Help! OM603: how to line up the cam for re-installation? - PeachParts Mercedes-Benz Forum

renaissanceman · #1 03-22-2017, 12:06 AM

After installing a fresh set of lifters, I'm having a hard time getting the cam lined up perfectly so I can get the cam sprocket back onto the end of it. I put the timing mark pointing up as stated in the FSM, but when I follow the tightening procedure on journals 3,4,5, and 7 it always slides one way or another, leaving me unable to install the sprocket...quite frustrating!

If I could spin the cam after tightening the bearing caps, that would make it so much easier, but I can't think of a way to do it without risking damage to something...

Any ideas?

moon161 · #2 03-22-2017, 01:43 AM

Is the tensioner out? I'm thinking you should have enough freedom at the sprocket with the tensioner out.

If that's the case and you still have problems, rolling the motor a bit this way or that via the main pulley/balancer should get you the few degrees it sounds like you need.

wait, what if you collapse the lifters? Then it should turn freely.

renaissanceman · #3 03-22-2017, 02:07 AM

I was able to bump the cam back a few degrees with a screwdriver on the alignment pin of the pulley side. It was nerve wracking as imagined that the tip of the driver would break off and fall into the timing chain area...but it worked out.

It's all buttoned up except the cam cover and crossover pipe. I'll finish her up tomorrow and crank for a while to get oil pressure up before firing her up and hoping for smooth, quiet operation with the new lifters!

Delivery valve seals next!

Maxbumpo · #4 03-22-2017, 12:40 PM

In the same predicament, I put a pipe wrench on a rough part of the camshaft and turned it so that the gear fit.

Junkyarddawg · #5 03-22-2017, 02:01 PM

Quote:

Originally Posted by renaissanceman

I was able to bump the cam back a few degrees with a screwdriver on the alignment pin of the pulley side. It was nerve wracking as imagined that the tip of the driver would break off and fall into the timing chain area...but it worked out.

It's all buttoned up except the cam cover and crossover pipe. I'll finish her up tomorrow and crank for a while to get oil pressure up before firing her up and hoping for smooth, quiet operation with the new lifters!

Delivery valve seals next!

There will be some lifter noise when you first start it up as it takes a while for all the air and cavitation to be bled out, but eventually it should quiet down, after you shut it down and let it sit for a couple hours the next restart should be as quiet as it gets. Make sure you replace all the O-rings for the oil filter pipe every time you change the oil, some people don't know about them and they can make for noisy engine operation, especially on start up, when they are worn or missing.
Happy motoring

renaissanceman · #6 03-22-2017, 05:43 PM

I just did the 2200 rpm for 20 minutes break in routine, and the engine roar and clatter was deafening for the first 10 seconds or so and then markedly quieter.

The volume continued to decrease over the 20 minutes. When let it fall to idle for a minute before shutoff, it was stupid quiet as compared to before. We'll see what a cold start sounds like when I take it for a drive in about 3 hours.

I think my idle may be slightly lower than before at right around an indicated 600 rpm. A lot of the shake at idle seems to be gone too.

So far I'm quite pleased!

moon161 · #7 03-23-2017, 02:49 PM

Quote:

Originally Posted by Maxbumpo

In the same predicament, I put a pipe wrench on a rough part of the camshaft and turned it so that the gear fit.

I think I actually did something more like that.

renaissanceman · #8 03-23-2017, 03:15 PM

The engine seems to be overall quieter and more responsive to throttle when cold -- but the throttle response could be just perception on my part.

It's still got some clatter at cold startup, but I do still have a leak in the flex connector between the exhaust manifolds and some slight weeping at the delivery valve seals. Hopefully taking care of these two things will eliminate it totally. I'll probably make sure I'm getting full boost by working on the wastegate and such when I've got everything taken out near the turbo to do the manifold flex connector. I've heard this is a %$&*^#@ of a job to do.

Maxbumpo · #9 03-24-2017, 09:30 AM

All that intake piping at the front of the turbo is like a Chinese puzzle. There are three hex-head sockets holding a small aluminum piece to the head, and getting access to these is REALLY tight. I'm not sure what hex key tool is the best approach, I think if you had a long shaft hex key you might be able to get each one in a straight shot.

I just went through all that pain to adjust the waste gate control rod on my '87 wagon. 1.5 turns tighter increased the full boost pressure from about 8 psi to about 13 psi, which restored a LOT of nice performance. I've still got to adjust the upper RPM cut-off on my pump (from a 3.5 liter engine which that car's transmission had lower shift points) and then I'll bet my 0-60 times will fall down to 11s or so, from about 12.5 now.