Engine sound - experts please weigh in here....

[JasonMcNabb]

Okay, I have a strange engine sound on my truck. I am open to suggestions and advice here.



My 05 has just passed the 200km's but now I hear what sounds like old fashioned v-belt squeal while driving down the road under part throttle. Nothing can be heard while coasting (in gear but foot off throttle) and nothing can be heard under accelleration 7/8 throttle or better.



This higher pitched faint squeal or chatter? or clatter? can only be heard under moderate load (level highway travel). Lift pump pressure seems unchanged 15-17 lbs and exhaust and boost show nothing strange.



Removed the acc belt and spun by hand the idler, the tensioner, and all accessories. Belt is less than 20k (was new in Jan) All seemed fine. Valve adjust was checked at 175k and all within 0. 002 of spec.



Rail pressure gauge is ordered, but may not get installed right away.



Thanks in advance for comments.

 

[Wingate]

I'm no expert, but have you inspected ALL of the inlet air piping, boots, and intercooler for leaks? Kinda sounds like a pressurized air leak. Possibly a rupture in the intercooler???

 

[JasonMcNabb]

why didn't I think of that

Well, I admit I did not check for leaks in the piping or cracks in the intercooler tanks.



Why would I not hear a problem at full throttle load if there was a leak somewhere? Anyway, still a good suggestion.



I'll check and post back this weekend. Thanks. Oo.

 

[p-Bar]

I'm with Wingate . try spraying shaving cream around all your connection and watch for air leaks

 

[Tinman]

I didn't get one of my IC boots tight enough after my IC and cam install. Sounded just like a belt scream. I replace the belt before I found the offending boot clamp. Give'm a good look see.

 

[BLNRAY]

shaving cream????????/