Oil in the Radiator
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Oil in the Radiator When I check the coolant level in the radiator I can see a little bit of oil floating on top of the coolant. After further inspection the under side of the radiator cap has a thick black grease film. The inside of the filler neck has this same film. There is no signs of water in the oil and the engine runs strong. The engine appears to have been well taken care of. I'm thinking maybe it previously had a blown head gasket and the radiator was not properly flushed. Can this grease be flushed out of the radiator ? Should I just take the radiator out, fill it full of a de-greaser, and give a good flush. Or maybe just buy a new radiator.
The coolant flows to the oil cooler mounted above the oil filter, and I have seen several leak allowing oil to eventually get to the radiator. The cooler can be removed and the coolant lines bypassed.
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I posted that the oil cooler rarely leaks and that blown head gaskets are much more common in these engines.
I did NOT state that it was NOT the oil cooler and that it HAD TO BE a blown head gasket. This will be determined by further diagnosis of the vehicle.
I've simply stated what would be the most likely cause of the problem.
The oil that flows through the cooler/adapter in under pressure from the oil pump. If there's a leak between the oil side and the coolant side of the cooler, it'll eventually pump all the oil into the coolant side. This is because the oil is normally at a higher pressure than the coolant. Shut off the engine and the oil pressure goes to zero and as the coolant side is under some pressure during operation, it'll then cause coolant into the oil system.
During a quick search of the LT1/4 section, there's zero results for "bad oil cooler" yet a good handful or results when searching for "blown head gasket".
I did NOT state that it was NOT the oil cooler and that it HAD TO BE a blown head gasket. This will be determined by further diagnosis of the vehicle.
I've simply stated what would be the most likely cause of the problem.
The oil that flows through the cooler/adapter in under pressure from the oil pump. If there's a leak between the oil side and the coolant side of the cooler, it'll eventually pump all the oil into the coolant side. This is because the oil is normally at a higher pressure than the coolant. Shut off the engine and the oil pressure goes to zero and as the coolant side is under some pressure during operation, it'll then cause coolant into the oil system.
During a quick search of the LT1/4 section, there's zero results for "bad oil cooler" yet a good handful or results when searching for "blown head gasket".
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Verdad Gallardo I Shine, you say you think the car had a blown head gasket and you suspect the oil in the coolant is left over from that. This is a possibility-if in fact the engine has had a blown head gasket. Do you know that a head gasket was replaced?
If you want to totally rule out the oil cooler as the culprit, you can remove the oil cooler completely (many consider the stock cooler as little help and prone to leaking oil onto the ground), completely flush the cooling system (engine, heater core, overflow bottle) and do an oil change. Drive the car for some weeks and see if the oil contamination returns.
It would be great for you if it was the oil cooler-it's considerably less work than head gaskets.
If you want to totally rule out the oil cooler as the culprit, you can remove the oil cooler completely (many consider the stock cooler as little help and prone to leaking oil onto the ground), completely flush the cooling system (engine, heater core, overflow bottle) and do an oil change. Drive the car for some weeks and see if the oil contamination returns.
It would be great for you if it was the oil cooler-it's considerably less work than head gaskets.
Last edited by Paul Bell; Nov 9, 2013 at 05:18 PM.
Sometimes they do indeed mix, in the bottom of the oil pan. There are times the gasket may only give and coolant will escape into the cylinder only. My question is, how does oil get into the cooling system where you can notice it from the radiator fill, if the oil cooler is not at fault?
Aside from the good number of posts here on LS1tech discussing oil in the radiator and head gaskets, there's the usual internet searches:
http://www.chacha.com/question/what-...n-the-radiator
http://www.yotatech.com/f120/oil-my-...s-mean-242717/
http://answers.yahoo.com/question/in...5225125AA1Vlyw
http://cars.blurtit.com/180652/oil-i...s-the-problem-
http://wiki.answers.com/Q/Why_is_the...in_my_radiator
http://www.fixya.com/cars/t5287257-o...flow_tank_mean
http://wiki.answers.com/Q/Oil_and_an...wn_head_gasket
http://www.chacha.com/question/what-...n-the-radiator
http://www.yotatech.com/f120/oil-my-...s-mean-242717/
http://answers.yahoo.com/question/in...5225125AA1Vlyw
http://cars.blurtit.com/180652/oil-i...s-the-problem-
http://wiki.answers.com/Q/Why_is_the...in_my_radiator
http://www.fixya.com/cars/t5287257-o...flow_tank_mean
http://wiki.answers.com/Q/Oil_and_an...wn_head_gasket
I really haven't seen any threads here or any f-body forum for that matter regarding oil in coolant due a to blown head gasket(s). Some of those links you've provided are completely inadequate. There are no oil ports between the heads and the block on the LT1 engine. It reads more like some of the descriptions are for OHC engines. The only part of the gasket that is exposed to oil is within the lifter valley. Because coolant is under more pressure than oil vapors w/in the lifter valley, coolant will always find its way into the engine rather than oil finding its way into the cooling system barring no oil cooler.
Regardless of how the oil gets into the radiator, it's usually a sign of a bad head gasket. This is somewhat common with SBC engines. Even my 1999 Savana blew a head gasket-at 200K.
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