Quick question on Timing Chain timing....... - PeachParts Mercedes-Benz Forum

deerefanatic · #1 02-11-2007, 11:53 PM

Well all,

My dad and I changed my timing chain Wednesday, when we did it, we ended up skipping a tooth on the cam sprocket... GRRRR......

I didn't realize it a first, I thought I had done everything right, but then upon closer inspection I saw that the pointer at the harmonic balancer was pointing at "18" and not "02". Turns out, that is the exact amount one will be off if they skip a single cam sprocket tooth.......... Not a problem, with the chain tensioner off, I was able to work the chain one link at a time around the sprocket and get it back in time..... (Now reads dead on "0" when the cam tower marks are lined up.)

I decided to check the IP timing while I was at it. It *appears* by just using the "welling-up" method to be about 20 degrees BTDC....... Not optimum I know, but that totally rules out having skipped a tooth on the crankshaft sprocket or IP drive sprocket, right?

Just wanna make sure..........

RAYMOND485 · #2 02-12-2007, 02:26 AM

1984 300d 142,000
Check The Cam Exaust Lope No 1 Is Pointing To The Left Drivers Side Of The Car Horizontally The Intake Will Be Pointing Toward To The Left 30 Deg To Make Sure The Piston Is At The Top If Not You Are180 Deg Off Slip The Chain One Tooth At Time On The Cam Gear When The Spring Out The Front Side Top Engine TENSIONER

deerefanatic · #3 02-12-2007, 12:49 PM

I've got the camshaft corrected, used that method.

I was just wondering about the IP. I was told by a member of another forum that due to the way the block is designed, it's basically impossible to skip the chain on the IP sprocket unless you drop the chain entirely down the chain galley.

Looks like I'm good to go!

Thanks!

GRIESL · #4 02-12-2007, 01:14 PM

Quote:

Originally Posted by deerefanatic

I've got the camshaft corrected, used that method.

I was just wondering about the IP. I was told by a member of another forum that due to the way the block is designed, it's basically impossible to skip the chain on the IP sprocket unless you drop the chain entirely down the chain galley.

Looks like I'm good to go!

Thanks!

I have same problem, so I'm curious to hear responses. I was told prior to head r&r that you could drop the chain in the case and not come off the crank, but nobody mentioned coming off IP. I PM'ed a dude who's been inside a 603 and he said if you saw the sprocket assembly, then you'd know there is no way to skip a tooth. He didn't know about the 617.

GRIESL · #5 02-13-2007, 03:05 PM

What would happen if when lining up cam timing marks the bottom crank was pointing to the Zero on the balancer, but the crank was in fact on Bottom Dead Center instead of TDC?

vstech · #6 02-13-2007, 03:37 PM

???

??? not sure what you are asking?

GRIESL · #7 02-13-2007, 03:49 PM

Quote:

Originally Posted by vstech

???

??? not sure what you are asking?

Well, here's the situation. Doing head replacement on a 617 turbo. Chain has skipped teeth on the cam during reassembly. Then chain felt like it was sticking down the case, so I tied the chain to a bungee overhead and spun it to kind of free it. Clearly not a good idea. So, I got bottom crank on zero and lined up the cam timing marks. Thought I'd be good to go. But the car is running real rough--way off timing has got to be the problem. So, I'm trying to rule out the timing chain having skipped a tooth on the IP as well. If the bottom turns twice for each turn of the cam, then isn't it possible that I'm off between those two gears? But it seems the only way I could be off is by 180deg., and that seems like the valves would definitely be hitting pistons, right? I turned the engine by hand before starting to ensure no contact between piston and valve. Any help is greatly appreciated.

vstech · #8 02-13-2007, 03:59 PM

ahh, well many things are possible, you could be 180° out IP / cam timing, you could have the timing off a tooth or so, if you did not remove the IP, it is unlikely to be out of time with the crank, but the cam could be out of time with the IP/crank.
John

GRIESL · #9 02-13-2007, 04:01 PM

Quote:

Originally Posted by vstech

ahh, well many things are possible, you could be 180° out IP / cam timing, you could have the timing off a tooth or so, if you did not remove the IP, it is unlikely to be out of time with the crank, but the cam could be out of time with the IP/crank.
John

Would 180 off on the cam jam valves into pistons?

deerefanatic · #10 02-19-2007, 11:22 PM

Well, a little update..........

The car runs just a good as ever, though the cold idle is definitely better now with the valve timing in check........ once I get the IP timed correctly, it ought to be fabulous!