My ol Lex has had this tapping noise eversince I bought it which I know is common in the higher milage V8's. I'm 99%sure it's the valves as you can hear them very well towards the back of the engine on both sides. I read once that there is a fluid you can put in your oil which will make the sound decrease for a bit depending on the severity. ANyone know what type of fluid this is?

Along with that there is a much louder ticking under acceleration and sounds to be coming from under the car upon closer inspection. Exhaust manifold gasket perhaps??

 

bump

 

What type of oil do you use?

 

5w30...should I try 10w30??

 

Yes, try using 10w30. I would have suggest 10w40 or 15w50 but since its freaking cold already, use Mobil 1 10w30. Its not the ultimate solution but it will help for now. Caution though since you have a high mileage car you might develope an oil leak. If you do, try mixing it with 10w30 coventional oil and synthetic. But i have been using it for years now and never had any oil leaks from my cars including my 370,000 km 1991 nissan sentra

In my 300zx I had that tapping and ticking sound, so I used Mobil 1 15w50 in the summer and never heard of the sound again.

 

merci beaucoup. I will try that asap. I might try just regular 10w30 forst......I had the bad leaky problem with changing to synthetic in a previous car with high milage....but I might give it a shot

 

http://www.cureline.net/lex/howtos/i...ing_engine.htm