Picked up all my parts today, still waiting on the fuel return hose. Ordered the Viton. Getting that last 90 degree elbow CCV tubing that sits in the valve cover was a task!! Finally it broke in half, with half coming out, and half going into the valve cover. Was able to fish it out OK.

Got my manifold and crossover back from the machine shop. They look perfectly clean!

Few questions:

-I am replacing clips and shims. Mine are so bad that it is even hard to use one as a template. It looks like the rubber shims are supposed to go under the metals plates that the clips lock into. There are three holes in the plate, with the shims tab fitting through the center hole, and the longer peice of the rubber shim going downward. Does all this sounds correct? Got a couple of them in and they seem to fit well this way.

-Also, wondering about the flap inside the air intake body, where the EGR comes into. I don't think this is a throttle, but what is the purpose of that flap? If EGR is "other-enabled" should this flap be also "other-enabled" to a locked open position? If it works in conjunction with EGR, then we may not want this flap to close off too far if EG is not ocming through.

I am getting tired and want to get this car back on the road.

The sequence is: plastic clip, injector hard line, rubber shim, metal bracket. The clips will be hard to get into the holes due to the springiness of the rubber; I ended up using pliers on many of mine when I did the 603 engine in my '87. The important thing is to keep the lines from either vibrating or rubbing (either will eventually damage them).

On my '96 I tried disabling the flap near the EGR valve and ended up with a code so I put it back together. The explanation as to exactly how the three flaps work to 'tune' the intake gets lost in the translation from German to English.

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

Out of town this last week, so no progress until tonight. Got the new viton fuel return lines, and the old ones came off pretty easy by just tugging on them. Only one was really hard, the one at the rear that has the plug in it (and very possibly the one that was leaking). Finally got it to break loose. This fuel return circuit must be pretty low pressure as this tubing does not seem to be on those nipples very tight.

Getting the crossover piping lined up and inserted into the collar at the air intake (near EGR connection) is much easier said than done. Especially with new o-rings, which seem almost too large and cause the fit to be extremely tight.

I am going to fire it up in the morning and see how things go (moment of truth when I start her back up). I left the plastic cover off for now and will run for a day or two and keep an eye out for any leaks. Of course, I'll have to deal with removing and then putting that crossover piping back on, but by then, maybe I'll be good at it.

I am still bothered that the actuator at the air intake may close the flap from the air coming in from the air filter. With the EGR other-enabled (for testing only), and this clean air inlet flap closed, it seems intake will be extremely starved for air. Tempted to disable that actuator. I see no sensor that would provide any feedback as to the flap's position, so it seems it will work. I think Jeremy said he had a code pop up when he did this.

Fired it up this morning and it started with no problems, and seems to be running fine. No real noticeable difference on my little 15 mph run around the neighborhood.

However, my check engine light is still on. Pulled code P0400 and also P0200 (which says 'Pending', haven't seen that before).

Any ideas on where to go next? Clearing these codes was the original reason for doing this, so am a little disappointed to not see that go away. The original idea was that the resonance flap was not opening all the way or was delayed in opening. So now maybe it is more of an electrical issue. I hate to think I may have to pull the manifold off again!

Also, my code reader just pulls the generic codes (like P0200). Supposedly Mercedes was able to pull additional codes with their reader (like P1975, which was specific to the crossover resonance flap). Is there any low cost method of pulling these Mercedes specific codes?

An update....apparently the 97 model (E300D) is pretty smart on the EGR. Removed the EGR blocking plate (used for testing purposes only) and cleared codes, and success! No more codes (at least for the few miles I drove it). There must be a flow switch or something that monitors EGR flow. There are wires going to the EGR that tells it if it is not opening...maybe it has trouble opening when the opening is blocked? I did not interfere with the vacuum or anything, just a blocking plate where is attached to the air intake body.

So now, do I re-otherwise-enable my EGR (to prevent additional intake crud build-up) and live with a check electronics light, or do I leave as is and just concede to another manifold intake cleaning in 50K miles (that is only every 5-7 years for me!). Tempted to just return to stock - having a light on all the time is very annoying. Unless anyone out there has any ideas.

