Blown Head Gasket

[RM955I]

V70, 2010, D5 twin turbo) 207,000

I sort of already know the outcome of this but thought I'd ask anyhow.

The head gasket has gone The coolant expansion tank is full of oil and there's no doubt it's the head gasket.

I'm a bit p*ssed off - I changed the oil yesterday and yes, it's the right spec oil in the right quantity: I've done my own servicing for years and it's just an unfortunate coincidence...some coincidence admittedly but there's no doubt: right oil, right quantity.

Presumably, it's scrap - very hard to justify the cost of doing the head gasket on a car of this age and mileage. Part of me thinks about flushing the cooling system and chucking some K-seal in it or am I just wasting money on oil and filter for something that is most likely FUBARd

[cheshired5]

The internal oil cooler seals are much more likely to fail than the head gasket and it's a considerably cheaper fix.

When this happens, the cooling system can allow in an alarming amount of oil so are you certain that the head gasket is the problem or are you basing the diagnosis solely on oil in the cooling system?

[RM955I]

Thanks for the reply. You are right...I’m basing my diagnosis purely on an expansion tank full of oil.

What am I looking for? Is it to take the oil cooler off and have it leak/pressure tested? Any advice would be much appreciated. Thanks.

[cheshired5]

You could pressure test the oil cooler on its own by connecting to the coolant in/out pipes on the cooler itself or you could pressure test the cooling system in general without disconnecting anything as shown in my video here.

The cooling system should comfortably hold 10-12 psi so if there's a loss in pressure, you could investigate further by unbolting the oil cooler where a breach would then be apparent if it is the cause.

You'd obviously need to drain the oil first.

[RM955I]

Thanks,

One last question before I dive into it - I'm assuming that as I look down from the front of the car the oil cooler is on the right by the air filter housing. Basically, this (picture)

I'm trying to work out how to access it - is it a bumper off job or can you get to it without too much fuss?

[cheshired5]

I'm not familiar with all of the ancillary locations on your D5 version but the picture on the right looks like it's a transmission fluid cooler.
No mention anywhere of your transmission type so don't know any more than what you've given us.

Follow the pipework to see if any go into the transmission.

D5 engine oil coolers are generally at the back of the engine near the sump drain bolt and look like the left picture.

[Sotosound]

I feel your pain.

Putting aside arguments about economical repairs, and the possibility of someone saying that the repair might cost more than the car is worth, the real question is about what the car is worth to you.

Also, can you afford the full cost of a replacement car, wherein the cost of purchase is often just the starting point of a new round of expenditure as you uncover all of the other issues that the seller decided to leave for the next owner to fix.

Obviously, you have to decide what to do, but if your car is otherwise in good condition then that is something to be weighed in the balance.

[RM955I]

A good point - As I need it for work and haven't got the time or inclination to take time off to pull it apart and then have a non-functioning car on the drive, albeit temporarily so I've taken it to a small local garage.

We've agreed 3 hours max to clean out the cooling system (which is full of oil), possibly temporarily bypass the oil cooler to see if we still have the issue (which is so, then most likely points to head gasket or something more serious) and we'll take it from there.

It pains me to take a vehicle to a garage but it's a time/convenience/cost equation - it's worth a couple of hundred quid for someone else to get covered in oil and check it over: after that I just wouldn't chuck any more money at it. It is (was?) a very good car that has cost me nothing more than tyres/fuel/oil/consumables.

I've never had to spend anything on it to be honest but at 207,000 perhaps it's had its day.

Short version..if oil cooler: great - fix it; head gasket...scrap it. I've got a contact in a lease company so maybe it's time to balance the cost of that versus spending money on a 3 or 4 year old car.

[yostumpy]

As I understand it, when a head gasket goes, there is some oil/ water mix. Is the oil watery? But mostly the water system is pressurized, and forced out of the expansion bottle cap, thus leaving water level low. Also when cold, the water pipes would feel hard to the touch, not be able to be squashed, due to the pressure of the air in them. I am thinking along the oil cooler leak theory.

[RM955I]

I think the simple answer is that the expansion tank is full of black oily water, and full to the brim, forcing its way out of the overflow. It’s not a case of some oil mixing with the water - it’s a black horrible mess.

The car is with a local garage now and we’ve agreed they’ll investigate and spend no more than 3 hours on it. By the time I’ve bought the kit to pressure test it and the chemicals to decontaminate the cooling system, I may as well pay someone else to do it. If it’s the oil cooler...happy days (compared to a head gasket).

It could very well be the oil cooler: I really hadn’t considered that at the time given the horrible mess and sight of a cooling system full of oil...time will tell👍