996 water in oil problem
Discussion
Hi Guys, I have just acquired a 2002 3.6 litre 996. It was cheap but had some known before bought issues which I have no doubt will be expensive to remedy.
There was a lot of emulsion under the oil filler cap but no sign of any oil in the coolant. There is a steady stream of coolant coming from the left cylinder bank into the exhaust resulting in water and steam out the right tailpipe. The engine, however, runs very smoothly on all six cylinders. I cleaned the emulsion from the oil filler pipe and changed the oil, but the white emulsion and droplets of water appeared within 20 minutes of reaching working temperature. Looking around the forum I can find plenty of cases of oil in the coolant which appears to be as a result of a cracked head allowing oil to force its way into the coolant, but not any examples of water in the oil. I think the water in the oil may be a head gasket failure, but how does coolant get to come pouring out the exhaust, but the engine runs as well, on all 6 cylinders, as it should when healthy?
There was a lot of emulsion under the oil filler cap but no sign of any oil in the coolant. There is a steady stream of coolant coming from the left cylinder bank into the exhaust resulting in water and steam out the right tailpipe. The engine, however, runs very smoothly on all six cylinders. I cleaned the emulsion from the oil filler pipe and changed the oil, but the white emulsion and droplets of water appeared within 20 minutes of reaching working temperature. Looking around the forum I can find plenty of cases of oil in the coolant which appears to be as a result of a cracked head allowing oil to force its way into the coolant, but not any examples of water in the oil. I think the water in the oil may be a head gasket failure, but how does coolant get to come pouring out the exhaust, but the engine runs as well, on all 6 cylinders, as it should when healthy?
The emulsion's not uncommon on all these engines. Is it definitely steam though? If there's too much oil white smoke isn't unusual - you check these engines cold, level, not running. If you check them like you do an air-cooled (fully up to temp, oil stat open, engine running, level) and top up accordingly you'll have way too much oil in there, resulting in the white smoke.
You may also have an AOS (air - oil separator) problem, which is fairly routine to deal with.
You may also have an AOS (air - oil separator) problem, which is fairly routine to deal with.
Thanks 'TheGoose' for your reply, any advice or knowledge better than mine is gratefully received.
There is water running from the seam of the right hand silencer, more of a steady trickle than a drip. It's a little corroded in that area so looks to have been happening for some time. The emulsion in the filler pipe was quite extensive with about three teaspoons of white clumpy mayonnaise. I am aware that this engine isn't dry sump and did check the oil level after refilling with the engine off. I put in 8 litres and a new oil filter, so it's just below maximum. Could a failing AOS cause moisture to get in the oil? The old oil was a murky brown colour, but as far as I can make out from the now sparse service history it may have been in there for 25000 miles, so maybe that colour is to be expected. I can also hear a rumbling bearing noise coming from the middle of the engine/ clutch area and I suspect an IMS bearing worn so have decided to have the engine out to do that, but my main worry is the amount of water coming out the exhaust. If it was coming into the cylinder and combustion chamber the engine would hydraulic lock I think or at least run lumpy on 5 cylinders, so maybe it's leaking from a crack in the head between a waterway and the exhaust port? I haven't been able to find any instances of this happening to anyone else's car, searching the Internet.
There is water running from the seam of the right hand silencer, more of a steady trickle than a drip. It's a little corroded in that area so looks to have been happening for some time. The emulsion in the filler pipe was quite extensive with about three teaspoons of white clumpy mayonnaise. I am aware that this engine isn't dry sump and did check the oil level after refilling with the engine off. I put in 8 litres and a new oil filter, so it's just below maximum. Could a failing AOS cause moisture to get in the oil? The old oil was a murky brown colour, but as far as I can make out from the now sparse service history it may have been in there for 25000 miles, so maybe that colour is to be expected. I can also hear a rumbling bearing noise coming from the middle of the engine/ clutch area and I suspect an IMS bearing worn so have decided to have the engine out to do that, but my main worry is the amount of water coming out the exhaust. If it was coming into the cylinder and combustion chamber the engine would hydraulic lock I think or at least run lumpy on 5 cylinders, so maybe it's leaking from a crack in the head between a waterway and the exhaust port? I haven't been able to find any instances of this happening to anyone else's car, searching the Internet.
