E30 Zone

Hi,

Am after some sudgestion. I've recently had the head done on my car (@160,000km), new valves, sleeves, springs, etc. The cam wasn't replaced as was still in good condition and was re ground.
I'm running a 5W-40 synthetic oil and wonder if a little tapping noise when starting up when cold is normal? Its disapears once engine start warming up, but I've been told this is normal on the M40 and also to cause I'm running a 5W-40 synthetic. I'm think next time I can the oil to go for a 10W-40 synthetic oil.
Another thing to is I haven't had the sump dropped and cleaned either since buying it as it has just about 170,000km. Am wonder if it may be a bit dirty and worth dropping the sum and cleaning it as it may be slowing the oil pickup thus causeing the tapping. But on the other hand I've never had the oil pressure light come on.

Not unusual foe the M40 to tap a little when cold, and personally I wouldn't worry about it.
A change of oil grade may be worth trying - may make it better or worse, but in any case, the knocking is harmless.
Oil spray bar in the head can become partly blocked, is almost impossible to clean, but is cheap to replace.
Shouldn't think there's anything to worry about in the bottom end, although the sump gaskets are probably getting a bit brittle by now and a change wouldn't go amiss.
Don't be surprised if you find a spare bolt or two lying loose in the sump. They are upper sump bolts which often work loose.

My M40 seems to tap all the time, when cold and when warmed up, its driving me mad!

on a recent m40 i sericed I couldn't believe how much crap was under the valve cover, on the plastic cover and generaly in the head.

I cleaned it with carb cleaner before changing the oil.

Engine was def quiter after!

thanks will give it a go

Brianmoooore wrote:Not unusual foe the M40 to tap a little when cold, and personally I wouldn't worry about it.
A change of oil grade may be worth trying - may make it better or worse, but in any case, the knocking is harmless.
Oil spray bar in the head can become partly blocked, is almost impossible to clean, but is cheap to replace.
Shouldn't think there's anything to worry about in the bottom end, although the sump gaskets are probably getting a bit brittle by now and a change wouldn't go amiss.
Don't be surprised if you find a spare bolt or two lying loose in the sump. They are upper sump bolts which often work loose.

Thanks for the info. Feel much better now

Cheers

nikkis318i wrote:My M40 seems to tap all the time, when cold and when warmed up, its driving me mad!

That's what mine used to do. I tried this nulon product which stopped it http://www.nulon.com.au/products.php?productId=e10
then my timming belt broke an got the whole head re-done. The timming belt was over due to be replaced, I already had bought it, just didn't organise get it done in time. My mechanic said that its was because of the nulon product I put in, because it was due for replacement and the nulon producted increased the compression and added more stress to the worn belt causing to go earlier. But I'm not so sure about this.

[quote="shiston"][
That's what mine used to do. I tried this nulon product which stopped it http://www.nulon.com.au/products.php?productId=e10
quote]
This crap is for worn engines, and I've never seen a worn BMW engine!
Wife's touring is on 250,000 miles and is as good as new, and a while back I stripped a 200,000 mile unit, checking everything as I went. Only thing out of new spec were the exhaust valve guides, and seats were slightly pitted.
M40 hydraulic tappets were their first attempt at these, and they didn't get it quite right for long term reliability.

heh eh ehe yeah I know that nulon stuff is for worn engines but that's the only the thing that would stop the continual loud tapping before I got the head rebuit.
But I suppose it was better the timming belt snapped cause then I head re-done as well cause I still would of had that loud tapping, where as now I get quieter tapping on when cold. It was expensive but i suppose its better in the long run