have a 90 Laredo 4.0 renix. The A/C has always been fine, and aside from a bad hose connection from bottom of coolant resevoir this is the first water issue I've had. Basically the engine gets close to redline within a few minutes and I'm loosing water fast from the front area of engine. The water collects heavily on bottom of fan shroud. The water that leaks is COLD even if I put hot water in. The bottom rad. Hose is hot the top cold on the radiator side,warm on engine side. I'm tracing the leak now and suspect the thermostat, and or waterpump. Funny the previous owner had a theromstat that's been in the glovebox . Thanks in advance.

 

What is your question?.....usually total cooling system TLC/maintenance and <$250 in new parts cures all leaks and overheating.

 

I was wondering the same thing.
As djb said doing a cooling system overhaul on it would be a good start especially if you're not sure when the last time anything has been don to it. It is a fairly cheap thing to do and well worth the money. BTW, the $250 does include a new radiator and all of you cooling system parts that you will need from any Auto Zone or advanced Auto parts store. Make sure the new t-stat is a 195deg.

 

My mistake. My question is what does it likely mean if I put hot water in the resevoir, and cold water is whats leaking out. And is black RVT sealant fine to use as a gasket by itself for the thermostat housing?

 

Hot water in and cold water out means nothing.....what's important is, getting any/all leaks and overheating issues resolved. Any/all auto parts stores have RTV sealant specifically for water pumps/t-stats (antifreeze/coolant resistant). RTV color is not important.....what it's designed for to seal is. Read the RTV pkg label.....what's it for? U'll have a better chance at a leak free seal if u apply a thin coat of the proper RTV sealant to BOTH sides of a gasket.

 

Thanks for info. Radiator is shot.

 

Now would be good time to grade to a open system . Eliminating the troublesome pressure tank for a regular rad with cap and over flo tank.