No Chris, it's definitely coming from the seam of the right exhaust and steam/water drops out the tailpipe, however, you are correct about the header tank. When the engine gets up to temp the header tank does start to leak and drops water around the left silencer. I was aware of this and will change it when I have the engine out. Still not sure why coolant is getting into the exhaust system.
Faster than a drip, a steady trickle. I've had it running for about half an hour at a time. Doesn't seem to use any in that time, but then needs a couple of litres once its cooled down. I'm not running it now as a large amount of blue smoke started to come out the exhaust which I think will be a faulty Air Oil Seperator.
Just a thought but is there a coolant pipe or connection above the exhaust that could be leaking, and this leaks over the exhaust causing it to appear to be 'coming' from exhaust? It's a bit difficult to picture so some photos may help. Water leaking at that rate doesn't sound like a head gasket to me.
TwoLeadFeet said:
Just a thought but is there a coolant pipe or connection above the exhaust that could be leaking, and this leaks over the exhaust causing it to appear to be 'coming' from exhaust? It's a bit difficult to picture so some photos may help. Water leaking at that rate doesn't sound like a head gasket to me.
Water leaking at that rate doesn't sound like a head gasket to meThe water is definitely coming from the silencer seam along with steam coming out of the exhaust. It's slightly corroded in that area and there is no coolant coming from above either side around the exhaust. I agree that it can't be leaking through the head gasket into the combustion chamber as this would result in rapid pressurisation of the cooling system. There is still the issue mentioned earlier of the water in the oil. I am sure this is way more than the normal condensation these engines have. After changing the oil I could see emulsification very shortly after running the engine, and even a few droplets of water in the oil filler pipe.
Well, a few months have passed and things are looking up for my 996. I fitted a new aos, a new coolant header tank. During this work I had the gearbox and flywheel off and fitted a new IMS bearing, as I thought I was able to hear a bearing rumble coming from the flywheel end of the engine when I was lying underneath. With the box off and the engine lowered a few inches I was able to get fairly easy access to the AOS. I made my own extractor made from an appropriately sized socket and an installation tool from another socket. The bearing came out and new in without drama. I re-used the outer three bolted bearing cover. On reading a few threads on the subject and on the advice of the bearing supplier after telling him where the bearing was going, I decided to fit it without the bearing seals.
I'd read a lot about the IMS bearing and as mine has lasted to now (126k), I decided to replace it with a new improved version of the same bearing. I rang up my local supplier in Bristol. I gave him the numbers on the original bearing and he said he had several in stock and that would be £8.34 including vat? It wasn't the same make as the original, it was branded as an 'SKF Explorer'. If you google 'skf explorer' there is and interesting PDF explaining the improved manufacturing process.
Any way, after all this work the engine seams to be running fine with no coolant leaks, the only problem now being Abs/ Pms lights showing on the dash which I have traced to a faulty Maf. This is to be replaced as the one I removed to attempt to clean with cfc maf cleaner was from a 2000 car, and mine is a 2002. The part number is correct, but it looks like someone has cut it open and resealed it with black silicone!
I'd read a lot about the IMS bearing and as mine has lasted to now (126k), I decided to replace it with a new improved version of the same bearing. I rang up my local supplier in Bristol. I gave him the numbers on the original bearing and he said he had several in stock and that would be £8.34 including vat? It wasn't the same make as the original, it was branded as an 'SKF Explorer'. If you google 'skf explorer' there is and interesting PDF explaining the improved manufacturing process.
Any way, after all this work the engine seams to be running fine with no coolant leaks, the only problem now being Abs/ Pms lights showing on the dash which I have traced to a faulty Maf. This is to be replaced as the one I removed to attempt to clean with cfc maf cleaner was from a 2000 car, and mine is a 2002. The part number is correct, but it looks like someone has cut it open and resealed it with black silicone!
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