Suspected head gasket failure!

[Tun]

Engine temp went very high (3/4) when sat in traffic last night and then I started to notice excessive white smoke when moving off. Last couple of days the car has developed a miss fire on initial start up. Thankfully I was close to home and got the car back but needless to say it wont be turning a wheel until fully investigated.

As the title suggests I think the head gasket has gone but, as the car is 28 years old, I'm not expecting to just get away with replacing just the head gasket. I will inspect the oil and water at weekend and do a compression test if no contamination is found.

Any pointers would be gratefully received, car is 1988 UR with MB engine.

[Hoyle]

I used a USB endoscope on mine down the plug holes - another option for you.

Other than that - the contamination and pressure test you mentioned should give an indication.

[vorsprung durch technik]

Bloody hell Royston,if it's not raining it's pouring. Sorry to hear of this bad news mate.I'm sure the compression test will confirm one way or tuther. Looking on the bright side,at least you'll end up with an as new head.I would check for valve guide wear while your in there,there's bound to be some. New guides, recut valves seats, a skim new valve stem seals etc etc and you'll be good to go for another 30 years of fabulous 10v turbo fun. You could even have it all port matched and ported to make it even better than new.

Keep the faith Royston.

[Ben]

Could just be condensation in the exhaust. All my Audis blow steam in colder weather.

Any bubbles in the return to the header tank? does the exhaust steam smell a bit sweet?

[Tun]

I'm fairly certain that the head gasket is the problem but I can't confirm until weekend. What I'm after is any tips for doing the job and any known problems that I am probably going to come across when I tackle it.

[Hanuman]

Sounds horrendous, but don't give up hope.
Presuming that we are talking about the MB quattro.

My WR cylinder head failed letting water migrate through the water jacket walls into the exhaust tracts. It was the same- big clouds of white smoke.
I had expected things to go wrong as the car had been seriously abused while it was in the 'care' of directline, anyway. Being pretty busy with work, I put it away in the garage until I had a chance to work on it.
When I found the time, I did a compression check, and all was well, except for the loss of coolant issue. It wasn't apparent at this stage what the actual problem was.

Move on a while, with work taking up my time, then redundancy! Followed by a new job in Scotland, and I had to fix the quattro.
So it was cylinder head off time, for a closer look. 2 cylinders were full of water. I mean full. The head gasket integrity was ok, but showing signs of issues. The ports on two cylinders were full of dried coolant.

I bought a replacement head, had it worked on by an utter genius, reassembled the engine, and ran it.
The cyclinder head which failed appears to have been porosity related, as there are no cracks. We are planning on rebuilding that head (there's a technique available to deal with the porosity)

At the time, I was reluctant to get so deeply involved in the engine, even though I'd worked on plenty of others before. In hindsight, it was no big deal.
It took a day to strip the top end down, and a day to build it back up, all in a garage with no lighting, and no electricity. But the issue of getting a replacement head sourced, refurbished, etc made the whole event last a few weeks.
This all happened in the winter to spring of 2004/2005, and the WR had 130k on the clock. It's going strong at present, with only CamBelt changes, and currently has 189k miles.

Problems and tips

Exhaust studs will break. Budget for a complete new set.
Head gasket set. Talk to Pete Reeve, get the Elring set.
Head bolts are stretch, I believe
What's the mileage? If it's all apart, it may be worth doing a lot more work against future issues; stem seals, valve guides.
Exhaust and inlet manifold are a bitch to get off in situ. I'm not surey whether I took the inlet off while the head was on the car, but in hindsight, I must have. The exhaust manifold was removed on the bench. Getting the Downpipe, wastegate, and turbo off were a bitch. Many new studs here, too.

I already knew the exhaust manifold was fubar. I invested in a new one, back when they were £600 from Audi.

[simons2]

I had a b3 with the head gasket just on the way out. Stripped it cleaned it all up and replaced and never had a problem. Didn't even need to get the head skimmed. Once head is off I would check to ensure no corrosion/thin walls on oil and water galleries and then when you rebuild replace thermostat (could have been issue) and water pump.

[mikes2]

I had the head off my MB about 4 times in the first 2 years of ownership. Got it down to a 5 -6hour job to remove it

When I had white smoke, it was a problem with the head bolts not clamping the head down at the front of the engine. Oil was a light coffee brown colour.

You'll possibly find a cracked exhaust manifold when you're in there

[Tun]

Originally Posted by mikes2

I had the head off my MB about 4 times in the first 2 years of ownership. Got it down to a 5 -6hour job to remove it

When I had white smoke, it was a problem with the head bolts not clamping the head down at the front of the engine. Oil was a light coffee brown colour.

You'll possibly find a cracked exhaust manifold when you're in there

Cheers Mike, does the exhaust manifold need to be removed from the head? and can I take it I can leave the cambelt on the bottom pulley while doing the job?

[mikes2]

You can leave the manifold on - just makes it heavier. I leave the wastegate and corrugated pipe on as well. Just undo the 3 nuts from below for the downpipe

I'd suggest taking the turbo off though because there isn't really room to lift it up and out with the turbo still attached.

Is the timing belt fairly new ? You can leave it on the bottom pulley and just rotate the water pump to release the tension. The danger is getting the fluids onto the belt which is why I usually replace it.

You'll need to remove the cam pulley to get the rear timing belt cover for lifting the head so make sure you're at tdc