[duttojo]

Hi,

I've a 1.8 A4 74k miles. Its behaving weirdly at the moment, if I drive for about 100 miles, or get stuck in traffic, the car starts to judder/ shake when I start off in 1st gear, almost as if its going to stall and I have to compensate by giving it more gas. On shorter distances its fine, but have noticed that revs are dropping when I start off in first

Anyone any ideas?

thanks

 

[bmwspec]

i would start with your spark plugs. check and make sure that all of your plug wires are all the way on your spark plugs and your coil. take your plugs out and look at the electrode (spark) end. do any of the plugs look to be wet. also, do this right after you run your car for a minute. if a plug looks to be wet it's suffering from the fuel mixture being too rich (or not enough spark). check your spark plug wires and make sure they are not rubbing anything in the engine bay. check the outer layer (insulator) material of the spark plug wires for cuts or a worn surface which could ark the spark to a metal surface other than your plug. are the symptoms exaggerated when it rains? from your post, it sounds as if heat is playing a large role here. if this happens only after driving a while or sitting in traffic, heat may be one of the contributing factors. i know that with most cars, the ECU (computer) and the sensors run the car with a rich fuel mixture and advanced timing when the car is cold. as the car heats up, the car is made to run a leaner fuel mixture, with less advanced timming. you could have a faulty sensor somewhere (oxygen sensor/map ( manifold air presure ) sensor. if you have a way to extract codes from your car, this would not be a bad thing either. i hope this helps, and hopefully someone can back me up on this or give you some more ideas. it sounds to be an electrical problem of some nature. good luck :thumbsup:

 

[bmwspec]

someone on another forum mentioned something i should've never missed. check your all of your vacuum lines FIRST. this could also be the culprit.