GolfGTIforum.co.uk
Model specific boards => Golf mk2 => Topic started by: Bjork on 30 January 2009, 14:19
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Hi guys,
Ok, K-Jet 1800 16v engine (1991). Can't drive the car as engine is too bad. Engine turns over and exhaust smokes alot. Whiteish smoke but smells of oil.
Done a compression test as follows. (Done on warm engine):
Cylinder 1 = Dry test 4 bar/ 55psi
Wet test 7 bar/100psi
Cylinder 2 = Dry test 4 bar/ 55psi
Wet test 6 bar/ 85psi
Cylinder 3 = Dry test 0
Wet test = 0
Cylinder 4 = Dry test 0
Wet test = 0
Whilst doing the compression test there was a whitish mist comping out of cylinders 3 and 4.
Coolant is fine, as is the oil. (No oil in coolant and no mayo in oil).
Now I always thought if there was no compression between 2 cylinders it suggested head gasket, but there are no other symptoms of this. :huh:
Been thinking along lines of valves or lifters but could also be pistons or rings.
Could it be any of these or are do you think the above points to one thing more than any of the others?
Any help/advice would be greatly appreciated.
p.s. I've got a replacement cylinder head to go on the car but maybe this wouldn't be as beneficial as an engine transplant if it came down to Pistons. Or do you think I could tackle the Piston problem with the engine in the car and approaching them by going through the sump?
Cheers in avance. :smiley:
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To be honest your best bet is to whip the head off and look, you should be able to see at a glance if its any one of those problem (apart from the rings of course)
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Is fitting new rings a big job or do ya think that once the head is off then the hard part's out of the way?
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The zero compression on 3 & 4 would definately suggest that the gasket has burnt out between the two cylinders. This wouldn't affect the coolant or oil as there are no channels between the cylinders.
The compression is also horribly low on 1 & 2, as a comparison I was getting 115psi on all cylinders of my aircooled t25 which has a much lower compression ratio than the 16v kr.
The pistons and rings can be changed with the engine in the car by simply removing the sump and undoing the big-end shells. However it sounds like things are very worn so the bores are likely to need re-honing at least which is an engine out job.
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The zero compression on 3 & 4 would definately suggest that the gasket has burnt out between the two cylinders. This wouldn't affect the coolant or oil as there are no channels between the cylinders.
The compression is also horribly low on 1 & 2, as a comparison I was getting 115psi on all cylinders of my aircooled t25 which has a much lower compression ratio than the 16v kr.
The pistons and rings can be changed with the engine in the car by simply removing the sump and undoing the big-end shells. However it sounds like things are very worn so the bores are likely to need re-honing at least which is an engine out job.
The first part of this I agree with 100%. The head needs to come off.
The second part I agree with, but you may just need a change of rings and a glaze bust, unless the rings are broken. This can be done, as already said, with the engine in situ. This is also a good time to replace the big end shells and generally give all exposed components a damn good service. ie, clean out the ring grooves, clean the pistons of carbon and coke, service the head and re-lap the valves in etc. Also a good idea to replace the oil pump if you are keeping the car for a while.
I did this on my old 8v and it restored all the power it once had. Well worth doing.
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Cheers guys. What is a glaze bust as you mentioned?
Was thinkning if it did come down to a full engine out job might be tempted to try and source a decent transplant engine.
As for now the car's going nowhere so head off and a bit of investigation. I'm sure I'll be back for advice when i get stuck. :laugh:
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Transplant seems the easiest and probably cheapest option really although you can never know the condition of a second hand engine without stripping it I spose.
Head on its own isnt too bad a job but getting the pistons out when the engine is in the car is just daft IMO, too many chances to drop stuff in the engine and not notice, too much time spent bent over the engine bay (I have a bad back lol) etc etc and it really isnt that bad a job to get an engine out once you have started.
Personally Id be thinking, Hmm, fate seems to be telling me to stick an ABF in that hole there.
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This is very unlikely but I thought its worth a post...
Double check your injectors are seated properly with a good seal in cylinders 1 and 2. You never know, it could be a massive air leak through the injector port.
