Seeing as sometimes water can end up in oil sometimes with oil cooler failure, is there a way to know for definate whether a failure is oil cooler or HG?

TheBoy wrote on 20. Aug 2006 at 22:37:

Seeing as sometimes water can end up in oil sometimes with oil cooler failure, is there a way to know for definate whether a failure is oil cooler or HG?

Given the fact that the water pressure wouldn't exceed 2bar and the oil pressure can reach 5 bar i would say that if the oil cooler is gone then you will have oil in water as well as water in the oil. So if you see water in the oil is either condesation or head gasket, or too old oil that has lost its properties.
The only way that water can enter into the oil via the oil cooler is when the engine is stopped and hot and therefore the oil pressure is 0 while you still have 0.8ish bar coolant pressure. I donno if i have been clear but what i want to say is that if there is a hole then fluids can be transferred both sides depending on pressure and sometimes viscosity.

Speaking entirely hyperthetically here, lets say you bought an Omega off Ebay for example. And that red 2.5v6 Omega happened to have brown gooo in the header tank, you can be 100% sure that either the oil cooler has gon, on someone at the auction house took a dump in the header tank. My money is on the oil cooler.

PM to Mark. He has just done the oil cooler on his MV6. I am sure he will know exactly what to check anfd where.

And, I am still wiating for my commission! ;) hyperthetically of course.

wrote on 20. Aug 2006 at 23:25:

Speaking entirely hyperthetically here, lets say you bought an Omega off Ebay for example. And that red 2.5v6 Omega happened to have brown gooo in the header tank, you can be 100% sure that either the oil cooler has gon, on someone at the auction house took a dump in the header tank. My money is on the oil cooler. PM to Mark. He has just done the oil cooler on his MV6. I am sure he will know exactly what to check anfd where. And, I am still wiating for my commission! ;) hyperthetically of course.

;D ;D ;D

wrote on 20. Aug 2006 at 23:25:

Speaking entirely hyperthetically here, lets say you bought an Omega off Ebay for example. And that red 2.5v6 Omega happened to have brown gooo in the header tank, you can be 100% sure that either the oil cooler has gon, on someone at the auction house took a dump in the header tank. My money is on the oil cooler. PM to Mark. He has just done the oil cooler on his MV6. I am sure he will know exactly what to check anfd where. And, I am still wiating for my commission! ;) hyperthetically of course.

In this purly theoretical discussion, it might interest you to know hyperthetically speaking i spotted it first and had an offer accepted!  ;)

TheBoy wrote on 20. Aug 2006 at 22:37:

Seeing as sometimes water can end up in oil sometimes with oil cooler failure, is there a way to know for definate whether a failure is oil cooler or HG?

As far as I can see all of these will point conclusively to head gasket problem - and not oil cooler issues.

1. The obvious thing to do is a cylinder compression test, looking for a single cylinder or adjacent pair with lower compression than the rest. A dry-and-wet test will confirm that any low compression isn’t the result of worn piston rings (though theoretically under rare circumstances you could have an oil cooler problem AND an unrelated leaky valve, which will look like a blown head gasket...).

2. The advice usually given by Car Mechanics Magazine is to ask an MOT testing station to lower a gas analyzer into the expansion tank (not actually touching the liquid) while the engine is running, any sign of exhaust gasses detected will indicate a definite head gasket failure.

3. I noticed in the past that when a head gasket problem becomes severe (that was on a 4-pot 8v TC Alfa-Romeo unit), if you place your hand over the exhaust you can feel condensation which is actually coolant droplets – and they will have a distinct smell of antifreeze. Also, you could sometimes smell the antifreeze on the spark plugs.

I believe there are now chemical kits that fit to the coolant expansion tank. If exhaust gases are detected the liquid changes colour.

No idea on cost or availability - but seen them used on telly.....

Here's one:

http://www.arrowheadradiator.com/head_gasket_or_combustion_leak_test.htm

I reckon its the oil cooler, as just dropped the oil out of it, and not a sign of water in it :)

Could you not also use mileage as an indicator of HG/oil cooler failure? For example, mine had covered 158,005 miles when the headgasket went, if yours had say covered 135,000 or less wouldn't it be fairly safe to say it's most likely to be oil cooler failure?

Exhaust fumes in the header tank are a very definite sign of HG, mine STANK when it finaly kicked the bucket!!

Just done my oil cooler, no water in oil, brown toffee oozing ( and i mean oozing ) from header tank and just to throw a spanner in the mileage theory mine has also done 158000

I strongly suspect that head gasket failure will be closer related to age and servicing than mileage....