V6 Head Gasket Question
 

I know V6 head gasket problems are meant to be rare but I have a sneaking feeling mine has gone. I've always lost a bit of coolant but lately its got worse. Runs fine. No airlock, No overheating, No drips. No mayo & oil looks fine.

So must be just ingesting it into the combustion chambers
Question 1 - is that a common scenario?

Or

Question 2 - if the HGF is in the rear bank is there any chance that no mayo would be visible in the front?

Anyone had something like this?

I wouldn't discount the inlet manifold gaskets leaking coolant into the engine. I know of two cases, there are perhaps more.

Just finishing off a thermostat change at the moment and not the keyhole method as I wish to change the paper inlet gaskets at the same time.

Good luck

Interesting, I hadn't considered that.
I guess I could pull the inlets off and, if they look ok (would it be obvious?), remove the rear rocker cover and take it from there.

Have a look at the image and tell me what you think? It's from a Norwegian V6 that was diagnosed as head gasket failure.

https://www.the75andztclub.co.uk/for...950e9a5b0a.jpg

Good luck

HGF on the V6 does not seem to be as common as on the 1.8's, but I'm sure it does occur.

My V6 dumped 2.5 litres of coolant into the oil over a very short distance. Car limped home with a misfire. Code reader showed front bank lambda sensor. On removal the sensor was caked from the water damage. A replacement sensor tried out of interest and the engine ran fine. Haven't got round to investigating any further, but fairly certain it has HGF on the front bank.

Inlet manifold gaskets had been changed.

The other possibility on yours could be the oil cooler perhaps?

I cant completely rule it out but I'd expect some sign of water in the oil if that was happening and I cant see any.

Hello Peter,

Small, persistent coolant loss can be caused by flattened 'O' ring seals on the expansion tank cap. Have a look at that.

Is the coolant level too high? Can you see the 'MAX' tab inside the expansion tank when you peer inside?

When you say "no airlock", could you let us know what you've done to eliminate that possibility? For example, have you drained, refilled and bled the cooling system including raising the expansion tank?

Does "no overheating" mean that your engine has passed the radiator fan "demist" test and with the instrument pack diagnostics activated the running temperature is in the low nineties when the car is moving?

Oh, and any coolant pools in the 'V'?

I cannot stress enough how important it is to check the basics and make no assumptions. ;)

Best wishes,

Simon

I fitted a new cap a little while back. It fixed the pressure problem I had at the time but I suspect this is different - no unusual pressurising and no sign of any loss via the cap.

I only ever fill it to the correct max mark.

Yes, tried that. Haven't re-drained this year but if I pull the inlets off I will do it again. Have lifted the tank and filled etc a few times.

I've not tried that recently, will give it a go. I have watched it on OBD reader while driving and seems fine.

V is fine. There is a trace of dried pink round the base of the thermostat but its old and dry. I guess it might have leaked when a previous owner had it but no sign here for 5 years.
Thanks for this Simon - I'll do the demist test but I think the next step is to check the inlet gaskets and perhaps peek in the rear rocker.

Just one more thought Peter; if that were the case I would expect to see a lot of steam from the exhaust. I'm sure you would have mentioned that! :}

Simon

I've not noticed any but then I'm usually in the car :¬)
I'll check tomorrow.
The coolant has to be going somewhere but blowed if I can work out where.

Just a thought - if the water-pump were leaking it would emerge from a drain hole. Wonder it that drain hole could be blocked?

I think I'll have one more go at the checking for air-locks, run a demist check (although if I'm stuck in traffic long enough the fan will come on).
Then its pulling the inlets off and the rear cam cover.