Mysterious coolant leak....????

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NotMyRenegade

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Hello again.....back with another mystery....I checked other posts to see if someone else has experienced this problem but never found any.....maybe because of my ADD...LOL...so I apologize if it has been discussed already.

The Mystery....lately my partner has had a coolant leak....doesn't leak when the engine is hot or warm...I have checked that. When she gets home from work I keep a close eye on things...no leak. Get up in the morning...it leaked....fill it with coolant...drive all day...no leaks....come home....no leaks....next morning....it leaked. Now.....day 3 same routine and the next morning no leak???? So we put our heads together and came to the conclusion the two days it leaked the temperature dropped to -1 , -2 degrees and day three the temp was 10 degrees overnight. The leak is not coming from the water pump. I can see the coolant is dripping from the hole in the middle of the engine guard (plate) but I can't find where it is coming from. I am wondering if it is from the timing cover and I'm dealing with expand and contract of the gasket due to the temperature? At first I thought it was a faulty frost plug but that would leak all the time. Has anyone had this happen to them and what was the diagnosis....Don't want to have to take it to a garage cause she doesn't trust them . I guess if I have to I can take the ..rock guard??? off and might be able to have a better perspective of the situation but I thought Hey maybe someone here knows what's goin on and save me the trouble. One more thing...is it just me or is this engine design flawed because of this style timing cover. Its a head scratcher for me .
 

duderz7

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I had a water pump leak that behaved very similar, the weep hole on the water pump is actually on top of the water pump housing, have you checked there?
 

DadOSix

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Check the return line on top of the coolant reservoir tank. My 06 has a habit of leaking a bit there - there is a crack in the plastic, even though the insert sleeve is still there. It’ll weep a bit when hot, and promptly dry itself up.
 

NotMyRenegade

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I had a water pump leak that behaved very similar, the weep hole on the water pump is actually on top of the water pump housing, have you checked there?
yes I did....no leak there....when she first bought it the water pump was leaking and I replaced it......about 4 years ago now
 

NotMyRenegade

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Check the return line on top of the coolant reservoir tank. My 06 has a habit of leaking a bit there - there is a crack in the plastic, even though the insert sleeve is still there. It’ll weep a bit when hot, and promptly dry itself up.
yes.....I checked there and it seems fine.....I have checked all the obvious possibilities and everything seems ok.....the mystery is it leaks when the engine is cold and the temperature drops below 0 degrees.
 

KJowner

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Sounds like something shrinking in the cold, I would remove the sump guard and have a good look for any dried coolant, if nothing is visible wrap rag around the joints and pump so you can see where it's coming from in the morning.
 

jimfry

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Hello again.....back with another mystery....I checked other posts to see if someone else has experienced this problem but never found any.....maybe because of my ADD...LOL...so I apologize if it has been discussed already.

The Mystery....lately my partner has had a coolant leak....doesn't leak when the engine is hot or warm...I have checked that. When she gets home from work I keep a close eye on things...no leak. Get up in the morning...it leaked....fill it with coolant...drive all day...no leaks....come home....no leaks....next morning....it leaked. Now.....day 3 same routine and the next morning no leak???? So we put our heads together and came to the conclusion the two days it leaked the temperature dropped to -1 , -2 degrees and day three the temp was 10 degrees overnight. The leak is not coming from the water pump. I can see the coolant is dripping from the hole in the middle of the engine guard (plate) but I can't find where it is coming from. I am wondering if it is from the timing cover and I'm dealing with expand and contract of the gasket due to the temperature? At first I thought it was a faulty frost plug but that would leak all the time. Has anyone had this happen to them and what was the diagnosis....Don't want to have to take it to a garage cause she doesn't trust them . I guess if I have to I can take the ..rock guard??? off and might be able to have a better perspective of the situation but I thought Hey maybe someone here knows what's goin on and save me the trouble. One more thing...is it just me or is this engine design flawed because of this style timing cover. Its a head scratcher for me .
put some dye in it and start looking
 

ikuo78

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I don't think it has anything to do with it since it's a closed cooling system, but it's a good idea to replace the pressure tank cap.
 

NotMyRenegade

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Sounds like something shrinking in the cold, I would remove the sump guard and have a good look for any dried coolant, if nothing is visible wrap rag around the joints and pump so you can see where it's coming from in the morning.
Yes it is something shrinking from the cold.....I was hoping someone could give me a definitive answer...lol...what do you mean by sump guard?
 

KJowner

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Yes it is something shrinking from the cold.....I was hoping someone could give me a definitive answer...lol...what do you mean by sump guard?
The large steel plate under the engine
 

jeepop

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What brand water pump? Wrap paper towels around the water pump tonight. I took replaced mine when I got my jeep and had to replace it again. The water pump is on the list of parts I have replaced twice.
 

David A. Warr

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Check the hose clamp on the bottom rad hose. Often they look ok but have lost their tension. Put a proper clamp on there. Throw away the spring clamp.
 

NotMyRenegade

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What brand water pump? Wrap paper towels around the water pump tonight. I took replaced mine when I got my jeep and had to replace it again. The water pump is on the list of parts I have replaced twice.
Not sure of the brand name....purchased it at NAPA which is the premier auto parts store in Canada....but I checked it thoroughly....its good
 

NotMyRenegade

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Check the hose clamp on the bottom rad hose. Often they look ok but have lost their tension. Put a proper clamp on there. Throw away the spring clamp.
Yes ...I did check that and yes it has a very small leak there so I bought a new thermostat and new hose clamp to be replaced when I find the main leak
 

klc

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Also Skid Plate.
 

lfhoward

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When installing the new thermostat, make sure it is clocked correctly. The hole and rubber tab have to be in the right orientation, or I’ve heard that the thermostat housing can leak there. Never had this happen to me though. When my coolant leaked it was always the water pump going bad (2x) or a tech didn’t tighten down the upper radiator hose clamp enough. One time the radiator developed a leak and it had to be replaced. Mine is at 226,000 miles now so it has seen its share of maintenance.
 

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