How the hell do you check timing on the M50?

[Jon K]

I have my GM coil pack installed and wires custom crimped and all, and I need to see the timing on the motor! It's not running yet, but I want to see that I have the timing right while cranking and correct IF it runs. I bought a timing light and my GM coils are using spark plug wires, so all the stuff I need is here, but I can't come anywhere near seeing the TDC mark on the front of the motor. What is the trick!?

[Mitch90535im]

How much did you give for the timing light? The cheaper ones are practically worthless because the strobe is not strong enough to see the mark. Maybe try it in a dark garage.

Follow-up - Looking at Bentley's, there are no precise timing marks to set the timing on the M50. Betley's basically says "special BMW service tools are needed to assure proper timing".

[Jon K]

$79 it has their "brightest xenon bulb available" - it's from Autozone. That's not the point. I can see the light just fine - i literally cannot see the mark on the timing cover... its obstructed by belts/fan/pullies/hoses

[Mitch90535im]

See the follow-up I posted from Bentleys info. (117-1)

[Jon K]

yeah there are no degrees printed or anything but there is a TDC mark and thats what I want to view. That's the camshaft timing... I want the crank timing...

[Jeff N.]

Jon - I have to wonder if timing is every meant to be checked. Think about it - it's all computer driven. The reference sensor should pick up the correct timing and the ECU fires the plug. The only timing mark you really need is mechanical TDC for assembly.

At least - that's how I think BMW might think about it when designing these engines.

Building your own ignition and fuel injection system is just a bit outside of what they were planning for I think.

Sure there's a way to do it but I suspect it will take some creativity.

[Jon K]

Im thinking of taking off the fan clutch and shroud and using a mirror... poop.

[Robin-535im]

Im thinking of taking off the fan clutch and shroud and using a mirror... poop.
Why not just make your own marks with white paint. If there's anywhere you can see an inch of the pulley, put the thing at TDC and make 2 marks, one on the pulley and one on the car. Get a piece of cardboard and a protractor and make the marks on that, then you can have all the timing marks you want. Under the car may be the easiest access if you remove the platic valance thing.

On the Motronic the timing is constantly changing, as a function of engine temp, air temp, air flow, etc. Is the MS more static?

[Jon K]

MS changes too but I can set it to a static time figure to confirm MS timing = actual timing

[yaofeng]

I have my GM coil pack installed and wires custom crimped and all, and I need to see the timing on the motor! It's not running yet, but I want to see that I have the timing right while cranking and correct IF it runs. I bought a timing light and my GM coils are using spark plug wires, so all the stuff I need is here, but I can't come anywhere near seeing the TDC mark on the front of the motor. What is the trick!?

Is the valve train sealed? If not, at #1 piston TDC the first lobe on each cam shaft is facing each other at 10 o'clock and 2 o'clock angle. I know this is not accurate. But there are other indications. You have a non-VANOS engine I presume. There is a mark on the intake cam sprocket indicating so. Since your flex damper does not have any marks. You can line the top end up and trial fit the flex damper to see if it matches up with the picture on No. 1 piston TDC flex damper orientation in another post I uploaded. Since the flex damper has a locating pin, it goes in only oneway.

[grave77]

have you checked in bently manual, looks clear, you have to reach to the crank flyfeel and wipe it you can pull the 1st cyl spark plug and inseart a pin just the the oil level pin. re scan the front crank wheel and look at the spots where the pin reach the max hight. you should be 4 spots to check.