jiggybonz

hello. I am at a standstill with my '95 Cherokee(I6) and could use some help. I had a small coolant leak from the radiator for a little while on the passenger side near the battery. Foolishly, i tried to band-aid it with Bars Leak. That didnt work so and it resulted in an overheating issue the following day. So i replaced the t-stat. The next day it overheated worse and really started to spit from the radiator. So i broke down and changed the radiator(and the HCV after it broke from yanking on a hose to hard). So today i buttoned it all back up and it is still getting to hot to fast and now i have no heat either. With no leaks at least. I did flush the heater core and engine block prior to connecting the new radiator for fear i would clog the new rad with old crud. So any ideas would be great!! Another day of calling off from work and my Mrs. may insist I take it to "the shop". I am not ready to admit defeat, but she doesnt make a habit of losing disagreements!

thundaluvin

First off you need to flush the ENTIRE cooling system. Get that Bars junk out of there. Make sure to flush the heater core both ways. flush the radiator. flush the block. Put it all back together. fill it with coolant, and be sure to burp all of the air from the system. Use CLR to flush the radiator, heater core, and block. Make sure to flush completely with water after using clr to get it all out.

rideordie66

fan clutch mite be bad or t stat bad or in wrong. Are you sure the temp gauge is correct?

Marnrfn

No heat means there is no hot water being pumped through the Heater core. I would grab the front pully and wiggle it up and down. If it moves then your water pump is shot. Not sure if a 95 has the same set up as my 88 but worth a try?

kidkodiak

Is your electric fan kicking on? Does it come on when you turn on AC? Fan clutch might help too, they wear and then don't blow enough air over things to help keep it cool. You might want to replace the thermostat again after you do the cooling system flush and get rid of the junk you put in previously to stop the leak... and get an OEM from Jeep, personal opinion. I'm not a big fan of Stants or similar, and the Jeep factory 'stats are only about $3, at least here.

So in order of priority, things to try?

1. Full system flush (Like the prev. poster said, get that crap out of your engine. Not sure about C-L-R myself, never did it, but it works for backflushing things. Just have to rinse really really good). Then replace the thermostat

2. After #1, check fan clutch. How easily does it spin when the engine is hot (but turned off, try turning the blades and see how much tension is required to turn 'em. Seach for posts here for details, there are a ton.)

3. Check to be sure your alt-fan (electric fan) is turning on correctly. It should kick on when your engine hits about 240*? Around there.

4. Check the coolant temp sensor, it controls when the electric fan kicks on. It's either on the radiator (it is on my 1990), or it's on the thermostat bellhousing (it is on my 2K1). That's another cheap part to replace if you need to.

5. Engine Temp sensor bad? This one is a stretch, but one more potential factor.

Just some ideas, I'm sure others have other suggestions.

thundaluvin

I just bought my 88 2 months ago with a blown head gasket, the po tried bars junk. I put the clr in the heater core, radiator and block. Left it over night, and flushed it the next morning. WOW! I wish I had pics of what came out. I swear by clr. I've used it on other vehicles with similar results. My heat cooks now.

tjwalker

I'd concentrate on that overheating first as it is more important. Then see where you are at with cab heat (most likely a plugged heater core).

Couple of questions to help narrow the cause down.

Is it overheating ONLY at idle, ONLY on the highway, or BOTH?

You have replaced the radiator, thermostat, heater control valve.

But not the water pump.

Unless this is only overheating while at idle (in which case the fan clutch is suspect) I think I'd be shopping for a new water pump. And get a new radiator cap on there. They are only about $5.00 and are often overlooked.

thundaluvin

x2

jiggybonz

all good stuff, fellas! thanx. i did actually replace the rad cap. thought it couldnt hurt. and i did flush the heater core and the block seperately prior to hooking up the new rad. although, not both ways and i did not try CLR. and my Pops suggested looking at the t-stat again also. i've read on this forum that they can sometimes be bad from the parts store. or the dummy who installed it, put it in backwards! has anyone here ever bought a "bad" one? and i will check that fan clutch. thanx for the quick responses and i will try a few of these things tonight and let you know! also, to Tjwalker- i have really only had it at idle because i havent felt comfortable taking it for a spin. and i was hoping it wasnt the WP because i did not see any weeping from the weep hole. But i gather that doesnt necessarily mean it is not bad?

tjwalker

You are right. The water pump can have performance problems without leaking. The impellers start to erode as they are plastic. Therefore, they don't move the proper amount of coolant. If the water pump is old, it really is in play here and should be replaced. Get a NEW one. Never a rebuilt or reman. here. They are only about $50 or so. Hopefully you can do the labor yourself.

Also good that you replace the cap. So often, the cap is overlooked and is important to cooling system efficiency.

Don't forget the fan clutch. If the fan clutch is bad, it is an extremely common cause of temp. creep. They are inexpensive and easy to replace. And often overlooked.

A good stat is important. They can't be installed backwards though on a 4.0. I buy my stats directly from Jeep and also like the Stant SuperStat. Stay away from any no-name, cheap charlie, e-bay stat as there is a lot of junk out there. Go 195 degree only.