I'm new to the forum but I may have a serious problem with my 1999 E300D that may end up costing me a lot of money. Several people have suggested you guys could help so here's my story...

I bought a wonderful 1999 E300D with 75K miles on it several months ago. It seemed to run fine when I bought it buy with a hint a miss at idle. I had previously owned a 1984 300D that shook a lot so the 1999 model seemed smooth as silk by my comparison.

It needed glow plugs so i had a shop do that work for me. After I got it back the car had a very noticeable knock that it didn't have before and it ran rough. After my complaint they took the car back in and adjusted the timing. The knock was gone and I drove away. A week later it started missing during idle. Just one cylinder once in a while.

At this point I finished converting the car to VO. (I've been doing VO for years and know what I'm doing in this area.) As the weeks have gone by the miss has grow to become consistent at idle and I'm trying to get it fixed.

Here's what's been done so far:

1.) Air filter replaced
2.) Run 'Diesel-Purge' through engine.
3.) See-Thru filter added to fuel line feeding lift pump. No air seen in fuel.
4.) Cracked injector nozzle lines and found miss isolated to cylinder 3.
5.) Switched nozzles between cylinders 2 and 3. Miss still at 3.
6.) Removed all nozzles. Professionally cleaned & tested. All fine.
7.) Replaced injector nozzles. Problem still at cylinder 3.

Here is the most troubling symptom of all. The miss goes completely away when I first switch to VO. My feeling is this is because the VO is a slightly higher viscosity during the first few minutes as the cool initial VO mixes with the diesel fuel in the injection pump. Anyway, until the VO gets to around 160*F the car runs perfectly. At that point the car misses on VO just as it does on diesel.

Now my mechanic wants to pull the injection pump and rebuild it for $2,500. That's a lot of cash and I'm wondering if there might be something less drastic. It seems to me that the IP is not generating enough pressure on just cylinder 3 during idle. This could be rubbish but is there any way to adjust pressure on 3 without rebuilding the whole thing?

I've read a few things about delivery valve O-rings and delivery valve adjustments but without a picture I can't make any sense of it.

Can anybody help?
Thanks.

I'd strongly suspect your delivery valve is leaking in cyl #3. Those are reasonably easy to R&R, but I believe it entails removing the intake manifold on the OM606. It should be essentially the same procedure as the OM603, so search for threads that walk you through the process and the tools you'll need.

Also, you're probably due for an Italian tune-up, and best yet, there's no charge associated with that little procedure.

Yes, DV seal is almost assuredly the culpret. We had another member here with the same issue, he landed up pulling his cylinder head off before finding it was a $0.50 copper crush washer in the IP which was causing the misfire. Replace the DV seal and you will see...and it will cost you a LOT less than $2500. If your mechanic seems unfamiliar with the procedure to retorque them do it your self or find someone who know what they are doing.

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Marty D.

2013 C300 4Matic
1984 BMW 733i
2013 Lincoln MKz

If you are handy with tools, the delivery valve job is doable. Just do your research regarding the procedure, and keep everything as clean as possible. I would suggest that you make a cardboard cutout that will fit between the IP and the belly pan. You will be working with small parts, and the last thing you want to happen is that one of them falls into the belly pan area. When reinstalling the delivery valves, remember your torque is in Newton Meters, and not foot pounds. All told, outside of the labor you put in, your talking about $6.00 in parts.

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96 E300d

Excellent! Thank you all for your guidance. I'll start my research on what's needed and do the job myself. I swear if I had the money to buy all the specialized tools I'd never take my cars to the shop.
You guys are great!
I'll let you know how it turns out.

It might be a good time to invest in buying a Factory CD manual. You will need the special Socket to remove the Delivery Valve and the O-ring and Copper Crush Washer.
Here are some threads:
http://www.peachparts.com/Wikka/OM602InjPumpFuelLeak

The source where I got the link from above.
http://www.peachparts.com/shopforum/showthread.php?p=1217286


The main category where I found both of the above: There are some threads for E300
http://www.peachparts.com/shopforum/showthread.php?t=227463

Some people who run VO, WVO and Bio Diesel change the Delivery Valve O-rings from the stock ones to Viton O-rings as it deteriorates the stock ones. However, I would just fix the one you have first before changing them all since you are not 100% sure a new O-ring and Crush Washer are the cure yet.
Also while the intake stuff is off I would do a check up on your glow plugs to make sure the Shop did not mess something up or as it happens sometimes even a new Glow Plug can go bad.

