Loss of coolant on Miss Rubi, our 2012 JKUR.

[crawler#976]

Took it into the dealership, and it shows a loss of pressure with a leakdown tester. They and I can't find out where it's going tho...

No codes are being thrown that would indicate a head or gasket problem.

So, any ideas would be welcome!

Mark

Sent via gigawatt laser...

 

[TexasTJ]

Is it on the floor maybe from the heater core

 

[crawler#976]

Nope, no signs of drips, stains, internal or external.

They put a new radiator cap on, but as I mentioned to them, that can't be the cure because the leak down test equipment replaces the cap.

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[toddz69]

Mark: Does the radiator overflow bottle have any way to vent/puke fluid?

Todd Z.

 

[TexasTJ]

My 2012 dose.

 

[Chuck59]

Thought / idea / from experience and worth a try. Where the temp sensor attaches, sometimes there is a small pin leak around the threads. The leak will be so small and the engine heat will be enough that the coolant will burn off. It may be hard to see / detect. Set there and stare at it.

Good luck

 

[swift7777]

Any wheeling lately with possible off camber or steep sections? You can lose coolant from the overflow bottle vent tube in extreme angle situations, has happened to me before.

 

[Martyn]

Mark, how much fluid were you losing and over what period of time. And what kind of pressure loss, how much over how long?

 

[Chi-Town]

It's the head gasket(s). There is a known issue with the heads being machined wrong in many ways. The gasket surface and the valve seats. Tell the dealer to do the pressure test again and pull the spark plugs and listen for air.

 

[SiliconTi]

You may not get a code if the leak is small.

3.6 is known for head failures. There is a bad early batch that went out (i want to say about 50K engines) - Chrysler told dealers they expect a 100% failure rate on them.

 

[toddz69]

You can also get the engine oil analyzed pretty quickly and easily too ($25 and about a week for a report). I use Blackstone Labs for the Bronco at every oil change. I can send you a container if you'd like. Only pain for you is that you'll have to drain some engine oil.

Todd Z.

 

[nwoods]

Yeah, head gasket. Warranty item. Soft recall in effect.

 

[crawler#976]

Mark, how much fluid were you losing and over what period of time. And what kind of pressure loss, how much over how long?

It seems the fastest loss occurs at highway speed; when we last went to Flagstaff via I-40 (high RPM from Ashfork to William) it lost about half the bottle. Daily driving at lower RPM shows much less loss, about a quarter to a half inch a week right now.

They said the gauge on the tester dropped a few pounds in 20 minutes. I suspect it's a head gasket or head problem, but can't prove that yet. Oil remains clear and clean so far. Miss Rubi was built in Feb of '12, so she's an early production unit.

Sent via gigawatt laser...

 

[Ryanmb21]

Bummer. Good luck!

 

[Chuck59]

You may not get a code if the leak is small.

3.6 is known for head failures. There is a bad early batch that went out (i want to say about 50K engines) - Chrysler told dealers they expect a 100% failure rate on them.

That is so sad. How many years have these folks been building motors. (<- notice no question mark.)