HELP NEEDED!! 89 325i Sport Pulsing On Idle!!

[Tyler325iSport]

Hi, can anyone please help, i have a BMW E30 325i Sport F Plate with standard M20B25 Engine fitted. I have just serviced the car myself, New plugs, Oil Change, Oil Filter, Air Filter, Petrol Filter and Antifreeze change. The car seems alot smoother but on idle the engine pulses quite bad an shakes the car a little bit. Please Help!!

Many Thanks Tyler

[Tyler325iSport]

Also, I would just like to add before I serviced the car it would randomly kangaroo at low revs (like it was in a too high gear) it didn’t happen all the time mainly on longer journeys. At high revs it was fine but low revs now an again it would kangaroo. I was on a motorway driving and 70mph and it was kangarooing quite bad then lost power, I dropped it down to 4th gear an the engine still didn’t pick up speed so managed to get off the motorway an drive back home through county roads an the car was absolutely fine. I’m really not sure what the problem is and any help is appreciated. The car has 186k on, I’ve just put Mobil 1 super 15w40 in, not sure what the old oil was. The cam belt was done about 5 years at 168k

Many Thanks Tyler

[kam-325i]

The Idle problem could be caused by a duff ICV, an Air leak or A TPS that needs checking......

And change that cam belt........5 year old belt wont last much longer !!!!

[Speedtouch]

Try disconnecting the battery or ECU, leave it for an hour or so to reset it, reconnect then allow engine to idle for at least 10 minutes, switch off, then take it for a drive throughout the rev range.

This enables base idle settings to be learnt.

[Tyler325iSport]

ok thanks for that mate, the air flow pipe that connects from the engine to the air box has been bodged at some point with a glue gun but i dont get why its just started pulsing after the service

[Speedtouch]

What plugs did you use? NGK BPR6ES are best for this engine.

Replace any hoses or gaskets that may introduce air leaks; spray WD40 around inlet manifold gaskets and if the revs temporarily rise, a new gasket is needed.

[Tyler325iSport]

ok Speedtouch i will try that tomoz thanks for the advice much appreciated!! Just out of interested would you recommend the oil Mobil 1 15w40 ive put in i researched that 15w40 is better for high mileage engines then 10w40 is that right?

[Tyler325iSport]

bosch super 4 plugs mate

[Speedtouch]

Yes, that oil is probably fine - BMW used it in a million-mile test on one, so it's obviously pretty good.

I'd remove the Bosch Super 4's - other Zoners have had problems with them!

[Ajsingh]

Check the air flow meter.

I had this same problem on my 2.7 & after checking a testing various things, it turned out to be the AFM. I dont know exactly what was wrong with it but i swapped it with one from an e30 with no issues and my car was perfect. And believe me, i tested everything and looked for the fault but since swapping the AFM, its been spot on

[Tyler325iSport]

ok thanks for the posts people i will try all these suggestions tomoz an get back to you hopefully it will fix the old bird! Many Thanks