Guys this is really scaring me. Ok, last December I got a gryphon and waited on my custom tune. Stock, the truck ran and runs fine. After getting my custom tune in March (87 performance) I noticed a weird pinging sound? in the rear of the truck. I really have no idea how to describe it. It's like something metallic is being rattled around back there near the tires (my exhuast exits 45'd behind each rear tire fyi). It sounded like something was making some noise back there when I accelerate onto faster roads and the highway - say 1700rpms+. It's done this since the tune and it seemed like the rotor shield on the brakes rubbing since I know the front does it at times. I've been getting more and more nervous about it and just under an hour ago I set the truck back to stock for the first time since loading the tune. It didn't do it. Guys I floored the truck. It sounded better actually and while it didn't have the same custom tune aggressive idle and such, it failed to make that noise. I tried it 2 times on stock and 2 times with my tune and only in the custom tune file did the truck make that noise. I hammered it up hills where I can usually really hear it... nothing.


So wtf is going on? I am leaving it stock until I get this figured out. I've put a few thousand miles on the tune and now I'm worried. Is it detonation? Any ideas???

 

My suggestion is go to the PHP website, in the help forums and re-post this and/or email them. They're the experts, they wrote the tune, they can help you I'm sure.

http://forum.gopowerhungry.com

Of course it goes without saying you should have done this when you first realized there might be a problem, like 6 months ago.

Just my .02.

David

 

John, it could be detonation, but that sound would be from the engine, not the rear of the truck. I have no ideas except to get hold of Bill and describe this problem to him. Please note that PHP now has an online support system that may make getting hold of him easier. You sign into it here: http://www.readydeskhosted.com/phptu...r/rdlogin.aspx

- Jack

 

I posted in the forum but I will do this Jack. I know it might have been a good idea to do it earlier, but the truck runs fine. That sound is the only thing.

 

Have you tried premium gas?

 

No I have not... talking via online chat now with Corey and BIll is joining in she said. I will report my findings

 

have you done any datalogging??

 

I haven't actually Jerame... Bill thinks it might be mods to cam timing and a slightly advanced spark timing.

 

Good to see Bill and Corey are helping you.......

 

same thing I'm thinking which is why I was wondering if you did any datalogs for him to review

 

He checked it over and said it would be ok to keep running it. He will revise the tune when he reaches me number so know it's just a waiting game

 

I'd put some premium gas in it till it's fixed - pinging and detonation will eventually burn valves and pistons.

 

I run 87... what do you recommend... 89 or 91/93?

 

try some 93 and see if that solves the issue

 

I'll do that... I'm on the ****ty stock tune for now though. I have 3/4 of a tank of 87 left