So much for getting your question answered. I went through this on a tuned pipe and here is what happened. I was using the little blue tube of "Permatex High Strength Red". This works good on most areas and is questionable around heat even though the heat rating is high.

This was not working for me because when this stuff gets hot, it liquifies and becomes useless-----so I was told to use Permatex "Sleeve Retainer". It is still in an identical little blue tube like theother but says "Sleeve Retainer" on it. This is used for sleeve and bearings and such. You will notice that the temp ratings are almost the same but does not liquify for some reason and works great around the engine and is only a few dollars.

You should be able to get it at a NAPA. I could not find it at stores like Pep Boys, Checker or Autzone although they had the regular stuff but not the "Sleeve Reatiner. This should cure your problem