Engine Shaking---W123 OM617 Turbo---Ideas? What Next? - Page 2 - PeachParts Mercedes-Benz Forum

Diesel911 · #16 08-10-2017, 03:29 PM

Quote:

Originally Posted by iladelf

Thanks for being cooler heads than myself, everyone. I just get real discouraged and angry fiddling with this old car. Seems like every two months or less, I'm doing something to it. For sure, these old W123 diesels are not low-maintenance. From fuel filters to valve adjustments to motor mounts to power steering fluid r&r to fixing a/c or heat to automatic door looks to power window operation to steering/suspension issues to exhaust flex pipe replacement to the injection pump to the injectors to...

It...never...ends. Sure, some of this you'd run into with any car, but I have never, ever owned a car that required so much of either my time, my family's time assisting me or in a mechanic's shop.

Back on-topic, I intend on moving some of that rat's nest of vacuum to at least get a wrench on to loosen. Still don't think I'll have enough room to fit the 12mm in to do the adjustment. With a night of sleep, perhaps it will become an easier project to do. For the record, the back of this bolt looks gold, so that to me would indicate the replacement rack damper bolt. Doesn't mean it's still functioning well, though.

Ya, in the first 3-4 years after I got mine it spent 3 Months out of the Year in the Drive Way waiting for parts or me to learn what was needed to fix it. Sometimes it was some Tool I needed to make or acquire.

Once you have enough labor invested in it you value it more don't want to get rid of it and start over on some other vehicle. Somewhat like a imperfect Marriage.

Junkman · #17 08-10-2017, 03:35 PM

Let any car become ragged out and it takes lots to bring it back to specs. I've been cussing my 00 Ram that falls apart around the lovely Cummins. **** Dodge. They let some stuff into production that never should have been.

Diesel911 · #18 08-10-2017, 03:41 PM

Quote:

Originally Posted by chrisgt

My car went from fine to violently shaking all at once when the little spring in the damper bolt broke, so it's definitely worth a try.

Ya, do what is easiest and free first to include eliminating air leaks and a valve adjusutment.

After that next cheapest is replacing Mounts.

On mine the new Damper Bolt did not have any + effect till I fixed all the other stuff that can cause shaking. Others have had better luck and just replaced the Bolt and got results.

After that Injectors and uneven compression issues are about all that is left.

I have not read anything that has odd loading on the engine like the AC or Transmission can be cause so they are not on the list of stuff to check, fix or adjust.

iladelf · #19 08-10-2017, 03:49 PM

And the hits just keep on comin'. First pic shows what kind of a rat's nest I'm dealing with. So, go to remove the rubber Y from the VCV, but hear a "tick" sound when I go to move it...and find the black vacuum line pointing towards the passenger compartment...is now no longer connected to whatever it's supposed to be connected to. (see subsequent pic) So, what is that vacuum line supposed to be hooked to? Let me guess...somewhere on the frickin' transmission, which I won't be able to get to without jacking up the car and contorting myself like a gymnast to actually hook it back up, only to have it fall right off again when I go to move that vacuum line mess above.

jabstick420 · #20 08-10-2017, 03:56 PM

I believe that's a vent line that goes through the firewall and sits behind the cluster.

its left open.

jabstick420 · #21 08-10-2017, 03:57 PM

looks like you have the old style primer pump?

that could be a potential leak.

iladelf · #22 08-10-2017, 04:28 PM

Upon further review online, jabstick, I agree that the "loose" plastic hard line is indeed just a vent, so that's good news. I actually think it was just sitting loose inside the engine bay. Does it HAVE to be re-routed through the firewall into the cluster area? I have no idea where to shove that thing through the firewall. Wouldn't think it would matter where a vent was located, other than it would be better to be in the passenger compartment, due to potential contamination/blockage from either rain, road grime or leaking lubricants in the engine bay.

Regarding the primer pump and all the other ideas, I think they're all fantastic, but to me, the simplest thing to attempt is the rack damper bolt adjustment, buy a new one if needed from the Pelican and try again, then fiddle with all the other stuff (proper fuel supply, injectors, compression, etc.). Of note, I don't think the issue relates to these other things. Why? Its performance is quite snappy; it will spin rocks in a gravel parking lot all over the place, and gets right on it when I need to. Believe it turns that 11 second 0-60 quite easily (IIRC, that's up to spec).

Regarding this car, I grew up in this ride; 'twas my fathers. While he did much of the basic maintenance, there are things he just didn't take care of, and they're now coming back to bite me. I call it the Curse of **rgsma (real name deleted). Seemingly everything that guy's Youtube page posts about, I seem to immediately have problems with, as if my car is watching the videos with me and decides to test my loyalty by throwing craps.

Don't get me wrong; Mr. Snergsma (don't want to use his real name here on the Pelican) has provided me with parts and how-tos that, along with the Pelican and others, have helped me to keep this thing a daily driver. And I apprecate that, along with the help from you fine folks. I try to help others on here when I can as well.

iladelf · #23 08-10-2017, 11:14 PM

A question; tried this today, and basically had to remove several vacuum lines to either a)get a large wrench on the lock nut or b)get a stubby wrench and my hand in the confined space to move the smaller nut. There was no way I was going to be able to get both hands in there to hold the lock nut with a wrench after loosening while turning the adjustment nut inward.

