2012+ JK guys... Water pump issues?

**whatevah** · Apr 11th 2016

Been hunting down a coolant leak the past few days. Only leaks when the engine is warmed up and under throttle, so it's difficult for me to do. I thought it was a hose since I saw coolant dripping from it, replaced it with a Mopar hose and new clips, but it's still leaking expensive coolant. My only other thought is the water pump since the radiator and overflow bottle look dry. I'm gonna look at it more and likely get a new Mopar pump from Quadratec in the daylight hours.

Anybody else had any problems with their water pump or a coolant leak? Almost 5 years old and 62k miles, so I guess it's due...

**Slimer** · Apr 11th 2016

If it's only under throttle that tells me it's a pressure thing which could mean your radiator cap isn't releasing pressure.

How many miles do you have on the Jeep? Water pumps are generally good for 100,000 miles or there-abouts. I think I changed my truck water pump at 96,000 miles actually.

**whatevah** · Apr 11th 2016

I think the throttle correlation is just because the extra pressure from the pump moving faster and getting past the pressure threshold, I really don't think that the cap is the problem. I can easily squeeze the radiator hose, there's so much air in the system that I'm confident the pressure is far below the 18psi cap.

62k miles. The later 2012 and 2013 build year Jeeps have known bad pumps, but mine was built in 2011.

**whatevah** · Apr 11th 2016

John, it wasn't the pump. Upon further inspection, starting with a dry motor... The leak is coming from the thermostat housing. The face of it has a mark from the molding process, and it's leaking there. Just got one from the local dealership, this one has a part number a few generations newer (AF vs AH suffix) but still has the same mark from the mold. Looks like the rain is staying north for a while, so I'll chill for a while to let the system cool and swap it out.

**whatevah** · Apr 11th 2016

[img width=1200 height=675]http://uploads.tapatalk-cdn.co…3453dcebb2b0aff9b976f.jpg[/img]
Well, like the man said... There's your problem.

**astape** · Apr 12th 2016

Odd, probably a casting flaw. I guess u r just the lucky one to get it.

**Slimer** · Apr 12th 2016

I see the crack and the casting flaw but I'm not sure where that is relative to the mating surface where the coolant is flowing through. Can you file the new one down to remove the flaw?

I'm more concerned with why it cracked.

**Spedly** · Apr 12th 2016

Quote from Slimer

I see the crack and the casting flaw but I'm not sure where that is relative to the mating surface where the coolant is flowing through. Can you file the new one down to remove the flaw?

I'm more concerned with why it cracked.

It isn't near a mating surface. It is the top of the thermostat housing. The whole thing has coolant running through it.

**astape** · Apr 12th 2016

That circle on the front is not a casting flaw its in the mold, probably a vent. I was saying that the housing probably has a density issue of casting flaw allowing the crack to have started. That housing goes through a lot of heat cycles and if there is an air pocket in the metal it can crack. Just a theory.

**Slimer** · Apr 12th 2016

Quote from astape

That circle on the front is not a casting flaw its in the mold, probably a vent. I was saying that the housing probably has a density issue of casting flaw allowing the crack to have started. That housing goes through a lot of heat cycles and if there is an air pocket in the metal it can crack. Just a theory.

oh....

2012+ JK guys... Water pump issues?

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