Hi guys, I'm stumped with my cooling system. This post will probably be long, but hopefully someone can help me. Here goes.

For starters, a few days ago I changed out the thermostat in my Camaro and gave its radiator a good flush. Today I was driving over to a friends house. I got there, and there was lots of steam coming from the engine, so I immediately thought that I had screwed up with the thermostat job. I looked under the hood, there was coolant all over the intake manifold (and beside the overflow) and the overflow reservoir was empty. It looked like it was leaking from either where the rad hose meets the thermostat housing, or where the housing meets the intake manifold. Either way, I had just tinkered with both of them the other day and figured I didn't seal them properly. I thought I would just let it cool down, try to make it home and fix it tomorrow.

I got home with no leaking whatsoever. I filled up the overflow in my driveway and tried for the hell of me to replicate the leak. Nothing worked - heater on/off, thermostat kicking in, etc. My only thought so far was that there was some sort of air bubble from my rad flush that shocked the hose or something and caused it to leak a bit (seems far fetched).

Not only that - it seems that since this incident, a weird noise has popped up in my engine. It sounds like it is coming from the thermostat housing or the area around it, but I can't be sure. Its a buzzing, and it gets more high pitched and slowly tapers off as I increase the RPMs.

I'm going to drive the car to work tomorrow and hopefully it either happens again and I can get more info, or its just gone completely.



If anyone has any ideas of what happened, I would love that. I am completely stumped

 

Water pump? Bearings going out.

 

First of all, always make sure you have no leaks after opening the cooling system. Test it by getting it up to temp and pressure before you go an a test drive.

The steam you are describing sounds like leftover water/coolant on the engine from when you opened up the stat housing. Your noise could be anything that spins, including the water pump. ID the noise with a stethoscope, or simply hold a tire iron to your ear and touch it to the component you suspect is noisy.

 

could always rent a pressure tester and test the pressure as well. might notice a leak or two coming out of somewhere.

 

Update: I drove it the last few days, and it is really weird. It will leak one way going somewhere, but as soon as I look at it and try to get it home to look closer, it stops. Starting to get on my nerves. Going to replace the rad cap tomorrow because mine seems flakey, and see if that does anything.



I got it up to temp at least three times before the leak happened. I pinpointed the noise to the PCV valve, not sure if its loose or what but since its such a simple job I'm just going to replace it tomorrow as well.

 

how bad are your hoses?

 

Replace your rad cap, like you plan to. They should be replaced with new on regular intervals.

If you've got the stock aluminum t-stat housing, what kind of shape was it in when you pulled it? Corrosion around the base can make it hard to seal with the paper gasket. I'd recommend using one of thicker/rubber ones. Can get it at most parts stores. Re-usable and no need for RTV (Room Temperature Vulcanizing).

 

My t-stat housing was leaking after I changed th stat and I got a new gasket and put a layer of gasket making silicone on each side, put it back together and let it dry overnight. It hasn't leaked since. Mine would leave fluid on the lower parts of the intake around the housing with just the gasket and no silcone.