Water on my Zetec spark plugs.

[TomF]

I have a Seven SV with the very nice Zetec 2.0 SVT in it. But I keep getting rusty plugs leading to lumpy idles and the other day I lost a cylinder altogether (sounded like a Harley!). The car's a daily driver, and I do drive it in the rain, and obviously the engine bay gets pretty damp when that happens. But I keep it in a garage, and I was assuming any water on the engine would evaporate off pretty quickly.

 

The problem seems to be the plugs sit in a little trough (or rather, a bath!) under the cam cover. Of course the leads have big insulating rubber jobbies to close that off, but if the water does get past that, it can't get out again, and it can't easily evaporate off. So the plugs rust.

 

I found a thread with some pictures of the same thing, though he's got it much worse, and it's from a completely different cause: http://www.fordownersclub.com/forums/topic/16039-water-in-plug-ports-issue-with-pictures/

 

There are little holes for a cover that is normally fitted in the original Ford, but the cover's too big to fit under the hood of the Seven. I could have one made I guess. I'm also not super convinced a cover's going to help that much - the other worry is that it's not direct water but condensation - and a cover won't stop that.

 

This ringing any bells with folks?

[jlumba81]

I bought a svt spark plug cover w/ the idea of shaving it down enough to clear the bonnet. Ended up being more complicated than I thought it would be. I'll just take off the bonnet ever once in a while and just spray out the water with compressed air. I did put some dielectric grease in the spark plug boots to help prevent shorts. Oh and wear goggles or look the other way cause the water sprays everywhere.

[Off Road SHO]

Is the rust forming on the top side of the plug that is in a "plug well" of the valve cover? If it is, this is common. When the engine is hot, so is the plug well and therefore surrounded by hot thin air. When it starts to cool down, this thin air creates a small vacuum that sucks in cooler, moist air. The water vapor condenses out of the air and rusts the spark plug. If the spark plug seal at the top of the plug well is a tighter fit than the rubber seal at the bottom of the plug well, the aforementioned vacuum will suck in oil from the valve train area instead of air, leading to a plug well full of oil. If you have a lot of crankcase pressure from excess blow-by or malfunctioning PCV system, the oil will get in there that much quicker.

 

Tom

[MHKflyer52]

Try coating the top of the plugs with DC111 grease. Here is a link to it.

http://pilotshq.com/product_info.php?products_id=5988&m1track=googlebase&gclid=CLfqycmQwLoCFStxQgodHVMAWg&osCsid=4e0115f80812fbddcd420a623737efa0

 

We use this for a very similar issue at work and have not had an issue with rust since using this as a barrier. One suggestion that I will say use a small amount and spread it thin as it goes a long way. Plane de-natured alcohol will clean it off anything you put it on.

Hope this helps.

:driving:

[slomove]

I had the spark plugs drown in heavy rain several times. Very embarrassing with people watching you take off sputtering and stalling. It helps a lot to park the car in a slope nose up. Then the water will run out of the rear drain holes of the valve cover and not run into the plug wells (at least that is for my older ZX1 with silver top).

 

But the real solution was to just cover the bonnet so that the water does not get in. Even better might be a custom sheet metal shield over the engine. Maybe I do that sometimes.

[Dave W]

I had the same problem with a 4AGE. The hood Louvers allowed water to settle on plug seals and work its way into the plug well. It's a fair amount of work but I made a solid aluminum plate that covered all the plugs, then glued heavy foam on the under side of the plate, then bolted it down to seal area. This assumes that you can run longer plug wires in from the front or rear into the plug well. Solved the problem and the polished plate looks a lot better. Dave W