Replacement head gasket E34 M50 non vanos

[Joda]

Changes the head gasket yesterday and have to refit the intake today, but I'm a bit unsecure about something with the cam timing. On the front of the intake cam there is some kind of sensor fitted just behind the cam sprocket. The crank is turned to TDC on sylinder 1. Should this "sensor-thing" face towards the exhaust cam or the sensor fitted on the outside of the head? I can't remember...

Also, do I need to have a professional to adjust the cam sprockets? Mounted them in the exact same as it was before I took the head of. I`ve turned the crank 3-4 turns and it seems to function well without any valves hitting the pistons.

[Joda]

Nobody got a Haynes or other manuals?

[genphreak]

Changes the head gasket yesterday and have to refit the intake today, but I'm a bit unsecure about something with the cam timing. On the front of the intake cam there is some kind of sensor fitted just behind the cam sprocket. The crank is turned to TDC on sylinder 1. Should this "sensor-thing" face towards the exhaust cam or the sensor fitted on the outside of the head? I can't remember...

Also, do I need to have a professional to adjust the cam sprockets? Mounted them in the exact same as it was before I took the head of. I`ve turned the crank 3-4 turns and it seems to function well without any valves hitting the pistons.

The cylinder identification sensor plate is positioned to the front of the intake cam.

When removing and reinstalling the arrows on the cam sprockets have to point up AND the damper show 0 TDC on the timing cover notch. You must lock the crank using a snug fitting rod (BMW have a special tool) to fit into the special opening in the bellhousing (just under the starter motor) and a hole in the flywheel.

After that you should have locked the cams at TDC using special tools and good care lining everything up square.

Then check the dowels line up the head on the block and that the word 'OBEN' on the gasket faces up. If unsure about the Cam positions, get good help, the manuals are very specific about this. No contact is great, but its when your head is tightened down that counts... is it?

Others might pipe up here with more exp. than me- but the sprocket positioning I can't remember- but I do know the camshaft threads need to show towards the left side of the sprocket slots.

Sorry if it is not specific enough bud, I am no M50 expert

[yaofeng]

Genphreak described locking the flywheel well. You don't need a special tool to lock the cam shaft at No. 1 piston TDC if you don't want to spend the money. I didn't. Nor did I fall into the trap of buying the special tool to remove the cam shafts. If you watch the cam lobe orientation and remove the hold downs carefully you won't have a problem.

I know Bentley is somewhat vague on the orientation of the cams, especially on the Vanos engine. But on the non Vanos engine it should be clear. Once you lock the flywheel the first two lobes on both the intake and exhaust cam should be facing each other in the 10 o'clock (intake) and 2 o'clock (exhaust)orientation. But each cam sprocket has an arrow at 12 o'clock. So you shouldn't miss it.


Cam lobe orientation at No. 1 piston TDC.


Timing mark on the exhaust cam sprocket at 12 o'clock when No. 1 piston is at TDC. On the Vanos engine there is no such mark on the intake cam sprocket. Because of the variable timing I think.

[Joda]

You misunderstand my problem. I NEED to know how the part shown as number 3 (impulse sending wheel)here in this chart is positioned when the engine is at TDC at sylinder 1. Can someone tell me?

http://www.realoem.com/bmw/showparts...86&hg=11&fg=25

[Dave M]

Gen and Yao have done a good job explaining things.

Below is a pic of cam alignment. Use can use a 'staigth edge' (large straigth ruler) across the squares at the back of the cams to get things lined up at TDC on #1, thats all the special tools do.



Compare the orientation of the bolt holes to the exhaust cam in Yao's pic with mine below. Mine is off by one tooth. Whil Bentley states "line up the bolt holes to the left hand side of the slots", it should look more like Yao's than mine. While doing this, ensure that the chain primary chain tensioner is in, or apply some tension by hand.


Bad photo, but you might be able to see both cam sprocket arrows pointed 'north'. I wish I had a photo of the cam sensor thing, but it fits on the intake cam, bolted behind the sprocket. It needs to be mounted correctly (can't recall whether its up or down), just have a good look at how its shape matches that of the sprocket as it is possible to put it on upside down. I caught myself trying this once, ooops

Giood lck, keep asking questions and please provide pics as they help us help you.

Dave M

[Dave M]

You misunderstand my problem. I NEED to know how the part shown as number 3 (impulse sending wheel)here in this chart is positioned when the engine is at TDC at sylinder 1. Can someone tell me?

http://www.realoem.com/bmw/showparts...86&hg=11&fg=25

See my pic #1. The semi-circular cutout in the sensor that matches the cutout in the cam end is just visible. This would indicate (as does the parts diagram) that the long sensor end is pointed DOWN.

Are you in a hurry? Kinda sound cranky.

Best of luck,

Dave M

[SnakeyesTx]

Good god, that's a lot of blood on your cams caps

[Dave M]

Good god, that's a lot of blood on your cams caps

Gerbils

[Joda]

Thanks guys! An yes, I kind of rushing getting my precious back in business...

Tried cranking it over yesterday without sparkplugs. Everything seems fine so far. But I'm afraid i have to refit the impulse sending wheel tonight..

I'm also somewhat comfused where to fit the to ground cables up on the cylinder head cover. It's been 4-5 months since disasembled it...