e36 325i m50 really rough idel

[markmac]

hi guy my car was going great till i lent it out to my younger bro ,when i went to start her she sounded really rough as if off a plug and the revs where a constaint up and down same tempo .and like a can popping sound .well i,ve put new plugs in the old ones where covered in black oil and cleaned air mass senser as recormened a new senser is 160 from my work but don,t want to buy if the fault is,nt that any idea,s

[Crazynavyjeff]

You sound like you have a vacuum leak. The M50 are known for leaks at the rubber gaskets between the intake manifold and head, I check with the engine at idle and using carb cleaner with the red tube on the spray nozzle spray a little around the gasket area....if the rpm increases or smooths out....you found the leak....you can use this method around all the rubber vacuum hoses as well. It takes a good day to repair and a couple hundred bucks for all the gaskets and hoses...all of the might as wells that happen if you take the intake manifold off, it is not hard to do but just takes time.

[flitty1]

check out my (rough idle) posts bmw must have bought a job lot of crap rubber from somewhere because all of their intake pipes leak ! however if plugs are fouled by oil this sounds a bit more serious do a compression test on each cylinder and make sure the oil level is below the max on the dip stick< dont put anything on the maf or you will kill it ! unplug it instead and see what happens when you run it, has your bro been drag racing ha

[medic1dl]

Check/clean the ICV. It regulates the idle.