Check your cam oiler!

It's been posted before, but with new E24 owners showing up, I figured it might be time to renew the message:

This is why us oldsters always tell new BMW owners of models that have M30 engines to check the cam and valvetrain oiler tube and bolts. It's very common to pop off the valve cover and find one or both of the hollow bolts loose or completely out of location, just like this:



Scary, huh? With that bolt out of place, the rear of the valve train gets no oil. Looks like this one hasn't been out long, since the cam lobes are no more worn than normal for a 74k mile M30. The front bolt wasn't loose, but it wasn't tight enough, either. The cure? Loctite on the threads, then torque to specs.

Please see the photo of a mod I always do to BMW m30 engines, The banjo's have only 3 outlet holes so one of the holes CAN NEVER LINE UP WITH THE AXIS OF THE SPRAY BAR so causing a lack of oil and THIS is the main reason why m30 camshafts fail, Please believe as I've modied 100's of these, Peter

Peter, that's an interesting modification , but I don't believe having one hole in the bolt blocked by the fitting is the cause of cam failure. Having the bolts come OUT which precludes any oil at all reaching the spray bar is the real culprit. Having two holes lined up and flowing oil is more than adequate. The proof is that engines that have had no bolt shake-out show no abnormal wear on the cam. When BMW realized there was a problem with oiling of the cam and parts, it was due to the bolt(s) loosening and coming out. Their fix was pre-Loctited bolts, not ones with a groove machined into the body. I'm not saying the groove is a bad idea. To the contrary, I think it's a good idea, just not one that's absolutely necessary.

Thanks for your reply but I'm speaking from experience dating from 1972 working on these engines and from 1982 within my own business. Yes I have seen a small amount of banjo's come ou but believe me I have never yet seen a camshaft fail due to a banjo coming out, But that I must add must be sheer luck. It was through my own 1983 E28 528i loseing it's camshaft that I studied this problem and I concluded by the fact that there is only 3 outlet holes and it is impossible for 2 outlet holes to line up with the axis of the spraybar. All of the cam failures I have seen have been on either cams for numbers 1 and 6 cyls on 6 cylinder engines and 1 and 4 cyls on 4 cylinder engines. So cams for cyls 2 3 4 and 5 have double the chance of getting enough oil onto them then cams on 1 and 6 cyls and on 4 cylinder engines cams for 2 and 3 cylinders have double the chance of enough oil. I have modified 100's of these engines and I have never had another customer having a camshaft failure. I modify the banjo's on my own metal working lathe and I have made my own cutting tool which has a shoulder which allows a 2 mm deep cut and it's width covers the area of the oil outlet holes. It is a very cheap mod to do and I'm sure that you could find an engineering shop to mod some banjo's for you and it will save a very exspensive camshaft replacement job. Whilst I'm servicing these engines I always check the tightness of the banjo's as a matter of course whilst I'm adjusting the engine valve gaps. One further point I wish to make is that if you look at the spraybar where the banjo fits into the boss you will see that the mis directed oil will hit the inner area of the spraybar boss which will then not allow oil to flow around the boss, But just mod the banjo's and you have a 100% fix, Peter

You almost have me talked into pulling it back apart and modding the bolts, which I can do myself (retired machinist, 27+ years Journeyman). I even have my own shop at home. My lathe even came with a cat! ("Sparky" has now passed on, but the big Monarch lives).

Again thanks for your reply, It won't cost you anything apart from four new banjo washers. If you take the banjo's out just have a close look at the oil outlets and you will see clearly that one side cannot line up. Again I have done hundreds of these mods. I do also own a 1986 e24 635 auto which I've owned since early 2000 and the only issue I've had with it is auto gearbox oil contaminated with engine coolant which seaps through the engine radiator into the gearbox cooler but I fitted a seperate remote atf cooler but this is also a known issue on other auto BMW's and some Mercedes cars which were fitted with Valeo radiators. If you need any further advise please feel free to ask me, Peter.

Done!

Sent from my MB860 using Bimmer App

Thanks for your replies and your pic. E24's are lovely cars and a joy to drive, Peter

I agree! I'm taking the '84 633CSi for a 350 mile jaunt Saturday. Looking forward to it.