..So this happened last night to my wife's '01 T/A WS6, 70K on the clock..

She's going back to work from lunch yesterday, on the local highway (I94E for you Michiganders) when "something" from the truck in front of her (maybe) bounces into the undercarriage of the car. She felt and heard a distinct "thud". The car immediately starts to skip, and then clears her throat, no problems the rest of the way to work.

As she's coming home, the car starts to bog on throttle application, and she says the car starts to shake, and lose power, and the tranny won't upshift from 2nd to 3rd. Fearing a meltdown, she pulls into a parking lot and calls me.

I check all the fluids, all good, tranny's nice and pink. start 'er up, select D, and creep about the parking lot. At idle, brake on, the car surges back and forth; with part throttle, alot of bucking and surging, 1st, 2nd, and 3rd gear shift points are waaay up there. I managed to limp her home, with burning tranny fluid filling my nose.

I couldn't find any indication of physical damage underneath when I checked her out last night. SES light did come on, and would flash periodically during the ride home last night (low power mode the whole way home). Never got above 35mph (didn't want to risk any more damage).

So; any guesses as to what might have happened? I'll be examining the car in detail later today, but I suspect I've lost the transmission.

Oh, and you tranny vendors who regularly post here, we'll be talking soon..

 

First i would recomend take it to a local shop that has a scan tool to see what the codes are. Also what does the tranny fluid look like now after the drive home? Not sure if you indeed have a tranny issue sounds more like a tune/elec. problem. Check that out first and go from there... keep us posted.

Patrick@Century

 

I'll be swinging by my local Autozone and picking up a scan tool. Gawd, I do hope it's electrical! that I can fix! cheaply too! Thanx for the suggestion.

 

I bought a used engine/trans for my v6-> v8 swap a few years back. The front edge of the tranny pan had been hit and mashed in a bit, and later pounded back out. However, the internal wiring harness had been pinched in the initial impact, and one of the wires was broken inside the insulation, making intermittent contact.

 

I am also not so sure this is a tranny problem the description sounds moe like a running issue, And these things can and do affect trans function

 

UPDATE:

After work I picked up an Actron Autoscanner from Autozone. After another inspection, where I still didn't find any physical problems, I hooked up the scanner and pulled off two codes:

PO135: o2 sensor heater circuit malfunction, pre-cat, left bank
PO0300: the good 'ole "random misfire detected"

On a lark, I check the tranny fluid again. It's halfway up the dipstick, waaay past any cold/hot settings. so, there's definately too much tranny fluid in there. that's one thing. The Book says an overfilled transmission could cause bogging and lurching; could that trigger random misfires though?

BTW, it started up and idled fine. Only when I gave it gas did it start misfiring again.

Any ideas?

 

it possible snice u got a 02 senser code it could have hit the o2 senser causing problems and that and will cause a misfire...

 

Did some more reading from the more experienced (read: older) forum members, and there seems to be a correlation between a busted O2 and random misfires. I did a real-time recording of the car while running, and yep, the pass. side front sensor's voltage isn't cycling at all. Dead. Soo, I'm going to run out and get some Corvette rear o2's, which burn hotter sooner, and replace both of them. Rear o2's are sims and they are fine. fingers crossed! Gonna drain a quart or so out of the tranny too.

 

I bet money that there is nothing wrong with the tranny at all. Its all because of the bad 02 sensor.

 

change the sensor, i had to last week. mine was about to die, then the ses light came on and it was the sensor on the left bank

 

I agree, I was thinking it was an 02 sensor from the first several sentences. Bob

 

There is good advice here. When diagnosing any automobile Driveability issue it is very important to resolve the obvious issues first. Sometimes the obvious components do not seem like the correct avenue to pursue, but you gotta do that each and every time.

An O2 Sensor has a very broad range of authority over the fuel management system. There is no doubt that this could easily resolve your issues. Be sure to inspect the wiring harness very well.

Good Luck and get back to us!

g

 

SHE'S ALLIIIVE!!

This afternoon I replace the O2's with new Corvette rears, and ran engine cycle test. The O2's worked fine, and LTrims, voltages all within parameters. I run up the throttle, and dangit, SES dashes my hopes! Scan the code immediately and find "misfire in #6" staring at me. Okay, we went from "random misfire" to identifying a particular cylinder. Shut 'er down and tear into the engine.

I pull the #6 plug, and lo and behold, the diode is bent and the sheathing is cracked to hell! Turns out my wife's fantastical story of jumping roads and things flying into the undercarriage might be true..So, after replacing the plug and also dropping a quart or so out of the tranny (overpressure's bad, they tell me), we go for a little jaunt down the highway. Running like a scalded cat, she is!! Thanks everybody for the tips and suggestions. Here I thought my tranny had taken a **** on me, when it turned out to be electrical after all. See you on the Road!

 

Glad to hear it was only a sensor. That's a lot cheaper than a tranny. I will definitely keep this event in mind should my engine go into the limp mode.

 

UPDATE: The wife went North today in the WS6. 300 miles, nary a hiccup the whole way. Even the gas mileage went up! We were averaging 250 miles to a tank; this trip, she used a little over 3/4 of a tank. Goes to show, maintenance pays!!