99 e300d idle problem when hot - Page 3 - PeachParts Mercedes-Benz Forum

KarTek · #1 06-23-2013, 11:23 AM

At this point, I'm running out of ideas that aren't expensive... Going more on theory than anything else. Possibly a crack or some defect in that particular element that opens up and lets high pressure fuel leak back when the pump heats up?

Oh, and just a reminder, make sure you put that #4 adjustment tab back exactly where it was originally.

mbonly · #2 06-23-2013, 02:11 PM

Around how much it would be if I have the pump sent out and where its the best place?

KarTek · #3 06-23-2013, 04:14 PM

Before you go to crazy, I thought of one more thing. You can try re-torquing the DV holder for #4. I had a pretty bad clack in my engine and re-torquing it cured it. If that doesn't help, try removing the DV holder and checking and/or replacing the crush washer.

I got no idea on the cost of pump service. If something is cracked, you'll need a new pump. I have a spare body if it comes down to it, a shop can swap over your internals to that.

mbonly · #4 06-24-2013, 12:25 AM

ok will do that.

pimpernell · #5 06-24-2013, 08:35 AM

If you remove the delivery valve holders, make sure you DO REPLACE the crush washers. Failure to do so will result in more problems.

mbonly · #6 06-26-2013, 03:56 PM

Quote:

Originally Posted by KarTek

Before you go to crazy, I thought of one more thing. You can try re-torquing the DV holder for #4. I had a pretty bad clack in my engine and re-torquing it cured it. If that doesn't help, try removing the DV holder and checking and/or replacing the crush washer.

I got no idea on the cost of pump service. If something is cracked, you'll need a new pump. I have a spare body if it comes down to it, a shop can swap over your internals to that.

Hey KaeTek here is something strange: Do to work reasons I had not used the car since last sunday when I did the adjustment on the rack TABS, this morning I noticed that the car is shaking at idle even when its cold and it didnt do that before. Could have gone a little too much on the adjustment and now am suppling too much fuel to #4? the symptom is the same but it seems more pronounced now and it seems to be spending more fuel.

Smile123 · #7 06-26-2013, 12:23 AM

Quote:

Originally Posted by mbonly

Hi all, nice to be back to this board, om606 newbie with an idle problem. Its a 1999 e300 turbo diesel with 198k mi and when its starts up in the morning it runs smooth at idle, even after a few runs around the block after the engine has come up to normal operating temp it still runs fine but after a long drive on the highway and you come to a red light the engine starts to rock from side to side as if it was running on 4 cylinders and the whole car rocks, this is more pronounced when the brake pedal is pressed. I tried adjusting the cable that operates the accel position sensor but this only makes it run at higher speed when the car is cold but when is hot it runs bad. The car runs like a rocket otherwise, where should I start?

My car has the same problem a few months ago. I thought may be I had a bad engine transplant ( 1991 350SD body with a 84-85 5 cylinder engine). When I stopped at the traffic light, the car rocked left and right, then I put it to 'Park' or 'neutral' the rock stopped. It's quite annoying. Now whenever I stop at red light ( which is quite a lot in Queens, NY), I use my left foot on the brake and use my right foot on the accel softly to avoid rocking. I spoke with the mechanic today, he said may be it is the 'idling valve'. Whatever it is, when you find out how to fix the problem please post it so that I can follow your foot step. Thanks.

mbonly · #8 06-26-2013, 03:48 PM

will do

KarTek · #9 06-26-2013, 05:11 PM

You absolutely MUST put that tab back exactly where it was before or this is the result. Moving it 3mm is a whole lot of fuel and if it's still in the same position, that cylinder will be kicking out more power than the rest, hence the shake.

