Fluctuation temp/ sporatic coolant puddles

Ok, first things first:

94/4.0/AW4/231/126k

About 3 weeks ago I was going through the drive through and noticed my temp was up to ~235. Once I started moving again it dropped to ~205 and stayed there. I checked the coolant level and it was a little low, added some. 2 weeks ago I found a small puddle of coolant under the front of the Jeep. Behind the radiator and centered from right to left. No problems with temperature at all while driving between these 2 incidents. This past weekend I replaced the radiator cap and tried to find a leak. Ran the Jeep for 20+ minutes and the only thing that happened was I had to add some more coolant via the reservoir. No leaking, no temp fluctuations once I got the coolant filled up. Sunday on my way home from work my temp was all over the place, but never over ~210. Bounced down as low as ~155 and just seemed to be very erratic. Yesterday I stopped about halfway to work and when I came out of the store I had a puddle right where the first one was and a little bigger. I had been using a little coolant, maybe half the amount between 'full' and 'add' on the reservoir but have had no temp issues. I'm thinking water pump. I realize that without actually finding the leak this can't be confirmed but does this sound right? I'm also going to do the t-stat, hoses, and fan clutch. I figure they are probably the OEM ones so they owe me nothing and are past due. Anyone have any other suggestions?

I wouldn't replace the clutch unless I was certain it wasn't working correctly (testing it is covered a few times around here somewhere), and I would recommend flushing the system out just before I replaced the pump and t stat as well.

Sometimes the temp can spike pretty quickly, it's freaky when it happens but it seems to be "normal" if it happens periodically. Also the temperature readings will fluctuate quite a bit if there is any air in the system, so fix the leak first

Losing coolant, otoh, is not normal. Find the leak first

Ah, yes the source of the leak. My main concern. I was thinking water pump as I said. I just went out and laid under the Jeep while running. Coolant is dripping/streaming off of behind the crankshaft/vibration damper pulley. Also some dripping off of the bracket that holds what I assume is the transmission cooler line that runs under the oil pan. I felt around under/behind the water pump pulley and didn't feel any fluid. My Haynes (I know, I know) manual has a picture of where the weep hole is and I don't think I felt in the right places. I'm heading out with a flashlight to see what I can find...

So with the help of said flashlight I confirmed the water pump, off to the parts store. New water pump, fan clutch, hoses; already had the t-stat and gasket.

Remove fan w/clutch: check
Change clutch: check
Remove t-stat: check
Remove water pump: .....
Reinstall belt and remove water pump pulley: check
Remove water pump: check
Install new water pump: check (w/ exception of lower hose)
Install t-stat: check
Reinstall belt: check
Reinstall fan w/clutch:..... ..... ..... .....

Any suggestions on getting the pulley nuts started??? I think a ratcheting wrench would be the best but I don't have one and don't want to really buy one just for this. Any other great suggestions? I'm on the home stretch and would really like to feel the satisfaction of getting this done. Any help is greatly appreciated.

An open-end wrench works, just slow as heck

chameleo78 said:

So with the help of said flashlight I confirmed the water pump, off to the parts store. New water pump, fan clutch, hoses; already had the t-stat and gasket.

Remove fan w/clutch: check
Change clutch: check
Remove t-stat: check
Remove water pump: .....
Reinstall belt and remove water pump pulley: check
Remove water pump: check
Install new water pump: check (w/ exception of lower hose)
Install t-stat: check
Reinstall belt: check
Reinstall fan w/clutch:..... ..... ..... .....

Any suggestions on getting the pulley nuts started??? I think a ratcheting wrench would be the best but I don't have one and don't want to really buy one just for this. Any other great suggestions? I'm on the home stretch and would really like to feel the satisfaction of getting this done. Any help is greatly appreciated.

Click to expand...

LOL! Made my day, thanks!

Getting those started are a pain, I used a way old tappet wrench on them. To get them started w/o pulling the radiator I used my nut starter--a magnet I epoxied to a strip of metal--put nut on magnet, slide into position and use a little pressure on the nut to the stud, then reach in there with the tappet wrench and turn the nut.

Pull the radiator, makes the job easier.

Reinstall fan with clutch: check (a wrench with a longer handle made a huge difference)
Reattach lower radiator hose: check
Start to check for leaks:..... .....

Leaking at the bottom of the t-stat housing. I pulled the housing again and some of the neverseize I had applied to the bolt had gotten smeared on the gasket. Went out and got another gasket and used a little RTV on this one and now everything seems good. I ran it for a good half hour and it never pulled any coolant from the reservoir and never went above 210 on the gauge. E-fan never kicked on either; only when I unplugged the CTS or put the A/C on. No apparent leaks. I'm quite happy with myself even if it did take a little longer than I expected and I managed ruined a $1.85 gasket.

A little suggestion for anyone removing any of the pulleys. I used one of the bolts as a "brake" while loosening the other 3 on the water pump pulley. I was then able to use one of those as a brake for the 4th one.

If no fluids transferred to or from the bottle then you probably need a new cap. Make sure it's a relief cap. NAPA sells Standt relief caps with the lever, they're about $15 but worth every penny. Make sure it's a relief cap or it will boil over at the cap instead of going to the bottle.

Ummm... I put a new Stant radiator cap on last week. It's the one that the parts place had listed for my model and year. I think it was $4-5. Are you talking about the older cooling systems or am I missing something?

I forgot to mention the part where I had installed the t-stat housing the second time and realized that I had left the t-stat laying on my bumper. It was a :gee: moment but all is good now as far as I can tell.

Stant Lev-R-Vent /Balkamp Safety radiator caps. Running one of these myself.

DO NOT OPEN RADIATOR CAP! Start over if you do!

Engine hot at shutdown for the night-check level in coolant expansion tank and make note of it.
Next AM, cold engine (SEVERAL HOURS) Recheck level again-should be say 1/2 - 1 inch lower. (both levels between full/add marks) IF so, all is well.

This is normal as hot coolant expands pushing Air/Coolant out to expansion tank. When engine cools back down it pulls coolant back in, (the air bubbled out!) A few hot-cold cycles purges air out of system, IF expansion tank is kept between full and add marks.

(Opening the R. cap lets air in which breaks the siphon to the E. tank.)

A good system , when its settled in, should not need coolant added but say, maybe 1 or 2 times a year, then ONLY at the Expansion Tank. Leave the Radiator cap alone!

Good Luck,
Orange

I used rtv and it leaked.

Dry has worked well.


Just my input.

Orange,

Thanks for that info.

Everything I've read about the caps with levers indicates they are just so you can manually release the pressure in you cooling system. Which as Orange pointed out is not necessarily a good thing. Any cooling system with a reservoir requires a vented cap which Stant lists on their site and is what purchased. Venting is different than Stant's Safety Release caps which have the lever.

The lever is secondary and unrelated. Basically you need a cap that will allow the spring seal to raise enough for the overflow nipple to be exposed but not raise so high that the coolant boils out the top. Some caps are specifically designed to do this, and the seal will open up in the area by the nipple first. I've had caps with arrows that had to be lined up with the nipple or else they would boil over, for example. The stant relief caps I use now also work for the overflow, but I had to pay extra for the relief model. The lever is really unrelated, although it will also shoot coolant down the nipple if the cap is installed correctly, which is a good test. Maybe all of the Stant caps are relief caps now, dunno, I've had mine for about 3 years I guess.