STILL OVERHEATING (HELP ME PLEASE)

[RedWrang]

Ok Ive asked this before. My 87 258 is overheating. I have a new radiator, no thermostat, new fan clutch, and now a new water pump. Still it overheats, everything related to the cooling is new. I am not loosing any water at all. No water in oil, good compression. As soon as I crank it it runs fine, when i drive about 15 miles it starts to heat up. At a red light I can put it in neutral and rev it up and the temp drops to about 180. If I let it go it will get past 210. Now keep in mind I have the A/C on too. While driving on the high way it stays around 185-195 or so. Its just when I stop it heats up. Anyone have this problen cause its getting really irritating to even drive it anywhere. Thanks for any info that may help. :-( :-x :-? [addsig]

[XJNick]

If it only overheats when you're stopped, it's probably an air-flow related problem. If you have a clutch fan, try a new clutch. If you have an electric A/C fan, check that it runs ANY time the A/C is switched on (regardless if the compressor is engaged or not). Does the A/C cool well? If it only overheats with the A/C on, it is possible the A/C lines and or condensor have become restricted resulting in higher system pressures & a hotter condensor coil. Also, I'd put a thermostat back in there.

Hope this helps
-Nick

edited by: XJNick, Jun 22, 2003 - 05:45 PM[addsig]

[Bounty__Hunter]

Check the fan clutch. Could also be the tranny overheating, since the tranny fluid flows through the radiator. [addsig]

[MORGSTER]

RedWrang

Does it actually overheat?
Or is the gauge telling you it's hot?
When it reads hot is there water overflowing?
Do you lift the hood and see a overheating motor?
Do you lift the hood and hear the sounds of an overheating motor?

I was baffled by the temp readings for a long time in my 4.2 YJ and after all of the part replacement I found the culprit to be my temp gauge sender. The temp reading made some unusual changes that didn't make sense. Running hot on cold days and cold on hot days. Idle with the air on without problems, turn off the air and it gets hot. Running fine on the highway and all of a sudden it creeps up to hot. I'd pull over, lift the hood, and there would be no sign of over heating.

For a piece of mind or to rule it out replace the temp gauge sender. It is pretty cheap and easy to do, about $13.00 at the part store and about 5 minutes to change.
[addsig]

[geronimo_e]

check your rpm's sometimes too low will not give enough cooling power to the radiator, and not enough pump flow, it shoud be around 700, I agree on the thermostat, put it back in... good luck.[addsig]

[firemanharry]

Did you say NO thermostat? I had problems with a few engines heating up with no thermostat. It seems that the coolant was moving faster than the radiator could cool it. Maybe when idling there is not enough airflow through the radiator compared to the coolant flow? Just a thought since it's happened to me.[addsig]

[RedWrang]

Ok guys thanks for some valuable info. In a last ditch effort, this evening im going to put a t-stat back in it and get a temp sending unit and give it a whirl. [addsig]

[jay89]

Just a thought I changed my fan clutch and it still kept over heating until I read somewhere that there are 2 different fan clutches a regular one and one that says reverse on it. You may have put in the wrong clutch and not even known about it. I went back and forth the to auto parts store until I got the right one. Also make sure the belt is tight.[addsig]

[MORGSTER]

Here is a Tech tip quoted from Four Seasons Temperature Controls Tech Page.

http://www.4s.com/fourseasons/tech_t...ipsenglish.cfm

Fan Clutch Rotation:
If the pulley uses a V-belt, direction will always be clockwise.

If the pulley is poly-grooved and in contact with the grooved side of the serpentine belt, direction will be clockwise.

If the pulley is flat and in contact with the backside of the serpentine belt, direction will be counter clockwise.

If the wrong direction fan clutch is installed, the engine will overheat from the lack of airflow across the radiator. Also, the clutch may break apart from operating in the wrong direction causing damage to the fan blade, radiator and hood.

From past experience, on Jeep YJ's for example.
Water pumps, fan clutches and fans.
If you have V-belts it is standard rotation (Usually several short-skinny belts)
If you have a serpentine belt it is reverse rotation (Usually one long-wide belt)

Tell the parts person what type of belt you have, this should help.

Disclaimer:
Double check this info with Jeep before you install your parts :-D 8-) [addsig]

[Utah_jeepster]

One last thing.. do you still have the cooling shroud on? Removing the shroud makes the fan less effecient.[addsig]

[RedWrang]

Yes the fan shroud is still on it. And yes I did get the reverse rotation clutch, mine has the serpentene belt on it. Next is where is the Temp sending unit located on the block. The one I thought was it is not it. Im going to try a manual gauge and see if anything changes. Thanks for all the info so far. [addsig]

[RedWrang]

Also 1 other thing, What temperature are some of yalls Jeeps with a 258 running?[addsig]

[MORGSTER]

I have a 1989 4.2 I-6 and my temp sending unit is located on the drivers side of the motor, straight down into the block, right next to the rear valve cover bolt and above the exhaust manifold. It has a wire plugged into the top that pulls off.
Use a 1/2 inch deep socket to remove and replace it.
A little anti-freeze will come out of the hole when it's removed, no problem, just put the new one in and plug the wire back on and your done.

Note:
Make sure the motor is cold and the radiator cap has been removed to release any pressure before removing the sender.

edited by: MORGSTER, Jun 23, 2003 - 07:23 PM[addsig]

[MORGSTER]

Red Wrang:
It seems to be common practice to install lower temp sending units (165 or 180 degree) or even remove them (Which is not a good idea, that has been explained many times) when concerns of high temperatures appear. Years ago that helped (I think. LOL. that was in the 60’s) Now, with all of the computer controlled, smog systems, using a lower than factory recommended thermostat could cause other performance and economy issues. With finding and repairing the problems that cause those higher temperatures and then running the recommended thermostat you should never overheat. I run a 195 degree thermostat (which keeps the motor running at 195 to 200 degrees) plus an extra electric fan installed in the front pushing air back through the radiator, with a under dash on-off switch, just in case, for those rock crawling days at idle speeds in the 120 degree desert.

Thankfully it's never been needed.

My other YJ has the clutch unit and fan removed and replaced with a large puller type electric fan that has it’s own thermostat to turn the system on and off at my desired temperature. (Manual under dash switch too) It is also set at 195 degrees, which keeps that motor running at 195 to 200 degrees. This set up, along with the ability to control the fan cycling there is that extra power the motor no longer needs to run those parts.

Additional information about applications or even problems can be found at:
http://www.stant.com/default.cfm?CFI...TOKEN=29885932[addsig]

[jay89]

My temp runs under 200 about 190-195. It never goes over 200.[addsig]

[RedWrang]

MORGSTER thanks 4 the info. I found it right where u said. I didnt get a chance to do it this afternoon but will pick one up in the morning and let yall know how it does . Thanks again for all the help so far. [addsig]

[MORGSTER]

RedWrang.

Just a reminder from an eariler post re: temp gauge senders.

Note: Dealer price quoted at parts department $24.95
Dealer price quoted by service writer $31.95 + install (Way too much!!!)
Price at local part store $12.95 (2 minutes to change)(It pays to shop)

Good Luck :-D [addsig]