[GST528I]

My 99 528i has issues when it rains. The check engine light come one when its wet. Also it has started being hesitant after driving 10 minutes on wet surface. The rpm idle drops and the car shakes as if it has a hard time staying on. It also shakes when i drive at normal speed and hesitated when i put my foot down.
But when i turn her off and turn it on back on the problem goes away and the acts just fine until driving in rain again for 10 minutes.

Any help would be appreciated. Also not sure if this is related but, the ABS and ASC light use to come on and go off until i had the car washed. (Hadn't washed it for a while). hasn't came back on.

Thanks again for any help ..

 

[GST528I]

After reading similar threads would it be correct to replace the MAF , o2 sensor

 

[BMR_LVR]

Check for vacuum leaks if you have not already. They can really cause a boat load of problems. May be sucking moist air into the engine. Also, pull the codes and see what the CEL was all about.

 

[slvr03e39]

Check the spark plug wires, if they are arcing its going to happen much more when its very damp out. Its may just be time for a tune up. I definitly would not start throwing parts at it, much to expensive. Open the hood and take a spritser bottle full of salt water and while the car is running spray down the spark plug wires if it starts misfiring or you can see it arcing its time for wires.

 

[BMR_LVR]

Check the spark plug wires, if they are arcing its going to happen much more when its very damp out. Its may just be time for a tune up. I definitly would not start throwing parts at it, much to expensive. Open the hood and take a spritser bottle full of salt water and while the car is running spray down the spark plug wires if it starts misfiring or you can see it arcing its time for wires.

Uhh, his car does not have spark plug wires

 

[GST528I]

Uhh, his car does not have spark plug wires

Thanks i was wondering which wire:dunno: could have sworn i havent seen any

 

[GST528I]

daym first time the car did this on a dry day ... im getting worried.

 

[Philboski]

Gotta get the codes checked -- they'll at least give you a direction to start. It could be as simple as a leak dripping on something.

 

[16valex]

It sounds like time to replace your coils and spark plugs. This unlikely but does your car has a CAI in place of stock air filter housing? If you do, then put back the stock one and see how that go.

 

[GST528I]

It sounds like time to replace your coils and spark plugs. This unlikely but does your car has a CAI in place of stock air filter housing? If you do, then put back the stock one and see how that go.

Has the stock air filer housing and stock airfiler.

I'm gonna go get the codes checked today.
thanks for ur help.
will post ones i know the codes.