Strange Overheating Problem

[jland13]

Hey guys, glad I found this site. I am hoping to find a solution to my problem. Here goes:

1984 Chrysler Lebaron Turbo, I had an over heating problem, checked and saw I was almost out of coolent in the resevoir. I put some in and was still over heating. This time it got worse, the ratiator was smoking and I could see at the top of the radiator coolent was spraying out so I figured I had a leak. I bought some radiator sealent and it still was doing the same thing. I had my friend check it out and he told me since it was an old car it was probobly the themostat. I got the right thermostat and gasket, and I replaced them. I put the gasket on the wrong side (in between the thermostat and the head as opposed the the thermostat and casing) and this time the car was overheating WAY faster. I checked and could see coolant leeking from the thermostat casing. I figured I did it wrong, went got a new thermostat and gasket, did it right and still no go. The hose from the radiator to the engine gets very hot, but has no pressure. I can see smoke and coolant coming from the bottom of the thermostat casing still, my radiator doesnt get hot at all now, and the fan doesn't come on. Any thoughts or suggestions?

[KManiac]

A little more information would be helpful.

Since you say this car has a turbo, I can only assume you have a 2.2L four cylinder. How many miles on the car?

Now that you replaced the thermostat correctly, are there any visible leaks with the radiator cap on and tight?

When you say the radiator hose gets hot and has no pressure, which one are you refering to, the upper hose between the thermostat housing and the top of the radiator, or the lower hose between the bottom of the radiator and the water pump?

When you say that coolant was spraying out of the radiator, was this from the tubes in the core, a crack in the upper tank, or from the radiator cap?

How long does it take for the engine to overheat? Does it overheat quickly within a few minutes of start up from cold or does it overheat slowly after driving 50 miles or more?

When working normally, the water pump draws "cool" coolant from the lower radiator hose into the engine. The engine heats the coolant inside the engine. Hot coolant in the engine opens the thermostat and hot water flows through the upper hose to the top of the radiator. As the water passes down through the radiator, it cools. Cool water flows out of the radiator through the lower hose.

At normal start up, the thermostat should be closed and the coolant does not circulate until the coolant in the engine warms up enough to open the thermostat. Then the thermostat will open and close throughout operation to maintain the coolant temperature in the engine.

Thermostat failure may or may not result in overheating, depending on how it fails. When the thermostat fails in the closed position, the hot coolant in the engine cannot reach the radiator and the engine will overheat within minutes of starting from cold. When the thermostat fails in the open position, coolant circulates freely and the car never warms up.

Think about all this information and get back to us with a detailed description.

[jland13]

Thanks for the reply, sorry for the vague question, I didn't want to overwhelm with details (:

Since you say this car has a turbo, I can only assume you have a 2.2L four cylinder. How many miles on the car?

180,000, engine replaced around 170,000. Yes it's the 2.2 4 Cylinder

Now that you replaced the thermostat correctly, are there any visible leaks with the radiator cap on and tight?

Cap is on tight, visible leak from under the thermostat housing by the bottom bolt.


When you say the radiator hose gets hot and has no pressure, which one are you refering to, the upper hose between the thermostat housing and the top of the radiator, or the lower hose between the bottom of the radiator and the water pump?

Upper hose

When you say that coolant was spraying out of the radiator, was this from the tubes in the core, a crack in the upper tank, or from the radiator cap?

Crack in upper tank

How long does it take for the engine to overheat? Does it overheat quickly within a few minutes of start up from cold or does it overheat slowly after driving 50 miles or more?

Before I changed the thermostat it was 10 minutes, now it is immediately. The radiator fan is not coming on, and the radiator is not getting hot.

[KManiac]

Thank you for the additional details.

Regarding your radiator, the stop-leak is a temporary fix. I suggest you get a new radiator. These units consist of a metal core with plastic tanks press fit on the ends. This construction makes them difficult to repair. A new radiator should run between $100 to $150 and can be purchased on the web.

I suggest you remove the thermostat again to make sure it is installed correctly. They go in one-way and the thermal element side must be positioned facing the engine. The mounting surface on the head should be flat and the thermostat housing (that bolts to the head) should have an indentation where the thermostat fits. Place the thermostat in the housing first, the place the gasket over both the thermostat and the end of the housing. Then bolt it in. I suggest applying a bead of #2 Permatex on both sides of the gasket before you install. Also make sure that old gasket material is scaped off first.

Note about thermostats - Some thermostats have an air bleed hole to allow trapped air bubbles to pass into the radiator at start up. Others do not! If your thermostat do not have a bleed hole, an air pocket will exist behind the thermostat when you refill. If an air pocket exist below the thermostat at start up, this will delay operation of the thermostat since there is not direct contact between the coolant and the thermal element. The temperature gauge may peg out on H before the thermostat heats up enough to open. If your thermostat does not have a bleed hole, I suggest drilling a small hole in it.

You say that your upper hose gets hot, but the radiator stays cold. The upper hose only gets hot after the thermostat opens. The situation as you describe can only occur if there is something blocking flow of the hot coolant from the hose into the radiator. Remove the upper hose from the radiator and check for debris in the radiator.

One more thing, with the car cold, turn your ignition key to the "on" or "run" position (engine not running) and watch the operation of your temperature gauge for about one minute. If it moves up off of C without the engine running, you may have a faulty temperature gauge sending unit.

My 1991 Shadow has a 2.5L turbo and I have owned this car for 15-1/2 years. I have numerous posts in the Dodge/Nonspecified and Dodge/Shadow boards regarding my car and experience with overheating problems. These would be a good read for you, so check them out.

Let us know if you have any questions or comments.

[jland13]

Hey thanks for the help. I tried everything you said and unfortunately the car is still over heating. This time is seems as though the smoke is coming from the radiator as opposed to directly under the thermostat housing. It could be a clog but I have no means to flush the radiator, it is stuck in a public parking lot.

[jland13]

So I was able to get it home. This time when I got home the radiator was warm, and there was no smoke comming from anywhere, but the temp guage was still almost over heating. I couldn't tell if the radiator fan had come on or not. I also noticed it gets hotter when I am sitting, and cooler when I am driving. At least I got it home now so I can work on it. If it was the temp guage sender, could it effect the flow of coolent? Or just the temp guage?

[KManiac]

Well, a hot radiator at least tells me that the thermostat is opening. Have you taken a look at the water pump?? A loose drive belt will keep it from pumping correctly and cause overheating. Also, check the electric fans, too. If the fans don't operate, the car will overheat, too, especially when sitting and running.

Start by replacing the radiator and check these other items in the process.