Intake Manifold Bolts... Teflon Tape???

[Sonicfrog]

Anyone have any objections to using teflon tape on the intake manifold bolts, especially the long ones! Murphy, the $500 87 Turbo Wagon actually got the name "Murphy" - as in Murphy's Law - because both of the long ones broke when I was rebuilding it when I first bought it.

 

I'm almost done with the head gasket replace, and one of the bolts was very close to breaking. So I'm thinking teflon tape on those, and on the turbo water port tube screw on the bottom of the engine, which also broke the first time working on the car.

 

Any objections?????

[MilesFox]

i was going to use teflon tape on my brake line fittings, but couldnt find it. I opted for anti seize, and then found my thread tape. D'OH!

 

I don't think its a bad idea. I would try it if i thought of it.

[NorthWet]

I have not heard of teflon tape being used on anything other than pipe-thread, which is tapered enough to allow the tape to get squeezed into the joint space. I would think that the tolerance on standard fastener threads would not work with tape.

 

My preference is to use stainless steel fasteners where they might be exposed to coolant.

[skishop69]

+1 on the stainless. Love the stuff. Anti-seize is perfectly fine and preferred. Northwet is right about the teflon tape. It will actually cause the threads to bind and possibly lock up.

[El Presidente]

Teflon is designed for tapered threads and willn't give you the protection that anti-seize will. Anti-seize has anti corrosive agents as well as particulate metals(usually AL, or CU) to prevent gaulling when pulling the bolt out. Teflon doesn't have either and willn't fill all the voids in the threads where corrosion likes to hide and build up. Anti seize will cause all your torque values to end up higher than your torque wrench is set for, because stock torque specs are for dry, clean threads, but ARP makes an automotive anti seize that gets it right where its suppose to be. I can't remember the name but I recommend it 110% Where teflon puts your bolts at is a toss-up because it doesn't uniformly fit in the threads

 

Heli-coils(I only use heli-coil brand) with the appropriate grade steel bolt is better than replacing the bolt with a stainless one, because the quality of stainless can vary from manufacturer to manufacturer. Most stainles grades can't be hardened too. Heli-coils work great for any damaged/ likely to be damaged hole, and leave the bolt hole stronger than before, they are also stainless, but I use anti-seize anyway to keep torque values the same between unheli-coiled and heli-coiled holes. I just put a Weber on my GL last week and 2 holes were toast and 2 were starting to get buggered up. Took me about 20 min. to heli-coil all 6 intake holes, just be sure to tape the intake ports up so your motor doesn't swallow a bunch of shavings. Also, set the coil about 1 1/2 turns UNDER the sealing surface, because thread stretch can interfer with the two pieces being joined.

[Sonicfrog]

Thanks for the replies.

 

The teflon tape seemed to work well on the water port. Will use an anti-lock thread coating on the intake bolts.

[idosubaru]

anti seize. i've used it a ton and had to go back into engines later that i previously used it on - they come right out.

[edrach]

If your bolts are stretched to the point of almost breaking you should replace them with new.