TJ overheated, how much damage?

[sssboi]

Hey guys,

Went out on the beach today for some 4wheelin and the jeep went really well all day even though it was 36 degrees. When we we're about to leave the trail, after airing up the tires, when I jumped back in the car the temperature was all the way in the red, pretty well in the middle of the red. I turned the car off for a minute and then started it back up and got onto the highway (it was only 50m away and I knew the airflow will cool it back down). As soon as we started accelerating on the highway the temp dropped right back down to normal and everything "seemed" fine for the rest of the way.

How do I check if I've caused any damage by the overheating?

And what can I do to make the car run cooler from now on?

Really hoping I haven't done any severe damage

[alexbrown64]

If it was running OK and temps were down when you were driving, but they crept right up when the car was sitting idle while pumping up the tyres in the 36C heat, may suggest that your fans may not be working correctly. I would check the fans, do a pressure test for any minor leaks, ie in the radiator, cap etc..
I think with the steel head of the TJ, a quick overheat isnt going to kill it. Alloy heads hate getting overheated.

Cheers,

[Redemptioner]

didn't over heat it if no water came out

You will blow coolant long before you do any real damage to a tj motor, you would know by now if you had done any damage and there was no description of misfiring or knocking so you won't have done a thing to it.

Get the fan/thermostat/pump sorted though

[sssboi]

Thanks for the reassurance guys! Really appreciate it

Just took the jeep out for a quick spin and there were no obvious leaks (don't have a pressure testing kit) and the fan was on and spinning, so I couldn't see any issues there. The jeep has been running VERY slightly hotter than usual the last few weeks, but still within the normal range so it hadn't concerned me.

I'm going to start with changing out the thermostat, does anyone have a part number for an 89c (slightly cooler) thermostat? Or should I just stick with the standard size high flow thermostat?

From there what other modifications should I consider?

[sssboi]

Originally Posted by Redemptioner

didn't over heat it if no water came out

You will blow coolant long before you do any real damage to a tj motor, you would know by now if you had done any damage and there was no description of misfiring or knocking so you won't have done a thing to it.

Get the fan/thermostat/pump sorted though

It did blow a little bit of coolant (not while I was airing up), but it seems to do that every time I wheel it. The coolant is sprayed on the inside of the bonnet and I've been told it's from the fan blowing it back from the overflow. But again, nothing that hasn't happened before

[sssboi]

The woes continue. Decided to replace the thermostat today, got it out, cleaned it up and replaced it with a 82c thermostat. Applied the gasket and tightened it up till it was snug. Started the car and leaks from the bottom of the housing...So I loosened the screws and cranked it back up again thinking it hadn't seated evenly. This time I cranked it further and the housing cracked.

Not sure if the leaking was caused by a crack from the first time I cranked it. Anyway upon pulling the housing and gasket out, I found the gasket had some damage on it as shown in the pictures below. So I've ordered a new housing and gasket which should be here in a week.

As for getting a good seal on the thermostat housing, do you guys use RTV? Should I put some RTV on the gasket? I found the mating surfaces to not be perfectly cleaned, so I've given it a once over and it "seems" to be pretty good. Any advice on getting it to seal back up nicely?

[Redemptioner]

Depends on the gasket but usually yes, a thin film on both sides of the gasket is recommended. If you use a gasket with a raised centre it is not necessary but still recommended. Get yourself a torque wrench so you can torque things to the correct setting and prevent yourself from breaking things from excess force