Lower Head Studs Leaking Coolant

[mred03gt]

The lower head studs that go into the water jacket are leaking. I used thread sealant the first time and RTV the second. I did a search and it appears that I can redo these again one by one in the car. The problem is how can I re-torque them in the car when I can barely have enough room to remove them. Is there a trick to it and what can I do to keep these things from leaking. I have already yanked the engine once and replacing all the gaskets is getting expensive.

Thanks

Scott

 

[Rick 91GT]

Scott you can get in there, you'll need to to use a small extension if the rear lower studs are leaking. It's tight but I have done it....

Drain the coolant, use the block drains if you can or it will still make a mess. Do one by one, ARP sealant or Permatex should work be liberal with the amount you use. I had a few issues with a few sets and ARP told me to put alums eal through the motor as a last resort, I hate doing that though. Depending on the condition of the threads in the block, bolt tolerance it is possible to have them seap.

 

[mred03gt]

Thanks Rick,

I will give it a shot this week.

Scott

 

[joncash]

Remember the bolt holes have to be clean and dry for the sealer to do it's job. Engine coolant is slippery like oil and won't allow the sealer to "stick" to the iron of the block and steel of the fastener. Blow out the bolt holes with compressed air if it's available and clean them with brake cleaner to make them squeaky clean.

You really shouldn't use RTV as a sealer because it acts like a springy cushion between the fastener's threads and the block's threads when it cures, which will affect the actual clamping of the fastener, which must stretch slightly to hold the gasket as it should. The best thing to use is teflon thread sealer paste. It's in the plumbing supply section of any hardware store and usually comes in squeeze tube.

All that said, I had the same problem with my head studs because I forgot to brake clean off the oily coating that ARP covers them with before I installed them in the block. I was very reluctant to go through the process of removing, cleaning and retorquing the head studs one by one so tried plan B: one small can of metallic radiator seal. You just have to accept that in order for the particles to fill the breach (i.e. the unsealed threads) it has to leak for a little while. Over a period of a few days it will leak less and less and should stop completely. Make sure the overflow tank is topped off and ignore that little puddle--it will eventually go away. It worked great and I'm very glad I didn't blow a bunch of new gaskets and time tearing apart a freshly assembled engine.

Good Luck whatever you do

 

[speedytang]

Just remember that anythinig you use on the threads changes the torque setting for that bolt. ARP has the new torque rating listed when using the product they sell.

 

[Rick 91GT]

I had a long talk with ARP about this issue since I used there stuff exclusivley and he told me if there sealer did not work properly to try the high temp Permatex.....lol

The ARP stuff is non-hardening, unlike the Permatex.

 

[joncash]

The type of sealant won't affect the torque specs on studs (which his thread title says he's using) because the portion threaded into the block isn't supposed to turn when tightening the nuts. The torque spec changes with different lubes because of differences in resistance to turning due to friction between the threads at the side the nut is being fastened.

 

[8950HO]

:OT:,rant.
Why would Ford design a block where the lower head bolts enter the cooling system?(IDIOTS).

This whole engine has been "Mickey Moused" right from the factory,eg...

THIN BLOCK!!!

5/16" connecting rod bolts,(joke).

5/16" rocker arm and intake manifold bolts,(gee...why not 3/8")?

7/16" main and head bolts,(1/2" main and head bolts should have been used,and more than 10 head bolts per head would have been nice,along with beefier main caps).

I think the bean counters at Ford beat the engineers.

It`s a wonder the late model roller engines can put out the elevated HP they can before blowing up.