Valve cover sealant question

[ekw]

I replaced my injectors over the weekend. everything went well and generally I did not have any problems. Thanks to all of the information gleaned from these forums.

I do have one concern though and could use some advise.
I started my installation on the Right side of the truck wanting to get the more difficult side out of the way first.
I had some black high temp silicon sealant which I used for the lower to upper valve cover sealant.

I went to the auto parts store needing some cleaning supplies and more silicon for the passenger side valve cover. I started reading the lables and noticed the gray high temp is also high torque presumably the stuff the factory used. So I picked up the grey and used it for the installation of the passenger side valve cover.

So my dilemma is do I remove the right side valve cover and injector supply tubes to replace the black with grey silicon? Lots of work but I would rather do it now before all the wiring and accessories are installed and 2 months from now I find it is leaking.

[DmaxMaverick]

That's a really good question. Unfortunately, it's one only you can answer. It's your coin to toss.

I've used the black Permatex RTV for many valve covers in years past. I've since moved on to the orange, and finally the gray (current choice). I know of guys (one with an auto shop) who still use the black, and claim it works well. I didn't have a problem with it years ago, just went with the best available at the time. I believe the gray is better for engine sealing in general, but would use black, or orange, if it were necessary.

That said, you are correct in that it will only be more of a job later, and if you don't do it now, there will be that feeling of uncertainty. If it were me, it would likely come down to a coin toss, right before I redid it anyway. My luck rarely runs in my favor, so I err on the side of caution. I wish I could offer some more definitive advice, but it's just one of those dilemmas. Good luck, whichever way you choose.

[ekw]

Not wanting my truck to be the experiment I skipped the coin toss and I pulled the valve cover, replace the black RTV with Grey. I am VERY happy I did so as the difference between the Black and Grey is Black and White!! The side that I installed with the Ultra Grey was already dry and very rubbery. The Black was stringy, still a little wet and mostly squeezed out down to the aluminum. I also got a chance to check the injector inlets for derbies after installing the supply lines. Maybe I got lucky but not even a speck of anything. I think living in Arizona helps a little as we do not get much rain and no salt in the winter so the corrosion was limited to the very end of the fitting. I cleaned the treads really good the cone and used a long steel wire brush I got at ACE and cleaned from the top through the rather large gap between the fitting and supply tube. I inspected the insides of the tube after cleaning with Brake Cleen and they also looked very good. I am wondering if sealing that gap from the top would be a good idea? that is where all the derbies make entry. I noticed that the fittings under the FICM were much cleaner. Silicon seal or some sort of plastic shield would help or cause some other problem.
I am down to installing metal tube to the thermostat housing (getting new O ring), new fuel filter, antifreeze and Air box. Went well thanks to all the help I received in these forums and I have to also than thank the how to http://www.dieselbombers.com/chevy-gmc-duramax-01-04-lb7/25030-replacing-duramax-lb7-injectors-01-04-tips-hints.html which has the torque values and lot of good pictures.

EKW

[More Power]

I am wondering if sealing that gap from the top would be a good idea?
EKW

Actually, that has been recommended by GM for quite a while now. I'd not go overboard though with gobs of sealant. Not too little, not too much... ;)

[THEFERMANATOR]

Also keep in mind that the grey that GM uses is a MUCh better quality than even the ULTRA grey you buy in the stores. The strongest I have ever seen was FORDS grey engine sealant, but I wouldn't use it on anything fragile as it bonds TIGHTLY!