valve adjustment OM617 engine, rotate engine
 

I'd like to find out from those who have done a valve adjustment on the 617 engine what is the best method of rotating the engine. Apparently, the choices are :
1) use the starter
2) use the power steering pump
3) use the crank (may require removing fan)

I did it once and used the power steering pump, but I've seen recommendations against that because it may cause later problems with removing the nut.

Anyone who has done this, please reply with your method and what your opinion is of it and any other method.

Thanks in advance.

I use the power steering pump. It didn't take enough pressure for me to worry about overtightening the nut.

P/S nut

Thats how I've always done it. overtightening the nut? come on, is it really THAT much of a problem? how many people are resealing their own PS pumps anyways. Besides if its that tight take it to a shop and have them zip it off with an impact.

I use the starter, per the FSM.

I wouldn't recommend anything but using the crank. Using the PS nut may work but there's a chance you could overtighten it and it does put undue stress on the PS belt. You can rotate the crank from below without removing the fan and it's much more controlled than using the starter.

But you can't see the cam while rotating from below.

I also use the p/s pump nut, it doesn't really take that much pressure to turn the engine. Plus, I found out my old belt was in bad shape, it slipped like crazy when I tried to turn the engine, so I replaced/tightened it, and it gripped much better! :D

I used the nut on the power steering pump, however, I also removed my glow plugs (time to check them anyway) and that kept the engine from building up compression and made it much easier to turn. I also grabbed a belt and pulled on it in the direction of rotation at the same time so as not to put all the turn stress on the power steering pump nut!!!!:scholar: Had no problems!

The FSM specifically says NOT to use the PS nut to turn the engine...
it is not that someone might want to reseal the PS unit.... but if you want to replace it you may need that pulley to move to the new one...and it is a TAPER shaft...so overtightening it has nothing to do with the nut... but everything to do with the pully and the PS shaft.
There is a ZEN about some things... perhaps this is one where you could go with the idea that not all mechanicing jobs are ONE PERSON deals....
pulling the glow plugs , and then having someone underneath with a proper ratchet works very well .

I'm relatively new to these things, and I found it pretty easy to remove the fan and shroud on my 240D and then rotate the engine from above using the crank. Just don't forget to put one of the fan's bolts back in once the fan is off so that the holes stay aligned during the cranking. I didn't and then had to loosen the alternator belt in order to get the holes aligned again and the fan back on. Still, I'd say it added less than 10% time/effort to my very first valve adjustment job and felt worth it to do the job "right."

Ditto: 27mm Deep & 1/2" ratchet on the crank bolt.............Per the FSM.
Also, the easy thing to do is count your strokes (3 is a good number IIRC) and you should have another cam lobe in position to measure. Less up and down exercise that way.

One wrench on the PS pump (just don't jerk the wrench, use nice even pressure) and one hand on the crankshaft pulley to help it turn (you can jerk this one with your hand to get things moving). This puts very lttile pressure on the PS pump (or maybe my compression sucks).
Also, if you adjust each valve as it comes up (rather than starting at the front of the engine and moving towards the back), you don't have to rotate the camshaft much at all. (Just make sure you write down the one's you have done so you don't get confused).

P/S nut, then your in position to check your chain stretch, unless you want to haul out the dial indicator and make a big deal outa that too:D I realize if your doing it for pay that might be another thing.

I don't understand what the danger is to the PS bolt/pump by turning it there. Could someone elaborate?

I have so far used the PS pump but it sometimes is hard to turn and i have worried about overtightening it. I also have a tough time getting to precise spots for IP and valve timing checks/adjustments. Is this easier down below?

Apparently, the power steering pulley is on a tapered shaft, so the harder you tighten the bolt, the farther onto the wider part of the shaft the pulley goes. So, it's not that the nut would be hard to get off, it's that the pulley might be hard to get off if your ever needed to. My feeling is that it will just be more fun/challenge to get off. I don't think it hurts anything though.

I would bet that turning the crankshaft itself, with a long wrench, is a lot more precise since the PS pulley tends to slip.

[QUOTE=Jkid;
I would bet that turning the crankshaft itself, with a long wrench, is a lot more precise since the PS pulley tends to slip.[/QUOTE]

Nah, just push on the belt when the compression holds you up, still ALLOT easier than using the crank nut.

