95 E300D my 1st attempt to route the engine vapors away the intake valve area - PeachParts Mercedes-Benz Forum

Texasgeezer · #1 01-15-2018, 12:20 AM

I plugged the old small holes in the top of the intake with black Permatex silicone and topped the glue with a round headed thumbtack that fit perfectly. Yesterday I installed a new rubber elbow feeding the black gizmo. I trimmed a little of the bottom of the new rubber elbow in an attempt to make it easier to remove years from now. I then connected 1/2 inch piping to the outlet. To do this I used 5/8" heater hose. Tight fit on both but made it tighter with cable ties. If it leaks I'll install hose clamps. If the plastic pluming doesn't hold up I'll replace it with 1/2" copper.

I drilled out the thin metal on the top of the valve cover near the rubber plenum from the filter box. The hole is just beneath the black plastic cover that bolts to the top of the intake cover.

If any of you decide to do it this way, remove the top of the filter box along with the rubber plenum. This will allow an almost perfect angle to drill the hole into the valve cover.

You should place a metal plate on top to protect the fuel injection lines. The aluminum can grab your drill bit and suck it into your lines. I used a 4" metal piece that was bent 90 degrees and rested in front of the injection lines and on top of them. Glad I did, the drill bit jumped forward twice.

I didn't like the look of the plastic so I ended up wrapping it in plastic electrical tape, the old style cloth tape is not readily available at autoparts stores anymore.

I plan to add a catch can to collect the oil and will possibly tap into the filter box to suck the fumes ( hopefully without the oil ) back into the intake path.
Trying to decide whether to go below the filter or above it and what size hole to make into the filter housing.

When I started the car after doing the shut valve today, I did notice an odor and could feel vapors puffing out the end of my plumbing. Probably won't wait too long to add a catch can. Ran too little to see how much oil might drip out. When I cleaned the outside of the black gizmo and blew into it, there didn't seem to be any resistance to air flow.

torsionbar · #2 01-15-2018, 06:09 PM

I have heard that the oil vapors are beneficial to the engine as they provide lubrication for the intake valve stems and seats, and they won't last as long without it. I have no data, but makes sense to me.

On my om606, I disabled EGR but left the CCV system intact for this reason. The restrictive intake mud that accumulates is a result of the two combining - take away either one, and the accumulation stops.

For plugging the 12 little holes in the intake manifold, the thumb tack is a clever idea, but since the manifold is aluminum, it would be cleaner to TIG them closed. Goo is less preferable, but JB Weld is probably a more reliable goo on a metal substrate than silicone.

tjts1 · #3 01-16-2018, 04:16 AM

Welcome to the club.
http://i.imgur.com/0XZ98Of.jpg

http://i.imgur.com/2OltI59.jpg

Maxbumpo · #4 01-16-2018, 08:20 AM

I must have missed it - what is the problem that this modification will solve?

Diseasel300 · #5 01-16-2018, 10:14 AM

Quote:

Originally Posted by Maxbumpo

I must have missed it - what is the problem that this modification will solve?

The 606's have a truly stupid PCV setup where instead of dumping the fumes in the intake snorkel like every other engine ever made, they distribute it to a hole in each of the 12 intake runners. The plastic has a habit of getting brittle and breaking off. Not a great design.

tjts1 · #6 01-16-2018, 10:16 AM

Quote:

Originally Posted by Maxbumpo

I must have missed it - what is the problem that this modification will solve?

The crancase ventilation routing on the NA om606 is individually routed to all 12 intake valves through a maze of tiny plastic tubed that fail and allow dirt into the intake. Besides that, after a few years the intake ports are caked in a thick grease like substantial made of EGR soot and oil which blocks off a large portion of the intake ports and kills power. The problem builds up slowly so most owners fail to notice the loss in power and efficiency.

Texasgeezer · #7 01-16-2018, 02:45 PM

It is hard to believe that Mercedes would ever implement this method that combines engine oil vapors & liquid with exhaust particles. On my car the thicker areas reminded me of asphalt. I used a small metal spoon to scrape the intake holes in the head. About 1/2 the intake holes just had dry exhaust particles.

I then followed this up with an attempt to clean the remaining residue via paper towels with a little bit of B12 spray onto the towel. I wrapped that around a 3/8" 6" extension and was careful not to go deep enough to contact the valves. Kept doing this until the paper towel wasn't picking up much more. Some valves have a good buildup of that asphalt coating but I don't know of a good method to clean them. Since fuel doesn't flow past them I guess they will stay that way for a long time.

I do not believe that the oil has any benefit for valves or valve seats. My guess for the valve seat problem is that cylinder has excessive heat from lack of proper cooling. From my reading that is the cylinder near the firewall/cowl that might have the problem occur. From what I've read the heat buildup in that area also makes the glow plug harder to remove. On my car that is the only glow plug where the harness wire connector was siezed to the glow plug. I had to peel it off with pliers, acted like is was welded but knew it wasn't.

I'm thinking about running a slightly lower mix of antifreeze and a little cooler thermostat in an attempt to provide better cooling for that area.

Diseasel300 · #8 01-16-2018, 03:56 PM

The ingestion of exhaust soot and oil vapors is a byproduct of EPA legislation and CAFE standards. *ALL* engines have a PCV system dating all the way back to the 1950s and 60s which replaced the "draft tube" of the earlier cars. As a result, you're going to have oil vapor and residue in the intake manifold. Add in EGR and you now have a carbon source present. Add a couple hundred thousand miles, and you now have a bunch of soot stuck to oil residue and it turns into a hardened mass, choking down the manifold's ability to breathe.

This doesn't just affect Mercedes, the modern direct-injected gasoline cars are having a terrible time with the valves getting gunked up from EGR. The concept behind the OM606 PCV design was to try to improve the induction action of a N/A diesel engine by placing the "vents" for the PCV system as close as possible to the valve and at the end of a narrow intake runner. The concept was sound, the implementation not so much.

Texasgeezer · #9 06-26-2018, 03:43 PM

Vincos Universal Oil Catch 400 ml and about $34. Well made & with an oil dip stick and o-ring seal to check collected oil level. Hose supplied with the catch can has a strong chemical smell and wife made me hang it outside for airing out.

I intend to connect my engine oil vapor plumbing to the catch can by a 1/2 ID hose & then connect the can's outlet to my air filter housing ( probably below the filter initially ). I don't think the filter will get coated with much oil from the vapor, but I could be wrong. If so I'll probably have to route it to above the air filter if it clogs the air filter.

I plan to attach a baby's cotton sock to the protrusion inside the air filter housing ( hopefully that will collect most of the oil that might foul the air filter ).

Mike D · #10 06-26-2018, 04:24 PM

Quote:

Originally Posted by Texasgeezer

I didn't like the look of the plastic so I ended up wrapping it in plastic electrical tape, the old style cloth tape is not readily available at autoparts stores anymore.

Ace 3/4 in. W x 30 ft. L Friction Tape Black(461200) - Electrical Tape - Ace Hardware

I feel the same way about the PVC electrical tape. I go with shrink wrap and the friction tape.