FINDInG TDC IN an M42

[Simon S]

lol

[Dj Buttchug]

yupp. pics i took when doing my hg

cams should look like this

crank like this

[Simon S]

Wish this was a little better pic..

The notch on the pulley is sort of hard to spot.
I used a silver paint pen on the arrow found on oil filter canister – and a small paint dab on the pulley notch.

[bmwman91]

fiftytakedowns (or someone), do you happen to have a picture of this "notch?" I have my timing case apart right now to replace a dead idler sprocket, and I will be pulling the timing case to re-seal the rear gasket. I used the "screwdriver in a hole" trick last time, but would prefer something more external.

Is the "notch" on the crankshaft snout, the crank sprocket that drives the chain, the flange that mounts on the crank, or the harmonic balancer? I have an M20 flywheel in there, so the original option is out.

[fiftytakedowns]

found it, thanks.. the notch itself is on a toot.

[rjcaptsean]

On mine it pointed to a small notch on the pulley portion. The "missing tooth" area is almost at the 12 o'clock position and the small notch on the pulley tooth was pointing to the arrow.

Of course I don't have mine in and running yet...

[fiftytakedowns]

Still confused.. the arrow points to the missing tooth? or a notch in the crank pulley?

[vpilarrt]

The "missing tooth" is on the harmonic balancer and is the tooth for the crank position sensor - its more of a bump than a tooth.

[Dj Buttchug]

^ nope your good.

[rjcaptsean]

Ok.. I might have screwed up big time. Geez.. it wouldn't be the first time today of course.

I did not have the Oil filter housing mounted but I used the "screwdriver in the hole" method of finding top dead center for Number 1 cyl. This ended up with the woodruff key on the crank being relatively at the 12 o'clock position. I see on the above pic that the small pin on the crankshaft pulley being at 3 o'clock and mine is at the 9 o'clock position. Could I have it 180 degs off? (The black square is the woodruff key)


As for the "missing tooth" on the crank gear... I don't see one.

[fiftytakedowns]

If it's off a tiny bit, it won't cause a misfire. The cams are adjustable 6deg forward and backward.

Good to know, I'll mark it off the list. Of possibilities.

[KenC]

If it's off a tiny bit, it won't cause a misfire. The cams are adjustable 6deg forward and backward.

[fiftytakedowns]

I think I got it really close cause the car runs smoothly, but like I said I wanna make sure the cam sensor isn't causing a misfire due to poor placement.

[Dj Buttchug]

if you have the crank set and the cam gear arrows pointing upwards its hard to have the timing off.

You can also check the back of the cams. they are square and they must line up horizontally with the head.

The only way you could really make a mistake is if you remove the cam gears from the actual cams. Then you couldnt rely on the cam gear arrows or the square cam ends for reassurance.

[fiftytakedowns]

Legit I'll have to check that out