Turbo spool question! - Diesel Forum

dustymoran · 01-30-2007, 10:51 PM

Everyday on the way home from work I have to climb a very large hill that is pretty long, and I have to start up it from almost a dead stop. Here is what is wierd, if I lug it up the hill and shift before I hit 2200 rpms all the way to Overdrive I can slowly push the throttle down and accelerate fast from 60mph (1700 rpms) and you can really hear the turbo sing. Or if I cram it up the hill just running it pretty hard I can hold it in 4th gear ( the gear before OD) and really make it scream and throw me back but then when I hit Overdrive at 65mph or so it doesn't seem that I can build any boost no matter how much I mash down the throttle and it will just hold constant speed up the hill and It cannot gain any spead while in OD. But normally if I take it easy up the hill til I get into OD then I can tap it and go from 60mph to 80mph really quick. I have noticed it twice but today it was worse than normally. I was thinking it might be something with the VGT not reseting the vains once I drop Rpms again. Has anyone else had this problem or does everyone else just have automatic trucks?

gone9camping · 01-31-2007, 09:20 AM

I have an automatic and my Turbo will Scream while pulling my 5ver on an incline. Also it's done it when I stop at a stop sign, like at an exit ramp. I think this is normal I don't know for sure. [img]/ubbthreads/images/graemlins/shrug.gif[/img]

craigwe · 01-31-2007, 09:21 AM

next time it happens, let completely off the throttle, pause and then roll back off.. i think its the vanes sticking, and by you giving it more throttle they will never reset... when you let off and then roll on, you will here to turbo spool up very fast to get into sync with the rpms, load, etc..

dustymoran · 01-31-2007, 03:28 PM

The last time that it happened I tried that and it didn't seem to help. I let completely off of the throttle and it still didn't build any boost when I reaccelerated. Today I climbed the hill from a dead stop, I shifted into 4th from 1st gear at 10 mph, it lugged for a second and then built boost then I shifted into overdrive at about 35mph and It barely lugged, then the boost came in and I was up to 65 in no time at all. It doesn't make any sense unless the vanes are just sticking all the way open after I boost it hard in 4th before goin to OD and then it just boggs all to hell, but if I lug it down in all the gears til I hit OD it will build all kinds of boost up the hill even at 1200 RPMs and it picks up speed fast up the hill,and this is a prety good sized hill.

dustymoran · 02-09-2007, 06:20 PM

Ok I am certain now that my vanes are sticking, I now have a boost gauge and can clearly see that if I build full boost in 3rd or 4th gear which is close to 30 psi, when I shift to the next gear it has no power at all and will not build any boost until I let off the throttle until the engine fall down on rpms a lot. I have been driving it hard trying to burn any crap out of there but I think the problem is problem rust or hard coke deposits. Is there anything else that can be done short of taking it back to the dealer for a new turbo or tearing into this one and cleaning it. My truck only has 45,000 miles but I hate to loose it to the dealership for a week to have the turbo replaced.

modifiedoneton21 · 02-10-2007, 04:19 PM

Better find a different dealer.. After diagnosing the problem I dropped my truck off the night before, so it would be cool for the tech and had it back by 10 A.M. He told me it takes him just under 2 hours to RR a turbo. I think the book says more so they get their money..