'98 Duratech O/D indicator flashing

After car has been running for 10-15 minutes the speedometer will start hunting (RPM's remain stable) and then shortly thereafter the O/D indicator will start flashing. Shifting will get a bit rougher than normal as well. If I'm in cruise the car will surge somewhat.

Does this sound like the VSS problem I've seen in other posts? Haven't had a chance to get any codes yet. Thanks for any help!

Does sound suspiciously like a bad VSS or connection to it. I'd suggest getting the transmission codes read though before shotgunning the VSS.

Since the O/D light was flashing rather than the Check Engine light, the generic OBD-II scan tools that the parts stores use probably won't be able to find any codes related to this issue. Rather, you'll probably need to visit a transmission shop, dealership, or independent shop with a professional scan tool and the software to read transmission codes.

I'm not sure a VSS would cause only a transmission code and not a powertrain code, but I'm not sure what else in the transmission would cause the speedo to fluctuate either, unless you have an issue with the Transmission Range Sensor.

-Rod

I have been through this.

A Generic OBDII scan will probably give the code , I can't remember, for a bad shift solenoid.

It may be as easy as that because the OD solenoid does not get much cooling and will overheat and malfunction first.

Or it could be the actual valve is bad.
Another potential problem is the Clutchpack

Mike
:smokin:

Hi all,
I had a chance to run some diagonstics this evening. Took the car for a drive down the highway and as expected, about 15 minutes into the drive the speedometer starts fluctuating and then the O/D indicator starts flashing (no check engine light). I misrepresented the shifting issue before. It seems to shift okay, but at higher RPM's. I'm not feeling any clunking or shift problems you would normally associate with a mechanincal problem.

There are no diagnostic codes, at least none that show up on my meter. Now here's the kicker-if I pull over and turn off the car and restart, the O/D indicator turns off and the car acts normally again for another 15 minutes. It seems that would rule out a thermal issue since the car is already warm when I restart. Transmission fluid seems okay as well. Would it make sense to do an ohm test on the VSS as my Chilton manual describes? Any other thoughts on this one?

If you can get to the VSS to do the ohm test, I'd suggest doing that as well as removing the VSS, connecting it to a variable speed cordless drill, then monitor the DCV output while running it from very slow to the max speed of the drill. See if there is a speed where the DCV seems discontinuous.

Are you always getting to a certain speed after 15 minutes of driving by chance to where this may be a speed-related issue rather than time-related? For the amount of frustration this could cause to get to the VSS (I haven't checked the manual for the location) it may be worth the expense to get the transmission codes read.

-Rod

I don't believe it's speed related. I was cruising at 70 for about 15 minutes when it cropped up. Another time I was just driving around town at city speeds and it popped up about 15 minutes later.

Yeah, the manual says you have to disconnect the catalytic converter y-pipe to get to the VSS. I haven't crawled underneath yet, but I can only assume it's going to be a bear to get to. If I can't get to it easily I'll bring it in to get the transmission trouble codes. Unfortunately it's going to be a couple of weeks now before I'll be able to get back to it. Good thing I live close enough to work to bike and have another car! Will keep you all informed, thanks again for the advice.

I posted a resoloution to my problem, but it disappeared from the forum. For those wondering, it was the VSS. Brought it to the shop and the mechanics had to break it apart to get it out as it was so badly rusted. Said I would have ruined the transmission trying to get it out myself. Ran about $300 which I feel is good for transmission work. Thanks all!

Right, I remember seeing your post about the tranny shop saying you wouldn't have been able to do it from home. I don't see a message that a post was deleted. Weird....

-Rod