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8.1L driveability problem...engine problem?

15020 Views 22 Replies 12 Participants Last post by  dionysos412, 
mr_udy
My '02 8.1L w/ 36k on it just developed a driveability problem.

Apears to want to stall when slowing to a stop (rpms go below 500) and sometimes feels like transmision isnt downshifting causing the truck to sorta want to keep pushing forward for a brief second.

Truck accelerates fine unless coming off of the stumble where it feels like a sudden acceleration from the brief delay.

Truck idles fine when in nuetral or park (no load).

Woried that it was a tranny problem....but fluid level is correct and looks good-red. I dont believe its been serviced yet...could a spin on filter replacement fix whatever is going on? Thought I may have read a while ago that that can cause driveability problems....

Problem apears to occure when warmed up...but cold out. Might be coincidence as it just started getting cold around here.

Does this sound like the infamous 8.1L crank sensor issue?

I'm gonna post similar message in Allison OEM in case its a tranny problem.
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mr_udy
Damn dude! Thanks....whata I owe ya? :bow:

Sounds exactly what I am experiencing. Only had truck since october so kinda wondering why it reared its ugly head now. Hope it has nothing to do with my 285s I put on a few weeks ago...

I wonder how much dealer will charge for this.....anyone have it done?
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mr_udy
whoops....just saw .4hrs....thanks again
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mr_udy
nah..I think your right. I never actually stalled...sorta felt like it was gonna. I think you hit the nail on the head!

Not sure what to do now since it apears I cant have it reflashed with 285s....or can I? Will it simply relearn speed/rpm relationship if I have it reflashed with the bigger tires? I did have it recalled for 265s when I upgraded to those....ran fine...probably cause computer understood speed and rpm relationship. Now, from what your info said, I bet I am having a problem with speed and rpm different.

Also, this only really seems to happen the last couple days...coincidentally with the plow on. I wonder if it'll sorta go away once the added strain of plow is off....dont understand why that would matter but its worth a try. Maybe additional tire squish from weight of plow doing something...front and rear "rotations" not the same?

I wonder if its simply an annoyance or am I causing damage? If its an anoyance, esspecially if truly only with plow, I can live with it. I dont want to do any damage to expensive tranny though!
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mr_udy
bilcar99: What size tire are you running? What year truck?

Thanks all for your help...I'll post what I find.

I am leaning towards the recallibration. BUT, I'm gonna clean my TB anyway...my old mechanical one on 5.3s always "coked" up...free service. Since I have'nt stalled yet, gonna save the crank sensor for last. By the way, where is the crank sensor? Front? Easy replacement?
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