with 72k miles in 7 years with no known problems. Suddenly today while driving with lite heat on with defrost (default a/c on), there was a burnt smell and engine started revving up without vehicle speeding. Then a/c failed. Vehicle speeds upto 60 miles and after that engine revs up. with in few hours acceleration failed completely. when pulled over to shoulder and with auto shift moved to park w/o turning of the engine it starts to work. Can someone guide me as to what happened? and how much cost I am looking at? and best place to get it fixed.
I’m not sure that anyone can really help you given the lack of clarity in your description. What exactly happened is entirely unclear. Slow down. Use full sentences. Go step by step. It will probably get longer - use paragraphs when it does.
Here are a few confusing things:
“engine started revving up without vehicle speeding” - you make it sound like you had no part in this. Were you pressing the gas or did the engine rev on its own?
“Vehicle speeds upto 60 miles and after that engine revs up” - do you mean 60 MPH? And once again, what was your role in this. Are you controlling the rev of the engine with your foot?
“with auto shift moved to park w/o turning of the engine it starts to work” - What starts to work?
The whole post is full of things that no one can understand. We are not inside your head, nor were we inside of the car.
I agree with cigroller.
Until the OP can put the problem(s) into some kind of understandable order, helpful responses are unlikely. Right now, the “question” is just a stream of consciousness with little direction to it.
Thanks. sorry for not being so clear. let me try again. This is my first posting.
While driving my van there was some burnt smell. with in minutes a/c failed and in the next few minutes without me depressing the pedal engine started revving up.
“engine started revving up without vehicle speeding” - you make it sound like you had no part in this. Were you pressing the gas or did the engine rev on its own?
This happened after I removed my leg from the pedal (when a/c failed).
“Vehicle speeds upto 60 miles and after that engine revs up” - do you mean 60 MPH? And once again, what was your role in this. Are you controlling the rev of the engine with your foot?
This happened while I was driving. yes I was pressing the pedal. Yes 60 MPH. I was trying to pick up the speed after a slowdown.
“with auto shift moved to park w/o turning of the engine it starts to work” - What starts to work?
Van starts to work(accelerate). To put in context while driving on a high way to adjust to traffic I had to slowdown to about 45-50 MPH and then while trying to pick up the speed above 65 MPH I was pressing the pedal and at 60 MPH if failed to accelerate and unlike before (the first incident when a/c failed) van didn’t pick up the speed until I pulled over. Then I didn’t stop the engine. I just put the stick in Park waited a few minutes and started driving. Van starts to accelerate and I made to my home.
I am glad you are inside my head or the car. How else would I be able to get your response? 
I sort of meant that you needed to clarify everything. The couple of things I pulled out were just examples. Here are some more examples. I have no idea what you mean when you say that the AC failed. How would you know while driving with heat on? (Yes I know the AC compressor runs with defrost. The question is how you know the AC compressor stopped running). So something happened, but I don’t know what, then something funny happened with the engine. Then you drove for several hours after that without incident? Any more smell? Then…? When you say the engien revs up, you mean that the RPMs get higher, but no power seems to make it to the wheels?
Most of your description sounds like an overheating and slipping transmission. But there is much less than enough info to try to verify that or guess about any connection with the A/C / defrost / heat.
Here are 2 things to do anyway. 1) Check your serpentine/accessory belt. Make sure it is there and look for signs of heat stress. (Just in case there really is some AC issue) 2) check your transmission fluid as described in the owners manual. It should be at the right level, nice and clean red looking and shouldn’t smell burned at all.
Thanks for your suggestions. I’ll check them as soon as I go home tonight.
When I say AC failed. It stopped working.
How I know that #1) Condensation started building up because of the proportion of heat vs cold in the vehicle changed. #2) I tried to turn of heat and turned on AC and verified the air blowing from vents. #3) All of us in the van could feel heat building up.
I didn’t say compressor stopped running. I checked under the hood when I pulled over and the compressor is running. Yes something fishy with the engine happened as it feels like it got stuck at a low gear (when it accelerates upto certain speed).
I did get the smell initially after starting again, but it sort of not noticeable after few minutes.
Engine revs up mean exactly what you described. RPM rises but no power to wheels.
I can’t think of any details I might have missed. But do let me know if I can provide any more details.
We had one of those and the AC is extremely prone to failure. Our repair was well over a grand as it included purging the entire ac system due to probable shavings ruining a new compressor in short order if not done. I imagine your compressor froze up and the smell was from friction on the belt, and it finally got the compressor to move and all was well. If you do not need ac, as my wife does you can get by with an replacement wheel in place of the compressor, but until you do something you are on borrowed time.