So is this failure just something random or is there some upkeep of the belt tensioner that can prevent it?

-Jason

__________________
1991 350SDL. 230,000 miles (new motor @ 150,000). Blown head gasket

Tesla Model 3. 205,000 miles. Been to 48 states!
Past: A fleet of VW TDIs.... including a V10,a Dieselgate Passat, and 2 ECOdiesels.
2014 Cadillac ELR
2013 Fiat 500E.

That's exactly what I would like to find out myself. I'm to take out the serpentine belt and install a new vac pump...don't want it to come to costly engine repair....

An OM606 timing cover will fit on the OM603?

__________________
It's not the years, it's the mileage.

The variables I can see are the condition of the spring, small shock, and pivot bearing on the belt tensioner assembly. The other points of stress may be the motor mounts. Like I said mine happened at 25 MPH going over a speed bump.

I had most of my tensioner system replaced at 176,000 miles...which was 10,000 miles ago.

New Shock, New lever, New Pulley...I had to replace them because it wasn't so straight anymore. Something like from " | " to " / ". Also had motor mounts replaced 3,000 miles ago. The only thing I didn't replace was the spring itself. It still looked good to me...good idea or bad idea?

Hope this is good PM.

__________________
It's not the years, it's the mileage.

Others have commented that failed motor mounts can cause problems with the 603 engine (and perhaps others). When the pneumatic motor mounts die, they allow the engine to sag quite a bit--an inch or more--and this can cause trouble. It's relatively easy to learn how to inspect the motor mounts and the serpentine belt tensioner; everyone with this kind of hardware in their car should learn how or make sure someone else regularly checks. I would think that the OP's failure (breaking of the timing cover) is unusual.

__________________

"Buster" in the '95

Our all-Diesel family
1996 E300D (W210) . .338,000 miles Wife's car
2005 E320 CDI . . 113,000 miles My car
Santa Rosa population 176,762 (2022)
Total. . . . . . . . . . . . 627,762
"Oh lord won't you buy me a Mercedes Benz."
-- Janis Joplin, October 1, 1970

As far as motor mounts, There are only 2 of them right? Just 1 on each side?

Do you look for cracks? Rough idling?

What's the typical service length of the motor mounts?

__________________
It's not the years, it's the mileage.

The original timing cover was a flawed, weak design. I don't think anything is going to prevent the failure. My tensioner components were all fairly recent, and mine failed when starting the engine one afternoon (very loud cracking noise). I also don't think the motor mounts have any effect on it either. Kind of like the #14 heads... some crack, some don't, but there isn't much you can do about it except install the upgraded part when it fails.

The W124 has 1-piece hydraulic motor mounts. You measure them to determine if they are good or not. Click here to view the factory PDF file, see pages 3 and 4. However, I don't believe the W126 uses these, so if you have and SDL, this won't apply. Typical service life seems to be 50-100kmi (with OE or OEM Sachs/Boge mounts), with the left mount lasting longer than the right mount. I've heard the aftermarket stuff can fail within months, but I don't have personal experience with those.

__________________
Dave
Boise, ID
Check out my website photos, documents, and movies!

I believe so, but you also need to swap to the 606 vac pump & IP timing device (pump drive) as well. The 606 cover has an additional oil feed for the 606 pump, which is why you can use the 606 pump on a 603 cover.

--------------------------------------------------------------------------

EDIT:
(This is what I get for posting before reading updates)
[GSXR has already answered the application questions][Thanks, Dave]

Whoops,now I'm confused (Not unusual)

"The 606 cover has an additional oil feed for the 606 pump, which is why you can use the 606 pump on a 603 cover."

So...I could use a 606's Timer and Vacuum Pump on the 602's TC ?
OR I need a 606 "Set" TC,Vacuum Pump and Timer ?
(for installation on the 602)

---------------------------------------------------------------------------
auspumpen,


(I'm looking at the US EPC and the Russian EPC.)

I'm assuming from what you posted on the forum,that
the 604/605/606 Timing Cover will fit the 601/602/603
engines...With the added benefit of being able to use
the direct drive vane type Vacuum pump.
(Rather than the seemingly self destructive reciprocating Vacuum Pump)

Would you not have to also install the 606's I.P. "Timer" to drive the Vane Type Pump?

Have you the Mercedes model number ? (124.XXX) for the "Donor" 606 Type?
Have you the Timing Cover's Part Number?
have you the Timer's and Vacuum Pump's Part Numbers?

Thanks,

__________________
'84 300SD sold
124.128

Yes, two motor mounts, left and right, on the engine, and a solid rubber mount back on the transmission. When the mounts fail, they collapse. I'm sure that someone here has posted pictures of "old" and "new" mounts. A good shop light and a set of Mark-I eyeballs are needed to detect collapsed mounts. As the mounts absorb some of the engine vibrations, you can often hear and feel that "something is wrong" when the mounts collapse.

It's recommended to replace both of the mounts at the same time. Not a difficult job, you unbolt the mounts, jack up the engine an inch or so, remove old, insert new, fit the bolts, and lower the jack. Although my indy did the mounts on my 603, I did the mounts on my 606 and it was not a bad job at all.

Service life is probably 100,000 miles but I would like to hear other opinions.

