Summer temps - XJ Starting to run hot.

[Steve_Moore]

You do make a good point. As I said I am hyper sensitive to where the little bastard needle is.

I put the 3 core in today. Took it out the highway and put the cruise on 80 mph and drove out about 5 miles.

Exited and pulled over to look for leaks. Clean and the radiator had that "new hot paint" smell! lol

Ran 210 the entire 5 miles. After I pulled over to check for leaks the needle moved slightly above 210, technically the needle was still on 210 hash mark.

I got back on the highway going the opposite way. It took a couple of miles for it to drop back to 210.

I ran the A/C the entire time. I'll double check the coolant level tomorrow as I just topped off the new radiator before warming it up and then doing the test drive.

This coming week will be the real test, as we are expecting 90's in the afternoon, and that is always the time that I have issues. I am thinking about taking the old radiator to a shop to have them test and fix any leaks. It would be nice to have a spare.

That's exactly what mine does. It goes about a needles width above 210.

 

[Mudderoy]

The belt was squeaking so I tighten it up last night. I checked the coolant level in the radiator. It was full. I check the over flow bottle. It was down much lower than when I checked it after the new radiator install.

The temp has been no higher than 210. Well it heats up a little when I slow down from 70/80, but then drops back to 210 after a few minutes. Again about a needle's width above 210.

Still no leaks. I'm a little concerned about how tight I had to make the belt to stop the squealing though.

 

[Ecomike]

It hit 95 F here in Houston yesterday. Even with the AC on, multiple short trips of stop and go driving, for 3 hours between 2 and 5pm, mine never got over 195 F. Dash gage Temps confirmed with IR gauges.

I have a 2 row radiator, with plastic ends, Renix, 87, 180 F thermostat, and a POS plastic expansion bottle and cap (with a hose clamp on the cap) on mine. Radiator is 3 years old already. Closed system.

 

[Mudderoy]

Update:

As stated before, thermostat, thermostat housing changed.
3 core radiator installed
upper and lower radiator hoses replaced
heater hoses replaced
water pump replaced

I didn't have any coolant available so I filled it up with water.

Replaced diff gear with 4:56 gears.

Coming home on I-10 at 3200 rpm for 5 minutes. Temp neared the first hash mark after the 210. I exited I-10 and rpms dropped to 2200 or less. The gauge stayed there for a couple of minutes and started coming back down to 210.

By the time I got home, another couple of minutes it was close to the 210 hash mark.

No leaks, no smells of coolant. Reading back in the responses it sounds like a water pump issue, or clogged something. With a new radiator I'm not sure what could be clogged unless it was in the block.

The mechinical fan clutch was replaced about two years ago.

I'll check the coolant level, and I'll probably drain off some of the water and replace it with the antifreeze I bought to see if that helps.

It's running fine, and it didn't over heat, I am just confussed as to why it would get so high above 210. I understand it is generating more heat the faster I run the engine, but still....

 

[markw]

I dunno. Mine has been 210, a hair below, since the day we bought it new. It is a 1998 XJ Classic.

I've been fighting the engine cooling system since 2001! lol

When was the last time you tossed a radiator in it? Do this, warm it up, and then feel the core of the radiator. Pull your aux fan off to do this so you can feel the whole thing. It should be even temperature, I'll bet that the bottom 4-5 inches are cold compared to the rest of it. If so, it's plugged, time for a new one.

Heh, I should read to the bottom of the thread. Check for air blockage in the A/C condensor, flush the system and toss in some coolant. I was amazed at the amount of crap in mine when I had a freeze plug go in the back of the block. I replaced all the plugs and did a flush. Also, a trick when the temp goes up is to turn on the heater full blast as that's an extra radiator.

 

[Mudderoy]

When was the last time you tossed a radiator in it? Do this, warm it up, and then feel the core of the radiator. Pull your aux fan off to do this so you can feel the whole thing. It should be even temperature, I'll bet that the bottom 4-5 inches are cold compared to the rest of it. If so, it's plugged, time for a new one.

