Timing chain cover M50 - any DIY?

**katit2** · 04-15-2019, 11:53 AM

Hi!

I wonder if anyone did this job? It seems that M50 got only one chain cover which requires main pulley removal. Do I need to drop oil pan for that?
I have all tensioners, pump and alternator out. Good access to do it, but I wouldn't touch it if oil pan has to come off.

**The Chauffeur** · 04-15-2019, 12:04 PM

Don't take my word for it.

https://www.bimmerfest.com/forums/sh...d.php?t=462003

**katit2** · 04-15-2019, 12:28 PM

Ok. Not doing it this time then.

It's a big job, book time is about 6 hours so figure at least $600 in labor. The timing cover gaskets are about $10. You might need a thermostat o-ring so that's a couple dollars. Figure at least $650 at a shop plus incidentals.

You basically have to strip the front of the motor including the balancer and front hub, belt tensioner, water pump, etc. I'd remove the radiator to have a little more room to get an impact on the crank bolt. (it's just so hard to remove!!!) Then you've got to pull the valve cover and possibly the vanos unit. Then you'll need to drop the pan to get the bolts from the bottom and to get the gasket to fit right. It's a lot of work if you've never done anything like it before. It's not a big deal to me because I have the tools and experience.

If you've a pair made out of steel and a decent set of tools on hand, you could give it a shot. It's gonna be hard to drop the subframe when the cars on the ground though. There's nothing excessively difficult, it just takes time and patience.

**whiskychaser** · 04-15-2019, 02:52 PM

If/when you come to change the actual tensioner arm and guide rail, you will have to remove the timing chain cover. The cover is sandwiched tight between the head and the oil pan. It is so tight that you might even break it when you try to remove it. If you do manage to remove it without damaging it, you will be sure to disturb the seals on both the HG and pan gasket. You can drop the pan with some difficulty. But you need to bear in mind that the timing cover also carries coolant. Get a leak where it mates with the head gasket and you may end up with the coolant in the oil or a leak to the outside. Neither are particularly good outcomes.

The OE gaskets for the block/timing cover seal are thinner than your average postage stamp and will not stay in place without gasket seal.

I would not want to give anyone the impression that what is a very simple procedure can prove challenging. Honest

**fo3** · 04-15-2019, 02:56 PM

I looked into this job last year and came to the conclusion it's best left until you want to change the head gasket and sump gasket just for fun!
E: ...and while you are there do an engine rebuild.

**katit2** · 04-15-2019, 03:10 PM

Head does not need to be off, but valve cover is for sure. I did this while ago on M62 which was more involved, but I don't want to do that now (no time).
Honestly - with 100k miles on engine I don't feel like opening it like that right now. It's not dripping. I just see area wet after I took all belts and pulleys. Will clean it and let it be..

Engine smokes a little too, needs valve steam seals. And I have manual conversion. And it's good idea to reseal intake. And...
Long story short - if I was doing it now I would probably pull whole engine and reseal everything. But I won't.