Hello all,

I have a 98 300TD and it's knocking.

First off, let me tell you what I've done to the car. About 2 months ago, I replaced all the fuel lines and O-rings. When I had it apart, I cleaned the manifold and everything. After putting everything back together, I ran 2 bottles of Diesel purge through the system and replace both fuel filters.

Now, when I first start it up in the morning to warm it up, it starts fine. After about 2-3 minutes, it starts to knock really loud. Once the car warms up, the knocking goes away and the car runs fine.

Does anyone else have this problem or anyone know what the problem is?

Thanks

If it was older I would say nailing, but I don't think that is an issue with direct injection diesels.

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1959 Gravely LI, 1963 Gravely L8, 1973 Gravely C12
1982 380SL
1978 450 SEL 6.9 euro restoration at 63% and climbing
1987 300 D
2005 CDI European Delivery
2006 CDI Handed down to daughter
2007 GL CDI. Wifes

The 606 isn't direct injected, it's basically just a 603 with twice the valves.

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Dale

http://i52.photobucket.com/albums/g1...MG_2277sig.jpg

1990 300D 2.5 Turbo -155k
2000 E430 - 103k
2014 Jeep Grand Cherokee Ecodiesel 4x4 - 11k
2014 VW Passat TDI SE - 7k Bro's Diesel
2006 E320 CDI - 128k Pop's Benz

Pre-glow - A moment of silence in honor of Rudolph Diesel

Try a search for "Nailing"

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1979 240D- 316K miles - VGT Turbo, Intercooler, Stick Shift, Many Other Mods - Daily Driver

1982 300SD - 232K miles - Wife's Daily Driver

1986 560SL - Wife's red speed machine

It is probably still related to the delivery valve seals you did previously.

I did mine about the same time. I ran a second two cans of DP through mine 2 weeks ago and the inj noise finally became much less noticable.

I'd try again on yours and if that doesnt work pull the injectors and have them re-balanced and pop tested.

Big rig diesel shops can usually do this work.

MB will only sell you new injectors. New nozzles are no good unless balanced. Nozzles dont go bad often.

Injectors require a special MB socket to remove them.

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Terry Allison
N. Calif. & Boca Chica, Panama

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

Remove the black plastic injector cover from the top of the engine.

When it's knocking, give each injector line a gentle touch, that should help you find which cylinder is doing it. While you're there, check the plastic clips that hold those lines are all intact.

It sounds unimportant but those clips stop the lines from breaking. If they're slightly out of alignment it can make the injectors a lot noisier (you can test that by nudging them).


Oh, and when did you last change the oil, and what oil are you using?

I got the socket, took them out and sent them to a shop to have them checked. 5 our of 6 were ok. They found low pop off pressure and bad spray pattern on one of them. Took it apart, cleaned it and it passed test. $70. I figured I would do that once every 100K and be done with it. I didn't want to go with DP and have to risk moving the lines any more than I have to every so often. Engine had a little more power and was smoother according to the wife who drives it most of the time.

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01 Ford Excursion Powerstroke
99 E300 Turbodiesel
91 Vette with 383 motor
05 Polaris Sportsman 800 EFI
06 Polaris Sportsman 500 EFI
03 SeaDoo GTX SC Red
03 SeaDoo GTX SC Yellow
04 Tailgator 21 ft Toy Hauler
11 Harley Davidson 883 SuperLow

You only remove the prefilter (feed) line and unscrew the clamp and remove the reutrn hose (black).

Setting up the temp tank takes me a few minutes and running two cans of DP costs about $12. Does more than only clean the injector nozzles too. I like to run it to operating temp and shut it down for a few hours and let the DP sit in there and work (pump, injector lines et al) then start it up cold again and run the rest through.

Saving an old pre-filter fuel line and attaching some tubing to it makes it that much faster and easier. I've never lost my prime doing it that way.

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Terry Allison
N. Calif. & Boca Chica, Panama

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

Thanks for all the replys.

I will take apart the injectors and have them tested. I guess this is kind of good since I bought the Bosio nozzles about a month ago.
I guess I have no excuse not to replace the nozzles now.

Replacing nozzles does not enusre proper spray or that they have balanced pops.

Take the injecters and new nozzles somewhere that can do that work and then take em home and install them.

__________________
Terry Allison
N. Calif. & Boca Chica, Panama

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