OM617 Timing after Rebuild - PeachParts Mercedes-Benz Forum

MrUkrainian · #1 11-23-2015, 10:59 PM

I am in the process of rebuilding a om617. I'm not sure how to time the engine. Does the injection pump gear have anything to do with the timing or is it just the angle of the pump? Any input would be appreciated. Thanks

leathermang · #2 11-23-2015, 11:26 PM

You do not have a Mercedes 617 FSM to refer to rebuilding your engine ?

engatwork · #3 11-24-2015, 06:11 AM

Quote:

oes the injection pump gear have anything to do with the timing or is it just the angle of the pump?

Yes. I just went through this exercise on a 606 engined 98 E300. You will need to look up where to position the crank and then how to properly position the injection pump prior to inserting it in the timing sprocket.

Stretch · #4 11-24-2015, 06:18 AM

You are best off starting with the valve timing. Fit the chain with the rocker arms removed from the head and you reduce the chance of pistons hitting valves. (Check how to do this in the FSM)

Only ever turn the crank in a clockwise direction (seen standing in front of the engine as it sits in the car)

Once you have the chain and the rocker arms in place make sure the glow plug are out to help you turn the crank for the next stage => fitting the IP.

For fitting the IP the rough position is found by aligning marks (see the FSM as encouraged in post #2. It is free to access on www.startekinfo.com - see link in my signature for tricks on how to get it to work if you don't use MS explorer)

For fine tuning the IP it comes down to one of the several tests you can do. More often than not most people seem to do a "drip test" - however with a MW turbo OM617 IP most of these have an inspection cap on the governor that allows you to attach the "A-B" timing light. It isn't necessary to get the special tool for this => you can do the alignment visually. If you happen to have a MW turbo IP let me know and I'll find a link for you.

MrUkrainian · #5 11-24-2015, 09:18 AM

I do not have a FSM. I understand the IP needs to be timed by the angle, but does the gear on the timing chain have to be in a certain position? Or can the chain be installed and the only way I need to time it is by the angle?

leathermang · #6 11-24-2015, 09:28 AM

Rebuilding a 617 without access to the FSM in some form is really risky.... the people who made the engine were very picky and put lots of warnings into the FSM... warnings which you do not get in the Haynes manual ... or on any Forum... the specs are so close compared to ' normal ' cars.... suggest you pause and find some way to access the FSM .. and a paper manual has loads of advantages....

Stretch · #7 11-24-2015, 09:40 AM

Quote:

Originally Posted by MrUkrainian

I do not have a FSM. ...

It isn't difficult to access and it is free!

MrUkrainian · #8 11-24-2015, 11:46 AM

Where do I find it? is it online?

Mölyapina · #9 11-24-2015, 11:51 AM

The link is in Stretch's sig line. Here:

Mercedes Startek have done the right thing - to help you do the right thing!

Stretch · #10 11-24-2015, 01:00 PM

If you get stuck finding the information you need give me a shout I can provide direct links to PDFs if need be (but it is useful if you can find stuff for yourself)

I would need to know if you want turbo or non turbo information though.

BillGrissom · #11 11-24-2015, 02:40 PM

I understand the IP to timing shaft interface has a notched spline, so the gear must be installed at a certain clocking. Most people who change the timing chain do so by rolling-in a new one, so the sprocket teeth stay aligned.

I also have an engine to rebuild, but so far I just stripped it and installed new cylinder liners. Haven't taken the block to a machine shop yet and would be cool to do it all myself since I now have a mini-knee milling machine (perhaps too short) and viewed youtubes of people decking heads via the sandpaper-on-glass method, albeit aluminum. It is fun to go cheap and laugh at the finicky.

I also don't own a FSM, but did download the cheat version. Many things in the FSM are a bit confusing, especially not knowing the relevance or necessity of some special tools. People have long argued about the piston size group specs, i.e. is #1 really supposed to be a different diameter or was that a factory sorting system that doesn't apply to rebuilds.

leathermang · #12 11-24-2015, 02:58 PM

Quote:

Originally Posted by BillGrissom

..... Most people who change the timing chain do so by rolling-in a new one, so the sprocket teeth stay aligned.

...... People have long argued about the piston size group specs, i.e. is #1 really supposed to be a different diameter or was that a factory sorting system that doesn't apply to rebuilds.

The Warning in the FSM about the teeth staying ' aligned' ... is to KEEP tension on the chains as they are connected and rolled in... if not... you can drop low enough due to gravity at the IP to jump a sprocket...

The main thing about the pistons and sleeves that was discussed lately is that the clearance for the number one piston to sleeve is different than the other three or four cylinders...

MrUkrainian · #13 11-25-2015, 12:25 AM

I appreciate the replies. It is a turbo 617. The timing chain was removed so I am sure the gear turned for a fact. I pulled the pump out after that. Timing the crank and camshaft shouldn't be too hard, but the IP is a little confusing.

cooljjay · #14 11-25-2015, 02:02 AM

The ip "should" be off the car.....The ip has a mark on the gear that slides into the block, there is also a cap that is removed to lock the ip in this position, then there is also a mark on the block and ip housing that is lined up on install. This would put the ip at the correct position, when the car was new....Later when the car is running, you would need to drip time the ip...for fine tuning but with a rebuilt engine, I would imagine this isn't needed...

Personally thinking, I don't think rebuilding one of these engines, is for you....there are a TON of parts and specialty tools needed to rebuild them properly...If you don't even have the FSM...That tells me right there, I wouldn't have suggest doing a rebuild...

This site is set up, like the cd's you can buy....Go threw the engine job section and do some reading...

W123-dokumentacja cz. 2

mannys9130 · #15 11-25-2015, 03:36 AM

Definitely get the manual and reference it often.

You'll need the diagrams, specs, procedures, sequences, etc.

Do you have a torque wrench? Assembly lube?

Be careful when you crimp on the timing chain master link and make sure you actually mushroom the ends of the pins.

When you finish with the cam timing make sure everything is correct and spin the engine with a wrench a few revolutions to be sure you don't bend valves. There is very little room between the piston and valves. The clearance is stupid small.

Last, I suggest you put a sticky note on the steering wheel that says "CHECK ALL FLUIDS!!!"