I am about to change the valve cover gasket on a 2002 Ford Focus SE Wagon with the DOHC Zetec engine. I have never done this kind of thing before, and although it seems simple, I am concerned after reading so many warnings about how your engine can be destroyed if debris falls in while you are taking off the cover, scraping off the old gasket, etc.

My questions are:

1) Does this mean that the tiniest little dust-sized fleck of gasket getting in there is gonna cause major damage? Or does it mean more like "Don't let leaves, nachos, and 2-inch chunks of gasket material fall in."? How much is too much?

2) What are tricks that you all use to prevent debris from falling in while you are working? (besides being really careful)

3) If I do drop some gasket material down in there, are there any good tricks for getting it out?


3 Answers 3


Yes, debris will cause damage, however the valves cover gasket doesn't stick that hard and if it is the original, they come with some kind of rubber material, very easy to take out even in one piece almost always. Some gaskets are made of cork material, those would break but still won't generate much debris neither. The tip is: take time, warm up the engine just a little bit, not to operating temperature, just a bit warm, a temperature you can be comfortable with, then uncap the cover. If you need to scrap something, do from inside to outside, or running the scrapper longitudinally but ending with a wrist twist to outside. You can place a clean rack solid where you think debris would fall.

When all is out, use a scrubbing pad to clean the surfaces, again, carefully. When adding the new gasket, put a thin, very thin layer of high-temp silicone to both sides.

If something falls inside, you will need to either pick it somehow if it is big, or blow it out with a compressor, but put some rags in the other side, since it will also spit out a lot of oil :)


Any debris will cause abrasive damage: the bigger the debris, the bigger and quicker the damage will be. Other than being careful, you can always cover up the engine if you are working in a dirty, dusty or drafty area. Changing the motor oil after your post-repair test drive is one way to mitigate the dust-sized debris.

  • 3
    The oil filter should take care of trapping fine debris.
    – Zaid
    Commented Jul 14, 2016 at 7:49

Fill the area with foamy shaving cream. Do all your gasket work, etc, and then vacuum out the area with a shop vac. wipe off any areas the shop vac can't get to. Rinse away any residue with fresh motor oil. The tiny bit of shaving cream residue going into the oil return passages will not be a big deal. I would change the oil and filter soon after such a procedure anyway.

I've done the same thing working on carbs (tiny butterfly screws, for instance) and most effectively when helicoil or other thread insert work on spark plug holes. Crank to BDC, fill cylinder with foamy shaving cream, drill/tap/insert, and then modify a shop vac nozzle to fit into the spark plug well while a helper slowly manually turns crank back to TDC. The residue is benign and won't harm anything.

I prefer Barbasol or Brut ... truth is, the foamy kind is getting harder to find. Do not use "gel" type!

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .