dry





inlets look wet on 1 3 and four (hard to photo)





it's definately been burning oil [:^(]


just look at the top of the pistons
piston 1

2

3

4


cylinder walls






i haven't got a clue whats gone wrong with it. cylinder walls look ok to me (but i'm not sure what to look for.) you can still see the cross hatching and the walls are smooth with no deep marks.

what does everyone think as to whats gone wrong?
what do i need to replace to fix whatever is wrong?
what do i look for/check/examine?

HELP[:^(]

 

Bores don't look great for a fresh build, If the bore did not hone even
it should have been rebored.
Pop the pistons out, start with this one

If the bores were right and rings and piston are found to be ok on this pot
I would say something is not balanced right, ie a rod.

 

i would think its down to the rings

 

i would bank on rings being the problem too, i had similar problems with my rallye, had another set of rings after 1000miles as i was getting blow by round the side of the piston. drop a piston out, if theres black down the side like oil has been coming by it you will know where your problem lies.
as others say i doubt its the head after its been rebuilt.

 

i try and find time at the weekend to pop one of the pistons out.

if it is the cause, is it a case of rehoning and yet more new rings. (if the bores are still ok)

 

You really need to get the block checked for ovality in the bore. A rehone and new rings won't sort the problem and you'll just waste more time and money if the problem lies there.

 

Just read the whole thread, should be good once you get through the probs stick with it mate it will be a minter

 

this morning i started to do a bit more to the golf to investigate the oil problem.

so first off was to drain the oil, and remove the million bolts holding the sump on.

then remove the oil pick up pump and remove the big end nuts.

heres what i found:
the new shells were starting to show wear already, in the centre where the oil hole is located on the crank. (is this normal???)


does the piston look ok? you can see where it slides down the cylinder by the marks on it



what about the cylinder wall. there are some straight lines running top to bottom. matching the piston marks.



sides of the wall



the crank

oil hole


and how can i check for oval bores, what do i need?

 

That's not 'showing wear' they're fooked, I've taken out shells that have done 100k that looked better than that.

From the pics they show signs of overheating either from oil starvation or incorrect clearances.

Also there are score marks on the crank, again suggesting metal to metal contact

 

Looks like there's been sh it left in the oil gallery of the crank after machining, and it's managed to attack the bearing material.
I'm surprised the machine shop didn't poilsh the journals and hot dip the crank before they returned it to you.
I wouldn't put those bearings back in there. It looks liek overheating right through the middle.

To check the bore you'll need either a bore gauge or a setof internal mics, bore gauge being the best, as it's far longer and more accurate.

 

definately not going to reuse the shells. you can feel an edge on the oil hole in the crank.

would the local garage have a bore gauge do you think?

i'm really considering dumping this engine now. seems like a lot more work is needed.

if i were to go to ABF can i still use the head as i've read brooksters post of the pistons catching. head no. is 051 103 373 (theres a H the other end, don't know if it's significant)

cheers for the help mart

 

Yup, you can still use the head

 

I'd suggest you want to get another bottom end. This one needs a lot of work to sort it out, that'll probably cost you more than a whole running engine.