I think I Figured Out Why The Jeep Was Overheating...

I started working on the Jeep that I picked up last week, after playing the CL Challenge game. It only has 80k miles on it, but I was told that it had a cooling issue.

I think I found the problem.

I had so much trouble removing the old gaskets that I caved in and, (very carefully) used a Dremel tool with a flapdisc, with the old thermostat still in place. The whole time, I heard the last words that my mother spoke to me before she died, echoing through my head. She said, "Son, even if you forget everything else that I've taught you, please, always remember: Don't berkeley up the gasket surface".

Thanks, Mom.

Yep, that's the problem. What year and model Jeep is it?

'98 TJ Wrangler Sport.

Yikes, looks like someone used saline solution instead of antifreeze.

I don't think I've seen one that bad before and I've seen some really badly maintained cooling systems over here (one of the explanations why lots of people break down here once the outside temperature goes above 73F). I4 or I6?

Wise woman, your mother.

BoxheadTim wrote: I4 or I6?

4.0 six cylinder.

I saw MANY 4.0's (and 2.5 4 bangers) with those stamped steel impellers that had just rusted away. There would be a steel disk left which does not stir coolant very well. Bet the radiator and heater core are both clogged with brown goo too.

Long time ago, Mazda tried plastic water pump impellers. The damn things would crack and, when the engine got hot enough, spin on the shaft making it overheat. Weird. They caught the problem real quick and went to a cast aluminum piece instead.

Yeah, I think you might be onto something there.

PS 4.0's need to be filled with coolant through the heater hoses or you'll trap an air bubble high in the cooling system that's very hard to 'burp'. That hose at the upper right of your pic: cut it at about the halfway point, then use a funnel to fill the engine and heater core with coolant. Then put it back together witha brass hose splicer.

pretty ridiculous rot you have there...

i picked up an accord engine with only 27k on it a while back.. only problem? coolant ate through the thinnest portion of the block. nice.

Jensenman wrote: PS 4.0's need to be filled with coolant through the heater hoses or you'll trap an air bubble high in the cooling system that's very hard to 'burp'. That hose at the upper right of your pic: cut it at about the halfway point, then use a funnel to fill the engine and heater core with coolant. Then put it back together witha brass hose splicer.

Thanks for the tip, but did you mean upper left?

Also, a new radiator is going in and heater hoses (at least) seem clear.I'll try to flush the core.

Woops. I always think of stuff in engine compartments as if you are sitting in the drivers' seat, years of service advisoring.

The heater core should flush pretty easily. The top hose is where coolant leaves to go to the heater core, the hose going to the water pump is the 'return' side. That means most of the goop in the core will be on the side where the hose from the thermostat connects. Stick a garden hose in the hose from the water pump and turn it on full blast, then watch the crud come out of the other side.

I saw a heater core once where the complaint was insufficient heat. During the backflush, what looked like a dog turd came out; it was Stop Leak.

It may not hurt to run a gallon of vinegar thru on the first flush. It will help clear some of the calcification (is that even a word?). Then clear water, then a good flush product (per their instructions), then use a stop-leak when you put it all back together (something like Alumi-seal).

What kind of flush product do you guys like for ill-maintained cooling systems like this one?

You call that bad? Wow, I call that normal. I gotta work on better cars.

Yeah, run some vinegar thru the system....i reccommend a few flushes since the rest of the system will be full of crud.

As long as the HG didn't blow as a result of cooling issues, this tractor motor will run forever. What's the rest of the Jeep look like? how much did it run ya?

eebasist wrote: What's the rest of the Jeep look like? how much did it run ya?

Perfect and $1500.

You just destroyed the collector's value of the Jeep. That was original coolant. They're only original once, you know.

Woody wrote:

eebasist wrote: What's the rest of the Jeep look like? how much did it run ya?

Perfect and $1500.

Wow. You stole that thing.

Yeah, that does look very nice indeed.

Jensenman wrote: PS 4.0's need to be filled with coolant through the heater hoses or you'll trap an air bubble high in the cooling system that's very hard to 'burp'. That hose at the upper right of your pic: cut it at about the halfway point, then use a funnel to fill the engine and heater core with coolant. Then put it back together witha brass hose splicer.

I always had to jack the front end of mine way up in the air and then leave the cap off while it sat there running away...

thanks for the hint.

STOLE is definitely the word. God do i need a 4.0 wrangler!!

Wow - that was a great deal!

dj06482 wrote: Wow - that was a great deal!

Looks like it came from right in your neighborhood, too.

New radiator, thermostat, water pump and hoses today. Tune up tomorrow. New top on Wednesday.

It cleaned up nicely.