Noise when coasting from 40 & up

[Parainvestigator]

Hey guys...
Here's my problem; 2000 windstar. After getting on the highway tonight, each time I would let off of the gas I could hear a loud noise as I was coasting. It sounds like a bearing noise from the engine compartment. As soon as I touch the gas, it goes away. As long as I'm on the gas, it's not there. While sitting at idle and reving the engine, it's not there. If I drop the trans into nuetral while hearing the noise, it goes away. I just had the transmission relaced in December after it blew up. Am I looking at another transmission problem? Any help is apreciated.

[huskerdooo]

Please let me know what it is, mine does the same thing! I figure it is a bearing thing or cv thing.

[Ed_Strong]

I would go back to the place where you had your tranny replaced and explain it to them, then make sure they can pin-point the problem. Don't take any guessing from them, that would just mean the possiblity of them to start throwing parts and money to try and fix the problem.

I just wasted my time and money on a wheel bearing that did not need to be replaced. I made the wrong assumption and paid the price for it... worse the problem on my van is still there and I can not make sure where the problem is. Would like to take it in for a diagnose, but now I'm short on cash and don't know any good thrustworthy mechanics on my side of town.

[garync1]

Originally Posted by Parainvestigator

Hey guys...
Here's my problem; 2000 windstar. After getting on the highway tonight, each time I would let off of the gas I could hear a loud noise as I was coasting. It sounds like a bearing noise from the engine compartment. As soon as I touch the gas, it goes away. As long as I'm on the gas, it's not there. While sitting at idle and reving the engine, it's not there. If I drop the trans into nuetral while hearing the noise, it goes away. I just had the transmission relaced in December after it blew up. Am I looking at another transmission problem? Any help is apreciated.

Bearing noise as a knock or a ping?? I have a feeling when you put it in N and the noise goes away may make me think its a trans issue. Did the trans come with a warranty. If a local shop did it other than the dealer I hope they used Mercon V as well.Would like to know what you find out.. MY 2001 one which the trans is leaking when hot and it pings a little now,Kinda like a chain going crazy inside . Im going to have mine replace when it dies.. Would like to know what you find out..

[toplinegrowth]

I have the same problem, so I e-mailed one of the above posters. Here is his reply:

"Sorry, I still do not know what it is. I figure sooner or later something will get worse and it might be more obvious. "

I replied to him as follows:

"
Thanks,

I think I am getting closer. There is a device that locks up the torque converter at high speeds to increase gas mileage. This needs to disengage when you take your foot off of the gas or the engine will act like a brake on the car...the engine speed while coasting is not fast enough to keep up with the speed that the transmission is turning. The sound we hear is the transmission turning the engine faster than it wants to go.

The torque converter lock up device must be still functioning at the low speed range. Or else the engine would stall as soon as you came to a stop and you would need to start the engine by pushing it.

So, there must be a control linkage that senses when your foot is off of the gas and then disengages the torque converter lock up device. And that must be broken. I am going to discuss with my mechanic."

Does this make sense? Any comments?

[toplinegrowth]

More, from an e-mail, on what could be going on with the lock up clutch on the torque converter:

There is a throttle position sensor (TPS), I believe. This sensor must go into the pcm. I guess then the pcm would control the lockup of the transmission electrically?

The TPS sensor would probably be viewable via the OBDII interface. My bet though is that the output signal from the PCM would be bad rather than the TPS. A TPS issue would give some performance issues.

[toplinegrowth]

I took the 2001 Windstar to my mechanic on Friday. He freely admits that he does not have any transmission expertise. (This guy is very honest and really knows the other sections of cars.) He checked for codes and any obvious sensor/communications malfunction, but could not find anything. He thinks it is the transmission and probably the torque converter. He referred me to a transmission shop.

Any thoughts before I go to the transmission shop.