My 90SE seems to think it's a popcorn maker. Here's the catch though. It only makes this tapping noise when the following conditions are met: 1.the outside temperature is at least 60F. 2.only at speeds between 73 and 85 mph. 3.only when there is a demand on the engine, (no noise when coasting at these speeds) it sounds like its coming from the front right of car. No one seems to be able to figure this out. ANY IDEAS or PERSONAL EXPERIENCES WELCOME

 

What octane gas are you using and have you checked your timing?

 

I only use the best gas, 92 or better. And I had a mechanic check the timing already. any other ideas? Both of these were good suggestions because i know that if I don't put the best gas in it runs like crap, and i mean crap!! thanks

 

I'll take a stab. Could possibly be a sticking valve. Does the engine miss when those conditions you mentioned exist.

 

Does it happen when you're parked?
Is it similiar to the issue addressed in the FAQ?

I remember one day someone warned me about it while I was driving (how kind )

 

have the mechanic check your exhaust manifold studs.. usually that just happens on a cold engine, then goes away after 2-3 minutes, but it could also happen on the highway at speed.. you're just not likely to hear it unless it's really bad.

 

No, I don't believe it sounds like a valve. Thanks anyway

 

Well actually I had Nissan look at it and they agree with you, but I thought that it just didn't seem like a good diagnosis because i wondered why it would do it at highway speed and only when it's warm outside. So you think that this is my problem, because now i think i believe them.

 

it sounds like an exhaust leak to me. You might want to run a heavier oil just to make sure its not something in the engine, but my moneys on the exhaust.

 

I agree, thanks for the info