Injection timing the OM617 turbodiesel - illustrated
 

Go to Cars - Technical - Motor on my web site.

Enjoy!

Thomas,
Nicely Done! Thanks for sharing!

R Leo

So, Thomas, what's the upgrade policy on the CD? ;)

Dave
 

It's a loss leader, so probably annually!

that is a great pictorial thanks i will certainly use on my 300tdt next weekend

can this be used on a 616 240d motor?

Once again, job well done. Very professional and methodically organized pictorial, too.

Always nice to see Bertie the Border Terrier in slide 25.:)


Did you notice an increase in power and / or fuel economy since you completed the job?

If so, how much?

Paul
 

Thank you.

I prefer to answer your question after several tanks of fuel have passed through the engine to minimize errors in the data.

I'll post later.

Madsen
 

The injection timing device will work on the 616 injection pump.

I'm not sure, however, whether 15 degrees ATDC is right for your engine. Maybe others here can advise?

Great pictorial! Just a few comments/edits:

1- You can get the fancy RIV tool for $200-$225, last time I checked, if you know the cheapest source (email me for details). This tool comes in VERY VERY handy if you're messing with the timing chain or doing major work, where the pump can get more than a few degrees out of time. That way you can spin the crank while watching for the light to come on and not risk damage. It even alerted me that I had the camshaft 180 degrees out while replacing my valve stem seals. ;) (long story, don't ask.)

2- The lock pin tool works on all OM60x engines, and certain OM617.95x engines. There are a few variants in the 1981-1983 range that may not have the 17mm hex plug. CHECK YOUR PUMP before ordering the tool! If you don't have the hex plug, you can't use the tool, and MUST use the "wet" methods. AFAIK, no OM616 engines can use this tool (at least no USA models).

3- Spec is 15.0 degrees ATDC, +/- 1.0 degrees. I found that on my OM603, I picked up a little MPG setting it at 13.5-14.0 degrees. I'd recommend setting it at 14.0. The newer OM60x engine spec is 14.0, +0.5, I think. :)

4- The tool probably won't "pop" into place on it's own. It has a slot, and the slot must latch onto a tooth/nub on the internal flywheel. This requires you to gently turn the tool shaft (with the red cap) as you ease the engine over, or as you wiggle the pump around. It's not hard, but don't expect it to pop in by itself (might happen but won't always).

5- I think I disagree with the "correction factor" based on timing chain stretch. That would essentially set the IP to match the camshaft, not the crank. I believe (?) the IP timing should always match the crank. If you want to fix the cam timing on a 617, order one of the offset cam keys. This leaves the crank & IP settings alone. For a 60x with a stretched chain, there are no offset keys, you must replace the chain (if it is 4 degrees stretched or more). Otherwise, set it at 14.0 (or 15.0) based on the crank indicator, regardless of what the chain stretch is (IMO!!). Also note that on the 60x engine, the TDC indicator can move withing a 3 degree range if the lock bolt is loosened. On my engine it was off 1 degree (verified with a dial gauge on the piston while the head was off.) Hopefully this isn't a common problem. :eek:

6- If you replace the timing chain due to stretch, you will have to re-time the pump, if pump timing was correct with the stretched chain! The new chain will advance the pump timing by half the chain stretch. Example: Your chain is stretched 4 degrees, pump is 15.0. Roll in a new chain, stretch is now zero, pump is now at 13.0. Check chain stretch FIRST, replace if necessary (60x), or adjust with an offset key (617). Then set the IP timing. This is a miserable enough job that you don't want to do it twice. ;)

7- NEVER EVER EVER rotate the engine, or IP, with the lock tool engaged! You may cause severe damage to the pump internals. This is where the expensive RIV tool is nice, you don't need to worry about this. :D :D


Here's a photo of the RIV "A-B" tool:
http://www.W124performance.com/images/OM603_injection/IP__RIV_tool.jpg

Here's a photo of the lock tool:
http://www.w124performance.com/images/OM603_injection/IP__lock_tool.jpg


Best regards,

I've always wanted to "reverse engineer" the RIV tool, since it looks so simple externally. I'm sure there is more than meets the eye, internally, but what? Had it apart? ;)

The wiring and "light box" are quite simple, I believe. The main cost is the screw-in fitting. It's a very tight tolerance item, with two spring-loaded metal contact pieces that are electrically separated, embedded inside a round nylon housing. One contact triggers light A, the other light B. When both are lit, the internal flywheel tang is dead center on the two contacts so they both are triggered. Nifty piece. Would be quite hard to replicate, IMO.

