broken 12 HT

[hj herby]

I have got a blown head gasket on my rig .I will start removing it this weekend.Anybody got any good tips?or advice? Specialy with the rebuild I will run water injection afterwards so if there is any prep work I can do with the engin out. Or just moral support .

Thanks all

 

[crushers]

are you sure it is a gasket and not the head?

 

[hj herby]

broken 61

THE HEAD but why? Is this common with the 12HT? I think she is a little tired ,maybe I put too much turbo pressure on when she was cold maybe,and maybe it just blew a gasket? maybe?????????hopefully!! she has 303000 kms low oil pressure,etc..............

I am a mechanic but allways like to get advice from the experienced

 

[Japan4X4]

Pull the head. Let us know how it looks.

 

[crushers]

the reason i ask is i have yet to hear of a 12HT head gasket blown.
so you are a mech then you know how important all the facts are to the dscussion. i was guessing maybe overheating that ended with a cracked head.

too much boost?? maybe, what was your gauge reading? your loosing coolant? compression down in two ajacent cylinders?

but as Dave says, pull the head and let us know.

 

[hj herby]

My reson for thinking its a head gasket is bubbles in the rad!
and all my experience with marine diesels and generators tells me head gasket.But Dave is right the proof is in decapitation!She never over heated.

 

[jinzuke]

crack

That could mean a crack in the block or head.

 

[lowenbrau]

My estimation...

The good news is that your head gasket is ok. The bad news is that you need a new head.

 

[crushers]

Dr Bruce...

ouch.

My estimation...

The good news is that your head gasket is ok. The bad news is that you need a new head.

 

[Tapage]

If will be the gasket .. what symptom gonna see ?

Mixed cooland with oil it's to me head gasket .. but it's the same opinion that I have if see bubbles in my rad ..

 

[canucksafari]

UD / Nissan Truck Used Parts

Ooops, wrong spot - time for a coffee.

 

[goldchaser]

Nissan!

 

[UpsideDown]

It could be any of the above... a cough can be cancer, a cold, pneumonia or even the flu (or you're a smoker).

It's impossible to know until you get it apart. All you're doing is looking at symptoms. You need to do a biopsy, an endoscope, or a full-on surgery to get your answers.

Bubbles are common in aluminum head/cast iron block engines and MLM head gaskets are supposed to help. But with the 12Ht you have iron on iron and a traditional head gasket material.

There are too many other factors as well, a super-common failure point for head gaskets is the totally inadequate coolant maintenance (as evidenced in General Motors products and their use of "long life" organic acid coolants :whoops.

It the engine has 300k Km on it, you should consider doing rocker arms, machine the valves, and a few other things while you're in there.

Good luck on the project, but I think Br. Lowenbrau may be correct.

 

[UpsideDown]

[.... snip ...] she has 303000 kms low oil pressure,etc..............

I am a mechanic but allways like to get advice from the experienced

Check your gauge. The pressure is probably ok.

 

[bigbrowndog]

My reson for thinking its a head gasket is bubbles in the rad!
and all my experience with marine diesels and generators tells me head gasket.But Dave is right the proof is in decapitation!She never over heated.

How long have you had this truck? I am wondering if the thermostat has been removed to cause the head or gasket problem. With the 12Ht and 2H it is not a good idea to run them with out a thermostat as this eventually causes problems in the head when the engine is hot with the water flowing through the less restricted water passages and cooling them while the more restricted and often hotter areas have less flow and less cooling creating hot spots in the head. And of course remove and replace the head using the right headbolt sequence. goodluck, cheers.