oil in coolant

[redroverm37]

1987 RRC 3.5 motor
How does oil get into the coolant? I have what apears to be motor oil in my radiator overflow, do not see any in top of radiator. not a lot but 2-3 oz. No oil cooler in radiator so that eliminates a leaking cooler tank. Motor runs fine, but all the hoses look like they are swelled from oil. No coolant in oilpan. I just bought this Rover at estate auction and have no idea of its history. only 121K miles
it almost looks like someone put oil in the radiator overflow tank! Any Ideas?

 

[landrovered]

Head Gasket

 

[eliaschristeas]

pm me - i have some awesome motor's for you that will cost you less than a h/g repair

 

[57loboy]

Head Gasket

x2 and then some...

 

[redroverm37]

I guess a compression test is next....thanks

 

[kevin-ct]

I have seen the front timing cover also leak coolant into the oil. I would flush the coolant system with dish soap (cuts the oil) and replace the coolant then see if it returns.

Kevin

 

[redroverm37]

Seen that too. But unable to figure out how oil gets into coolant from front cover.
I see no pressure build up in overflow tank when running, but who knows....Its a Rover!

 

[MUSKYMAN]

I would flush the system as well but I would just use a good commercial cooling system flush, they are made to cut oil as well as scale.

then with the system empty you need to pressure test the cooling system to see if it holds pressure, you should be able to pump it up to 15-20 lbs and have it hole the pressure without leaking down.

a compression test may show a problem if its just a head gasket failure but if it is a cracked liner the block may need to be at running temp to actually leak.

 

[ptschram]

I prefer to pressurize the combustion chamber rather than the cooling system. The cooling system is only designed to tolerate ~15 psi while the combustion chamber will see much higher pressures. For me, it is easier to apply shop-air to the combustion chamber than regulate it down to 15 psi to keep from blowing things up.

Either way, this is a 20+ year-old truck, flushing the cooling system is unlikely to do any damage.

 

[MUSKYMAN]

we will have to disagree on this one Paul...oil in the coolent is most often from it getting drawn in during the cool down cycle. Because it floats it accumulates on the top at the highest points.

pressurizing the combustion chamber wont test the whole cooling system it will only test a very small part of it.

allthough the cap is designed to evacuate fluid/pressure after 15lbs that dosent say that it can only hold 15lbs there is a margin there that 15-20 lbs would not surpass.

this is the tool for the job

http://www.sjdiscounttools.com/sta12270.html

 

[kevin-ct]

Seen that too. But unable to figure out how oil gets into coolant from front cover.
I see no pressure build up in overflow tank when running, but who knows....Its a Rover!

the front cover has water jackets for the water pump. If that paper thin gaskets rips or if the bolts on the front cover are loose it will let coolant leak down into the oil pan.

Hmm, I do have a nice 3.5L with only 4000 miles on it in my shed.

 

[KevinNY]

What about the trans cooler line that passes through the end tank of the radiator? I've seen it happen on a toyota once.

 

[MUSKYMAN]

What about the trans cooler line that passes through the end tank of the radiator? I've seen it happen on a toyota once.

both the trans and oil lines run through the tanks, The design is actually pretty solid acording to my radiator guy but yes sure it can happen. A good radiator shop will test both cooling circuits when they flush and pressure test a radiator.

 

[ptschram]

we will have to disagree on this one Paul...oil in the coolent is most often from it getting drawn in during the cool down cycle. Because it floats it accumulates on the top at the highest points.

pressurizing the combustion chamber wont test the whole cooling system it will only test a very small part of it.

allthough the cap is designed to evacuate fluid/pressure after 15lbs that dosent say that it can only hold 15lbs there is a margin there that 15-20 lbs would not surpass.

Fair enough.

I prefer to go through the spark plug hole as it is easiest and less likely to cause a bigger problem.

In the event of a major head gasket failure, there is free-flow between the combustion chamber, the water jacket and the oil passages. There is a P38 in the shop right now where that was the case. I quite often encounter situations where there is a clear passage between the combustion chamber and the water jacket. As a result, I tend to lean toward working through the spark plug hole.

If pressurizing through the spark plug hole proves a passage exists where it's not supposed to, we know what we have. If not, we have merely removed one avenue and must continue on.

As Chris has said on many occasions, there are few wrong answers and this is certainly an example.

Cheers,
PT

 

[redroverm37]

no oil cooler tanks in this radiator. no oil cooler period. transmission cooler in front of AC condenser.