Pull screen/vents in base of distributor to prevent moisture?

lunytnz · January 21, 2015

A post by a mechanic, a few years ago, mentioned 2 tiny screens, at the base of the distributor housing, that can get clogged with debris over time and you end up with moisture inside the distributor. He also mentioned white deposits that can indicate ionization. He said you could remove the vent screens with a seal pick to help prevent the problem.

I just pulled the distributor cap and rotor on my 99 5.7L, and I see some moisture on the rotor, and white deposits, but don't see any vents or screens in the base of the distributor. Am I missing something? Do they happen to be under the cam position sensor?

I would *really* like to prevent this problem from happening again. A ventilation problem seems to make sense as a cause of the problem, but I can't see any screens. Is moisture getting in because the cap isn't sealed well? Or is it just a matter of condensation within the cap? (which means moisture is unavoidable and you just need to make sure there's enough ventilation).

And, if I'm going to replace the cap and rotor, should I go with a cap that has brass pins or aluminum pins? I heard someone say that caps with brass pins develop more problems than aluminum ones.

Thanks much!

SouthernSilveradoGuy85 · January 21, 2015

I had a problem of the distributor cap on my 98 5.7 and it was because the cap wasn't sealed good enough. It doesn't have any vents, it has to be sealed to stop moisture from getting in there. Any kind of moisture will make it hard to start or not start at all. Make sure to get a quality cap though. I replaced it with an ACDelco and had no problems after that.

00Silverado4x4 · January 21, 2015

I had a problem of the distributor cap on my 98 5.7 and it was because the cap wasn't sealed good enough. It doesn't have any vents, it has to be sealed to stop moisture from getting in there. Any kind of moisture will make it hard to start or not start at all. Make sure to get a quality cap though. I replaced it with an ACDelco and had no problems after that.

Exactly, what he said...