[SethB]

So,

For a very long time, over a year, I have had this very slow coolant leak. It does not leave any drips while running.

Well, I thought it was my radiator (hit an animal, bent my intercooler, and thought maybe it screwed up the radiator. I also saw some crustiness and discoloration on the top of the radiator. Pictures attached)

But today, I had just started the car before it had time to warm up, and wanted to look underneath to see if I was leaking trans fluid as I had just replaced the axle and wanted to make sure I tightened the drain plug as I drained and saved the fluid.

But, when I did that, I noticed some fluid on the downpipe, right after the cat. Shut off the car and jacked up the front, crawled under and sure enough, it was coolant. Tried looking up but couldn't see much.

I have a picture of where I could see wetness. Its not the best picture, but that is the most I can see up to where it was wet.

 

[steve12955]

You may have leaks in two locations. At the top of the radiator, hopefully the clamps are just loose but the black tanks on either side of the radiator fins are plastic and get brittle and develop hairline cracks with age.

The leak in the back could be from any of three hoses that connect to the thermostat housing or the housing itself which is located beside and below the turbo on the driver's (left) side. The housing is plastic. There is also a 1-1/2" or so diameter pipe that runs behind the engine that connects the water pump on the passenger (right) side to the thermostat housing. The pipe is sealed at either end with large o-rings which can fail. However, to replace the $1 o-rings requires removal of the housing which is a lot of work (drop downpipe, remove expansion tank, move stuff aside, etc.). If you're going to do the work, replace the thermostat, gaskets, hoses, etc. You may also want to replace the water pump since it's one of those "might as wells."

 

[SethB]

You may have leaks in two locations. At the top of the radiator, hopefully the clamps are just loose but the black tanks on either side of the radiator fins are plastic and get brittle and develop hairline cracks with age.

The leak in the back could be from any of three hoses that connect to the thermostat housing or the housing itself which is located beside and below the turbo on the driver's (left) side. The housing is plastic. There is also a 1-1/2" or so diameter pipe that runs behind the engine that connects the water pump on the passenger (right) side to the thermostat housing. The pipe is sealed at either end with large o-rings which can fail. However, to replace the $1 o-rings requires removal of the housing which is a lot of work (drop downpipe, remove expansion tank, move stuff aside, etc.). If you're going to do the work, replace the thermostat, gaskets, hoses, etc. You may also want to replace the water pump since it's one of those "might as wells."

Well, funny you mention the thermostat housing.. I replaced the thermostat around the same time I hit an animal. I can't really see if its leaking from there or not. I have an endoscope so I will take a peak around tomorrow morning to see if its leaking.

I have come across the pipe you are referring to in my searches. I will hopefully look through there too.

Also, should I replace the radiator? I already have the new one here. My mechanic said they can leak from the side tanks cause they are only crimped on. I guess I will just replace it anyhow.

But about the other leak. I am hoping its just the thermostat.

Thanks for the reply!

 

[cloves]

I would head to the autoparts store and rent their coolant pressure test kit. You will be able to hear and see the leak without having the car on and should be able to find it. Other options is to put UV leak tester in the coolant (make sure its dexcool compatible)

 

[SethB]

I would head to the autoparts store and rent their coolant pressure test kit. You will be able to hear and see the leak without having the car on and should be able to find it. Other options is to put UV leak tester in the coolant (make sure its dexcool compatible)

That might be a good idea. However, looking at the pics I took this morning, I think I found my problem.

The thermostat housing is cracked, and it appears the seal is squeezing out. So I am going to replace both, and go from there.