1.6 HDI Coolant Leak - oil cooler ?

[geoff]

M59 DV6ATED 1.6 HDi Coolant leak - presumed to be from the oil cooler. 

Driving along at near midnight the cab heater lost temperature and the needle on temp gauge went down a third.

From this I knew there was a coolant leak so not wanting a head gasket failure I stopped straight away to check and found the expansion tank empty, and had to fill up using a carrier bag dipped into a ditch with running water. This got me home eventually.

With the engine running a quick look shows water dripping down from the front of the engine and onto the hydraulic cylinder directly below the oil cooler.  
It looks like the oil cooler and its seals are going to be the culprit...... well I hope so as this looks nice and easy to sort out Lol !!

Time to spend money  

CatCar is useful once again as it gives good images to study together with relevent part numbers.

From their diagram it seems a leak could be occuring from where the oil cooler is bolted against the oil filter housing.


Ebay sells everything it seems

Cooler and seals ( 1103K2 ) @ £29

Filter housing  ( 1103N9 ) @ £36

Combined unit ( listed under 1103N9 ) @ £ 51


Before I order will have another look in the morning - bit like cutting wood, measure twice and cut once.

Comments and advice welcomed.

[Sol]

If you want to test for sure, rig up a connection at the expansion bottle cap for a pump. Hand or foot, then put a bar or so on it, and spray soapy water (use fairy) all over the place. Bubbles will show you where the leak is.

You can use a rubber demijohn bung and tyre valve, may need plumbers tape to max out the bung, so you can pressurise the system to a value with water coming out. Silence is handy due to the engine not running, easier to identify the leak.

[geoff]

Thanks for that

[geoff]

Scrounged a schraeder valve from the local tyre shop and fitted it into a rubber door stop ( like using a demi-jon cork ) then wound some insulation tape around it to get to size and inserted it into the header tank.

Footpump used to pressurise and water could clearly be seen coming from the oil cooler where it joins the oil filter housing.

Ebay found a set of both front and rear seals for less than a tenner - item no 223564157567
Unable to buy just seals locally from motor factors

Front seal - oil cooler to housing - 1104 36
Rear seal - housing to block - 1103 S0

Duly ordered

Looks like the exhaust / turbo heat shields need to come off for this job so it may well give me a chance to repair my heat shields - stress fractures and vibratory noise - welder here I come better get it dusted off

[geoff]

Whilst I had the footpump on the go and with the header tank plug still installed I pumped up again and had a listen at the exhaust and also the air inlet manifold

No sounds of escaping air there so no apparent head gasket failure - test done a-la cylinder leakage test

[Sol]

Perfect! That's a great way to find a leak eh?

[geoff]

Sure is !!!

[geoff]

Made some progress here .....

A bit fiddly to remove the oil cooler but definitely DIY

For access I needed to remove the radiator and also the catalytic converter, could probably get away with moving cat to the left a touch but I needed the cat out altogether to fully remove the rear heat shield.

With the cooler off the vehicle the issue was obvious, the seals were good but my loose and rattling rear heat shield had jiggled about so much it had piecred a hole in the alloy oil cooler casing - new cooler required £29 + VAT from the local motor factors

I've fitted the cooler but not filled the engine yet as I'm waiting for a new rear heat shield to arrive in the post.

Cheapest heat shield I found was on eBay for £27    ... item :  325539583368

Lesson for me was to fix the heat shield sooner !

[geoff]

All sorted and no leaks ... yippeee !

Anyone doing this job or a full coolant renwl job eg radiator replacement ... don't forget when refilling to open the bled valve on the thermostat and the one on the hose next to the bulkhead otherwise it'll overheat ( no I didn't forget ... Lol !!  )

[evdama]

I'm having a WTF? with this .
Same engine as this ,I saw the coolant level was at its minimum for the first time ever in its 12 years.
Topped it up.
Checked again after a 10 mile trip.
It was back at minimum again
Reading this thread ,fearing the worst,I refilled again.
Just got back from a 25 mile trip.
It's still at maximum.
The oil is still (nice?) and black so at least it didn't go into the engine.
Wtf?
I will check again on Sunday when everything is absolutely cold.