Need advice for valve cover RTV replacement

[Infinitiguy19]

I found a place I can work on my car in peace FINALLY. I plan to do the valve covers and I just want some tips or advice before I undertake such a task as it will be my first time taking them off and putting them on with new RTV. I removed the valve covers from a 1991 Q45 I parted out and the engine was out already. I somewhat hated doing it because of all the screws but sadly the engine will remain in the car so it will be 10 times if not more worse.

I assume oil leaking on to coils 1 and 2 is whats causing the the minor idle stumble and not redlining at 6900 RPM's. If not well I might have a heart attack but I will cross that bridge when I get to it.

I have the 4 half moon gaskets that go on the rear of the valve covers (Thanks One Ton Garage). And yes sadly I have to leave the car overnight to let the RTV cure, but it beats paying $700-$1000 having someone else do it. Oh I almost forgot I know about the procedure when putting the valve cover back with new RTV, I read it the service manual.

Whats the best and longest lasting RTV?

And any tips or advice on this?

I sure hope I have extra screws for this just in case.

I am also glad that I will get to see how the top end looks and if and Hydraulic Lash Adjusters (HLA) are indeed bad or not (1 MM wiggle test on rocker arms).

[Lokim]

I usually use Permatex's Ultra Black RTV, but Great Stuff is OEM for many manufacturers, including MB. I have limited experience with it, but when I have used it it is awesome and easy to work with.

-EDIT- Not great stuff, thats expanding foam (works good, though.) The RIGHT STUFF is what I meant.

[qship96]

Nissan has their own RTV listed, but I am sure it is just a overpriced rebranded tube of rtv. Any auti parts store should have what you need.

[Lokim]

I usually use Permatex's Ultra Black RTV, but The Right Stuff is OEM for many manufacturers, including MB. I have limited experience with it, but when I have used it it is awesome and easy to work with.

You can pick up either at Schmuck's/O'reilly's, Napa, Auto Bone, etc.

[Q45tech]

Be sure to read all the Permatex pdf about the dozens of different types of black RTV....... curing time, hydrocarbon vs temp resistance, dielectric strength [near spark plugs].

[Q451990]

I use Permatex Ultra Grey http://www.permatex.com/products/Automo ... _Maker.htm

It's the only readily available RTV (other than the Nissan Orange stuff) that states on the package that it's an equivalent to Nissan's OEM RTV - and from a cosmetic standpoint it blends in nicely with the silver heads and covers. My local dealership used it on my old Q, but had a bad habit of starting the car up right after they finished putting it back together. Seeing fresh RTV sag and hang down on your exhaust manifold really sucks. Let it cure overnight...

Be sure to order new rubber washers that fit under the bolts that fit under the spark plug covers. In the absence of new ones, put RTV on top of the old ones.

The most difficult part is getting the covers back in place without touching them on something on the way in. I seem to remember removing the EGR tube to make it easier, but had to find a special wrench in my dad's garage to do so. The FSM specifies guide pins, but they don't exist. I wonder if using some peices of threaded rods or long bolts with the heads cut off would serve the same purpose.

Spend extra time cleaning the old RTV off and crap off of the inside of the covers. I would have several old toothbrushes and a case of brake parts cleaner on hand. The last time I watched an experienced tech do this on my Q at T3, he used what looked like a heavy duty Scotchbrite pad attachment on an angle dye grinder to get the old RTV off of the covers and heads.

Have fun!

Heath

[Infinitiguy19]

Thanks all for responding I will look into the Nissan OEM RTV and see how many times the part number has changed. but if its 60U00 that tells me its the original which I hope it is.

Heath I also saw that tool and and there is no Kent-More part number listed but with my thousands of screw and bolts I am sure I will find something.

Thanks for the tips and advice again!

[Q451990]

The Nissan stuff is a burnt orange color RTV that they use for everything, so it's not going to look like the powder blue factory RTV or have a 60U00 p/n. I'm not a huge fan of it... seems more difficult to work with. T3 used black BG branded RTV on mine in '03 and it has held up well.

Heath

[elwesso]

I assume oil leaking on to coils 1 and 2 is whats causing the the minor idle stumble and not redlining at 6900 RPM's. If not well I might have a heart attack but I will cross that bridge when I get to it.
.

Dont expect any change, im just saying.

Good advice too about the RTV, the gray permatex is nice.. A lot nicer than that orange stuff that nissan uses, however the nice part about the nissan stuff is when you're inspecting a used car you can tell when stuff has been replaced.

[lino]

I've used the same stuff as you Heath. I used it on a Mercedes. My mechanic who's very picky when it comes to engines and engine rebuilding asked me specifically to get it. I still have some left over which I'll be using to do the same job as you Paul.



Closeup:


It says OEM specified right on it:


Here are the instructions Paul:

[Infinitiguy19]

I assume oil leaking on to coils 1 and 2 is whats causing the the minor idle stumble and not redlining at 6900 RPM's. If not well I might have a heart attack but I will cross that bridge when I get to it.
.

Dont expect any change, im just saying.

Thanks Wes that makes me want to do it so much more.

I found some red RTV by Permatex that says it can take up to 650*F intermittently so I will grab some of that.

I really do think that this will fix it because what else could cause hard starting (Not stating on the first turn over), slightly rough idle ALL THE TIME and no being able to set the Idle Air Control Valve/Auxiliary Air Control (Valve) to +/-2.5 turns because Idle would go to 1000+ RPM's.

Oil in the plug wells can partially short out the coil boot to the plug limiting the
voltage.
(Q45Tech)

If it doesn't solve the problem then this still makes a great learning experience.

[elwesso]

have fun!! doing the valve covers once and youll learn one thing... you wont wanna do it again!

[lino]

I thought it was the plenum job you don't wanna do again Wes. Are you telling me that there are more ugly jobs

[elwesso]

the plenum is easy.. Thats my preferred "big job" on the Q, I cant say Id want to do one every day, but doing the plenum is a lot better than valve covers...

[OwnerCS]

Glad to see this thread come along.

As soon the weather cools off around here, cause I'm sans garage air conditioning,
I'll be using Permatex Ultra Grey when I do my Q's timing chain, valve covers, and (who knows what else) project.