gasket sealer type to use?

A friend has a minor leak around his 1991 Civic valve cover.
He replaced it with a new Honda OEM about a year ago and it
recently started leaking again. I vaguely remember mention
of an aproved sealer that could be sued that would mess up
the O2 sensor. I tried going back and searching with no luck.

He has a new OEM valve cover gasket and would like help changing
it Monday evening. Any suggestions as to what type sealer is
good?

Terry

 

Just to get the ball rolling, as someone who has replaced various components
on her 19991 Civic that use sealant like you mention (e.g. valve cover
gasket, oil pan gasket, engine block coolant drain bolt) a few times now:

I don't think I've used sealant either of the times I've replaced the valve
cover gasket (also known as the "cylinder head cover"). My Chilton's manual
says use it "if necessary." (Instructions for replacing the gasket are in
section 3, "Engine and Engine Rebuilding." They're also probably free online
at www.autozone.com 's free repair guides.) Putting the cover in place
carefully is important; if the gasket becomes twisted during installation of
course it won't seal correctly. I recommend a torque wrench for the cover
nuts. They're only supposed to be tightened to 7 ft-lbs. on my Civic. I
tighten each one gradually, and bicycle spoke fashion.

Also, the grommets that go around the four (on my car) cover bolts do harden
and fail after a while, leaking oil. How old is your friend's car? Maybe the
oil is coming from these. His car may be due for new grommets. I estimate
six years is a good time to replace these.

The sealant you have in mind may be "Permatex Ultra Grey," advertised as
"sensor safe RTV silicone gasket maker." One can go to www.permatex.com ,
click on "Automotive" on the left, then "Under Hood." The different sealants
and their applications are listed. Note that the "Ultra Grey" description
specifically states it's good for valve covers. There are other Permatex
sealants listed there that are also said by Permatex to be good for valve
covers.

I'm pretty sure Autozone carries most Permatex products.

If you need a low range torque wrench just for this job, consider a cheap-o
Pittsburgh model from Harbor Freight. Currently it's a little under $30, but
HF has a lot of sales. I mention it because valve cover replacement jobs are
the main reason I have a low range torque wrench. I compared the cheap-o
torque wrench to my larger torque wrench and it seems accurate enough. It
just probably won't last as long.

 

wrote in

Any sensor-safe RTV is OK. Permatex is good. You're supposed to use
Hondabond, the closest aftermarket equivalent of which is Permatex
UltraGrey. I just use pretty much any hi-temp RTV I can find. Right now
it's the orange stuff, just because I had a tube handy when I did the
valves last.

You put a tiny dab in the sharp corners where the cam bearing caps meet the
cylinder head.

If the gasket is OEM and the surface is totally, squeaky clean, with no
grains of grit /anywhere/, the use of RTV in that location is optional and
you can just smear a micro-thin layer of oil on the gasket before assembly,
then wiggle and thump it into place to make sure the sharp corners settle
into place properly.

Also...and this is critical...do NOT lose those little rubber grommets on
the nuts. They prevent leaks.

 

Elle:

He changed the valve cover gasket and those little rubber seals
in May 2004. He had "seakage" at the start, but it was so slight as
to not be an issue. It is now seaping way too much and he has to
go to Columbus next week. I have a nice selection of tools, with
the correct torque wrench. I suspect he might have pinched/twisted
the gasket.

Thanks for the reply
Terry

 

TeGGeR® :
Thanks for the quick reply. He is picking up some
Permatex ultragray this (Sunday) afternooon.

We will change the gasket Monday evening.
He will leave the car stting all day so we don't
have deal with a hot engine.

I changed mine, and a young friend's and never bothered
with sealant. But this guy is a little spooked.

Thanks
Terry

 

I've tried Permatex Super Blue (or whatever "Blue" it was called).

They can be replaced. I replaced a bunch of them on an '89 Integra
valve cover. The originals were hard and shriveled after about 70K
miles.

Oh - the spark plug tube gaskets sometimes need to be replaced when
removing the valve cover. About $2-3 each.

 

just a data point - new oem gasket on mine doesn't leak at all - no
additional sealant.

 

Yes, but my point was that some people lose them, don't bother replacing
them, and end up with oil leaks. Then they try to stop the leak by
tightening the nut down really hard and end up snapping the stud.



I replaced a bunch of them on an '89 Integra

Mine are still fine after 250K and 14 years.

I replace those every few years.

 

No sealant on my OEM either, and it's new this year. I'll put some sealant
on next year when I reuse it.

 

had the cover off mine twice already - still no leaks!

 

Are we talking about the same thing? Little black round combination
metal/rubber thing with a hole through it. Has maybe four little
dimples at the top. Threads go through the hole and nut screws at
the end of the threads. I found mine slightly dry and definitely
nowhere near new looking. I figured at $2.50 a pop, it wasn't too
much to replace them.

BTW - I only applied the dab of sealant on the valve cover beacause
it was recommended in my factory service manual. A dealer parts
dept said they could sell me some special "black" Honda silicone
sealant, but that Permatex "Super Blue" or similar sealant should
do the job just fine for less.

 

Evidently not.

Mine are one-piece, made of some sort of hard rubber or plastic material.

The grommets on our Tercel are more as you describe, with pliable rubber
surfaces. I just replaced all of them on the Tercel.