Engine/Transmission (1998.5 - 2002) High Boost on Stock Truck

[seagrave2001]

My truck has been running fine ever since I got it and put a boost gauge on it... And the highest I ever got it was 21 - 22psi at WOT. The one weekend I was towing 4 quads & a bed full of coolers & camping gear. . Well some of the hills in Pa going up to Potter County are pretty big and it was moving up them and at one point my truck hit 26psi and when i got to my destination I checked for a over boost code & found nothing... Is this alright that no code was set, or could there be something wrong or altered with?

 

[Challenger-II]

DITTO!! :{



My stock 99' truck is doing the same thing... . AGAIN! The last time I was over-boosting, the dealer replaced my turbo because the wastegate isn't serviceable. I was setting codes for over boost back then. Just this week I notice that under heavy acceleration, I can reach about 24-25lbs. Before, no more than 20lbs.



I haven't checked for codes yet... will do it tonight. Anyone have an idea what would cause this? I'm thinking a sticky or sluggish wastegate?

 

[Challenger-II]

Yep!!!..... checked for codes last night and sure enough, over boost codes were set! :{ :{



How about it guys..... anyone know what would cause a higher boost on a stock truck?

 

[CTLindsey]

I don't mean to hijack your thread but I have the same truck and can't get over 16# of boot at WOT Are you saying you were getting 21-22 normally?

 

[RJPotts]

I'm not sure why it would throw an over boost code but, here's a quick lesson in turbos considering you have no other problems.

OK, your turbo's turbine is spun by exhaust heat (not exhaust gases), this heat comes from burnt fuel. When you're towing your truck requires more fuel because it is under more of a load than running empty.

As for why its doing it now and never has before, without any diagnostics tools, or being able to see the truck I would guess air quality has something to do with it, MAP sensor may be going bad, or a few other things.

I would check the MAP first, it is what is saying the truck is doing something wrong when its still well within its limits.

Hope that helps,

-R. J.

 

[Graphic man]

for everyone it sounds like a stuck waste gate to me!!



my truck did the same i can hit 40-42 with a comp on 5x5 and a stock HY35

but thats a little high



SoCalShark

i would check for boost leaks go over and tighten all clamps and check boots for and holes and cracks

 

[Challenger-II]

for everyone it sounds like a stuck waste gate to me!!

I agree!!! I sprayed some WD-40 on the pivot points of the wastegate where it goes into the turbo and now I do not exceed stock boost levels anymore. Easy fix this time. It appears it was getting stuck and not dumping the boost when it should have. Gotta love WD-40! :-laf