An impact wrench is handy for getting the P/S or alternator nut off, hard to hold onto those puppies.

wouldnt a simple gear puller and maybe a peice of steel to go behind the p/s pulley be an easy way to remove it, IF it were to overtighten onto the tapered shaft? just ask any old shadetree mechanic and there's at least two ways to get the job done. one may be RIGHT, but the other one works too with no real damage.

I went to the auto parts store, picked up a remote starter, "bump switch", hooked it up to the relay box located on the passenger inner fender. Pop off cap, I think there are three screws, clamp one lead off starter, touch another screw, pull trigger to see if the engine turns, if not, try a different combination.

starter works alright for me... If that makes you queasy, just take the fan off... it adds about 20min onto the job total once you get the hang of dealing with those tiny 10mm bolts with your fingertips.

I always wondered though, how far does the camshaft turn when you bump the starter? I sort of figured that it would be hard to get the shaft to stop exactly where you needed it. (especially for checking the timing chain).

Also, do you really need a remote switch, or can you reach down far enough to just jump the terminals at the box with a wrench or something?

I have been using the ps bolt and I have to say it has never really tightened, I feel like you can tell if the bolt tightens because you would feel it turn without the pully turning. Also, it just doesn't take much force to turn the engine over this way. I believe there is a mechanical advantage due to the small size of the pully, it takes more force to turn the crank directly. It's hard for me to see how this could over tighten the bolt, maybe my compression just sucks. It is a lot faster to use the ps bolt and I have done it both ways. Has anyone ever had a problem with removing the pully?

If the P/S bolt works for you, there is no need to buy something. The bump starter is controled by how long you pull trigger. Squeeze and let go. When doing a valve job, no sweat. Timing change may be a different story. You're best bet is to experiment with how far the engine rotates when squeezing. Jkid, a switch gives you more control as to how far the engine turns. You would need a "u" shaped wrench or jumper wires. For me the switch is worth the price, as I want my eyes on the cam, and body parts out of the way of any spinning mechanicals .

I agree. I really appreciate the folks here that keep us shade mechanics up on what the manual says because thats the final word on the right way to do something and you stray at your own risk. :eek: I know someone has had a problem with that bolt so if you really wanta cover your back side dont do it:) I will take the chance:rolleyes:

I do the same thing. I think I have about five Snap On tools and one of them is a remote starter switch. This is also the way the FSM says to do it. It is so much easier than having to crank on any bolts be they the crank or the power steering pump.

For many things inside an engine compartment you can't find a strong enough puller which will fit into the space you have to work with...

My only experience with that shaft and pullley was when Tom Cane in San Antonio had a problem getting his off.... he brought it up here " to apply bigger hammers" ....It was off the car so we just had to deal with the PS pump and the pulley .... I have an oxy acet rig and a big anvil mounted out in the open on a trailer... so lots of tactics are possible given the working room...

It took us three heats with the oxygen acet and then pounding on that pulley ( about 20 minutes ) to get it off that shaft...( and I don't remember if we were successful as to saving it for future use ) before that I was like you guys... surely someone is kidding about the problem that can produce... but I AM THAT SHADE TREE mechanic...and you are on your own later if you use the PS nut to turn the engine..

Now you may think " it is my car, etc, etc"... true.... but when I see people posting on this forum who regularly say they are not going to follow the FSM or logical rules of physics... I promise you I won't be buying any car ...or anything else they put up for sale....LOL

OK, I have one of those push buttons that hook up to the starter, I'll try it next time and see. I know about the crank nut, thats out:D

Starter works well. Just make a short jumper wire from the + of the battery to the smaller of the 3 wires at the terminal on the passenger wheel well. (W123 location)

DANGER,
Shouldn't we include somewhere here that the glowplugs should be pulled out of their holes...or the SHUT OFF lever should be TIED CLOSED ...or something...
so that someone won't accidentally start the engine using the bump starter method ?
it could injure someone if they were not aware that is a possibility and make sure it can not happen...

well i have used the p/s nut as well as the crankshaft bolt on many cars (62 ranchero, 64 falcon wagon, 79 impala, the 300d, and i think the mustangII i had. cant remember if it was hydraulic or not), and i havent had any issues. and yes i even pulled the power steering pulley off the impala. while it was still in the car. used a 1/2"drive puller and a cheater bar, a peice of flat black iron we drilled out. done. it came off with just a little tapping (beating sorta) and some elbow grease. i am that shade tree mechanic too, hell, this is the first garage ive ever had. lol. i checked with my older brother who worked for an import shop for years....he said not to worry about using the p/s bolt. unless your compression is really really high.

and tell me, are you attacking me with every post i make. it seems so when i was asking for clarification last week on my valve adjustment.

