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I did search for this, and there are some oblique references to the sealant, but the full answer has come up that I can find.

The car is a 1998 Toyota Camry-XLE, 6 cylinder (1MZ-FE) engine with about 178,000 miles. The valve cover gaskets are leaking enough that it's time to replace them. The gaskets are molded rubber that sit in a channel in the head and the valve cover. There are lots of twists and turns in this cover though. I have read online everything from you should always use a sealant, to you should never use sealant, and pretty much everything in between. But what 99% of these never include is the reasons why.

So, should I use a sealant for this gasket change? If so:

  • What sealant is correct so as not to eat the rubber?
  • Where on the gasket should the sealant be applied, only at corners, or over the full length of the gasket?
  • How much sealant should be used?
  • What about the spark plug tubes, should they have a sealant around the rubber rings? Same sealant?
  • What temperature range is the best for the cover gasket sealant in this application?
  • Given the channel (not a flat surface) what the best way to clean out the old sealant without scratching or marring the cover or the head?

Thanks in advance for any help with this!

Pᴀᴜʟsᴛᴇʀ2
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cdunn
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3 Answers3

5

Generally you don't need to use any sealant on this type of gasket, mainly because the gasket is pliable enough and will seal on it's own. If I were going to use any sealant on it, it would be where the rounded part (in the back of this photo) which has a sharp corner:

enter image description here

The reason is, the corner of the gasket is a hard place to seal. Putting a dab of sealant in this spot can help alleviate the threat of leakage. This isn't always needed for any gasket with this same configuration, but it's just easy insurance against leaks if you aren't going to be taking the valve cover gasket off any time soon.

As far as what type of sealant to use, any which is RTV (room temperature vulcanizing) and can withstand oil should work out just fine. The type I'm talking about is like Permatex Ultra Black. It is highly oil resistant and will seal up just peachie.

As a side note, ensure you clean the gasket surface and valve cover really well. I found varnish on the head side of a valve cover I just did which could cause leakage. Cleanliness is next to godliness ... just sayin'. :o)

Pᴀᴜʟsᴛᴇʀ2
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4

You don't need a sealent on this gasket. The new gasket will stand much prouder than the flattened gasket you'll be removing, and the WSM doesn't specify sealent anywhere. Torquing the cover down to the correct spec will create a good seal.

Any existing sealant is probably from an older repair where the mechanic tried to seal a leak without removing the cover. Remove it with a non-marring scraper (plastic or similar - not a screwdriver)

PeteCon
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0

There is nothing wrong with using a gasket sealant on older cars. Yes the gasket from the manufacturer is fine. But the engine isn't brand new, it's old and may have slightly warped or has imperfections. Using gasket sealant just seals away those imperfections.

You just want to put enough so that you can smear it across the full length of the gasket and on the metal so it covers both sides. Temperature doesn't really matter, most sealants cure over 24hrs.

Rob
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