The van will bump at 1500 to 2000 rpms. Even at 60+ highway speeds. If I give it gas it has plenty of power. Sometimes when I start it up and put it in reverse, it will do it. I had the transmission replaced 2 years ago and it was just tuned up a few months ago. 135000 miles.

Thanks for help

Ah ha! "Things that go Bump!"

Sounds like a motor/trans mount. Carefully with a helper at the helm you could have one shift it while another is watching engine/trans from forward to reverse and usually see which one is caput - could be more than one or if nothing noted it could be something else altogether. That test may need minimal fighting engine against brake while in gear so if you try that to see stand to the side of it as van could move!

Again - if not mounts then I suspect an exhaust pipe bumping next on the list,

T
_________________________________________


Tom Greenleaf - MetroWest, Boston
http://acsource.net/acforum/index.php

Thank you for the help. My son and I tested as you described. When it is shifted into reverse and forward, there was movement of the engine/transmission. I do not know how much is normal. It did not bump or shutter at that time like it has been doing.

Maybe a better explanation of this problem is as follows: When going up a hill in particular, if I get it around 2000 rpms, the van will shutter. However, if I give it gas, it moves through it.

Thoughts?

There is some normal, allowable motion of the engine/trans on rubber mounts. If you could see one make an air gap it needs replacement. When rubber isolation fails it's metal to metal which is like a tuning fork in your teeth - don't ask why I would use that as an analogy

With updated note on when this does this is now may be "chatter" from transmission which I'm sure makes your day! If trans fluid is burnt looking it could be a clue on that.

If a mount it should show up fighting engine in gear against brakes sitting still - again using all caution to keep out of the way as engine could easily win over brakes and van move! Smile - I have a replacement shop door as proof that the door is not as strong as a vehicle Better a door than YOU or a helper.

Exhaust parts must flex with engine/trans movement also. That can cause vibrations, noise and maybe the shudder you are feeling. When cool sometimes you can just wrestle with the parts by hand or bump with rubber hammer and find faults that way. Some motion is allowed and needed within limits,

T

T
_________________________________________


Tom Greenleaf - MetroWest, Boston
http://acsource.net/acforum/index.php