Jeremy

__________________

"Buster" in the '95

Our all-Diesel family
1996 E300D (W210) . .338,000 miles Wife's car
2005 E320 CDI . . 113,000 miles My car
Santa Rosa population 176,762 (2022)
Total. . . . . . . . . . . . 627,762
"Oh lord won't you buy me a Mercedes Benz."
-- Janis Joplin, October 1, 1970

E250 diesel / chassis 210.010 / 605.912 engine
Timing Case cover (two):
604 015 01 01
602 015 01 01
Vacuum Pump (two):
000 230 31 65
000 230 36 65
Timing Device (two):
605 070 06 45
605 070 09 45
-----------------------------------------------------------------------------
E300 diesel / chassis 210.020 / 606.912 engine
Timing Case Cover(two):
604 015 01 01
602 015 01 01
Vacuum Pump (two):
000 230 31 65
000 230 36 65
Timing Device (two):
605 015 01 01
605 070 09 45
-----------------------------------------------------------------------------
E300 Turbodiesel / chassis 210.025 / 606.962 engine
Timing Case Cover:
602 015 01 01
Vacuum Pump (two):
000 230 31 65
000 230 36 65
Timing Device:
605 070 10 45
-----------------------------------------------------------------------------

[Sherlock Holmes mumbles..."It's not Empirical !"]

WAG:
602 015 01 01 is the "Vane Type" (Vacuum pump)friendly Timing Cover.
000 230 36 65 is the "Vane type" direct drive Vacuum Pump
605 070 10 45 / 605 070 09 45 are the Direct Drive type Timing device(s)

All of which are equally usable on the 606.962 AND the 602.962.

Confirmation(Affirmation)...Comments...Corrections ?

Thanks!

__________________
'84 300SD sold
124.128

Yes. The 606 pump & drive are totally different. I have some photos, I need to post them on my website.



You need a "606 set" with TC, vac pump, pump gasket, and timer. And even then, I would want to verify that there will be proper oil supply to the vac pump if a 606 cover (and pump + timer) were installed on a 602/603 block. I'm still not sure about the oil supply issue. As long as that checks out ok, the upgrade should be fine. Shame I didn't know about this when my timing cover blew up, d'oh!

I think the life of the gel filled engine mounts is more on the order of 30 to 50K miles, I have replaced one set after about 4 years of service and average mileage is only about 8K miles/year but lots of stops and starts, that's probably what kills them.
I wonder if Phil or the folks at PeachParts would share the sales volume on this part? like how many are sold per year, for the relatively lesser number of cars on the road with these compared to the solid rubber mounts on the 617 family I'll bet the gel filled mounts get replaced five times more often!

List on these suckers is over $100 now!
Incidentally the best test is to watch the engine at the moment its shut off. If it lurches side to side its probably shot mounts. I remember greasybenz bringing his '87 300Dt over and complaining about the fan hitting the rad shroud, I grabbed ahold of the crossover pipe and tugged on it real good and the engine rocked around, which it should not! When these fail the engine can rock forwards on braking and the fan hits the shround Don't let them get that bad! they don't look cracked looking like the "old style" all rubber mounts. I guess maybe the gel gooshes out somewhere?

Attached Thumbnails

 

__________________
'95 E320 Wagon my favorite road car. '99 E300D wolf in sheeps body, '87 300D Sportline suspension, '79 300TD w/ 617.952 engine at 367,750 and counting!

It depends. If the mount is an offshore copy, then yes, they probably have a much shorter life span. The OE/OEM mounts should last longer. See the PDF file I linked to in an earlier post, that shows how to measure them. In my experience, the right mount seems to fail sooner. I suppose you could squeeze some more life out of a set by swapping them left to right after 50k or so.



It would be interesting, but part of the problem is, you don't know what brand (or how old) the mounts are which are being replaced. Regardless, I'd rather change the 1-piece hydraulic mounts five times, than change the jigsaw-puzzle multi-piece solid mounts (with shock absorber, etc) on the 123/126 chassis - ugh, I hate that design.



Yes - ouch. An interesting side note is that the original mount was part number 201-240-29-17 for the '87 300D (and many other W124's, including all early 300E's). This was superceded to a different part, number 124-240-19-17. However, the newer part number is ONLY available via OE/dealer sources, not aftermarket. The aftermarket mounts are all 201-240-29-17. I have a suspicion that the newer mount may be redesigned and may last longer, but hardly anyone is willing to pay twice as much for it (OEM Sachs/Boge 201- mount is ~$50 or so, the OE-only 124- mount is over $100 wholesale). It's a shame the newer mount isn't available via OEM sources at a discount, like the older mount is.



Measure them per the FSM procedure mentioned above, replace if they're out of spec.



Whoa, hold on a sec now. The fan shroud is adjustable, first step is to make sure the shroud is adjusted properly. Then measure the mounts, if collapsed, then yes they will let the engine sit lower than normal. But even with NEW mounts, the engine will move all over when you grab the intake and yank on it. That's how it isolates vibration. Also, it is very, VERY common that the lower radiator support gets been bent inward, after kissing a parking curb. This shoves the bottom of the radiator inward, reducing clearance to the fan, and also makes the mount holes on the plastic sound panel under the engine not line up properly. The fan can hit the radiator and/or shroud under hard braking in this case, however this is NOT the fault of the engine mounts, and can happen even with new mounts. Don't automatically assume mounts are bad if the fan is hitting things it shouldn't!




I've never seen one leak fluid externally. My understanding is that there are two or more chambers inside the mount, and perhaps fluid migrates from one to the other, or the rubber portion inside simply wears out (similar to how the rear mount will collapse).

How about using the cooling air-duct from a '94/'94 E320 (the one that cools the passenger-side engine mount) to extend the life of the right engine mount? I am retaining the cooling duct in my '95 through the 603 installation hoping it will help.

Also, regarding the 606 timing device; Is the advance profile the same as the 603.96x? How about the 603.97x? Different RPM range on these engines, I'd expect the advance profile of the timing device to be different also, does anybody know?

__________________

Gone to the dark side

- Jeff