Price in Europe, in Euro $'s, is $151:
http://wwwsg.daimlerchrysler.com/Projects/wi/cda/etpl?ETNR=W617589082100&from=query&etpl_lang=01

Order from speed-autoteile.com (in Germany) and you can probably get it for +/- $200 USD or so - I think. :cool:

Suginami and gsxr
 

Paul S -

Some feedback on fuel consumption.

After several tanks of fuel, consumption is down 10%. Mixed city and highway (75-80 mph) with a/c on returns 25 mpg compared with 23 mpg before the adjustment.

One other data point. Coming back on I-80 the other day, I put 491 non-stop miles at a cruise setting of 79 mph on one tank, no a/c, and got 26.8 mpg, this just after going over 200,000 miles on the engine. The car runs at 105 mph at 4750 rpm, with a few more mph to come.


Dave M -

Thanks for your thoughtful response.

That electrical tool sounds super, but it's too much for me to justify, absent major IP work.

As for the 'correction factor', as I am not adjusting for chain stretch with Woodruff keys, it seems to me that you want the IP synchronised with valve timing rather than with the crank, thus getting injection at the correct point. I take your point about the 2:1 ratio of cam:crank degrees, and will update my piece.

Your point about not rotating the engine or IP with the tool engaged is right on, and addressed in my piece. I only install the tool after setting the crank, which remains untouched thereafter. With the injection lines removed, twisting the IP (after loosening the lock nuts) about its axis is very easy and I found getting the tool to click in was both simple and obvious, at which point all twisting ceases! You make an interesting point about twisting the red buttoned shaft to get it to go all the way in - I'll add that.

Thanks for correcting my error on the use of the tool with the 616 engine - I should have written it's OK on the 606, noy the 616.

Dave,

Not to hijack Thomas' thread, but; just as ignition timing has moved from static (really old timers) to dynamic (powered xenon timing lights), I'd think this might be the wave of the future: http://www.autotestsys.com/Merchant2/merchant.mv?Screen=PROD&Store_Code=ATS&Product_Code=FER-764&Category_Code=HT

Anyone tried one?

PS: there are different sized connectors that fit our injector lines.

Thomas,

Sounds good - thanks! Glad to see you got a MPG increase. I didn't on my 617, but I did on both my 603's. The electric tool does require some extra justification, that's for sure, no argument there. I'm still thinking IP injection should be related to the crank, irrelevant of cam timing, but until we find some data to support one method or the other, it's just an opinion difference. ;)



007:

Ah, the old clamp-type tool. The problem with these is that you don't know what to set it at! You need to set one car - any OM61x/60x diesel - with the lock tool or RIV tool. Then attach the pulse-type tool and read the output. You can't use the "15 ATDC" number with this tool, they're using totally different reference points that are not related. If someone would buy the pulse tool, and post what the magic readings are, we could use those on most all other MB diesels. :D


Best regards,

Well, now would be the right time for me to purchase the Ferret, having just done the tune-up, but I cannot justify the expense for something I would use so infrequently. I have searched everywhere and cannot find the right setting, as Dave points out.

However, if anyone out there is interested in buying one and mailing it to me, I would be glad to return it with the calibration setting, based on my newly tuned (and well running) 617 motor.

Dave - the more I think of it, the more I like the idea of the 3 litre 6 cylinder diesel in the W126. Quieter, as you have pointed out than the five, all the benefits of the mid-run W126 enhancements, a little more power, and doesn't explode like the 3.5 litre. Plus, of course, hydraulic valves, obviating the 15k mile adjustment, but I assume you still have to pop the valve cover to determine chain stretch. What's the key test to determine if the engine has overheated - compression? And why is the six so prone to overheating?