Doubt it though chap, but its a free test!
:smiley:
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Cheers Conker, I'll look at them.
DOA, think it might be the option I go for. Gonna take off head anyway and see if it's something obvious first because if I do decide to transplant I'm gonna have to shell out for an engine hoist. :sad:
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Done a compression test as follows. (Done on warm engine):
Cylinder 1 = Dry test 4 bar/ 55psi
Wet test 7 bar/100psi
Cylinder 2 = Dry test 4 bar/ 55psi
Wet test 6 bar/ 85psi
Cylinder 3 = Dry test 0
Wet test = 0
Cylinder 4 = Dry test 0
Wet test = 0
it's buggerd end off you should be hitting 13 bar. by the look of those reslults it's a suprise it runs
with compression ratios that low and white oil smoke out the exhaust the engine is DEAD don't even bother lifting the head just take the whole motor out and throw it away.
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Really?
Was dreading that. Might take it apart anyway seeing as I haven't the money to get another engine at the moment plus I might learn something as I haven't done it before.
Penny saving time!!!
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my logic is...
0 compression wet and dry between 3 & 4 = can be caused by headgasket and is quite a common fail but usally some compression is there even if it's only 1 or 2 bar. and when the section between the cylinders burns out it more often than not gets to the water way as well
but the white oil smoke is what makes me think it's gone, that much oil won't get past the valve guides so it's more than likely comeing up past the pistons. i'm going to hazzard a guess that engine died from pre ignition. blew gasket out on 3&4 ( and possobly damged pistons ) and piston damage on 1&2
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Died from pre-ignition?
If you could explain that it'd be great. As you may have realised I'm not really that mechanically minded. :embarassed:
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Pre ignition is when the spark occurs a few degrees before it is meant to. This will result in higher burning temperatures and peak cylinder pressure being reached before the piston goes over top dead centre. The result could cause detonation of some, if not all of the charge which is like an explosion occuring on top of the piston. This will damage the piston.
However, although Danny P may be right, if you had excessive damage to the piston, you would get no compression at all. If the bores are glazed, this means that they have become polished to a near mirror finish. This is also caused by hot burning temps or rich mixture. Polished bores will not allow oil to stick to them for lubrication and cooling purposes, and the rings will glide over the bores rather than do what they are supposed to and create a seal.
I still think that it is worth removing the head and find out for definate what is going on. The engine may be salvageable, but be prepared to change it if you discover something nasty.
You could remove the oil filter and cut it open and examine the element for signs of metal. If the pistons have been damaged, then you will have little white rocks in the element along with white flakes which will be bearing material. Particles that are attracted by a magnet is an indication that something may have gone through the oil pump.
For those not au fait with the workings of the internal combustion engine, take a little look at this.
http://en.wikipedia.org/wiki/Otto_cycle#The_Otto_cycle
It does not go into great depth, but it gives you an idea.
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just seen quite a few KR's that have just cracked the top of the piston exposeing part of the top ring do the pounding the pistons can get. KR's almost never melt them as there cooled so well.
sopose it is worth takeing the head off just to have look, have never seen glazed bores in a 16v yet tho, proably cos most of them get rallyed everywhere
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My last one was an 8v and you could shave in the mirror finish. It was caused by a bad ECU. I think it had been badly chipped and it caused it to overfuel. Fuel was mixing with the oil, vapouring off and being recirculated into the injection system through the breather. It took a while to find the cause of lack of power and generally running sh!t. The compressions were down to between 6 and 9 bar across all 4 pots.
I replaced the ECU and it immediatly ran better. So I re-timed it, (a decent ECU threw the timing out by 4 degrees. :shocked:) then set up the emissions. I then gave the engine a head off and pistons out service with new rings, big end shells and a head skim and decoke. The difference was staggering. I sold it to buy my current shed.
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Loving the advice I'm getting guys. I'll definately let you know how I get on and will post a few pics.
Definatley gonna tackle the head off job that's been daunting me for the last few weeks now. Been doing my research on here which has helped me feel a bit more confident though.
