overheat, thermostat?

so a guy is selling his jeep for $300, the only problem he says is that it overheats...could i get by with just replacing the thermostat?

brandon

Probably not, but I suppose it's a place to start. There's a ton of overheating threads in here and they boil (pun not intended) down to blocked radiator, old radiator, old water pump, bad or blocked hoses, incorrect coolant, etc. If you like the rest of the Jeep for $300 and are willing to spend some time troubeshooting heat issues then go for it.

Thats hard to say....
Depends upon how bad it has overheated and for how long...
More than likely..... you can get a way with replacing the t-stat, chemically flushing the cooling system and then have the radiator removed, chemically cleaned and the tubes rodded. Probably should replace the hoses and thermostatic clutch for the cooling fan too !!!
All this should help keep the engine cool.

Charles

$300 and it runs? Can't lose. Could be a lot of different reasons for overheating. Check out the obvious (and free) things first. If it's more than you want to deal with...resell it or part it out! You'd get more than $300 for the parts just from people in here!

If its a '93 and has intermittant wipers that work, I'll buy the wiper assembly!

See, you're on your way!!!

The old rule of overheating is to replace the thermostat and the radiator cap. Both can be damaged by the heat. Depending on the year of you XJ here are other things to consider.

The life of a radiator is 7 years, anything more is just gravy.

The fan clutch may last 5 years. Does your engine overheat in slow moving traffic or at speed? If it moving slow then the fan clutch may not be fully engaging and not pulling enough air. No good way to test it, just replace it.

So start with a new radiator cap and thermostat. Install them both and hopefully that will solve the problem.

What year is the jeep? Is it a closed system?

buy it!

Buy it if its in good shape, the cooling system is generally fairly easy to R&R. Get it home, on the way stop at a DEALER and pickup a new Tstat, pressure cap and 2 gallons of Mopar coolant, next pick up 2 gallons of distilled water from the food store, then pick up a prestone back flush kit and prestone 7 hour flush. Drain the system, replace the tstat and pressure cap and refil with water, add the flush, burp it and do the driveing around. Then follow the rest of the directions, refill with a 50/50 mix of coolant and distilled water.
If it starts overheating in traffic but is fine on the open road the next suspect is the fan clutch, if it still overheats then the next one would be the radiator, replace with a modine HD 2 core. The 7 hour flush will clean out alot of crap especially in the block itself, I do not like the 15 min fast flushes, had too many water pumps fail after using the short flushes.
One little note I picked up on one of the radiator manufactures sites is that a bad ground over time will cause the coolant to act like a plating bath, seperating out the minerals from the tap water and plating the insides of the coolant passages with mineral deposits, get enough mineral plating in there and it will act like an insulator. The bad ground makes the electrical system use the cooling system as another electrical path.

wow! thanks for all the input! i'm taking a look at it tomorrow, so i'll know exactly what i need to do before i buy it... basically all i know so far, is the body is in great shape also interior. the XJ drove fine, but he bought a new car and stopped driving it for about half a year. its been sitting for 6 months, and now he said it overheats

thanks
brandon

1989laredoxj said:

What year is the jeep? Is it a closed system?

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it is a closed system

martin said:

The life of a radiator is 7 years, anything more is just gravy.

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I still have the original radiator on my '92 XJ so I must have been enjoying gravy for the last 5 years. Now that I have a 4.6 stroker under the hood, I also have a bigger turkey.

Are you going to get into lifting it and throwing some bigger tires on?
If you are I put bigger tires on my jeep and started having really bad over heating problems. I upgraded to the open system, pretty easy to do. Now no over heating problems at all

1989laredoxj said:

Are you going to get into lifting it and throwing some bigger tires on?
If you are I put bigger tires on my jeep and started having really bad over heating problems. I upgraded to the open system, pretty easy to do. Now no over heating problems at all

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i already have a rigged XJ... this is just for some extra cash, or DD. i was going to fix it and resell it, or just part it out. what is necessary to convert to an open system? how much will it cost to just replace the thermostat and radiator cap?

brandon

shimmy said:

how much will it cost to just replace the thermostat and radiator cap?

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Peanuts, so replace both. While you're there, drain the whole cooling system, flush it, replace both radiator hoses (and heater hoses if they're bad), and add fresh coolant.