RPMs 1996 Windstar GL 3.8L

Within the last week my RPMs seem to bounce back and forth between 1700 (where they normally are at 90km) and 2000 RPMs. They do not do this constanty and actually seems to be very random. I cannot do anything in patricular to duplicate this (I thought it was my A/C fan causing it to do this but then it repeated this abnormality after the A/C was turned off). It may happen for a 5 minute drive then not again for a few days.

We have replaced the transmission range sensor within the last couple of months as the transmission was "dropping" 3rd and 4th gears occasionally, which did solve that problem.

Any ideas on what may be causing this new issue?

Thanks,
Naomi

Sounds like its downshifting. If your going up a slight elivation and it shifts once, then I would think its normal. If you have multiple shifts then this could indicate a problem aka hunting. Could be a torque converter issue?

Naomi

Try taking it out of OD and see if the RPMs stay constant.

Regards

Dan

I have tried driving at 90km and taking it out of OD but the RPMs still fluctuate by approximately 200 RPMs. Driving at 90km, the RPMs still go up to around 2000, stay there for a few seconds then come back down to around 1700-1800. They will stay there for a few seconds and repeat the same thing again.

Also, when I first start the van for the first time that day, the RPMs go to 2000 (after reaching 90km) and stay there for a couple of minutes then drop down to the normal range. It will stay in the normal range for a while (amount of time varies) then it will begin with its attitude.

Does anyone know what this means, how to fix this, and if there is some type of transmission additive (some type of antislip fluid, etc.) that I can do to stop this even, if it is only a temporary fix, as I cannot afford to replace the transmission right now.

Thanks,
Naomi

Hello

Is the engine speeding up (can you hear it going faster?) or is the tach just showing higher RPM?

Dan

The engine does not seem to be speeding up at all, just the tach going about 200 RPMs higher.

Also, the issue with the RPMs staying around 2000 for the first few minutes of driving time just started after my husband installed the new transmission range sensor. Is there any possibility that this new sensor might have something to do with the problem (connection not tight or something like that?)???

Naomi

Anyone have any ideas on this?

Naomi

There may be an intermittent connection issue. Was the connector (on the body harness) cleaned and resealed with silicon dielectric grease when the neutral safety (TRS) was replaced? Did you also check the valve body electrical connector in the top of the transmission?

I would suspect the phenomenon is less likely the trans shifting from D to OD and more likely the TCC lockup/unlock. It is a lot easier to tell (by ear and feel) if the range changes from OD to D, while the torque converter clutch operation is far more subtle, and would account for the relatively small difference in RPM change.

I'll check with my husband as to whether or not the connection was cleaned and resealed with anything when he gets home tonight.

As far as the transmission shifting...it doesn't feel like it's shifting into OD, the change in RPMs is not that much because when I push the OD button, the RPMs go up to around 2300 or 2400 (if I remember correctly) and this intermittent problem only shifts up to around 2000.


Naomi

My husband says he did not reseal the connector after he replaced it and will look into this on the weekend.

What is TCC lockup/unlock?

Does anyone have any idea on how much the torque converter clutch would cost and can this be replaced by a DIYer?

Thanks,
Naomi

My husband says he did not reseal the connector after he replaced it and will look into this on the weekend.

What is TCC lockup/unlock?

Does anyone have any idea on how much the torque converter clutch would cost and can this be replaced by a DIYer?

Thanks,
Naomi

Naomi

TCC is Torque Converter which is part of the transmission. Cost would be around (just a guess I've never just replaced one) 200.00 -$300.00.

The transmission needs to be pulled to replace the TC.

Regards

Dan

Thanks for all the information everyone. My husband is going to check the connection this weekend. To make this more of a mystery, I drove the van around yesterday and after my initial start and drive for about 5 minutes....the RPMs did not fluctuate again for the rest of the day!!!


Naomi