My boss has an 03 that has developed a really LOUD clatter. It began only at start up a couple of weeks ago, but has progressed to a full time noise, no matter engine rpm.

I took a broomstick and used it for localized listening around the block and it sounds the loudest around the exhaust manifold at #3 &#4 cylinders. I have a sneeky suspicion that an exhaust lifter has crapped out and letting the exhaust valve come and go based on compression. Any input or comments? Maybe even a valve spring has bit the bullit.

Replies are appreciated.

Gary

 

Probably a valve seat or an injector.

How many miles on it?

 

It has 297,560 miles, mostly highway and little load pulling.

Gary

 

Are the injectors stock?

 

There is not an aftermarket part ANYWHERE on this truck.

Gary

 

Sorry I meant original.. but if they are it's a good chance that's the issue.