# Loctite vs anti-seize



## cactusfarmer (Nov 8, 2003)

I've searched around the forum and spoke with a few follks and I'm still a little confused on this issue of using Loctite vs anit-seize. 

I'm getting ready to put my head back on my engine, which of course means putting back the intakes, timing covers, idler sprocket bolts, water pump, oil pan etc. Some folks are saying use Blue Loctite on all the bolts and others, say, "no you're putting a steel bolt into an aluminun head and block, you need to put anti-seize on the bolts. Still others say, don't use anything. 

When I took most of the bolts out, they had what appeared to be a dried white substance on the end, which I was told was dried anti-seize. 

Of course I know I don't need to put anything on the actual headbolts but a little oil, but what about the rest of the parts? What does the factory use?

Any suggestions?


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## lshadoff (Nov 26, 2002)

The Factory Service Manual says:

"Apply new engine oil to bolt threads and seat surfaces when installing cylinder head, camshaft sprocket, crankshaft pulley, and camshaft brackets."

Generally oil is applied to the threads of fasteners which must be torqued to a specfic value. If the threads are dry or dirty, the torque reading will be incorrect.

The purpose of loctite is to keep a fastener from unscrewing, usually because of vibration. It is a substance which hardens in a short time. The blue Loktite anti-seize is somewhat soft and the fastener can be relatively easily removed. There is a stud fastener Loktite which is much stronger, making the stud quite difficult to remove. Loktite thread cleaner should be used before applying so that it adheres properly.

The purpose of anti-seize is to keep fasteners from becoming stuck after they are tightened. When using steel bolts in aluminum, electrolytic processes produce corrosion which effectively seals the parts together (the white stuff you saw). Anti-seize prevents this. It is an especially common problem for parts that get hot, so it should be used on spark plugs and anything in the exhaust system.

Lew


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## cactusfarmer (Nov 8, 2003)

lshadoff said:


> The purpose of loctite is to keep a fastener from unscrewing, usually because of vibration. It is a substance which hardens in a short time. The blue Loktite anti-seize is somewhat soft and the fastener can be relatively easily removed. There is a stud fastener Loktite which is much stronger, making the stud quite difficult to remove. Loktite thread cleaner should be used before applying so that it adheres properly.
> Lew


Thanks for the tips.
I understand the part about bolts that need oil to before torquing down, however, I'm still not clear, on the timing covers, water pump and oil pan since they are steel bolts going into alumunin. Would you recommend the Loctite Blue for those bolts, or the anti-seize? 

Also what about the exhaust manfold nuts that go on the studs. Would you recommend the High-Temp Loctite Red for those since it's a steel nut going on a steel bolt in a hight-temp area?


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## Tavel (Aug 21, 2004)

woah thanks man. i had no idea about the differences either.


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## lshadoff (Nov 26, 2002)

cactusfarmer said:


> Thanks for the tips.
> I understand the part about bolts that need oil to before torquing down, however, I'm still not clear, on the timing covers, water pump and oil pan since they are steel bolts going into alumunin. Would you recommend the Loctite Blue for those bolts, or the anti-seize?
> 
> Also what about the exhaust manfold nuts that go on the studs. Would you recommend the High-Temp Loctite Red for those since it's a steel nut going on a steel bolt in a hight-temp area?


The only time I use Loktite is when it is recommended in the FSM or the fastener has a history of backing out. Also, some after-market parts will recommend a thread locker.

Anti seize is always good for steel into aluminum. I use the copper-containing Permatex anti-seize in a tube. Put a thin stripe on the bolt and work it in with your fingers.

I use anti seize on all the fasteners in the exhaust system from the manifold to the tail pipe. It is especially effective on catalytic converter flange bolts which will remove easily after years.

Lew


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## lshadoff (Nov 26, 2002)

Moved to General


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## nova73guy (Mar 30, 2004)

NEVER use loctite or anti-seize on head bolts! These are torque-to-yield bolts and must not be used with loctite, since you're torquing the bolts almost to their breaking point for maximum holding. Both loctite and anti-seize can cause faulty torque readings. ONLY use these when called for. As for the other bolts on the engine, I've never used any of this stuff and haven't had any trouble with leaks, or removing the valve cover or other stuff when needed. Like most everyone said, only use what the FSM says. In most cases proper torque is much more effective than loctite ever was.


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## cactusfarmer (Nov 8, 2003)

In most cases proper torque is much more effective than loctite ever was.[/QUOTE]

That seems to be everybody's thinking. The ony problem is these cars have all those tiny inch-pound torque specs. The smallest inch-pound torque wrench I can find in my part of the world starts at 150 inch pounds. I'm just figuring on using my foot-pound torque wrench and doing lots of divided and multiplying.


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## cactusfarmer (Nov 8, 2003)

I use anti seize on all the fasteners in the exhaust system from the manifold to the tail pipe. It is especially effective on catalytic converter flange bolts which will remove easily after years.

Lew[/QUOTE]

I'll definetly try that since I had to cut all my exhaust bolts off when I disconnected my tailpipe.


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