When I install studs (which hold the manifold) into my replacement head, do I seal them with something. I noticed that the holes go all the way into the cavity in the head (coolant cavity??). Do I use high strength thread lock, or silicone, or something else??

Thanks

Mark

__________________
1984 300TD Wagon, 407,800 mi (current daily driver)
1985 300DT Sedan, 330,000 mi (gone to that great autobahn in the sky)

After throwing nuts all over the road with my Harley in the early 70's I discovered Locktite... I have used only the red (stud and bearing mount technically ) ever since then... on regular bolts and nuts it only adds about 5 ft lbs of torque to taking it off... I would not use it on huge nuts like the flywheel nut for a Volkswagon... what counts is the surface area... but I use it religiously on everthing else....be sure the threads are clean of course to get the max effect....these things are posting out of order again.... Greg

Mark:

I just rebuilt a Euro 300D engine to replace my old US version 300D engine and replaced one of the manifold studs (length of the stud for mounting the AC bracket) and the studs for the engine mounts. None of the studs had sealant on them and none of them looked like they leaked. I used a small amount of green Locktite on them when re-installing just as insurance to prevent oil leaks (green is the penetrating type with the least amount of strength, I applied it before assembly). I did not see leaks on any of the studs after running the engine, but only 1,000 mi. so far. If you only have blue Locktite (medium strength) then that should work fine (I've used the green for other stuff). I would not use high strength Locktite (red color, as I recall).

Good Luck!
Tom

__________________
America: Land of the Free!

1977 300D: 300,000+ miles

American Honda: Factory Trained Technician & Honor Grad.
Formerly:
Shop Foreman;
Technical Advisor to Am. Honda;
Supervisor of Maintenance largest tree care co. in US for offices in Tex.

I believe red Loktite requires heat to remove. If so, I wouldn't use red Loktite unless specifically called for.

Sixto
91 300SE
81 300SD

After throwing nuts all over the road with my Harley in the early 70's I
discovered Locktite... I have used only the red (stud and bearing mount
technically ) ever since then... on regular bolts and nuts it only adds about 5 ft
lbs of torque to taking it off... I would not use it on huge nuts like the flywheel
nut for a Volkswagon... what counts is the surface area... but I use it religiously
on everthing else....be sure the threads are clean of course to get the max
effect....these things are posting out of order again....
It does not require heat to remove red locktite...it barely requires more elbow grease,, and it sure keeps stuff from backing off due to vibration....Greg