Yeah, that's a combination of heat, age, and weathering. Not really unusual. Time for them to be changed though.

 

So hopped in the truck this morning an CEL came on... Just got done running the scanner and PO720 came up.... I just changed the speed sensor recently, it's not like I can install it wrong??? Out with the old, in with the new, bolt it back down. Got the part from a local dealer. Any chance it is just a bad sensor? I still have the receipt to exchange it but the dealer is closed until monday morning.

I just got home and I am going to take it out and re-install it and then dissonnect the battery for 5 mins.

Last time just my brake/ABS light came on. I did disconnect the battery for 5 minutes. Also last time, just my cruise control did not work but truck ran fine. Now it seems like she shifts really late when I'm on it and fine if I baby it...

Thoughts?

TIA!

 

Which sensor did you replace? The one on the diff? or the one on the trans? I would make sure you were sure which one it was whining about.

 

Well, seems like this is snowballing now. Got under the truck to remove the speed sensor and it was a bit loose. So I cranked it back down, and unplugged battery negative for 10 mins. Check engine light popped right back on. Went to Advanced Auto to have them scan it again just to make sure I didn't miss another code, all it was pulling was PO720 again. I guess I gotta return it to the dealer on Monday...

Now after I reset computer, the truck now stalls out while going in reverse. If I don't give it gas, she will back up fine and not stall out. If I give it gas, she will stall out, unless I keep on the gas and nurse it back. No problems with driving and coming to lights, idles fine, just a hair over 600 RMPs and steady. Any thoughts on this? Could this be bad gas? or a plug going?

Still have the higher shifting of gears, which concerns me. Trans seems to shift fine, just at higher RPMs now...

 

I changed the RWAL speed sensor. Would the trans speed sensor stop my cruise form working like the RWAL?

 

Make sure the sensor is seated all the way down. Needs to be pretty close to be accurate.

Does the light come on before you start moving? If it does, you have a wiring problem, (or, the sensor could just be defunct....)

Does your speedo work?

So far as I know, cruise gets its cue from the same place as the speedo, the rear wheel speed sensor on the diff...... shift points and such are influenced by the speed sensor in the trans.....

 

i attribute all idle related problems to either TPS, IAC, or clogged IAC port on the back of the throttle body. its a crap shoot on which one, and i often replace both. which is why i have a supply of good used ones that can be swapped in (as in - the last time this happened it wasn't the problem).

IAC port can be cleaned out by spraying in a little brake or carb cleaner (don't get too much down in the plenum) and wiping out the well and poking out the little hole with something soft. there is no need to remove the throttle body.

edit - you can reset the pcm instantly by removing neg battery cable and turning on the headlights for 30 seconds to drain the pcm capacitors and memory. it won't hurt it.

 

Thanks Guys,

Just an update. Seems that the RWAL sensor was a bit loose. I cranked it down now and will check it in a few days to see if it loosens. My cruise control now works fine. Pulled the Trans speed sensor and it was filthy with like caked on fluid, no metal shavings or anything. I changed it with a new one anyways. CEL is off and she shifts like never before! Smooth baby!

Thanks!

 

Dhvaughan- seems like sensors are going on me, since I hit 100k. I will be looking into other sensors next.

Thanks

 

She is eating oil now at a good pace. I really wish I had the ***** to tear into the top end. Anyone close that wants to help?

I still have the ebay plenum plate, just gotta get the bolts and gasket kit.