"well i have used the p/s nut as well as the crankshaft bolt on many cars (62 ranchero, 64 falcon wagon, 79 impala, the 300d, and i think the mustangII i had. cant remember if it was hydraulic or not), and i havent had any issues. and yes i even pulled the power steering pulley off the impala. while it was still in the car. used a 1/2"drive puller and a cheater bar, a peice of flat black iron we drilled out. done. it came off with just a little tapping (beating sorta) and some elbow grease. i am that shade tree mechanic too, hell, this is the first garage ive ever had. lol. i checked with my older brother who worked for an import shop for years....he said not to worry about using the p/s bolt. unless your compression is really really high.
and tell me, are you attacking me with every post i make. it seems so when i was asking for clarification last week on my valve adjustment."

You asked the question in the first part of the thread and I answered it... very simple..
so now you offer up three American Gas engine cars as examples of why people should use the PS nut on their MERCEDES diesel when needing to turn the engine...
and then you quote your older brother " ..he said not to worry about using the p/s bolt. unless your compression is really really high. " and you can't figure out that his warning applies TO what you are argueing AGAINST because it DOES HAVE HIGH COMPRESSION... like 21 to 1..
Attacking what you say is very different from attacking you...

The experiences you have had on cars which for whatever reason did not result in extra UNNECESSARY problems... does not mean that people working on these diesels should not be warned THAT THE FACTORY SHOP MANUAL SAYS NOT TO USE THE PS Pump BOLT... Instead of the very very weak examples you have offered up... why don't you tell US WHY Merecedes felt it necessary to include as a warning in the FACTORY SHOP MANUAL a WARNING against using it ?

dude, please chill out. if there was severe issues with using the p/s bolt. then people would be posting it as well. but as far as i see.....people are saying to use it. i personally do not have the fsm yet, so i cant argue what is states. im sure youre quoting it correctly however. i am not making this a gas vs. diesel issue. but you advised not to use the p/s bolt because of the tapered shaft concern. thats why i stated the my experience with the ford falcon/ranchero, because they also used a tapered shaft. as did the nash rambler.

Very true. I can't even imagine the mess that would be created if the engine started with the valve cover off. With the engine cold, it's less likely, but it could still happen.

There's no doubt that using the crank is the safest method. People are using the PS nut just for a slight convenience and it's their choice, but they should be aware of the possible consequences.

" but as far as i see.....people are saying to use it. "--RETX
"If a thousand men say a silly thing it is still a silly thing. " famous saying

" i personally do not have the fsm yet," RETX

That is obvious and we had already figured that out.. what we can't figure out is why you are trying to convince people it is either ok or good to do something that you have been told both that the FSM says not to...and read about my personal experience concerning a problem pulley.

" why i stated the my experience with the ford falcon/ranchero, because they also used a tapered shaft. as did the nash rambler."RETX

BUT they have like 9 to 1 compression...and we are talking about 21-1 compression engines ... you still don't comprehend that your brother's statement "not to worry about using the p/s bolt. unless your compression is really really high. " applies TO THIS example. The UNLESS is the critical word in his statement.

Alright, I think it has been established that there are 3 different schools of thought on this one, and I'm pretty sure bickering doesn't really further the answering of the original question.

As far as reasons manufacturers put things in manuals:
probably 20 years ago when my dad was converting our boat from inboard-outboard to outboard, the directions for the motor mount bracket that goes on the back of the boat said that where it mounted, the transom had to be 3 inches thick. Anyway, my dad did not think it was necessary but built it up to 3 inches anyway. When he went to install it, the bolts that came with the mount were not even long enough to install it with 3 inches of fiberglass. Upon calling the company, he learned that the lawyer made them put "minimum 3 inches" because they knew nobody would actually do it, so nobody could claim their product screwed up.

So just because something is in a manual or directions doesn't mean that they aren't just covering their ass.

