Head gasket troubles, please help.

[BigRigTech]

I have seen ARP fasteners spec less torque with moly lube but usually they use factory torque's with engine oil. I doubt 15ftlbs in the difference would be your problem but it is worth double checking with ARP. Studs stretch easier than bolts as you don't have the "twisting" stretch that you have with a bolt head dragging against the face of the cylinder head. I know the ARP headbolts that I used in my 357W were spec'd with less torque than stock - but that was only if you used moly lube.

 

[frdtrckmnrich]

Well i pulled it out and tore it down, sure enough the gasket was blown. But it was blown on both ends. From what i could tell It seems as if both head gaskets were being pushed out the back. The drivers side was approximately 1/4" out the back and the passenger is about an 1/8th. Before removing the head i did recheck the torque and they were still at 85lb/ft.

Does anyone know what the coolant holes in the block are for that are capped off by the head gaskets and heads? Because those are directly blown to the cylinder itself. Along with the ends of the gasket being seperated from the cylinder ring.

 

[eyoung429]

Couple of quick questions.

Have you run a straight-edge from corner to corner and then down the center?

Have you also looked at the head mating surface and seen any galling?

First thing I would do if the heads are true and straight is to have them magnafluxed to see if you have a crack that is causing the issue.

Next thing I would do is order a set of head gaskets that are NOT the same ones that you used before.

 

[Agnem]

That says that the head bolts should have been torqued to 100lb/ft. Arp's instructions say 85lb/ft.

What would you do? 85 or 100 ?

He is showing you specs for a 7.3. Click the Moose Truck album link in my sig for similar drawings for a 6.9. 85 is the correct torque for you.

 

[Dirtleg]

Does anyone know what the coolant holes in the block are for that are capped off by the head gaskets and heads? Because those are directly blown to the cylinder itself. Along with the ends of the gasket being seperated from the cylinder ring.

I am still fairly new to these motors but it is my understanding that the 6.9 motors have the coolant holes in the corners of the block and heads and the 7.3 motors do not.

Sounds to me like you are putting 7.3 heads and gaskets on a 6.9 block. If the heads have the corresponding holes and just the gaskets don't then you just have the wrong gaskets.

 

[BigRigTech]

My bad, totally an over sight on the 6.9 vs 7.3...Sorry. ...Should have started reading at the beginning I guess....Friggin dislexia....

 

[Full Monte]

I don't envy you having to do a head removal twice. I did it once and swore I'd never do it again with the engine in the truck. I feel this way mostly due to the problems of wrangling a Banks turbo, which makes the job three times more difficult.

Two things: you must use the Ford Motorcraft thermostat, not an aftermarket type. The Ford thermostat is specially designed. I didn't do this, and had air-lock problems like you did when I ran the engine. The engine will keep a giant air bubble in the coolant passages. When you run the engine, it will overheat before it starts circulating properly and blow your headgasket. I avoided this problem by removing the glow plug controller in the back of the engine and "burping" the air out of the coolant passages.

There are a lot of guys here with more head-pulling experience than my single experience. I'd be interested in knowing if one has to burp the system when using the correct thermostat, or if the thermostat solves the problem.

 

[frdtrckmnrich]

Well technically i have removed the heads 3 times. Once in the truck, and i have pulled the motor 2 times now to pull the heads. In a way it is kinda comforting hearing that you had problems with air pockets. I have a guy coming over today to help me check the deck surface. If it checks good i'm gonna try another set of gaskets and your purging idea.

Thanks for all the help everyone i greatly appreciate it!

 

[frdtrckmnrich]

Anyone have good luck with any certain headgasket brand???????

 

[icanfixall]

Felpro...... They wont rip-rot-stick-stink-tear-or-pull-hair......Buy the best and don't look back.

 

[frdtrckmnrich]

Well i figured out the problem......

My torque wrench is way off. From what i can tell it is atleast 20ft/lbs lower then what it reads.

Man, that was an expensive lesson.If all goes well it will be going back in the truck tommarrow.

 

[BigRigTech]

One tool worth spending good money for....I own SK torque wrenches for work....They stand up well and stay accurate if treated/handled right.

 

[Agnem]

I've been preaching this for years. Send your wrench to teamtorque.com before you do a head job!! Or to somebody. They go out of calibration just sitting in your toolbox and are not worth a squat unless you get it freshly calibrated. So many people I've talked to take this advice with a grain of salt, as if it wasn't important.

 

[frdtrckmnrich]

I've used this same wrench on several gas motors recently and never had a problem! It has been a great tool. I guess that the compression on these motors leaves no room for error.

 

[Diesel JD]

What good is any torque wrench that won't be right at least for awhile? It seems you should get a good wrench and get it calibrated often.... but after every job.... but I guess this proves it can be a problem....