Need some help!

[Danboquist]

Okay to start off the truck is not throwing any codes except for a p0118 which is coolant temp sensor circuit high which I don’t think is the cause of my problem due to that code being there for a little over 6 months. I washed the truck this weekend and as I was driving around a little bit after it wouldn’t go past 60 then 45 then 30 and now 18 without the rod shooting up like I’m just reving it. It don’t accelerate until after 3,000 rpm’s. What could be the cause that I’m not thinking of? Could something have gotten wet? If so what? Also it will get up to 60 just high rpm’s past 3000 to get to that point. I’ve done replaced the fuel filter, air filter, replaced the EGR cause it threw I code for that yesterday still no fix. I also took the MAF sensor off and cleaned it.

Replace the coolant temp. Sensor. Cheap and easy. Confirm or eliminate it as a contributor to the problem. You do have the code anyway.

 

[1998_K1500_Sub]

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That flare-up around 22s into the video is disconcerting.

Earlier in the video, it appears the shifter is in OD. You're apparently "light on the throttle" at times (the exhaust note falls and rises, so I assume it’s because you’re changing the throttle) and yet the transmission didn't upshift.

 

[1998_K1500_Sub]

In the video, the engine RPM is about 3000 at 30mph, 4000 at 40mph.

You truck’s probably like mine with 3.73 rear gears. I calculated a few numbers for what my, and thus your, engine RPM would (should) be at those speeds with an 4L60E transmission… and your engine RPM isn’t where I think it should be.

At 30mph, my engine would be at ~2150 in 2nd, ~4120 in 1st. Yours is around 3000.

I think your transmission is slipping.

The engine RPM flare-up around 22s in the video also suggests the transmission is slipping.

Whether the transmission’s behavior is related to the “car wash” or simply a coincidence I can’t say.

IMHO amount of slippage indicates the transmission is in need of professional attention.

Let’s see what others say

Maybe @NickTransmissions or @tayto will comment.