Oil mixing with water fault on C70 T5 advise needed

**boycey** · Sunday 23rd November 2008, 17:12

Hi my mates Volvo C70 T5 came into my garage the other day with horrible brown thick emulsified oil/water mix coming out of the expansion tank.

So it was decided as it was building up pressure as well as the mixing of the fluids that the head gasket was at fault. The emulsified water/oil was solid everywhere in the radaitor, turbo Cylinder head and every pipe on it. (must have been like it a while)

Once we removed the Cylinder Head we found that the gasket looked ok and no obvious signs of wear. Also what doesnt help the situation one of the head bolts snapped in the block.

Has anyone got any ideas on another cause of the fault. Cracked Head, liners etc before we start spending any money on it.

Someone mentioned about an oil cooler being the fault, but I didnt know they had one.

Its a C70 T5 1999 done 125000 miles belived to be chipped.

Any help would be greatly appreaciated. thanks boycey

**irf** · Sunday 23rd November 2008, 17:17

i don't know about this is in any detail but i do know that the oil coolers can cause this problem and allow the oil and water to mix.

**t5 pete** · Sunday 23rd November 2008, 17:22

i had kind of the same problem there was no oil in water but was boiling over very quick it was acting like a compressor i cheacked every thing before taking the head of and found nothing so i took the head off had a look at the gasket there wasnt anu thing wrong with it the water jackets looked to be fine so i took the head for a pressure test the boke that did the test said that there wasnt any thing wrong with the head at all,i decided to have the head skimed even tho there wasnt any obvious hair lines in it after that i put it all back together with new head gasket set new thermostat and once all done the problem was gone and the car was fine i still dont know what was up with it to this day

**pangster** · Sunday 23rd November 2008, 17:52

Originally Posted by irf

i don't know about this is in any detail but i do know that the oil coolers can cause this problem and allow the oil and water to mix.

I heard this can be a problem as well and the symptoms are exactly as you describe as the oil cooler is inside the radiator.. that would also explain why the HG looks ok as well..

**t5 pete** · Sunday 23rd November 2008, 18:13

Originally Posted by pangster

I heard this can be a problem as well and the symptoms are exactly as you describe as the oil cooler is inside the radiator.. that would also explain why the HG looks ok as well..

the only other problem would be is the pressure that he states it could be a prob with the oil cooler and also a hair line crack in the bottom of the head i would personally change the oil cooler and have the head pressure tested and skimed

**Diesel64** · Monday 24th November 2008, 09:03

I have the same issue with my 850 and I'm 99.9% certain it's the radiator, which I'll be swapping out this week.

Encouraging to know you didn't find it was the Head gasket though.

Rufe can sort a new rad for you for about £108 all in (delivered + VAT).

Bob.

**ctautos@btinternet.com** · Monday 24th November 2008, 09:19

hi the car i am braking had a new gasket fitted to find it was the head i would change it

**jonno12** · Monday 24th November 2008, 09:25

Originally Posted by irf

i don't know about this is in any detail but i do know that the oil coolers can cause this problem and allow the oil and water to mix.

this is what happened to mine the rad split inside the oil cooler and was mixing it

**ctautos@btinternet.com** · Monday 24th November 2008, 09:48

i all so have a as new rad auto

**boycey** · Monday 24th November 2008, 20:43

That explains it then the oil has mixed with water in the oil cooler inside the radiator. This has then caused it to overheat and has proberly cracked the Cylinder head, which is causing the build up of pressure within the cooling system.

**jonno12** · Monday 24th November 2008, 21:26

mine over heated but the cylinder head and everything was ok just changed th e oil filter and oil after i did the rad

**jonno12** · Monday 24th November 2008, 21:26

all thanks to the mopp clan might i add

**pangster** · Monday 24th November 2008, 21:27

Originally Posted by jonno12

mine over heated but the cylinder head and everything was ok just changed th e oil filter and oil after i did the rad

sounds like a lucky escape! lol!

**jonno12** · Monday 24th November 2008, 21:30

it was until me n the misses split up and now im carless so i hope it blows up lol :"

**pangster** · Monday 24th November 2008, 21:39

Originally Posted by jonno12

it was until me n the misses split up and now im carless so i hope it blows up lol :"

LOL!!!..

**siamblue** · Monday 24th November 2008, 23:19

Originally Posted by boycey

Hi my mates Volvo C70 T5 came into my garage the other day with horrible brown thick emulsified oil/water mix coming out of the expansion tank.

So it was decided as it was building up pressure as well as the mixing of the fluids that the head gasket was at fault. The emulsified water/oil was solid everywhere in the radaitor, turbo Cylinder head and every pipe on it. (must have been like it a while)

Once we removed the Cylinder Head we found that the gasket looked ok and no obvious signs of wear. Also what doesnt help the situation one of the head bolts snapped in the block.

Has anyone got any ideas on another cause of the fault. Cracked Head, liners etc before we start spending any money on it.

Someone mentioned about an oil cooler being the fault, but I didnt know they had one.

Its a C70 T5 1999 done 125000 miles belived to be chipped.

Any help would be greatly appreaciated. thanks boycey

Being a garage why did you not do a gas pressure test on the car? that would've told you whether the head was leaking or not,

Gary

**boycey** · Wednesday 26th November 2008, 22:59

Sorry i dont mean to be thick but do you mean the fluid that changes colour??

**jez.w** · Thursday 27th November 2008, 10:39

You can test for head gasket leak using the liquid that changes colour when hydrocarbons are present (for leaks around cylinders). But this wont check for oil or water galleries leaking. Its possible to have a water or oil leak on edge of gasket but the cylinders are fine so it would pass the hydrocarbon test but still have a dodgy gasket leaking oil or water. You would need to test the gasket another way for this problem. So you could do the sniff test and it would pass but you could still have a broken gasket. This happened to me on a non volvo car where my oil was ok but i was losing water. My car passed the sniff test, but when you looked closely at the back of the block along the head gasket line it was wet, and so it was obvious that the head gasket was dodgy in my case.

**boycey** · Friday 28th November 2008, 23:57

Yes i have this equipment but did not try it as it was that blocked up with the oil/ water gunk sludge, i though it was pointless. The car had boiled up which made them check the water level.

**Diesel64** · Wednesday 3rd December 2008, 21:15

ok, so I know this thread is a bit old, but it seems relevant to put my findings here...

Changed out the rad on my 850 over the weekend (turned out to be a bit of a pig to do, but thats another story). I'm happy to report I don't have any more issues with oil getting into the expansion tank.

Just as well, cos when I started (did a flush/drain first) I found I had to remove the gunk that had built up from said tank with a teaspoon!

Hope this is useful to anyone with similar issues...