hi, i am new to this site and any help anyone can give me would be greatly appreciated.. i have an 01 s40 with about 53000 miles on it, anyways a couple weeks ago i started having problem when i accelerated hard the engine and whole car would shake, didnt have any problems as long as i accelerate slowly and smoothly, well now its doing it at take off too, and sometimes when its just sittng idling...looked under the hood and watched the engine shake, and when the engine shakes hard a little poouf (not loud) comes out of the exhaust any ideas? seems like once i am at a steady speed there are no problems with it... also sometimes when i drive 78 to 80 mph my car starts to overheat ( at least gauge says so) and i turn the heater on for a sec and it goes back down, weird thing is it only happens sometimes and only if i am going above 75 mph... any ideas? THANKS!

 

SOME OF THE SYMPTOMS ARE OF THE THERMOSTAT AND COOLANT TEMP SENSOR. IT CAN MAKE THE CAR ACT UP IN MANY WAYS? DID YOU GET THAT CHECKED OUT? DO YOU HAVE A CHECK ENGINE LIGHT ON? IF SO PULL THE CODES AND LET US KNOW...AUTO ZONE CAN GET THE CODES FOR YOU FOR FREE IF IT IS ON??

 

MY first guess would be the Plugs or the Coils.

 

check engine light blinks then goes off, i will definetly go see if there are any codes stored,..... if i need new plugs or leads or coil will the computer tell that in a code? i also noticed a crack (that goes all the way through) in a hose (about the diameter of a garden hose) that comes out of some plastic thing on top of the radioator and goes to the front of the engine (has a very slight leak of what appears to be coolant) could that be part of the problem as well?

 

It won't always set a code for the coil. Only once in a while it will.

The coolant leak will not cause the problem you have.