Carbon Build- Up in Intake
 

Hi Diesel Guys - I have sort of a problem with my 87 300 Turbo D- 124 running a Frybrid Veggie system. She runs great on veggie once warmed up, however very shakey and rough on diesel until warmed up.

Also I now have a bad oil leak and I am still trying to find out where. I ordered a new valve cover gasket but I think it may be leaking around the turbo or the oil line to the turbo - not sure yet.

I removed the intake plenumn and saw lots of greasy carbon inside the tube but it looked real clean looking down into the turbo. See pix. Thanks for any help in advance.

Sorry - trying to uplaod pix but the forum limit is only 65kb and my pix are 149kb- how can I resize them to fit or is there another way. I have no problem on other forums uploading pix.

pix?

typical EGR clogging?

upload to another location and then link to them here.

http://i127.photobucket.com/albums/p...atchero052.jpg
http://i127.photobucket.com/albums/p...atchero050.jpg
http://i127.photobucket.com/albums/p...atchero049.jpg
http://i127.photobucket.com/albums/p...atchero047.jpg
Lets see if these pix come up.

Very typical and very difficult to clean. Cleaning doesn't lead to a worthwhile improvement in performance or mpg, most say.

Sixto
93 300SD 3.0

OK, this dirty oily build up (which is soft and not too hard yet) is probably not the cause of my start up shake/knock? I'll change out the EGR valve, valve cover gasket and clean the plenumn and see if there is any improvement.

The oil leak can be very frustrating to track down.

Don't change the EGR valve, just plug it's vacuum line.

Do you mean, just leave it in there disconnected after the vacuum line is plugged?

Will the valve then be Open or Closed?

This could be the cause of the oil being forced out of the engine. A clogged EGR?

Buy some vacuum line and cut a small piece, plug it with a screw or something and slip that short blocked line onto the EGR. Also plug the end that you've now left disconnected.

A badly blocked EGR could cause performance problems and oil spewage. Happened to me on my TDI.

1: Yes. Plug the vacuum line with a BB or other object that will seal the hole and leave the EGR in place.

2: The EGR will stay closed all the time.

3: EGR has no effect on the oil leak but it will stop the build-up in the intake.

The leak will probably be one of the oil feed or return gaskets for the turbo.

For the rough running, do a search here for "Diesel Purge". It's the cheapest first step.

I see what your saying now. Cap off the vacuum line and the EGR, but hopefully the EGR is in the open position to vent gas pressure out of the vavle cover.

The EGR has nothing to do with valve cover gasses. The carbon build-up is caused by oily crankcase gasses (from the valve cover) passing through the intake and combining with soot from the exhaust introduced into the intake through the EGR valve.

When the EGR is disabled by plugging the vacuum line, the exhaust soot will not be able to enter the intake to create the build-up.

Definately typical oil/grunge build up from EGR. Mine looked just like that when I took it apart in October. PITA to clean it out.

Don't forget to pull out your over boost sensor and clean the tip of it out. It is attaced to the intake manifold.

-Jim

Unless the EGR is so choked up that it's stuck open.

Which can be remedied by removing the EGR an visually inspecting/cleaning it or installing a block off plate under the valve.

I'm going to pull the EGR valve and clean it out to make sure it is closed and cap off the vacuum line as well. Just to be sure I have the right part- it is right next to my greasy turbin outlet in my pix right?:D

Also I am going to try venting the valve cover vent tube into a catch can and see if that helps with engine idle. (no more oil going into intake).

I wouldn't bother with venting the PCV into a catch bottle. I did that, all I got was oil smell in the passenger compartment when sitting at a stop light. Clean the intake if you want, and forget about it. Nothing is wrong there.

About the idle/shaking issue, you have a number of things to check. The ELR (electronic idle control) may not be working properly, could be delivery valve seals, bad motor mounts (very common), injectors, etc, etc. But unless the EGR is hanging open (not likely, but possible) that has nothing to do with it.

As a new 1987 300D/TD owner, I'd recommend reading this article, which has some assorted background information on that particular model:
http://www.w124performance.com/docs/mb/articles/124.1x3_buying_tips.txt

Also check out this link for photos of the EGR disabling process.

:scholar:

Thanks Dave for the good info! The pix are very informative. I took out the EGR and cleaned it and tested the valve with a vacuum gage and it works normaly, but I will still bypass it. I capped of the vacuum line to it and just reinstalled it for now with its line capped also. I will make a block off plate later like yours later. Did you use any seallant on the manifold "bottle cap" plug or just bent the tabs and installed the clamp over it?

Nice Job!:D

Great link (buying tips), thanks so much!

There's a forum member here who sells a complete kit, with the two plates, bolts, gasket, and a tube of sealant. It's about $30 and well worth the money. You do need to use some high-temp RTV on the round exhaust manifold port, but it works well. Bend the tabs first, clean everything very well, then apply sealant, and clamp it in place. Allow 24 hours drying time if possible.

:wacko:

I provide a kit to eliminate the valve completely for a cleaner look underhood.

At the moment, the kits from the 2006 run are exhausted. I'll be making another run in the spring when folks are ready to work again..........

Brian - Thanks, and count me in when you start making them again.

I,m only 20 min. from you in Center Moriches!:)

OK, I have now cleaned my intake crossover, EGR mounting base and EGR (which will be removed again when blocking kit arrives). EGR is capped off as well as vacuum line. I have searched the forum and it seems to be a good idea to also remove the smog modules and lines too (for testing purporses, of course). Now what about this round module just below the EGR, which I think is the Air Reciculation Valve? It has a connecting rod to the turbo and a vacuum line to it also. I am ready to remove it also. Or is that a bad Idea?

http://i127.photobucket.com/albums/p136/gmaltz/DSC03292.jpg

Here is the ARC I think
http://i127.photobucket.com/albums/p136/gmaltz/DSC03297.jpg


Here is the rod connected to it that goes to the hot side of the turbo.
http://i127.photobucket.com/albums/p136/gmaltz/DSC03296.jpg

The canister below the EGR valve is the wastegate actuator. Don't remove or disable that!

Sixto
93 300SD 3.0

The ARV is the device below the wastegate in the second pic. You can't remove it because the compressor housing will be wide open. You might open it to make sure the plunger is fully seated, then put the spring on the other side of the plunger to make sure it stays seated. Or drift a 13mm(?) freeze plug into the port.

Sixto
93 300SD 3.0

Yes - the thingy with the rod, that goes to the hot side of the turbo, is the wastegate actuator - leave that connected (it is a pressure hose, not vacuum). The item below, part of the compressor housing, with a vacuum tube going to it... that is the ARV, and should be disconnected and plugged.

:wacko:

OK, now I get it. Gonna leave the wastegate alone and disconnect and plug the ARV. I just thought they were one and the same. Duh!

That one vacuum line threw me. I want to take out all those vauum "Limph Nodes" and the one line was buggin me. Didn't know what it was for. Now I do.

You guys are the GREATEST!


Here is a pix of my next surgical removal provided my tools are still sharp!

http://i127.photobucket.com/albums/p...z/DSC03295.jpg