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-   -   Cooling Issue (http://www.jeepforum.com/forum/f8/cooling-issue-1577553/)

briancj 09-11-2013 09:51 PM

Cooling Issue
 
Hi All, I recently bought a CJ 7 with an inline 6 engine and I am having cooling problems. I've already changed the thermostate and waterpump, and replaced the fan with a slightly larger flex fan. Coolant does seem to be flowing through the radiator, however, neither the hose coming off the block into the heater core nor the hose coming out of the heater core to the water pump are getting any where near as hot as the top radiator hose. My temp gauge gets well past hot within 10 min just sitting at an idle. I'm not sure what else to check and would appreciate any information you guys can provide.

Thanks

Brian

walkerhoundvm 09-11-2013 10:20 PM

1. Radiator recore

2. Heater core replacement. You could temporarily bypass this by rerouting your hoses, then see if your engine still gets hot. If it does - your radiator needs to be recored. If it doesn't, the problem mostly is a result of poor circulation through your heater core.

To me, it sounds like it's both, but do some research on the points above.

82JeepCJ7 09-11-2013 11:39 PM

Double check with a reliable gauge. The stock gauge is usually off.

WindKnot 09-12-2013 07:59 AM

Stop throwing money away and guessing. Changing the fan won't fix the problem. At best it's only going to treat the symptoms.

You need to establish whether or not you're getting circulation through both the block and the radiator. Rodding your existing radiator will most likely give you better results than replacing it with a new aluminum one. But it won't do anything if water can't circulate through the block. You might also want to verify that the bottom radiator hose is still in good shape. When they start to go bad they will collapse when running and stop the circulation. Most guys prefer a hose with a spring in it to prevent collapsing. Hose manufacturers say the new hoses won't do that though, even without a spring.

If your Jeep is typical, it had the four bladed fan with no fan clutch. That set up works perfectly fine to cool your engine. Even here in Arizona it doesn't overheat if it's working like it's supposed to. The 258 is a very simple machine and there's no reason to make it more complicated than it is.

That engine also tends to run warm. It's supposed to have a 195 thermostat in it. As others have mentioned, don't trust the TEMP gauge, verify it another way.

Neuner-9R 09-12-2013 09:32 AM

Are you sure you have the right water pump? There are clockwise and counter-clockwise versions depending on your belt type.


*edit* - I have a cold and pumped full of Dayquil so I 'bettered' my wording.

Matt1981CJ7 09-12-2013 10:29 AM

Does your radiator start loosing coolant out the overflow when the gauge is showing above hot?

Go to Home Depot and buy their $50 infrared thermometer. It will take all the guess work out of using the factory gauge.

Matt

Gigemags05 09-12-2013 12:06 PM

My bet is that its the gauge.


I had this exact issue occur and it ended up being the gauge. I bought an infrared temp gauge to confirm. Then replaced the gauge and have had no more issues.

walkerhoundvm 09-12-2013 12:16 PM

^^The gauge makes his hoses coming to/from the heater core warm not hot?^^

Gigemags05 09-12-2013 12:49 PM

Not sure on that. But with new thermostat, water pump, etc., I'm betting his gauge is off.

Maybe the thermostat isn't even getting hot enough to open before the gauge is erroneously reading hot. That ended up being my issue.

JeePete 09-12-2013 01:31 PM

Agree with the above...plus->

Another issue could be gunked up water passages in the motor.

How long have you had it and do you know (from the PO) if it ever sat for a long time?

Did you flush it when you were changing out pieces parts?

PERK 09-12-2013 02:10 PM

new cheap t-stats have been known to be bad,( just went through this with a buddies jeep) by a good one like Robert Shaw..

LumpyGrits 09-12-2013 05:23 PM

Do you have a fan shroud? You really need one.
Get rid of the 'flex-fan' and find a 7 blade OEM.
Are you sure you have the WP with the correct rotation. 2 WP's are made, one for v-belt and one for serpentine belt(reverse rotation).
Rod out or recore your radiator to at least a 3 row.
Run a 16-18 lb cap.
Do you have a 'bug-screen' on your grill? Get rid of it!
Confirm your not run'n a lean fuel mix(vacuum leaks)by 'reading' your s'plugs.
LG

wellmax 09-12-2013 08:51 PM

cheap easy test of radiator,
drain coolant,
take loose upper and lower radiator hoses from radiator, also take off radiator cap.

hold your hand over the lower radiator opening
have a buddy fill radiator with water.

when radiator is full remove your hand from the lower outlet and watch the water as it exits the radiator, if the radiator is open and clean, the water should shoot out of the lower radiator outlet, good steady flow.

if radiator is partially stopped up the water will slowly exit the radiator and gurgle along as it runs out.

you need a fast flow

this is a cheap way to check radiator,
if stopped up, have it rodded out, before you ruin that good motor, as overheating is the second fastest way to ruin a good motor, lose of oil pressure is the fastest way to ruin a good motor.

WSS 09-13-2013 12:45 AM

Quote:

Originally Posted by Matt1981CJ7 (Post 15938425)
Does your radiator start loosing coolant out the overflow when the gauge is showing above hot?

Go to Home Depot and buy their $50 infrared thermometer. It will take all the guess work out of using the factory gauge.

Matt

Look at this:

http://www.ebay.com/itm/Non-Contact-...item51b0a7cf49

only half a percent of accuracy difference from my $200 fluke, should of waited 10yrs.

:tea:

Matt1981CJ7 09-13-2013 05:49 AM

Quote:

Originally Posted by WSS (Post 15962625)
Look at this:

http://www.ebay.com/itm/Non-Contact-...item51b0a7cf49

only half a percent of accuracy difference from my $200 fluke, should of waited 10yrs. :tea:

Damn, that's a good price!! I think I paid about $70 for mine at NAPA. :tea:

Hey Brian, have you figured anything out, yet? :wave:

Matt


The time now is 08:43 AM.

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