M20 valve adjustment

Post Sat Jun 21, 2014 4:18 pm

I'm looking to adjust the valves on my M20B25 and wanted a bit of info.

What should I change whilst I'm at it apart from the rocker cover gasket? I remember someone metioning some special glue to put on the gasket to help with sealing and helping the gasket to sit properly? Is this true or am I thinking of something else?

Also, is it correct that the gaps should be set at 0.25mm?

Will adjusting the valves help cure the rough idle and the ticking noise on idle?

How much is a new gasket from BMW, or has anyone got a link to the correct gasket form either ECP of GSF, theres quite a few different shaped ones, and I don;t know which one to go for. (Haven't removed the rocker cover yet)

Thanks

Post Sat Jun 21, 2014 4:27 pm

I set mine slightly wider at .30mm. I find that this steadies the idle speed.

'Ticking' is most likely to be the injectors working away.

Make sure the oil filler cap is seating properly,an air leak here will affect the idle.

I attached a new gasket to the rocker cover with a smear of a silicone,this ensures that next time the gasket lifts off with the cover! Then a smear of oil to seat it on the head.
Do take great care not to trap the throttle cable at the back of the head

as that's how rocker cover's get cracked...

Post Sat Jun 21, 2014 4:31 pm

daimlerman wrote:I set mine slightly wider at .30mm. I find that this steadies the idle speed.

'Ticking' is most likely to be the injectors working away.

Make sure the oil filler cap is seating properly,an air leak here will affect the idle.

I attached a new gasket to the rocker cover with a smear of a silicone,this ensures that next time the gasket lifts off with the cover! Then a smear of oil to seat it on the head.
Do take great care not to trap the throttle cable at the back of the head as that's how rocker cover's get cracked...

http://www.gsfcarparts.com/110bm0060

Will this be the correct gasket to go for?

Also, how do I make sure the oil filler cap is seated properly?

Is there a way to check? I remember I took off the cap once to test what happens to the idle when the cap was removed and the car stalled. What does this mean?

Thanks

Post Sat Jun 21, 2014 4:47 pm

If your engine stalled when the oil filler cap was removed,then it is sealing properly!
Un-metered air entering these engines plays havoc with both the idle and general running.

That gasket will be just fine,same place I bought my last one from,but the price has gone up!

When you set the valve clearances,take your time,it's tricky to get a feeler gauge in the correct place.Make sure that the cam lobe for the valve you are working on is facing as far away from the rocker as possible(so you are checking the clearance at the right place)
Also,the engine must be stone cold.