So as your first post to the forum... you give an example from some jake leg boat conversion company instruction sheet and imply that there are no legit physics involved in this discussion.. just people with differences of " opinion " bickering ... That is just great. Welcome to the forum. I can think of several members with whom your thinking process will fit in exactly.

ok leathermang, stop. just stop being a freaking jerk. with the exception of maybe the last post by jcraig, youre completely jumping my case and maybe his now too. i am not the only one here saying to use the p/s nut. theres at least 11 other posts saying the same thing. so why single me out? seriously man, youre pissing me off. and if you would have read my post completely, you would have seen that when i spoke of my brother, it was from his years of experience in an import shop, everything from volvo to mb to saab.
so unless you have something constructive to say, other than what you have already stated, to use the fsm (which not all of us own), then youre just stirring things up. im done. i use the p/s nut.

Alright, I'm sorry. It seems that we have gotten off on the wrong leg, but as far as it being my first post, I don't feel that to be in any way relevant. I am not aware of anything that causes your intelligence to increase with the number of times you post(I certainly haven't observed this in some people on here). And I really don't like to clutter up forums like this, but I would like to clear some things up that you said.

First of all: I don't know you, and you don't know me. I did not attack you in any way, and I don't think you had any valid reason for responding to my post the way you did (or retx's for that matter). Certainly I probably do not have the experience you have(you being 57), but that does not mean that there is anything wrong with my mental faculties, and I do not think that you are in any position to imply that there is.

Second of all, yes, I was giving an example that sometimes companies will tell you to do things that are in excess just to cover their ass; I just thought I would add a little anecdote to help my argument.

Third, I never implied that there was no legit physics involved; my post said nothing of the sort. I said there were three different schools of thought on this, and there are.

Fourth, yes, this is just people with differences of opinion, for the original post said "what is the best way" and people have different opinions on that, including the MB mechanics: Expertise is one of the weaker truth tests(go read about philosophy). And as far as bickering, that only started on this last page with your unnecessarily unfriendly postings (IMHO).

Now, I'm sorry it came to this, but I am not going to sit here and let you try to lord your 30-some-odd years of farming, welding, and being a
mechanic over my head. And as far as being welcome to the forum, I have found that I do not particularly like this place and for the most part I will stick to benzworld (other posters, i am sorry that one person's actions cast all of you in a bad light, but they do). Hopefully this thread will be closed very soon. I will not be checking this again, so don't even bother to respond.

Your friendly, unassuming co-poster,
John

Don't let the door hit you in the a55 :silly:

Damn you guys are getting nasty. If somebody wants to use the PS nut they can use the PS nut. If they have to remove the PS pump to get the pulley off someday then so be it. Don't have a mud slinging fest just because some people follow the FSM to a T and others do what works best for them with their skillset and the tools they have on hand.

You don't learn the best way to do things by listening to people yell at you, you learn by trying (and sometimes failing). Let people do that and just offer friendly advice if asked for.

What's so hard about getting on your knees and putting a ratchet + socket on the crank? Too much work? The fan and shroud can stay on to do it and it let's you put the cam lobes exactly where you want them to be adjusted.

If your gonna use the starter remember that it may start on you. This happened to me a couple of weeks ago. That goddamn crank turned about 3 degrees then it fired sending oil all over the place. Pull up on the linkage going to the injector pump and this won't happen.

use a mirror
 

Just use the crankbolt with the proper socket and arrange a mirror so you can see the position of the cam lobes while you lay on your back and crank it. If not obvious, put a bright clip on the lobe of interest. You can usually get the right position without too much jumping up and down.

Maybe someone did not understand what I posted previously, count..........

Usually, when you remove the valve cover, one of the lobes is in proper position for clearance measurement. Take a sip of beverage, lay down and with a 1/2" ratchet and 27mm deep socket.......count..1....2....3..strokes from side to side. When you get up, the next lobe is in position. Just enough up and down to give your back a break from leaning over the engine and not wear you out.

The best thing I ever did was put a jumper box off of a 1982+ turbo diesel on my 1981 NA that did not mave one. It takes about 10 minutes total to install. One of the wires you dont use coming off of a screw on the box, you can cut off at a few inches and use it as you jumper wire and it will always be there for you.

This method i found to be a hundred times more to my liking than the Crank or PS bolt/nut. Much faster also.

How warm was your engine when you were doing the valve adjustment? I removed my linkage before I took the valve cover off. I don't recall if the FSM said anything about watching out for it starting. Glad that didn't happen to me. Sounds like a big mess to clean up.:(

With the small taps you give it with the remote starter, it shouldnt even think about starting. Especially with a cold block, your engine must have perfect compression or something!