Head Gasket or Water Pump?

[TJ Mick]

Context: Had my 4.0 litre re-built couple years ago and since I've only put on approx. 10,000 Miles.

Had my water-pump replaced late last year and a few weeks later started to notice some build up around my manifold bolt as picture.

It stayed like this for a few months, meanwhile the Jeep doesnt over-heat and I was losing minimal coolant. Engine is strong and overall the Jeep runs really well.

Few days ago I took it to a mechanic who peformed a pressure test and checked the bolt torque was correct.
After the pressure test the coolant is clearly visibly leaking from this bolt/area.

Mechanic who performed the pressure test suspects that it's a head gasket leak. How do I determine if it's a head gasket leak or related to the water pump.. or possibly something else?

Photos attached.

Thanks in advance.

 

[macleanflood]

Oil analysis or a combustion gas test are simple ways of verifying your mechanics gut instincts.

But I'd certainly throw a water pump at it before I did the head... although honestly the heads on these 4.0s are ridiculously simple to pull.

-Mac

 

[bohuggabee]

Context: Had my 4.0 litre re-built couple years ago and since I've only put on approx. 10,000 Miles.

Had my water-pump replaced late last year and a few weeks later started to notice some build up around my manifold bolt as picture.

It stayed like this for a few months, meanwhile the Jeep doesnt over-heat and I was losing minimal coolant. Engine is strong and overall the Jeep runs really well.

Few days ago I took it to a mechanic who peformed a pressure test and checked the bolt torque was correct.
After the pressure test the coolant is clearly visibly leaking from this bolt/area.

Mechanic who performed the pressure test suspects that it's a head gasket leak. How do I determine if it's a head gasket leak or related to the water pump.. or possibly something else?

Photos attached.

Thanks in advance.

View attachment 606220

View attachment 606221

View attachment 606222

View attachment 606223

View attachment 606224

Honestly. Your engine is so clean i suspect you dropped that coolant on there to troll would be knowledge guys. But as a guy that tried to repair a water meeter that ruptured in a blizzard. I know how leaks can be ever so slight. However. You provided enough photos to suggest you wanted to test people here and i wont correct the bias. To allow you to continue on. Ur the only guy going to understand how i understand you

 

[Zorba]

Check the thermostat housing/elbow. They are notoriously leaky as many/most of them have coplanarity issues. I fixed mine with Permatex.

 

[JKP]

Head bolt 11 requires sealant as it penetrates the water jacket. And that stud connects to the head bolt 11 hole.

 

[Gilaguy23]

Looks to me like the stud hole went into a cooling system passage. Not even sure if that possible in that location, but Ive had more then one D/C product with that issue.

 

[TJ Mick]

Sharing a latest image -

Do I need to mess with Bolt 11 considering it's evident that the weaping is coming from Bolt 1?

Can I not just remove Bolt 1 - add sealent and tighten?

 

[TJ Jim]

Sharing a latest image -

Do I need to mess with Bolt 11 considering it's evident that the weaping is coming from Bolt 1?

Can I not just remove Bolt 1 - add sealent and tighten?

View attachment 614787

That’s the first step I would try. @JKP is spot on.

 

[TJ Mick]

That’s the first step I would try. @JKP is spot on.

So remove Bolt #11 first? or Can I afford to try Bolt #1 first?

 

[TJ Jim]

From what I see bolt one first. Can’t tell by the picture if there is any leaking from eleven. The top bolt on the water pump requires sealant and I used teflon impregnated liquid sealant from a recent house plumbing repair.

Hopefully on a side note the person that installed #1 didn’t strip the threads.

 

[TJ Mick]

From what I see bolt one first. Can’t tell by the picture if there is any leaking from eleven. The top bolt on the water pump requires sealant and I used teflon impregnated liquid sealant from a recent house plumbing repair.

Hopefully on a side note the person that installed #1 didn’t strip the threads.

Thanks for the advice.

 

[JKP]

Bolt 11 penetrates the water jacket in the block. That is the source of the coolant.

Bolt 1 is just the lowest point that it can escape.

Bolt 11 needs to be removed and the threads coated with the correct sealant.

 

[TJ Jim]

Bolt 11 penetrates the water jacket in the block. That is the source of the coolant.

Bolt 1 is just the lowest point that it can escape.

Bolt 11 needs to be removed and the threads coated with the correct sealant.

Just bugs me that the coolant is on the outer side of the gasket? The fan sling’s coolant everywhere. My water pump leak has slung coolant all over the underside of the hood.

 

[JKP]

Just bugs me that the coolant is on the outer side of the gasket? The fan sling’s coolant everywhere. My water pump leak has slung coolant all over the underside of the hood.

Read post 1.

 

[TJ Mick]

**UPDATE**

Happy to report that 7 days have passed since I removed Manifold Bolt #1 and applied some sealant.

No leaks to be seen.

If it begins leaking again, i'll have a go at Head Bolt #11.

 

[JKP]

The manifold bolt doesn't penetrate the water jacket, it just intersects the head bolt hole. The head bolt is still leaking.

 

[Rickyd]

The manifold bolt doesn't penetrate the water jacket, it just intersects the head bolt hole. The head bolt is still leaking.

Yep,leave it long enough and it'll be a rusty mess in there.

Torque it to the spec for that one head bolt. It's less than the others because of the sealant

 

[TJ Mick]

Can I just remove Head bolt #11, apply sealant and re-torque without having to remove the other head bolts and worry about tightening pattern?

 

[JMT]

Can I just remove Head bolt #11, apply sealant and re-torque without having to remove the other head bolts and worry about tightening pattern?

Yes. I’ve done it before. Just follow the torque specs. Seems like it’s different than the others IIRC.

 

[JKP]

Yes,

The torque is less because the sealant acts as a lubricant.

I would drain some of the coolant to get the level below the bolt hole in the block too.