I recently replaced the freeze plugs in my 88 n/a, and have got everything back together now. And am trying to get the car back on the road. But after solving that problem, I am now encountering another problem. My coolant level keeps dropping since I have reinstalled everything, and there are no visible signs of leaks. And it's no longer mixing with my oil.

My question is: Where could the coolant be going, and how could I find out for sure?

 

No puddles under the car? Is the overflow tank filling up? Usually I would say that you probably have a blown coolant seal in the engine and will need a rebuild, but I wonder if it would be something else since it only started when you did the freeze plugs.

-Joe

 

Sometimes coolant leaks can be hard to find if they're buried somewhere in the engine bay. Try adding UV dye to your coolant and check for leaks with a blacklight. If no leaks are found, it may be a blown coolant seal, which will eventually require an engine rebuild. Does your car blow any white smoke out of the exhaust?

 

Favorite leak hiding places:
1) The 3/8" coolant hose under the UIM that runs to the TB.
2) The back side of the water pump housing. The high reving pump can erode the casting.
It's hot back there so a small leak will evaporate before you can see it.

Shut off the motor after is hot and see if you can smell coolant and find it's location that way.

 

There are no puddles.
I haven't checked the 3/8 coolant hose, but I do know the water pump housing is fine. I haven't noticed any coolant smell in the engine bay after it's hot.

I like the idea of the UV dye, but where can I find this stuff? And there is no white smoke.

 

are you sure that you fill in the coolant in full? not just radiator, also coolant tank, engine as well. make sure you start the car at normal temp, turn the heat on, so coolant will go into heater coil, and come back into engine. do that at the same time fill up the coolant tank. and make sure no air in the radiator. you might just checked it too quick.

update us with the result.

 

You know I didn't even think about that. And now that you mention it, the first day I checked after the repair, it lost more coolant than it lost this last time, at which I actually drove the car more.

As soon as I try that I'll let you know.

 

Also check the heater hose that goes from the firewall to the engine. It is a very common place for coolant leaks. You can barely see that leak. That hose usually goes bad from time to time due to oil leaks...