m20b25 tapping. different oil?

[lukec88]

hi my 325 is a bit tappy, i bought some stuff from halfords in a purple tin which is supposed to quieten tapping which it did a bit, would using a thicker oil be ok and would it help? any ideas what you lot have done would be appreciated. thanks

[daimlerman]

I would spend an hour or so adjusting the tappets.

[capri_rob]

I would spend an hour or so adjusting the tappets.

Or get someone who knows what they're doing to do it if you don't !

IMO this is one of those jobs that sounds & looks simple but you need a feel for it - I did mine on the bronze turd and I couldnt tell whether it made a difference or not - I'm sure a proper E30 boffin would have done a better job

[daimlerman]

I would spend an hour or so adjusting the tappets.

Or get someone who knows what they're doing to do it if you don't !

IMO this is one of those jobs that sounds & looks simple but you need a feel for it - I did mine on the bronze turd and I couldnt tell whether it made a difference or not - I'm sure a proper E30 boffin would have done a better job

This is just one of the joy's of being semi-retired,I have the time to spend to do a 'propper job'....

[capri_rob]

Well Malc if you can spare an hour next time you're over this way you can do mine for all the tea you can drink

[Tom_Maverick]

I did mine three times to get it right... third time I did it using clock guages... and not only was it a bit quieter (M20's all tap a little) but it went a lot better too! M20's shouldn't be silent, it means the valves wont close properly and it'll run like a turd.. and that poo in a can from halfords is a waste of money.. all it does is thicken the oil.. which is a bad thing... and will not stop your tapping!

don't forget the main dealer will do the job for around £100 if you have no idea how!

[samuraibaz]

Adjust ur tappets urself mate its a simple enough job should really b part of a yearly service just need a 10mm, a 4mm allen key, a set of feeler gauges & 3 hands lol just make sure each cylinder is TDC!

[Tom_Maverick]

And the engine is stone cold...

Gap should be .25mm

[walrus1968]

yeah had mine done on the white turd today for the 3rd time in 2 weeks too...The first time i did em...didnt work lol..second time my brother di em...worked but still had 2 rockers tapping loud...3rd time the mechanic i use did em...he spent 40 mins making sure each rocker was in the right postion for adjustment...success..seems a lot better now.

I thought it was an easy 2 min job but they seem very sensitive on these engines and hard to get right.

best of luck though as Tom said ..M20 engines are a little bit tappety by nature...

[jonny323i]

From what I was told once the biggest problem is there are ecentroc rollers involved and they wear a flat spot so when adjusting the gap can be out but they are peanuts to buy

[bss325i]

The injectors "tick" and that contributes to the overall noise of an M20.

You might even have a worn cam and rockers.

[clipper]

The injectors "tick" and that contributes to the overall noise of an M20.

You might even have a worn cam and rockers.

I found that mine has slight "mushrooming" on the top of the valve stems, so even with brand new excentrics the reading off a feeler guage between stem and excentric was misleading as the execentric disc sat down into the slight indent, I measured this indent at between 0.1 . 0.2mm. Once I had factored this wear into the gaps I was able to get a much better result in the valve clearance adjustment (by measuring the corresponding gap between rocker and cam lobe where there is hardly any wear at all) quietening the valve train and improving the performance.

I also found that using thicker oil makes the valve train noise worse, going back to 10W40 also quietened mine down.

But as people have said, even though I am cofortable with my clearances (except for the wear to valve stems which will one day need sorting) my M20 still ticks to a certain extent but 90% of it is due to the injectors.

[csl]

The top end in my car ticks with the injectors and is a bit annoying tbh but the sound of the original Boysen makes up for that and then some!
The engine is virtually new now and i have reset the tappets after a running in period and they set with no issues. Unlike the original,worn ones.

[Andyboy]

I've had a couple of noisy ones (cam okay but flat spotted rockers) where opening up the oil holes in the spray bar makes a difference. The standard holes are tiny and easily blocked, and opening them out slightly gets a lot of oil on the cam lobes without reducing oil pressure.
325i's like the exhausts a bit wider than stock - they can have a shitty idle when set to standard. Setting them at 12 thou can make a difference. When doing these, I use brake cleaner to wash all the oil from the lobes and rockers and spray WD40 on them. This just reduces the oil drag on the feeler gauge. With the feeler gauge in place, try to 'rock' the rocker - if you can still feel play, it's not right. I do them with the tip of the lobe 180 degrees away from the rocker. Pour clean oil onto the lobes/rockers before you fire it up again.

[Tom_Maverick]

Good point.. A new spray-bar is £40 from BMW and makes a world of difference, especially as the washers on the end of mine had given way a bit and it was leaking oil up the threads meaning less squirty squirty lube action onto the cam..

[Andyboy]

No washers on an M20 spray bar..............

[walrus1968]

I've had a couple of noisy ones (cam okay but flat spotted rockers) where opening up the oil holes in the spray bar makes a difference. The standard holes are tiny and easily blocked, and opening them out slightly gets a lot of oil on the cam lobes without reducing oil pressure.
325i's like the exhausts a bit wider than stock - they can have a shitty idle when set to standard. Setting them at 12 thou can make a difference. When doing these, I use brake cleaner to wash all the oil from the lobes and rockers and spray WD40 on them. This just reduces the oil drag on the feeler gauge. With the feeler gauge in place, try to 'rock' the rocker - if you can still feel play, it's not right. I do them with the tip of the lobe 180 degrees away from the rocker. Pour clean oil onto the lobes/rockers before you fire it up again.

great info...i think ill be giving this a try..well with supervision as im no mechanic lol

[clipper]

No washers on an M20 spray bar..............

I think he means the rolled section of the pipe below the threaded retaining nut. That seems to be a compression seal is it not? Seems likely that after a few removals / reinstalls, that could let oil seep by?