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84 300D, 82 Volvo 244Gl Diesel

I agree the first step is to replace #3 DV oring and crush washer.

Here's the 606.962 DV DIY. Personally, unlike what is shown in the DIY, I would NOT do this job until the IP was sparkly clean NOR would I remove anything from inside the valve EXCEPT for the spring and washer. Pulling the valve element and collar is a good way to end up having the pump re-calibrated on a bosch bench which is what your mech wanted to do.
http://www.peachparts.com/Wikka/OM606DeliveryValveSeals

If that doesnt help, I'd probably go back to stock configuration and troubleshoot it from there.

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Terry Allison
N. Calif. & Boca Chica, Panama

09' E320 Bluetec 77k (USA)
09' Hyundai Santa Fe Diesel 48k (S.A.)

I now have a leak somewhere near the injectors making my car stink. I'm not letting anybody else work on this car again if I have to use every vacation day I've got!

That has me thinking.... If I indeed have a bad delivery valve seal wouldn't I also have a leak at the injection pump? I haven't gotten it apart yet but now that I know how strong the smell is on a leak it makes me wonder.

Thanks for the link to the guide TMAllison!

Repeat our 606 mantra with me 3 times, "I vow to ALWAYS fix ANY fuel leak BEFORE chasing after other perceived problems"........

Find your leak. Use the wifes nose to help if needed. Fix it first. See if problem persists.

Since you've swapped inj's around, the first place to look is the cloth braided return lines at the inj's. They don't like being pulled on as they age.

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Terry Allison
N. Calif. & Boca Chica, Panama

09' E320 Bluetec 77k (USA)
09' Hyundai Santa Fe Diesel 48k (S.A.)

The leak wasn't hard to find. They replaced the Mercedes hoses with some little rubber ones. They were completely off and all the injector wells were full of VO/diesel.

I cleaned out the wells with a vac and Q-tips. I think I'll go visit the shop tomorrow. I'm never taking my car back there again but I want them to at least give me new return lines.

Now I'm really suspicious. All of the injectors were supposed to have been removed, cleaned and spray tested. I found rubber hoses hoses only on the 3rd injector. Why not all of them? The other returns look like the original ones. hmmm. I think I will call the injection shop they said they sent the injectors to in the morning and see if they remember getting 6 Mercedes injectors from my (old) shop. I'm gonna bet not.

I did learn one thing during the cleanup though. Number 3 cylinder is definitely not spraying during idle. When I took the injector line off of the injector it still had VO in it. All the others had diesel in them from the purge cycle. So now I know for sure the injector is not firing.

So....swap a diff inj in and see if the prob moves. If so, rebuild that inj. If not, look at DV #3.

You'll need the special 22mm, 4.25" deep well thin walled socket with cutout for the return line barb, and at least two heat sheilds as they aren't reusable.

Then consider if VO is really worth all the trouble......

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Terry Allison
N. Calif. & Boca Chica, Panama

09' E320 Bluetec 77k (USA)
09' Hyundai Santa Fe Diesel 48k (S.A.)

Doesn't sound like VO is the problem here...

So just to be sure I understand... this shop told you they swapped the injectors around -but apparently didn't- and charged you for it. Then they failed to reinstall decent return lines. And their recommendation to you was to have THEM rebuild the IP, before they even checked the DV o-rings.

is this correct???

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Jake
1999 e300d PlantDrive WVO/SVO conversion
**note to self: oil changed at 268k kms**
1990 Toyota 4Runner FrankenDiesel swap

I called the diesel injector shop myself first thing this morning. They were able to verify that 6 injectors were brought to them for cleaning and testing. So the injector work did take place but the shop broke 2 hoses in the process and replaced them with sub-standard hoses. Much better than my suspicions of no work done.

After I complained about the hoses and the mess the shop took money off the bill and got me a length of new hose. They offered to put the new line on but I declined.

So its on to the delivery valve job. I have viton seals on the way and I picked up the copper washers yesterday. I still need to rent a spline socket from someone. New ones are $50!

Whole hell of a lot cheaper than an IP job from Hackit & Wreckit Import Auto Repair, no?

Buy it for $50, I'll buy it off you for $25 when yer done. I can send you my $25 now if that sounds square to you

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Jake
1999 e300d PlantDrive WVO/SVO conversion
**note to self: oil changed at 268k kms**
1990 Toyota 4Runner FrankenDiesel swap