Your problem didn't seem to be related to tab position since moving it didn't help fuel output at operating temperature.

mbonly · #10 06-29-2013, 04:26 AM

UPDATE:
I moved the rack tab where it was before and it ran perfect again when cold but as soon as it got up to normal temp the rocking started again so I decided to do a little test that almost all of You would not approve: I figure that if the problem is not with the tabs then there must be a problem somewhere in the delivery valve perhaps the crush washer is not seating well or the DV holder is not torqued right so I ran it with the a/c on and it was a very hot day so she was rocking side to side pretty good then and although I was concerned about creating a temperature difference on a hot pump I bought a one liter bottle of cold water and punched a little hole on the cap and with the engine running and a/c on I squirted cold water on the #4 DV holder and by the time the bottle was 3/4 of the way down the rocking was gone and it ran almost as good as it does in the morning. when the bottle was finished I left the engine running with a/c on and in 5 min the rocking was back as bad as before. This leads me to believe that the problem has to be in the delivery valve or the crush washer, maybe it just needs to be retorqued. Any thoughts?

pimpernell · #11 06-29-2013, 08:24 AM

The crush washer is a one time use item. If you are going to re torque the delivery valve, you must replace the crush washer with a new one. I did the delivery valves on my 96, and was advised by some posters on the board that the crush washers did not have to be replaced. Car ran like crap, with the engine shaking and nailing. Redid the delivery valves using new crush washers, and the engine ran like silk. Make sure that you torque the valves according to the shop manual instructions. Good luck!!

KarTek · #12 06-29-2013, 03:38 PM

Quote:

Originally Posted by mbonly

UPDATE:
I moved the rack tab where it was before and it ran perfect again when cold but as soon as it got up to normal temp the rocking started again so I decided to do a little test that almost all of You would not approve: I figure that if the problem is not with the tabs then there must be a problem somewhere in the delivery valve perhaps the crush washer is not seating well or the DV holder is not torqued right so I ran it with the a/c on and it was a very hot day so she was rocking side to side pretty good then and although I was concerned about creating a temperature difference on a hot pump I bought a one liter bottle of cold water and punched a little hole on the cap and with the engine running and a/c on I squirted cold water on the #4 DV holder and by the time the bottle was 3/4 of the way down the rocking was gone and it ran almost as good as it does in the morning. when the bottle was finished I left the engine running with a/c on and in 5 min the rocking was back as bad as before. This leads me to believe that the problem has to be in the delivery valve or the crush washer, maybe it just needs to be retorqued. Any thoughts?

That sounds logical, just get another crush washer or a few as Pimpernell stated...

One other thing you'll need to know is that there's a multi-step torquing process for the DV's. It's like tighten and back off, tighten more and back off about 3 times. I'm sorry I don't remember the exact specs but a search here should reveal more info.

OK, I found some good readin' - Delivery Valve Torque specs

Smile123 · #13 07-03-2013, 09:23 PM

Quote:

Originally Posted by mbonly

UPDATE:
I moved the rack tab where it was before and it ran perfect again when cold but as soon as it got up to normal temp the rocking started again so I decided to do a little test that almost all of You would not approve: I figure that if the problem is not with the tabs then there must be a problem somewhere in the delivery valve perhaps the crush washer is not seating well or the DV holder is not torqued right so I ran it with the a/c on and it was a very hot day so she was rocking side to side pretty good then and although I was concerned about creating a temperature difference on a hot pump I bought a one liter bottle of cold water and punched a little hole on the cap and with the engine running and a/c on I squirted cold water on the #4 DV holder and by the time the bottle was 3/4 of the way down the rocking was gone and it ran almost as good as it does in the morning. when the bottle was finished I left the engine running with a/c on and in 5 min the rocking was back as bad as before. This leads me to believe that the problem has to be in the delivery valve or the crush washer, maybe it just needs to be retorqued. Any thoughts?

Did you get the problem solved? Waiting for your confirmation that it is the crush washer that caused the problem.

mbonly · #14 07-06-2013, 12:34 AM

Quote:

Originally Posted by Smile123

Did you get the problem solved? Waiting for your confirmation that it is the crush washer that caused the problem.

It was the crush washer, I replaced the washer and the rubber seal and it runs like a dream, thanks KARTEK for all your input. Only problem is that now it has a starting problem am going to start a new thread since am kind of lost on it.

KarTek · #15 07-06-2013, 10:16 PM

Good to hear you got the idle problem straightened out!