Oh, it would totally help the valves. I just don't see how it would help the manifold.

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"Senior Luna, your sense of humor is still loco... but we love it, anyway." -rickymay ____ "Your sense of humor is still loco... " -MBeige ____ "Señor Luna, your sense of humor is quite järjetön" -Delibes

1982 300SD -- 211k, Texas car, tranny issues ____ 1979 240D 4-speed 234k -- turbo and tuned IP, third world taxi hot rod

2 Samuel 12:13: "David said to Nathan, “I have sinned against the Lord.” And Nathan said to David, “The Lord also has put away your sin; you shall not die."

Depends on the year & model, and if your EGR valve is sealing properly when closed. There are a lot of threads on this topic, search the forum and ye shall find the answer...

Exactly. It doesn't help the manifold at all.

I finally had a chance to test out acceleration and the engine feels much stronger at the top end with almost no smoke past 4000rpm. Cleaning out the intake made a huge difference, more so than new injector nozzles or advanced timing. I should have cleaned it out earlier, well worth the effort. I need to find a good accelerometer app for my android so I can put some numbers on it.

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The after numbers will be more telling with before numbers.

Sixto
87 300D

I cleaned the intake on my 617 as well, and blocked the EGR.

I used wooden sticks, plastic scrapers from Harbor Freight, brushes, cans of carb cleaner, diesel, etc. Wish I knew someone with a hot water pressure washer.

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617 swapped Toyota Pickup, 22-24 MPG, 50k miles on swap

My 1997 E300D had 190K when I bought it. My manifold intake and air chambers were this bad and I cleaned them up and blocked off the EGR. This along with several other maintenance requirements got the car back to running like a champ.

The stickly crap in the air chambers was so bad and thick that I scrapped it out with a flat head screwdriver and I removed a ton of crap. What a dirty job, but it got done.

Pabster

Very true. Patoots are not known to be accurate performance meters.

Gasoline, compressed air and a lighter make quick work of that gunk!

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http://superturbodiesel.com/images/sig.04.10.jpg
1995 E420 Schwarz
1995 E300 Weiss
#1987 300D Sturmmachine
#1991 300D Nearly Perfect
#1994 E320 Cabriolet
#1995 E320 Touring
#1985 300D Sedan
OBK #42

This is what came out of 1 of 12 intake runners in the cylinder head. A butter knife with a bent tip made short work of it. Its the consistency of axle grease.


I haven't even started on the manifold yet.


The nice thing about the 606 is that it dumps its crankcase ventilation right at the point where the manifold meets the head so most of the manifold is not greasy like the 603 was. Once I scrape out the grease from the first inch or so, I can wash the soot out of the rest of it with my pressure washer.


Ever since cleaning out the intake on the OM603 this catch can (re purposed high pressure air filter) does a great job of keeping the oil out of the intake.


I'll be installing something similar on the 606.


Instead of the idiotic 12 plastic crankcase vents they installed at the factory which are mostly cracked and broke.

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After cleaning out the manifold and ripping out the left over plastic chunks I plugged each hole with a short sheet metal screw then topped that off with some silicone sealant so no dirt can get in.




I capped off 1 of the 2 ports and ran a hose from the other between cyl 3 and 4.


The new oil/air separator sits on the right by the by the washer reservoir then the hose from there dumps into the intake snorkel before the air filter. This should keep the intake manifold clean for many years to come.

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But the air oil seperator knocks out blow by. The issue of the black gunk is erg related. A 2 day soak in diesel fuel cleaned out mine with very little effort.

https://www.youtube.com/watch?v=3vOCwB2onGQ

I would bury it in sand or dirt to soak some of the heat away if there is any worry of heat warping.

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85 300D turbo pristine w 157k when purchased 161K now
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked

Its the combination of EGR and oil that creates the black tar inside the manifold. The parts of the manifold that are only covered in EGR deposts are cleaned off easily with compressed air or the pressure washer. I blocked off the EGR a few months ago so thats not an issue anymore. The existing oil separator was clearly not doing a good job.

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Prior owner did the EGR delete and manifold cleanout on my W210. It is still clean 18 months later.

I just did the EGR delete (thanks RollGuy) and cleanout with biodiesel (thanks Philly2tank) on my W124 and it subjectively seems peppier.

I suspect at some point I am going to have to face the dreaded oil cooler gasket change on my W164, and I am afraid of the crap I will find in the manifold on that vehicle.

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The OM 642/722.9 powered family
Still going strong
2014 ML350 Bluetec (wife's DD)
2013 E350 Bluetec (my DD)

both my kids cars went to junkyard in 2023
2008 ML320 CDI (Older son’s DD) fatal transmission failure, water soaked/fried rear SAM, numerous other issues, just too far gone to save (165k miles)
2008 E320 Bluetec (Younger son's DD) injector failed open and diluted oil with diesel, spun main bearings (240k miles)

1998 E300DT sold to TimFreeh
1987 300TD sold to vstech