About the 3.0 liter six cylinder diesel engine in the later W126 cars - I know that most here on this site are concerned about cracked heads and overheating on this engine, but I've discussed this with the legendary Enrique at Mr. MB Motors in Southern California, and he swears that the newer engine is a better engine than the five cylinder, and doesn't have a high failure rate of cracked heads and overheating.

I've got a clamp-type tool, but the clamp is the wrong size. It's an AVL 875 and the manual is in German.:mad:

Thomas,

I'll lend it to you if you can send it back with the right clamp and a translated manual.:D

RLeo is always smarting off in GERMAN.. lets make him translate it... LOL

Der Unterschied zwischen gescheitem Deutschem, das von den Computern und von Deutsch übersetzt wird, die intelligent gesprochen wird, ist sehr groß.

THAT DOES IT ! Send the manual to Randy....

I just got off the phone with AVL. They have an office a few miles away that they didn't have when I bought the unit. Someone there is going to try to find a translated manual as well as the correct size clamp.

6.35mm right? or is that what came with it and I need 5mm?

What size is that inj line?

6.35 mm is 1/4" inch and I heard that is not for our cars. I assumed 6 mm. from another website, but I'll throw a "mic" (pronounced "mike" ;)) on a line tonight and let you know what I get. I'll bet AVL will get back to you with the exact answer for Mercedes as I thought it's a German company. Dieselmota (something like that) is a guy (on some BBS's and on eBay) who imports a lot of German stuff, including AVL stuff. He'd know the size.

Edit (later that evening);) I measured 5.95 mm., so I assume the 6.0 mm. is the one to buy?

Enhancements added
 

I have updated the slides for Dave M's comments. Thanks again Dave.

Yep, still pop the cover to check stretch. But on the 603, it's easier & cleaner, IMO - no linkage to mess with either.

As to how to test for past overheating, there's no test that I know of. There is a rudimentary test for the result of overheating - the dreaded cracked head. To test, open the radiator cap with the engine COLD to release any pressure and equalize the system. Then fire it up, warm it up, and drive the car hard - numerous full throttle trips to the redline. Run it as long and as hard as you want. Then park it overnight. The next morning when COLD (same ambient temp as previous day, approximately), pop the hood and squeeze the upper radiator hose. It should be soft and squishy, as if the cap were removed. If so, the head is probably fine (assuming there is ZERO coolant loss). If it's rock hard and tight as a banjo string - can't pinch at all - there's an excellent chance the head is cracked. Figure $900 for a used head, $1800 for a new one (bare), and either a couple hundred bucks in tools as DIY, or ~$1000 labor at a shop. I like these engines so much, I think it's worth it, if the problem happens during ownership just eat the cost and fix it. The new heads are stronger and shouldn't crack in the future.

Why do they overheat? Well, the cooling systems are the common fault, often from not using MB coolant and not changing it frequently enough. Also the fan clutch has a finite life span as they slowly spew the silicone fluid out and stop working properly. You can re-fill the original fan clutch (with metal blade), the new replacement clutch (from the OM606, with plastic blade) may not be refillable. Well, nobody has figured out how to refill the new one - yet. Keeping the fins clean to ensure good airflow is required, and testing operation of the electric fan & it's triggering senders is a good idea as well. When shopping for a car with a 603, pay attention to the temp gauge. They should stay under 95C in most driving, maybe up to 100C on a hot day, idling with the AC on. They should rarely if ever get to 105C (full load up a steep hill with the AC on or something), and it should cool down (under 100C) as soon as load is removed. Mine are very stable in the 90-95C range unless under load, but always drop right back.