Heh, I should read to the bottom of the thread. Check for air blockage in the A/C condensor, flush the system and toss in some coolant. I was amazed at the amount of crap in mine when I had a freeze plug go in the back of the block. I replaced all the plugs and did a flush. Also, a trick when the temp goes up is to turn on the heater full blast as that's an extra radiator.

Yep, the radiator was changed less than a month ago, but I didn't flush the system. I figured that the radiator was 99% of the system anyway, but I was just guessing. I'll try flushing it. The wife hates all that crap on the driveway, lol

 

[sprngfldxj]

While looking at the old radiator and comparing it to the new radiator...

A couple of interesting developments.

1. I see a small amount of water next to the old radiator. Maybe I found a leak!

2. The "covering" or shroud that goes around the radiator is torn and missing a substantial piece on one side of the radiator! I bet it has been like this since they change the radiator about 7 or 8 years ago.

Too many assumptions. I should have looked more closely. Of course I saw everything better tonight, because it was dark outside and I was using a flashlight.

The new radiator goes in this weekend.

Mudderoy,
I replaced my radiator a couple of weeks ago due to having a leak right at the AT lower tube that exits the radiator. I also found that the tube was bent by previous owner, maybe unwillingly. I didnt want to have to deal with the cost of trying to repair where the brass meets the plastic only to have problems later in the same area.
After looking into a and asking alot here on the site, I decided to go with the 2 core because it seemed to not make a diff in the long run to make up for the cost diff.
I was told if you go with a 3 core it was good for hard core wheeling, that I dont so as of yet.

 

[Mudderoy]

I had to visit my mechanic today. He wanted to hear the whine I'm getting after we put in the 4:56 gears last Monday (a week ago). Anywho, I asked him about the temp, and he said it wasn't unusual for the temp to get above 210 especially on a hot day. So I guess I'm good. I checked the coolant levels before driving over there (about 20 miles) and it was up to the top.

I didn't drive at 3200, mostly 2800 so it really didn't get much past the 210.

 

[mrpeepers]

After replacing the Overflow Reservoir and flushing the system. I was seeing temp fluctuations from 180 downhill low rpms, to 250ish going uphill 1k to 7k ft elevation in 113 degree weather.

I live in Phoenix and drove to Payson at high noon and nearly saw temp hit 260, shut off A/C a couple times from fear. but once I was not climbing and it cooled off I was ranging 180-225 the rest of the trip.

I think the temp range seems normal for the circumstance, but could be improved.

 

[Ecomike]

00 rpm the way I drive

After replacing the Overflow Reservoir and flushing the system. I was seeing temp fluctuations from 180 downhill low rpms, to 250ish going uphill 1k to 7k ft elevation in 113 degree weather.

I live in Phoenix and drove to Payson at high noon and nearly saw temp hit 260, shut off A/C a couple times from fear. but once I was not climbing and it cooled off I was ranging 180-225 the rest of the trip.

I think the temp range seems normal for the circumstance, but could be improved.

Mine never gets over 2,400 rpm the way I drive. Runs around 1800 to 2200 most the time. It never has gotten over 201 F Verified with three gauges) with AC running in traffic or at 65 mph (max). AW4, with ambient hitting 98 F here. We have more humidity here than you do so that is a variable, but if ad 15 F to mine for your 113 F, I would still be no higher than 215 F peak on mine in 113 F weather. Sounds to me like your tranny is overheating and or the coolant is not holding full pressure.

Also my electric fan only runs with the AC on, and currently it runs about 5 degrees cooler with the AC on than with it off becuase my electric fan only runs with the AC on at these temperatures. My E fan will cut in with AC off if it ever gets above 201 F, but it has not quite reached that point this summer.