Have a great weekend guys. :smiley:
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Loving the advice I'm getting guys. I'll definately let you know how I get on and will post a few pics.
Definatley gonna tackle the head off job that's been daunting me for the last few weeks now. Been doing my research on here which has helped me feel a bit more confident though.
Have a great weekend guys. :smiley:
I took my head off on my own - its easy apart from the exhaust manifold (start soaking the bolts with oil/WD40 NOW) and the fact that its a heavy head to lift yourself - try and arrange a friend to help you lift it.
Top tip... Before you unscrew/remove each bit, take a digital photo of how it looked and when you come to refit everything you'll have a library of images to help you if you get stuck.
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+1
(http://img222.imageshack.us/img222/5405/minicimg4347mm5.jpg)
I labelled the poop out of everything when I had the engine out.
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Yeah I'll deffo take photos as I go along.
The exhaust manifold is what I'm dreading from the problems I've read you guys have had. Good advice on the wd-40, I'll do it everyday leading up to stripping it off.
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Good luck with the work you have set yourself. Even if you end up junking the engine, the experience you will gain from ripping the unit apart will be invaluable and hopefully give you an understanding of what other people on this forum are on about when it comes to motor tech talk.
Keep the questions coming. You may get differing opinions, but you will get the idea. :smiley:
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Good luck with the work you have set yourself. Even if you end up junking the engine, the experience you will gain from ripping the unit apart will be invaluable and hopefully give you an understanding of what other people on this forum are on about when it comes to motor tech talk.
Keep the questions coming. You may get differing opinions, but you will get the idea. :smiley:
Yeah cheers. Gonna be one steep learning curve!!!
I am looking forward to it in a way for the experience. It's just daunting but I guess you've gotta start somewhere. :smiley:
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... Good advice on the wd-40, I'll do it everyday leading up to stripping it off.
Hi
Instead of wd40, use a penetrating oil like 'Plus-gas'
or '3-in-one Penetrant spray'.
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... Good advice on the wd-40, I'll do it everyday leading up to stripping it off.
Hi
Instead of wd40, use a penetrating oil like 'Plus-gas'
or '3-in-one Penetrant spray'.
Brilliant......I'll get some. :smiley:
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3 of my manifold studs sheared, and two were completely round and inaccesible - they had to be dremeled off.
I had to resort to a pack of stud extractors to get the snapped studs out!
Might be worth investing in those Irwin nut extrators if things go wrong ;)
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3 of my manifold studs sheared, and two were completely round and inaccesible - they had to be dremeled off.
I had to resort to a pack of stud extractors to get the snapped studs out!
Might be worth investing in those Irwin nut extrators if things go wrong ;)
I'll look into that, cheers for pointing it out.
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6 sided sockers are very usefull, but a couple are spanner only :( if the nuts are really bad leave them and undo the downpipe and lift the head off with mani attached
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Would definately drop the exhaust and take the manifold off with the head. No need to remove it unless you are changing it.
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Would definately drop the exhaust and take the manifold off with the head. No need to remove it unless you are changing it.
Think I might change the head. Got a spare one so might see which looks in better nick.
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Would definately drop the exhaust and take the manifold off with the head. No need to remove it unless you are changing it.
I tried to do that but there wasn't just enough room to slide the exhaust out, and I didn't want to start taking the sub frame to bits. In of terms of undoing the downpipe at the flexi-joint thingy, those bolts look even worse than the manifold one's! (On mine anyway).
Still a good alternative though!
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Quick update.
Got the head off which looks ok but the cam chain is a bit loose, got a spare head and it's much tighter on that.
The head gasket has definately burnt out between cylinders 3 & 4. Could this be the only culprit or should I look intot eh pistons while I'm at it?
Gonna put some pics up in next couple of days, cylinder 4 piston is worrying me as a I can see more of the piston ring than on the others.
Think I was lucky with the exhaust manifolt too as it wasn't too difficult to get off. :smiley:
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pop some piccys of the pistons up, will soon tell