My car was riding a little rough. After a check-up, inside the distributor cap was green and very wet. After it was cleaned and dried everything is back to normal. I have washed the car only four times this summer and was very very careful not get water in the engine compartment. I used plastic to cover the entire engine. So I was very surprised to find water in the cap. I was told that my garage is very humid and this is probably where the water came from.

Does anyone agree with this and is there a solution to this problem?

Move to the Sacramento area. Its like 110 and no humidity here. (sorry - could not help myself).

But seriously, wasn't there talk of having the distributor cap drilled so as to allow the water buildup to evaporate? Isn't that the deal with standard OEM caps???

-mick

I have similar experience with moisture and 'green' in the cap. I have quite recently put a new cap /rotor and made holes in the cap. If I didn't live in such a remote location I would probably switch to a distributorless ignition.

The Diablo caps had little holes too prevent moisture whereas the identical Jaguar caps do not have these holes.
Drill two 1mm holes at the bottom of the cap and it should be fine.

Funny, the countach do not have this problem, only the Diablos...

__________________
RaymondQV
Countach QV Ex-Mimran #GLA12997, Urraco P300 #20530 sold in August 2008, Jalpa #FLA12203 sold in May 2006
www.countach.ch
www.jalpa.ch

When Frank Sinatra got his Miura S in 1970, he said: “If you wanna be someone, buy Ferrari - If you are someone, you own a Lamborghini”.

EXACTLY...

The stock one has 2 holes appx 1/8" drilled at 5 & 7 o'clock.
When I did the NAPA replacement with a Jag cap, I drilled abut 4 holes.

The plastic cover on top of the distributor should keep water away, but like you, I cover the motor when washing but do it to keep water spots of the motor... I like it clean all the time

Ok, I have an original cap with the small holes and still experience the green monster in my cap. (Although better than in my pants) I can understand drilling holes to make the moisture evaporate quicker, but don't this cause a problem when driving in the rain?

I really don't want to move to Sacramento to resolve this problem...sorry Mick

Bearing in mind that the dist cap from Lambo costs about £400, and the same Magnetti Marelli cap without the holes that fits a Jag is about £85, these must be some of the most expensive little holes on the planet [and speaking as a dentist this is really saying something]. It is quite ridiculous that I dare not wash my car without putting a cover over the engine for fear of moisture ingress that causes a running problem or the dreaded chk eng codes to appear.

The Napa brand cap is about $98US. Some say that it fails and is not as good. I don't know if this is true, but the price difference is rediculous.

hi mike how does your car run with the napa cap and rotor,i have a set but have not installed them yet?how many miles did you have on your cap and rotor before replacing with napa?
thanks
adam

I have about 1,500 miles on my Napa cap and rotor. That includes a lot of city driving and a few long road trips where I pulled her to 160mph a few times. Pulled the cap not long ago to inspect and it's like new inside.

Besides the price and holes, there is another difference in the caps ... the stock Lambo cap is much heavier and made of thicker plastic... weighs about twice as much as the aftermarket cap.

The only person who told me the Jag cap would not work was a shop trying to sell me their cap for $900 or something...

JAP- I don't think your problem is humidity... I mean I'm in Florida and nothings is more humid than here. I think you cap may not be sealing tightly. BTW I placed a light coat of dielectric grease around the area where the cap meets the distributor to keep out any water just in case.

Do you have the shroud that's installed over the distributor? I've seen a few cars with this removed. A plastic "U" shapped cover that painted silver and has 3 mounting points - desgined to keep water off distribuor.