Brubro67

Not that I can tell. Runs great overall. Had boost leak issue with '98.5 that I owned prior to this one. That was obvious and I still have my homemade intercooler pressure tester. Haven't bothered to test that since it runs so well. No drop-off of performance at all. It really sounds surprisingly like a loud cricket. It happens when accelerating, and I can make it stop usually by backing off the throttle. If I accelerate slowly, it usually doesn't happen. Sometimes it is normal under moderate or heavy load too. Truck is used primarily for hauling 10K loads on average, but it also does this when unloaded.

There are no error codes. Injector pressure is fine per Ultragauge info. Injector line hold downs are fine. No fuel leaks, or other obvious problems. I haven't tested lift pump pressure, but there is no delay in start (extended cranking) etc. BTW, truck has about 160K, only mods are aftermarket exhaust that I know of. There is nothing obviously modded other than that. Link on testing fuel pressure? I will do a search when I get home if you can't. Thanks!

Hello, I have an odd buzz or hum coming from what appears to be under the driver's area hood which projects through the driver's side dash. It sounds like a relatively loud high pitched cricket buzz. It started under load, but sometimes continues (more often now) during constant throttle. If I back off on the throttle, it most often stops. It seems to be increasing in frequency but sometimes does it very little. Since it happens only when driving, I can't pinpoint the issue. It is definitely not loose metal, heat shields, exhaust, etc. It seems electronic, tied to throttle response. I've searched on line with no luck. Any ideas?