1. Believe with the space clearance issue, I might be able to do this with a crow foot/socket wrench on the large 14 mm nut and either an S-type obstruction wrench or a flex-head combination ratcheting wrench on the other. Other ideas for that hard-to-reach area?

2. Once the large nut is loosened, is the small nut allowed to turn on it's own, or does it need to be loosened as well? I assume that a)both nuts loosen and tighten counterclockwise and b)if I have to really crank on the 12mm adjustment nut to loosen, it likely was previously tightened all the way in.

BillGrissom · #24 08-11-2017, 01:02 AM

Yes, they ran the vent tube into the cabin to suck in cleaner air. Should have a small clear filter before it gets to the VCV.

Most of your issues are general "workin on cars" stuff. Before complaining, peer under the hood of a new car, especially a hybrid. In my 65 Newport, it is easy to swing a wrench, but those days are gone.

Maxbumpo · #25 08-11-2017, 09:01 AM

Quote:

Originally Posted by iladelf

And the hits just keep on comin'. First pic shows what kind of a rat's nest I'm dealing with.

Wow, that is indeed a rat's nest! I do believe that someone has "fixed" your vacuum system, and now too much of the new design is blocking access to critical things, like the rack damper bolt.

I would suggest that you consider getting together proper vacuum line documentation and fresh rubber joints and line, and a few good pictures of what the set-up should look like (even better - get hands-on with a car like yours that has not been "fixed" like yours).

A great source of pix is online auctions like Bring-a-Trailer and such, where high-end cars that are low mileage and 100% original are sold. Usually they have great pix of the engine compartment.

Maxbumpo · #26 08-11-2017, 09:08 AM

Here's a list of 300Ds on BaT, the few that I looked at had nice pix of the engine bay which may help.

mercedes 300d For Sale - BaT Auctions

iladelf · #27 08-12-2017, 01:08 AM

Maxbumpo, was able to find a "shot" of what the vacuum line routing "should" look like. This screenshot (literally, I used my phone camera) is from Dieselgiant.com's promo video on performing the rack damper bolt adjustment/replacement.

I see the vac lines are mostly routed above and around the oil cooler housing. However, I see problems with that (if that's the way those lines are "supposed" to be) due to having issues with those lines tangling with removal of the oil cooler top to replace the oil filter. Pick your poison, apparently.

I will get at this tomorrow; will be attacking it with some offset tools, and hopefully get a few pics of that as well.

iladelf · #28 08-13-2017, 12:00 AM

Well, wasn't able to attack this with offset tools (didn't have available what I needed on location), but was able to get at the front nut...from underneath, instead of above. Then after attempting a few small tightenings of the adjustment nut, found it was bottomed out and could move no more. Result? Engine still doing the Hippy Hippy Shake.

Couldn't tell if rack damper bolt was the new or old one. Looked old, but saw a reflection of metal on the edge that could possibly have been gold-colored. Doesn't matter; time to order a new one from here on the Pelican and have a go at it again once received.

Maxbumpo · #29 08-14-2017, 09:36 AM

"screenshot": A better pic can be obtained using the [print screen] button on your keyboard, then open Paint and "cntrl-v" to past the screenshot as a JPG. Edit as needed, save and post.

When was the last time the injectors were serviced? Delivery valves?

My understanding of the rack damper bolt is that it cures a loping idle, not a shaking engine.

iladelf · #30 08-22-2017, 08:22 PM

So, bought a new rack damper bolt from the Pelican. After taking out the original, it was indeed the old, silver style, and the spring on the end was pretty easy to push in. That was my suspicion exactly.

I took the original out by using an offset 14mm S boxend wrench (HF has those) to loosen the locknut, then backed it out by hand. That said, that particular wrench was pretty much unusable in the adjustment/lockdown later.

Next, looked at the O-ring, which was fine, lubed it and placed it on the rack damper bolt after threading said bolt through the large locknut. I found you have to tighten the damper bolt quite a bit so that you can get it back into the hole without the bolt assembly hitting the oil cooler behind it. I then hand-tightened the whole assembly in, and began fiddling with the setting after starting the car. Mind you, the car was at operating temperature when doing this.

In order to do so, my brother cut off the ends of both a 14 and 12mm open end wrench, and we came at this FROM UNDERNEATH. Basically, right next to the oil cooler line that runs right by this area. It is still quite a sonuvagun to do, but...all of a sudden...after tightening...viola!, the car's idle starting leveling out and basically purring like a kitten, with very little engine wobble. The only problem was, at random points, the engine then would decide to rev-up a bit at odd moments, then back off to a normal idle. I suspected quite likely we had (have?) the bolt in too far, but as my bro said, probably a good idea to drive it a few days to see if it stays or if the spring loosens a bit on its own. Upon driving that day, it would kind of "hunt" a bit at idle, but not always. The last two days, however, it has behaved normally, with very good idle and little to no engine bay shaking.

Again, I may have to back that bolt off a bit if I get more random surges down the road, but for now, this has seemed to do the trick. YMMV.

Btw, it may be mere coincidence, but throttle response (always pretty good anyway) is better and the car seems to be smoking less than previous. Still goes black a bit when the throttle is hammered, but not as much as before.