98 Transport overheating in 5 minutes

Hello all,

My first post. So, forgive if I don't have it down yet.

My 98 Transport with 113K started overheating almost the same time that I poured one of those "Radiator Sealers" in the radiator. I know I clogged something, just don't know where to start? I am not a do it yourself and have to take to the local mechanic. He want $350 for the radiator, $220 for Thermostat and $170 for the water pump.

I must say that I do not loose too much coolant at all and do not have any coolant in the exhaust. From reading the forum, I hope it is NOT the head gasket.
I wish I could afford another car but right now this car is my only means of transportation.

Thanks in advance.

It is likely that you plugged the radiator. You may have clogged the thermostat depending on what you used as well. $220 is NOT what should be charged to replace a thermostat!
Please try to get a referral for a fair and reputable mechanic. Your system will have to be pressure tested to determine where it is leaking. It is possible that you could have a blown head gasket, but a reputable mechanic should be able to help you.

Thanks 500hpgtx.

I hope that I don't have a bad Head gasket.
It seems that replacing the thermostat on these engines is very difficult.
I called the local PepBoys and they quotes $450 to replace the thermostat.
Thanks.

This is a 3.4 engine, so thermostat replacement is not one of the easiest to do, however, the price should be under $200....easiest way to do it is to pull the throttle body....you will need a gasket for the throttle body....

We are also talking about three coolant components, so draining and refilling is figured one time......

How much was the coolant leaking BEFORE THE SEALER WAS ADDED?

Sad part is you can replace all three and still have a problem.....

FIRST THING DONE, should have been to find out where the leak was coming from....was it the w/p? If it was, than that is one of the easiest w/p's in the world to replace, a DIY'er can easily do it....

If the car was not overheating before and not leaking much coolant, that sealer could have compounded your problem......

These engines are known for lower intake leaks and should have been one of the first places to check....

We have no idea if the sealer actually clogged the radiator, or if this was just a progression of the original problem.....for example, losing coolant creates an air pocket......just adding coolant does not get rid of the air pocket.....finally, the air pocket gets to a point where it blocks the flow of coolant through the engine and it overheats......this is usually validated by lack of heat from the heater core, because it is air bound....

Thanks TechII.

I agree that even after all of this, I might still be junking this car. SAD is the right word.

As far as the leak of coolant, it was not visible anywhere but could be smelled under the hood...only under the hood.

What would be a good test to know if the water pump needs to be replaced also? The same mechanic who is estimating $220 for the thermostat is estimating $170 for the water pump. I think I might as well take the plunge and replace all three.

Thanks to all who have chimed in.
Regards,
Hammerman2.

Did you bleed the system of air? Like Tech II said, you could have an air pocket. Also, does it ever miss or stumble when you first start it? Try starting it when it is cold and you have the hood up. Immediately start it and run around and feel if the radiator hoses are pressurized right away. They should normally take a few minutes to pressurize after the engine warms up. If they pressurize immediately, you could have a blown head gasket. You should not jump to any conclusions and simply diagnose it to find out what is wrong.