RTV with valve cover grommets?

[Chris]

I am replacing the valve cover gaskets on my 2000 Z71 5.3L The grommets on the top are very difficult to install on the shaft (from what I have read). Would it be a bad idea to put some black RTV on the old grommets when I reinstall the covers? Here is a pic:

Topic

[Daniel]

I would just put some oil on them, install them, then put the bolts in.

[Chris]

I assume you are referring to installing new grommets?

[Daniel]

The grommets on the top are very difficult to install on the shaft (from what I have read). Would it be a bad idea to put some black RTV on them when I reinstall the covers?

Since this was your only question; yes I am talking about the grommets.

[Chris]

AH, I see. What I meant to say was could I use the RTV on the old grommets.

[Daniel]

You can, but it’s not going to hold much of a seal.

[Lorrin Barth]

You can use RTV anywhere there is a gasket or often in place of a gasket. I’ve heard of people using it to seal headers to the exhaust ports and they say it works. What you want to do is avoid using so much that is squishes into the inside of the engine. This can break off and get entrained in the oil, maybe plugging an oil passage or become stuck to the oil pickup.

Now, there’s all sorts of opinions about RTV, some like it and some hate it. But, can you use it – sure. About the only real caution I’ve heard is don’t allow RTV to contaminate an oxygen sensor.

[Daniel]

RTV is really only useful when sandwiched between two (inflexable) metal components. You can try it, but it’s probably not going to seal very well or long.

[Chris]

This is what I did; I smeared RTV on the shafts and seated the grommet to the end. Then I smeared some on the outside of the grommet and some on the valve cover when it seats. I then pressed it down into the hole and held the bolt up with a pin. All this was done after I cleaned the surfaces with alcohol.

I also sealed up the filler neck.

I figure it won’t be any worse than it was before. I will certainly update with results down the line.

[Author]

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