Coolant Leak â€“ The ongoing saga

camo · **Posted:** Wed Jun 08, 2011 1:10 am

to SmokinJoe. Im in Houston near hwy 6 and I 10. Do you happen to know any shop with experience in our CRDs?

SmokinJoe · **Posted:** Wed Jun 08, 2011 1:14 pm

Camo,

So far I've just used the Jeep dealer here, but I'm not impressed....
I've heard of a good diesel mechanic up in Willis that I plan to go visit, but haven't done so yet.
I have called/emailed around here in town, but no one has any experience.

If you hear of someone, please pass it along....and I'll do the same.

mattybombatty · **Posted:** Sat Jun 11, 2011 12:12 am

I've been running it various distances and stopping to check around the thermo for possible leakage, but have found nothing. There's never any sign of a leak after it's been parked either. Gonna replace the coolant reservoir cap and see if that helps.

racertracer · **Posted:** Sat Jun 11, 2011 7:53 am

Ok, here's the update.

I decided to explore Squeetos suggestion and went ahead with the removal of the thermostat for inspection and installing the Permatex blue gasket maker instead of using the OEM gasket.

(http://www.permatex.com/products/Automo ... _Maker.htm)

I found a stripped 8mm x 1.25 threaded hole. The location of the hole is on the bottom left of the thermostat and is home to the shorter length bolt. I used the wrong length bolt for that hole causing the threads to strip when I torque the bolt.

I mistakenly used the shorter ¾” long bolt instead of the longer 1 1/8”bolt. The shorter bolt didn’t grab enough threads and I unknowingly stripped the threads when I torqued the bolt.

I repaired the threads using a thread repair kit called Heli-Coil® Screw Thread Insert kit (http://emhartamericas.com/products/helicoil.asp).

It took a while to do the job but now the threads are better than new.

After waiting 24 hours for the blue gasket material to dry and filling the reservoir with Zerex Hoat coolant, I test drove the jeep for a few hours to see if the low level coolant light returned and it didn’t. This morning there was no visible sign of air escaping from the petcock on top of the radiator or any coolant puddle on the garage floor. Looking good so far. (Definition of "PETCOCK": A small valve or faucet used to drain or reduce pressure, as from a boiler.)

Although it sounds like the issue may be solved, I am not rejoicing yet, I will need to test run the Jeep for a few hundred miles or more before I can rest assured.

I’ll report back.

RacerTracer

KJ 119 · **Posted:** Sat Jun 11, 2011 10:51 am

Not sure if this is what DOC4444 was touching on, but it is a possibility that your head gasket might be going bad and you guys are burning the coolant. My boss's CRD was burning coolant, so he kept adding fluid till the engine finally hydrolocked on him. He promised me his old jeep, and like the bush-hog he promised me, I guess I'm eventually gonna have to go and repo it. :roll:

I sure hope this isn't any of you guys problem, but it is a possibility.

racertracer · **Posted:** Sat Jun 11, 2011 7:19 pm

All is well.... no leaks after 225 miles.

Sir Sam · **Posted:** Sat Jun 11, 2011 11:53 pm

lol @ petcock

KJ 119 · **Posted:** Sun Jun 12, 2011 12:50 am

Sir Sam wrote:

lol @ petcock

You wouldn't! :shock:

.....would you? :oops:

Sir Sam · **Posted:** Sun Jun 12, 2011 1:41 am

KJ 119 wrote:

Sir Sam wrote:

lol @ petcock

You wouldn't! :shock:

.....would you? :oops:

I have pethens, not petcocks, roosters are not allowed in the city limits.

racertracer · **Posted:** Sun Jun 12, 2011 10:12 am

KJ 119 wrote:

Not sure if this is what DOC4444 was touching on, but it is a possibility that your head gasket might be going bad and you guys are burning the coolant. My boss's CRD was burning coolant, so he kept adding fluid till the engine finally hydrolocked on him. He promised me his old jeep, and like the bush-hog he promised me, I guess I'm eventually gonna have to go and repo it. :roll:

I sure hope this isn't any of you guys problem, but it is a possibility.

Bub,

Your friend may have had an undetected external coolant leak that brought about the warping of the head.