HTH,

Paul, I agree with Enrique. The OM603 is a much better design in MANY ways over the OM617. Much more refined, quieter, less maintenance, more power, better MPG. But it just won't tolerate abuse and/or overheating like the OM61x, which was almost impossible to damage! Anyway, the 1986/87 six-cylinder 3.0L engines (OM603.96x) all came from the factory with cylinder heads that were weak - not strong enough in certain areas to withstand temporary hot running conditions. They will eventually crack. MB fixed this on later 3.0L engines (not shipped to the USA), as noted in the service manual, by making the castings thicker in some places. But all these USA 3.0L engines (86/87) ARE prone to cracking! I personally know of a good half-dozen or more, mine included. The fact that there were FIVE redesigns of this head (six part or casting numbers), and also FIVE redesigns of the head gasket (again, six total part numbers), shows that MB realized there was a problem with the original design back in 1986 and worked to perfect it as years went by.

The 1990-95 six-cylinder 3.5L engines (OM603.97x) all have a stronger version of the head, and these very rarely have head or gasket problems. However as you probably know, *all* those 3.5L engines had weak connecting rods, which oval out the cylinders, requiring a MUCH more expensive fix - which is NOT a DIY project like the head. Luckily, the 3.5L engines provide good used heads for the 3.0L! :p They're scarce and not cheap ($800-$1200 typically, used, with cam & lifters if you're lucky).

Now, the OM606 engine used from 1995-up in the USA does seem to be a much better engine, with no head or bottom end problems that I'm aware of. Perhaps that is what Enrique was referring to!? :D On a side note, I have heard of very, VERY few OM61x heads cracking, or gaskets failing. Check this forum and you'll find lots of threads on OM603's cracking, but few if any 616, 617, 601, 602, or 606.


Regards,

Dave
 

Thanks.

Do the fan clutches on the OM617 leak also?

I'm religious about cooling system maintenance and always use MB antifreeze, BTW. Really saw the benefits on the trip last week (2,500 miles in 5 days) where the engine would pull like the proverbial horse up steep mountain passes, while registering a modest increase in coolant temperature from 87C to 89C, a/c off.

Taking her up to 4,750 rpm (105 mph), with a little more on tap, on a level road, saw no increase in coolant temperature.

I'm on my third water pump (201k) and use one with the MB logo, preferring to believe tales of aftermarket pumps being less effective, although I have seen no compelling proof of this.

Come to think of it, I now have over 250k km during my ownership so I guess I'm eligible for the lapel pin. Got the grille badge with 153k miles on the odo (250k km).

I honestly don't know much about the 617 clutches. I don't think they leak, they seem to be a different design. The 603 clutches are always wet after a few months, and they collect dust and grime all over the face. You clean it off, and it's back a few months later. I've never seen that on my 617 clutch. Also the 617 clutch is easy to check with the "roar" test, plus it stops instantly if you kill the engine with the clutch engaged on a hot day. Not so on the 603, never roars, and just stops slower - never seems to fully lock. At least with the newer 606 clutch (which both of mine have). Kinda odd, and makes it hard to test!!

On a related note, my 617.952 runs at incredibly steady temps - 85-90C almost all the time. Even in brutal summer heat, whether idling or climbing mountains, I can't get it over 95C. Very, very stable. To me that indicates an excess of cooling capacity with things in working order (I have recent radiator, clutch, t-stat, etc). The OM603, even when perfect, will run hotter. High speed runs using max power will drive the temps to 100-105C even on level ground with cool ambient temps. That's the price you pay for 20% more horsepower with basically no increase in radiator area (I'm assuming). It shouldn't run towards the red (110+) unless something is wrong though, and it should cool down within minutes after the load is removed. At least my 603's behave that way!

:) :)

They must leak... the instructions say they are supposed to be stored Vertically even at the parts store....

Sorry to interrupt the flow of info guys, but I'm fairly new at diesels, can anyone explain to me or point me in the right direction on how you determine the amount of timing chain stretch one has on his vehicle? Thanks...

I'd still like to know what the newer and better engine number is for the 3.5L engines. OM603.97what?

There is one at work here, W126, a white one, and I just love the car.

Thanks

Since Dave's post the price in Euros has skyrocketed due to a weak USD.
FYI an RIV tool is presently on eBay:
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=4539684666&category=43989&sspagename=WDVW

I recently bid and won an Ebay auction for both the RIV timer and timing pin for $226--used. Figured I had to pick one up before the price climbed above $400, which it very well may.