I was of the opinion that the '96 and '97 had the same kind of EGR valve, that it could tell if you blocked off its vacuum supply but couldn't tell whether there was anything flowing through it. Perhaps, as you say, the '97 is smarter. Perhaps the first flap closes down partially when the EGR valve opens and the net effect on the airflow is measured by a sensor somewhere.

Some folks have connected the EGR inlet to a small filter so that the EGR valve still has air flowing through it. You can buy a tiny carburetor filter at auto parts stores. Then you'll have to block the outlet from the exhaust manifold. Use the clamp that's already there, cut a disk from copper (the end of a 1 inch copper water pipe cap works well), apply some hi-temperature silicone sealer, and clamp onto the exhaust.

Another thought that I had but never tried is to experiment with different kinds of tubing and come up with a configuration that allows the EGR to connect to the air cleaner housing so it sucks clean air instead of exhaust. That would also look more "factory" than a super-stock chrome filter hanging off of a tube.

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

I was a little premature in reporting no codes. The EGR code is gone (P0400) but the injection code (P0200) is still there. Based on info from the previous owner, the P0200 is actually a generic code for the P1975 code (crossover flap problem). If this is accurate (because my scanner may not be able to read the Mercedes specific code), then I am probably looking at tracing down the sensor wires on that flap. Still hoping to find a scanner that can read these specific DTC's. Until I can confirm a specific code, I may be chasing ghosts to keep working on flaps.

I am still seeing a little bit of diesel pooling in that last injection well. Not sure if it leaking on the return lines or maybe the injector itself. Is there any problem with a little diesel in there, or should I do some more work to get this solved?

The last thing, the AC stopped working after I put things back together. Could be a coincidence, but could I have done anything that would have messed with the AC? I don't think so, but willing to entertain any suggestions. If any knows of any threads that have some good AC troubleshooting suggestions, it would be much appreciated. I see lots of threads on AC, but I really have not found any detailed troubleshooting guides. My thoughts are to check the refrigerant pressures, and to make sure clutch is engaging, and then go from there. It was working great until this work that I did.

Thanks for everyone's help on this thread!

You may have disturbed a connection, pulled a wire loose or something. Look over the engine bay carefully.

__________________

"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

What about the pooling of diesel fuel in that last well? I extraced the fluid that was pooled there when I did the work in this thread, but it slowly fills back up again when I drive the car. Just replaced the return lines with new viton and do not think that is the source of the leak. Could it be coming from the injection line, maybe an o-ring? If so, is this easy to fix? Do I just undo the nut that connects the line to the injector and replace an o-ring?

I would first try tightening the nut on the hard line at the injector, being very careful not to overdo it. Since I have never had to do such an operation, I would also advise getting another opinion.

__________________

"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

I saw this thread got bumped and wanted to report out. I replaced the return lines on the last injector again. The new black, smooth viton lines seemed to be the culprit. I got some of the braided (more like the original lines) ones from ********, and they must fit a little tighter, because it cured the leak issue I was having - no more pooling diesel. That was a cheap fix. Was worried that I had nicked the barb on the injector, or that I was going to have a more painful repair on my hands.

Did you ever fix that code issue and the a/c issue? Jim

__________________
1997 E300D Wife's daily driver
1985 300SD my daily driver
1999 Expedition family road trip and material hauler

Hey Big Jim, after all that my "check engine electronics" message is still there! But I KNOW the flaps are working correctly, and I know my manifold is clean. Car is running very well and getting better mileage after cleaning. Got 34 MPG driving about 200 miles at 70 MPH a few weeks ago. Gets about 26 MPG around town.....not bad!

I suspect the code returns because there is a wire problem - signal from the valve switches is not making t back to the computer. So I am not too worried. However, one of these days I will remove manifold again, and I will check out the wiring. Still want to solve it. Another problem is that I cannot find an inexpensive scanner that can read P1475. Most shops don't even have them. The code readers just read the generic P200 which can mean about 5 or 6 different things.

Not sure what you are referring to on the AC issue. You might be talking about my 300E...it is still intermittent. Kind of forget about it until it starts warming up again.

Third paragraph, I thought it was the same car. Jim

__________________
1997 E300D Wife's daily driver
1985 300SD my daily driver
1999 Expedition family road trip and material hauler

On the AC issue, it just needed to be charged. Working great again.