I believe that any unresolved coolant leak will cause the aluminum head to deform and a leak to occur. The head is known to be the weak link in our engine and if the cooling system is left to run low on coolant with the low level coolant light on the dash, air pockets will develop that eventually warp the head causing the leak. Air pockets are not a good thing to have in a cooling system, especially in a turbo charged engine where high temps are common. I am glad I got mine fixed.

I appreciate the responses and support from the members here. Brain storming a difficult CRD engine issue with fellow CRD enthusiasts helped resolve this problem.

Thanks to Squeeto for pointing me in the right direction and thanks to all.

By the way Bub, how are you doing with your engine rebuild, can you enlighten us on the status?

72commando · **Joined:** Wed Mar 16, 2011 9:47 am **Posts:** 17

I had the mystery leak as well. After checking everywhere else I could think of, I figured it was a bad water pump. I removed the skid plate beneath the engine, drove around until it reached temperature, then parked and crawled underneath.

It's hard to see, but if you know where the water pump is, you can see it dripping coolant slowly on the passenger side. There's a lot of stuff in the way, and the coolant was pooling in my skid plate and draining as I drove, hence no puddles. The source of the leak is weep hole drilled on top of the wp unit. As the seal on the impeller side fails and coolant leaks, the weep hole allows it to flow out of the casing, delaying its contact with the bearings and it also shows you that it needs to be replaced.

I bought this jeep from my father, who drove it with the leak for a few thousand miles. I drove it for 500 while accumulating parts for the timing belt replacement, and bought a water pump too to replace while I'm in there. Yesterday, I pulled the pump. The bearings were completely shot, the shaft can almost not be turned by the bare hands. I can't believe I didn't lose the pump/belt and ruin my head.

edit: My Jeep just rolled over 88,000 miles. Please please check this out before things go catastrophic on you! :shock:

SmokinJoe · **Posted:** Sun Jun 12, 2011 11:54 pm

[quote="72commando"]I had the mystery leak as well. After checking everywhere else I could think of, I figured it was a bad water pump. I removed the skid plate beneath the engine, drove around until it reached temperature, then parked and crawled underneath.

It's hard to see, but if you know where the water pump is, you can see it dripping coolant slowly on the passenger side. There's a lot of stuff in the way, and the coolant was pooling in my skid plate and draining as I drove, hence no puddles. The source of the leak is weep hole drilled on top of the wp unit. As the seal on the impeller side fails and coolant leaks, the weep hole allows it to flow out of the casing, delaying its contact with the bearings and it also shows you that it needs to be replaced.

I never thought of removing the skid plate to check for a water pump leak. I'll try it. Maybe I'll get lucky.
Thanks for the tip.

Racer, glad you found your problem and got it fixed. Hope the solution to mine comes along soon.
I ordered an oil analysis kit from Blackstone. I need to change the oil anyway, so I'll send them a sample for testing. Hopefully it won't show any signs of coolant in the oil.

KJ 119 · **Posted:** Mon Jun 13, 2011 11:15 pm

racertracer wrote:

By the way Bub, how are you doing with your engine rebuild, can you enlighten us on the status?

Two words for ya Raff....Yard Art.

I use to have a love hate relationship with my Jeep. Presently it is a hate relationship.
Unfortunately, she got put to the back of my list of shiz to do. Life's never been better.

racertracer · **Posted:** Tue Jun 14, 2011 5:18 am

Sorry to hear it.

yakers · **Posted:** Sun Jun 26, 2011 10:41 pm

Fingers crossed, knock on wood and various other activities; chanting & burning incense, but I changed the coolant reservoir cap for a new one and driven 500+ miles and doesn't look like I am losing any coolant. Maybe the thing to try is a new cap <$10. Had 90K miles on mine so maybe its just due.

nalu · **Posted:** Thu Jun 30, 2011 7:21 pm

Thanks for the tip SmokinJoe! I had developed the same issue over the last couple of months. It definitely looks like it is coming from the water pump. Luckily I have one in the garage. I dread tearing into it again. I did the timing belt change at about 150K and should have done the water pump but didn't have the technology or extra gasket to go that deep. I did good not to mess up the timing.

Coolant Leak â€“ The ongoing saga

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