I have had oil seeping from one part of my thermostat housing, i immidietly thought blown head gasket, but there is no coolant in the oil, and i drained the radiator today, and there was no sighn of oil in the coolant. I noticed the small leak after turning on the heater one night, i bought the car over the summer, and had never turned on the heater, after a few minutes there was a lound buzzing sound coming from behind the dash. I shut the air off right after hearing the noise. the next day, i popped my hood and there was the leak. I have not turned on the heater since then and the leak has seemed to stop. Any Ideas would be really appreciated.

 

Ok im not sure if its just me but that really confused me...

Thermostat housing has nothing to do with the heater loop, which should in no way enable a oil leak.

I cannot see any way oil will come out of a thermostat housing and not get mixed in with the coolant.

Got any pictures of whats leaking?

 

Few problems here:

The thermostat housing is no where near a oil passage, sealed by something that could leak, and in the event of a leak, you would see it (oil) prominantly in the coolant. The closest thing that has oil, is the lifter valley, which is an intake thickness, through the coolant crossover, away. No way you are leaking oil from the thermostat housing. Seeping coolant, possibly. Engine gets dirty, grimey, whatever, then the coolant seeps and moistens it all and yes, it could take the appearance of an oil leak.

Buzzing behind the dash could be fan motor operation.

 

i'd clean it up and watch for where whatever it is might be coming from. like was said there's no way it's an internal oil leak getting out around the t-stat unless you filled your radiator with oil.

 

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[edit: wrong post...]

 

Could be coming from where the intake meets the block in front of and just below the thermostat housing but it would happen all the time, not just when the heater is turned on. Tricky problem.

 

yes it's more likely to be a leak from the block to intake or from a bolt from the intake to the head.

 

Thanks for all the replies, after replacing the coolant, and driving the car the past couple days the leak has seemed to stop, i plan on pulling the intake after putting her away for the winter, then maybe i'll figure out exactly what it was.

 

i am having the exact same issue, but i'm not sure if heater use has been a factor. no apparent oil in the coolant, no coolant in the oil, no loss of oil level, and no loss of oil pressure - just a small amount of oil seeping from the thermostat housing gasket. wierd.

 

I think when you disconnected the evap system harness you switched hoses by mistake. Try removing the evap hoses from it's connector (on top of the engine) and simply switch them and reinsert. Run the engine for about 10 minutes to chase the gas fumes from the oil cap and you should be fine if this is the issue.

 

8 years later , the original post in 05 come on

 

UMMM... Wrong post. But I'll leave it in case it helps someone.