water in oil - just headgasket?

[mannik 0]

Not so mechanically minded I am afraid so a simple question

 

I now have water in the oil - does this specifically mean that the head gasket has gone or can it also be a result of piston ring damage or any other engine fault as well?

 

Engine also beginning to sound like a tractor (or an old BMW E30 when the valves etc are on the way out).

 

Have been offered approx £2K for the car - should I sell? (car is otherwise in really good nick). Looked at '95 Corrado here in Sweden for £8K and I have to say that for the difference of £6K I guess I could get a complete engine rebuild - or is this an underestimate for a rebuild?

[dr_mat 0]

Water can get into the oil via a number of methods, not just the head gasket. What engine you got? Looks like a VR6 logo in your avatar, so it could also be a dodgy oil/water heat exchanger starting to leak. These are relatively cheap.

As for the noise, it's most likely tappets or timing chains - how many miles has your engine done?

[mannik 0]

Heater matrix has been replaced, but I suspect I have high pressure in the system since everything associated with the cooling system seems to be giving up.

 

First the hose into the heater matrix, then circulation pump, then the heater matrix (all replaced) and now the thermostat housing...

 

Car has done 100K miles with no regular service before I bought it.

 

Can it be a crack in the engine block?

[h100vw 0]

I doubt it would be a cracked block. Any good garage should be able to pressure check the engine to isolate the fault. You can 'sniff' the water for combustion gasses.

Like dr_mat says there are a couple of ways to get oil in the water. The fact that you are having pipes blow could be over pressure due to the headgasket. It could be old age, the rubber going brittle?

 

Leaks could be down to corrosion, the T stat housing for example. If the car has been run without antifreeze or a weak mix, for any length of time the aluminium may have corroded to a point where the pressure can escape. I had this happen on a 16V. The fan failed, I replaced it and while waiting for the new one to cut in, the top hose connection on the head blew off....... So new connection and fan switch.

 

Certainly for 6K you could have a new engine from VW. A rebuilt replacement from a 3rd party would be very nice with that budget!!! 3.1 turbo or SC???

 

Rattling top end is common on un-loved VRs with 100k. Around a 1000 to sort in the UK.

 

Gavin

[dr_mat 0]

The hose to the heater matrix is pretty much always the first to go (mine did). The aux water pump tends to go at around 100k too (mine did), as can the heater matrix. Thermostat housing too (mine did).. Nothing all that unusual in your story so far. Those hoses are all 8-10 years old now, so rubber gets brittle.

If the car's not been very well looked after you might well have serious troubles brewing, but a VR that's had regular oil and coolant changes should see you through way past it's current troubles. (Probably just the oil/water heat exchanger, like I say.)

[mannik 0]

dr_mat - Serious troubles being..?

 

(thanks for all the good advice - much appreciated)

[dr_mat 0]

Well - worst case scenario on a VR is chewed up cylinder bores - basically requiring new block or rebore and piston work.. Big deal, cost wise.

What do you mean "with no regular service before"? You mean you lost the service history? Or you really mean it's never been maintained?

[mannik 0]

there was no service book (or at least it is not stamped).

 

How would you know if it had chewed the cylinder bores? I ask because spark plug 6 was completely clogged according to VW and there suggestion was a new engine...was this because of the plug fouling?

[dr_mat 0]

Hmm, yeah, oiled-up spark plugs *can* be a sign of bore wear (oil blowing past the piston rings into the combustion chamber), but it can also be caused by head wear - valve stem seals (or the head gasket!).

Anecdotal evidence seems to suggest that cylinder 6 is the worst for this.

BTW if you call VW they should be able to report the car's service history based on the VIN number if the book has been lost.

[mannik 0]

What test should a garage perform then to see if the piston rings were gone?

cheers again..

 

I guess if the head has gone and the valve stems need replacing this is 'cheaper' than if the pistons need reboring??

 

Effectively this would mean a replacement engine from a donor as VW suggested?

[dr_mat 0]

A head recondition is expensive, but it's certainly not as expensive as a rebore, or a replacement engine. (Unless you fall lucky on a 2nd hand VR engine in good shape..)

Compression tests and leak-down tests will help to diagnose things, but to be honest, this is a bit out of my league.. There may be people on here who can tell you more though.

[dr_mat 0]

Thinking about it.. (but not knowing for sure) maybe:

 

Bore Wear would result in a good compression test, but cylinder pressure would not be maintained so you'd get a failed leak-down test.

 

Valve stem seal problems would show no problems with compression or leak-down.

 

Head gasket could show both poor compression and poor leak-down.

 

Someone can correct me if wrong, but using these two tests you should know for sure. Of course, adding the fact that you've got oil in the water, there's a strong possibility it *is* the head gasket, but you could have a combination..