 

[Mudderoy]

Hmmm maybe that is why my engine temp is going up when I'm traveling 70 or 80 mph. Well it was doing that 8 years ago. I guess it wouldn't hurt anything to replace the OEM transmission cooler for a larger one.

 

[mrpeepers]

00 rpm the way I drive
Mine never gets over 2,400 rpm the way I drive. Runs around 1800 to 2200 most the time. It never has gotten over 201 F Verified with three gauges) with AC running in traffic or at 65 mph (max). AW4, with ambient hitting 98 F here. We have more humidity here than you do so that is a variable, but if ad 15 F to mine for your 113 F, I would still be no higher than 215 F peak on mine in 113 F weather. Sounds to me like your tranny is overheating and or the coolant is not holding full pressure.

Also my electric fan only runs with the AC on, and currently it runs about 5 degrees cooler with the AC on than with it off becuase my electric fan only runs with the AC on at these temperatures. My E fan will cut in with AC off if it ever gets above 201 F, but it has not quite reached that point this summer.

so, with that said, what would you do first? take it to shop and test the pressure? how would i test tranny temp?

 

[Ernrok]

I had a simular problem. I stared with the thermastat. and that took care of the problem. I am going to replace the WP/FC, as a precaution, my xj has 116.+ miles. Just food for thought. Good Luck.

 

[Ecomike]

so, with that said, what would you do first? take it to shop and test the pressure? how would i test tranny temp?

I would look everywhere for tell tale signs (green corrosion or deposits) at the ends of hoses, radiator, cap, bottle is you have one, etc for signs of pressure loss under extreeme stress.

Make sure the Electric fan is always running even with AC off when temperatures reach about 205 or higher. Then pull some stuff out of the way so you can grab and feel (or use a handheld IR thermal sensor, under $10 lately at Harbourfreight.com) various parts of the radiator to check for cold spots which indicate blocked tubes in the radiator, poor flow, which reduces the heat transfer capacity of the radiator and thus the cooling system.

Also check for leaves, Mud, junk, trapped between the condenser and radiator. I had a new radiator in mine, and found a huge bunch of leaves in the middle of the two after only 2 years of local city driving!

Might also check the tranny fluid level.

 

[KMK172008]

wow 89* and thats it? I shudder to think how your jeep would deal with Texas Heat

 

[xuv-this]

i second ecomikes IR heatgun suggestion. it's a lot easier to troubleshoot and usually cheaper with the right tool rather than replacing part after part to guess where the problem is. i just put in a stroker and replaced 3 things that weren't broken, got the heat gun, then replaced the part that was.

 

[SuzysJ]

We run either RADIATOR MASTER RMI-25 or SCHAEFFER'S CLEAN & COOL as preventative measures. Never a cooling system problem on any vehicle. If, bought used, we do a thorough cleaning with a PRESTONE kit (the powder; long list of instructions).

At over 100-120m miles we replace freeze plugs and have shop get any junk out of block that accumulates below plugs.

Current XJ is at about 117,000 and, with new hoses and a HD ROBERTSHAW stock temp thermostat a few years ago -- and driven in humid South Texas -- AC is plenty cold and temps don't move past 220F on dash gauge.

I'm sold on these products after using them more than seven years and in six vehicles (including [2] XJ's that have gone over 100m) for a cumulative mileage of over 600,000. They don't replace the need to replace fluids at a reasonable interval, they function, IMO, as insurance.


http://www.schaefferoil.com/specialty/258_coolant_additive.html

http://advancedlubetech.com/RMISite/

 

[jeepowner]

If it heats up in traffic and cools down on hwy, its probably fan or flow related. If it heats up on the hwy and cools down in traffic, I would guess head gasket. More rpms equals more pressure. You can check by:
Let it get totally cold. Start it, take off cap. Let it warm up and check for bubbles.
Pull the plugs and look for a REALLY clean one.
Pull the plugs and fill each cylinder with compressed air, pull radiator cap and look for bubbles.