I have an 89' Cherokee, 2WD, I6 4.0L. I'm having some issues with it though...

I recently had problems with my cooling system. I pulled into school in the morning and I could smell antifreeze when i got out of the car. So I opened the hood and the radiator fill tank was steaming. Not a good sign I'm assuming.

Now the color of my coolant is dark brown. Really muddy dark brown. I know this is because of rust build up. My engine was running really hot, close to red. So I was told my thermostat most likely went bad. I was asked to see if the coolant had a bitter or sweet taste to it, and it tasted bitter. Apparently this made it almost certain it was the thermostat.

Now replacing the thermostat was a bit of work. I did it with someone else, and we weren't sure if we were supposed to drain the radiator first, but we had already broke the seal on the front of the engine where the thermostat is, so we cleaned it up by scrapping off what was left and using paint thinner to clean it. Put the new thermostat in, resealed it. Takes an hour or so to seal so waited for that time to pass.

Drained the radiator. Horrible brown color as I said before. Flushed some water through it. Now here is where I'm terribly confused: I bought radiator flush, poured it in through the fill tank. Then I go to put water in, and 5 seconds of water and the fill tank is overflowing. I know the system isn't full though. So what do I do ? I ran the engine with the cap off seeing if it would go down but it didn't even though i read it is supposed too. I pretty much gave up flushing and filling with anti freeze, as I dont get why it won't fill the system completely.

I also seem to have some weird idling problem. My RPMs will randomly drop, and my lights will all dim. It only does it when idling. Any reasons why this would be happening..? I also get horrible voltage drop when using the driver side power window. If you hold the button while the window is already up or down (going in the same direction) the voltage drops to almost 12 and all the lights dim.

 

Actually if all you did was drain the radiator, it would not take much to fill just the radiator.

I just replaced my whole cooling system on my 89 cherokee. What i did was fill the radiator and fill bottle. Put the cap ON, and run the motor till the thermostat opens up (around 190-200 degrees). Once the thermostat opened i would let the fill bottle empty, turn off the motor, use a towel and CAREFULLY open the cap. Fill and repeat until it takes no more fluid.

The thing with the cooling systems on these 89's, they REQUIRE the cap on the coolant bottle to flow because they are a pressurized system. that is why a bad cap, or small leak in the bottle can cause these 89's to overheat. Not a good design at all.

Hope this helps.

 

You say fill the radiator and fill bottle.... You mean fill the radiator through the fill bottle ? Sorry for my retardation lol, I'm just clarifying. And letting the fill bottle empty, is that with the engine still on ?

 

You seriously tasted your coolant?

 

Yes fill the radiator through the fill bottle, put the cap on, run the motor, watch the fill bottle and let it empty as much as possible without the motor overheating. Then shut the motor off, top off the fill bottle, and repeat the process until the cooling system is full and the engine temp stabilizes.

 

my immediate first thought.

 

You could also remove the temp sensor from the drivers side rear of the head,fill until water flows out sensor hole,then reinstall temp sensor and top off fill bottle.Turn heater control to warm and run motor to ensure heater core is full,then top off fill bottle.All air should be out of system at this point.

 

Not me no. Friend who is a mechanic. He knows about it, not me. I never asked him about filling the radiator though.

But thanks for the help guys. I'll attempt to fill with coolant later today.