Are the Head Studs the Problem??

[Tusker]

I put ARP head studs on my AAZ recently.  Very soon thereafter, I had the cap explode off the cooling bottle while I was screaming up a 20% grade flat out in third.  I caught it almost immediately and saved an overheat.  Put on a new bottle and was off and running.

A few days later, I was driving and smelled coolant, so I pulled over.  I found the push-on plastic fitting with the u-clip at the thermostat had blown off and the coolant hemoraging.  I put it back on, filled her up, and was off again.  The next time I drove the rig, the lower plastic hose fitting blew apart again.

Right about the time the first overheat happened, the rear main seal (which had 500 miles on it), started leaking like crazy.  If I clean the (Toyota) bellhousing off, it is pretty wet after 30 miles and soaked after 50 miles.

I suspect I have combustion pressure in my coolant, and wonder if the same thing is happening to the crank case.  I was going to pull the engine and replace the rear main, but I don't want to unless I have too.  If the head, or head gasket is the more likely problem I'll pull it off, have the head checkedm, and replace the gasket (a new 3-hole metal).

A buddy talked to a VW diesel mechanic he knows well (my buddy is a mechanic as well).  The guy said I souldn't have used the studs, and that was the problem.  He said the head (which I torqued to 70 ft-lbs the ARP way), may be warped from the concentrated stress.  He said to ditch the ARP's and go to stretch bolts.

I have certainly heard the opposite on here, so I wanted to bounce this off the guru's before deciding my next course of action.

Another questions:  Do you think I need to replace the rear main?  It was flawless for the frist 500 miles, and started leaking like a pig the moment I put the new gasket and studs on.  Thanks.

[935racer]

I think it could be a couple things or a combination of a few. Its possible your head wasn't competely flat when you installed the new head gasket. Its possible the deck of the block isn't flat. Did you retorque the head studs after the vehicle had been started? Don't it'll shift the gasket.

I use ARP hardware on all my engines, never had a problem. I've actually never been able to blow a stock headgasket with stretch bolts though. Even at 40 psi, its amazing what a 1.9 metal hg will hold with new stretch bolts and some gasket goo. I never retorque the stretch bolts after warm up or 1000miles either.

[Black Smokin' Diesel]

Question is, how can ARP studs cause such problems? They are just studs and nuts. That mechanic reminds me of my father. I laughed on the inside when he said my new wheels and tires combo caused my passenger side engine mount to go bad. Yeah right...

Run a compression test on the engine to se what's up. Maybe the head or block isn't flat or the HG was mis-aligned when it was installed. Or it's just a coincidence and something else went wrong, which I don't hope.

[Tusker]

I torqued the HG like the instructions said (the tighten-loosen-tighten sequence), but did not retorque after I was finished.  I don't see how the gasket could be misaligned with the alignment pins it has and the studs; is there something specific to watch for proper alignment?  

The "stud story" sounded fishy to me, so thanks for the conformation.  

Two more questions:
1) What do you torque your studs too?  I did 70 but am thinking about 50 this time around.
2)  Dave, you said you use some type of gasket sealer on your HG's.  What do you use?  Hylomar?

Thanks for all the help guys.

[DVST8R]

He uses Edelbrock gaskget goo. (there might be a real name for it I know its edelbrock just dont know exactly what it is called.)

[moosiah]

Hi tusker !!!!  don't forget that tiny leak at the back of the block that was a problem before.....  It sounds like there are 2 presure problems here .1 is in the crankcase causing the leaky seal, the other into the cooling system.... I watched you tighten those head studs by the book...... did you back off the boost?  I suppose one could dye test the head for hidden cracks , I wonder if that oil weep at the back of the block is indicating a low spot in the block at the right rear corner . ........ the rear main seal.... the main bearing are good right? how many miles since the redo?  how about a cooling system presure test? get the engine warm then presureize the radiator , pull the g plugs or the injectors and drop the oil out of the pan. kind of like looking for the dreaded 7.3 ford block pinholes..( you've got cavatation!!!! :shock: to the tune of you've got mail)  :cry:
 hey guys ,, you should see Tusker's zuki  !! toyo trany 12" stretch wb lifted a Super Zuki!!!!   oh, I forgot the loong springs too.!! all this and a 1.9td.  the frankenbunny was so jelous......  he can only trundel down dirt roads to camp, not follow the deer thru the woods

[HarryMann]

pull the g plugs or the injectors and drop the oil out of the pan

Why?

[Tusker]

Hi tusker !!!!  don't forget that tiny leak at the back of the block that was a problem before.....  It sounds like there are 2 presure problems here .1 is in the crankcase causing the leaky seal, the other into the cooling system.... I watched you tighten those head studs by the book...... did you back off the boost?  I suppose one could dye test the head for hidden cracks , I wonder if that oil weep at the back of the block is indicating a low spot in the block at the right rear corner . ........ the rear main seal.... the main bearing are good right? how many miles since the redo?  how about a cooling system presure test? get the engine warm then presureize the radiator , pull the g plugs or the injectors and drop the oil out of the pan. kind of like looking for the dreaded 7.3 ford block pinholes..( you've got cavatation!!!! :shock: to the tune of you've got mail)  :cry:
 hey guys ,, you should see Tusker's zuki  !! toyo trany 12" stretch wb lifted a Super Zuki!!!!   oh, I forgot the loong springs too.!! all this and a 1.9td.  the frankenbunny was so jelous......  he can only trundel down dirt roads to camp, not follow the deer thru the woods

Hey moosiah!  Funny you should bring up the oil leak.  You know what that turned out to be?  It was the VW oil sending unit at the back of the block leaking :oops:

Do you think the overpressure of the cooling system could be getting into the crank acse and the (new) oil leak is caused by the same thing?

I still have the boost up to 16 psi max.  It runs about 12 or 13 psi on the highway at 65 mph.  I could back it off some more but I wanted the added fuel and power so it was FUN to drive

Main bearings are brand new.  The engine has about 500 miles on it since I freshened it up, and I estimate it has no more than 100,000 on it total.  Head was rebuilt by the PO and never installed until I bought it.

I thought of pressurizing the cooling system, pulling the glow plugs, and looking for water in a cylinder.  I will probably pull the head, have it checkes, put a new head gasket on it, and pray for no more problems.  If I do have more problems, I will have to do something more extensive.

The engine was fine once I put it back together.  No problems, that is until I installed the ARPs studs and new HG...............

It is almost elk/deer season too.  Bad time for my VW Zuk to be sick in bed

[moosiah]

SO ..... harrymann.... you pull the glowplugs or the injectors so that when you preasureize the radiator IF there's a leak you can see where it is : filling up cyl #3 or dribbileing out of a crack near #2 .....  

[HarryMann]

Ah thanks! and then if it gets in the oil that has to be drained and changed - I see  :shock:

Mine was coming out of most orifices when it went, so didn't need to remove anything, mainly the exhaust.