1996 winstar shudders

My Windstar GL 1996 3.8 with over driver will shudder at 80 km per hour. If you watch the tack at that point it will move up slightly. It is pronounced when the air conditioning is on and feels like it is cylcling on and off. It is not noticed at lower speeds and almost never with the AC off. Vehicle has 123,000 on it and the trans fluid smells good and looks perfect. Also when it is idling with the AC on it will stall even sometimes when im at a light, but it always starts right back up. Any idea about these two issues?

Thanks

Randy

My 97 does the exact same thing.
I have not figured out what is the problem.
Have you found any info?

No i havent as of yet....could be some kind of sensor for the idle issue. I dont want to mess with anything till i have some idea

try fresh plugs, wires. a poorly running engine can make a tranny act funny. clean the IAC to address stalling

THe computer will unlock the torque convertor when the AC compressor is to come-on, thereby reducing the added drag normally associated with the initial compressor load. This results in complaints of trans slippage and tach increases. The OEMs really can't win. The only way to stop it is to reprogram the computer and I don't think a special chip is abailable for the Windstar. If it happens with the AC off, that's another, serious issue. As for teh idle, I would clean or replace the bypass valve and thoroughly check its connections to make sure there is good contact. As long as there are no vac leaks, this should cure the stalling problem.
Marc
98 Windstar
97 SHO

well the stalling issue is fixed, turned out it was a small "L" shaped vacume hose. Replaced that and it idles fine and hasnt stalled yet. The shuddering in the transmission seems now to only be when the AC is on and it happens a lot less now that the vucume line was fixed. I can feel just a twinge around 80 Km/hr (50m/hr) I will keep an eye on it but i hope this issue is done

I hate to admit this but I had overcharged my AC and that loaded the compressor something awful - enough to drop my mileage to 13 MPG. If your AC wasn't frigid and you added a can without using gauges, this could account for the shudder.
Just tossing possibilities out there. The AC is coldest at recommended charge and warms significantly whether charged high or low. I learned that the hard way.
Marc
98 Windstar
97 SHO

no the AC has not been touched and it works fine. I have noticed the shudder with the AC off so its not the compressor cycling. The shudder is between 80 and 85 Km/hr and will happen approximately ever 8 seconds or so untill i accelerate to 90 km or higher or drop down below 80. I also know it is not the transmission dropping down out of D/D to third because the tach jumps only about 200 rpm if that when it happens. Man i hope its not a real issue. It dont bother anyone else in my family but bugs the crap out of me.

I know it is not a Windstar but my 96 Contour does the same thing at 80 Km/Hr. Also when I accelerate slowly from a stop, the engine shudders slightly, kind of makes the car lurch slighty.

I was told at the dealer a few years ago that it was typical of the 96 Contour. Something about the transaxle locking and un-locking at that speed.

I'm still getting this to happen and I've just wrote it off as the nature of the car.

TaiBo

Have similair problem. At 70km/h when the tranny wants to shift from 3 to 4 gear it shudders. I usually take of my foot from the pedal and it shifts to 4, then accellerate.
Worse thing is that sometime after I start the engine I have to use some force to switch from P to start driving. Its happens rarely but it worries me.

Thanks for help

Windstar 3.0l 97

I had the shudder also on my 97 which was like driving over a washboard type road while the torque convertor was locking up.
The shudder was caused by the torque convertor not smoothly locking up due to aged trans fluid. I had the trans fluid flushed and had a can of trans fluid conditioner made by Wynn's added at the same time. It corrected the problem right away , although I was told it may take a couple hundred miles.

good idea cougarman...i will definately try that

Man this gets stranger all the time. I have always thought the shudder in the tranny is somehow linked to the AC given that it is really pronounced when the AC is on. Well figure this one out...Im driving 80-90 km/hour (50+ mph) and i turn the temp control to cold and then the defroster on and guess what the tranny shudders..i turn it off..the shuddering stops... How in the hell is the fan or defroster linked to the AC compressor. That is the only thing i can think of. Everytime i turn on defrost it shudders then stops then shudders etc...turn it of..it stops.

This is annoying

randy

the defrost turns on the AC compressor to de-humidify the air.

I had posted something similar last week with my '03.
With the A/c engaged, and foot on the throttle, I can see and feel the RPMs shoot up about 200-300 every 14-18 seconds. I'm assuming this coincides with the cycling of the A/C compressor. It feels like a downshift/upshift in a matter of a second. This causes like a "shudder" This can't be normal because it never did it before a month ago. Windstar has got about 36k miles on her. I took it to the dealer since it's under warranty and they will have it all day Wednesday. Let's see what they come up with.

Amantalv, thanks for the post...please if you find out anything let me know this thing is really annoying me. Good luck with yours too

OK..they had it all day Wednesday for nothing because I left them the Explorer key instead of the key for the Windstar! Anyway, they took care of it on Thursday. It ended up being an O ring in A/C system. Refrigerant leaked out enough to where it was running low and the compressor cycled on and off more than usual. This apparently causes this upshift/downshift in this tranny. Weird if you ask me. My explorer A/C has problems too and thank goodness I don't feel the same thing with the tranny or else I'd flip.