Mercedes-Benz Forum banner

1 - 5 of 5 Posts

·
Registered
1987 300SDL
Joined
·
129 Posts
Discussion Starter #1
I finally had some quality time with my baby today, and I'm tracking down an oil leak. I saw oil underneath coming from what looks to be an air intake hose, and the source is the crankcase, coming from what looks to be a ventilation hose.

W126 300SDL I6

Here's a picture - http://www.lewiscomputerservices.com/DSC02573.gif

It looks like I'm going to have to replace the air hose since it's rubber, but what about this hose? I tried punching in any numbers from it but couldn't find any matching parts online.

I'm shooting in the dark, but I also noticed some blowby when I took opened the oil cap, but there's no oil on the air filter (I'm coming from gas-only, so don't laugh at me if that last sentence made no sense). Don't know if that helps anyone.

What else should I be looking for/doing?

If you have time and want to help tackle another issue (I've got a million :)), what is this in this picture? http://www.lewiscomputerservices.com/DSC02572.gif
The reason I ask, is that there's supposed to be a vacuum line hooked up to it. If I connect it, I get flaring in the transmission. If I don't connect it, I get hard shifts. I'll take the hard shifts over the flaring, but I want to try to fix it.

Thanks!!!
 

·
Registered
1986 300SDL 311,500
Joined
·
287 Posts
I finally had some quality time with my baby today, and I'm tracking down an oil leak. I saw oil underneath coming from what looks to be an air intake hose, and the source is the crankcase, coming from what looks to be a ventilation hose.

W126 300SDL I6

Here's a picture - http://www.lewiscomputerservices.com/DSC02573.gif

It looks like I'm going to have to replace the air hose since it's rubber, but what about this hose? I tried punching in any numbers from it but couldn't find any matching parts online.

I'm shooting in the dark, but I also noticed some blowby when I took opened the oil cap, but there's no oil on the air filter (I'm coming from gas-only, so don't laugh at me if that last sentence made no sense). Don't know if that helps anyone.

What else should I be looking for/doing?

If you have time and want to help tackle another issue (I've got a million :)), what is this in this picture? http://www.lewiscomputerservices.com/DSC02572.gif
The reason I ask, is that there's supposed to be a vacuum line hooked up to it. If I connect it, I get flaring in the transmission. If I don't connect it, I get hard shifts. I'll take the hard shifts over the flaring, but I want to try to fix it.

Thanks!!!
The thing in your second picture is the EGR. It has to do with emissions. It's probably failed, and is leaking vacuum - and is also costing you horsepower. I removed mine and have never wished I had it back. I bought a kit from a member on another M-B forum who makes them and sells them, containing the gaskets and metal plate required to seal the gap left by removing the EGR. You don't need it. It's certainly not worth paying to fix.

The oil through the breather tube is a by-product of the blow-by and is reasonably normal. The oil is recirculated through the air intake (I believe) and is combusted. Just a way to vent the blow-by pressure.
 

·
Registered
1982 300TDT 150,000 miles 1985 380SE 130,000 miles 1991 560SEL 81,000 miles (a/k/a the nightmare)
Joined
·
1,993 Posts
The thing in your second picture is the EGR. It has to do with emissions. It's probably failed, and is leaking vacuum - and is also costing you horsepower. I removed mine and have never wished I had it back. I bought a kit from a member on another M-B forum who makes them and sells them, containing the gaskets and metal plate required to seal the gap left by removing the EGR. You don't need it. It's certainly not worth paying to fix.
I've read that bypassing the EGR vacuum stuff with boost power, but hamper fuel economy on the highway... Have you noticed any difference on either point since you've done away with your EGR?

Also, do you happen to have the contact info for this fellow you bought the kit from? Do you know if he has them available for W123 OM617s (I'm not sure that they're any different for W126s, but just in case).

TIA
 

·
CH4S Admin , Outstanding Contributor
1985 500SEC, 1991 190E 2.6.
Joined
·
40,112 Posts
I finally had some quality time with my baby today, and I'm tracking down an oil leak. I saw oil underneath coming from what looks to be an air intake hose, and the source is the crankcase, coming from what looks to be a ventilation hose.

W126 300SDL I6

Here's a picture - http://www.lewiscomputerservices.com/DSC02573.gif

It looks like I'm going to have to replace the air hose since it's rubber, but what about this hose? I tried punching in any numbers from it but couldn't find any matching parts online.

I'm shooting in the dark, but I also noticed some blowby when I took opened the oil cap, but there's no oil on the air filter (I'm coming from gas-only, so don't laugh at me if that last sentence made no sense). Don't know if that helps anyone.

What else should I be looking for/doing?

If you have time and want to help tackle another issue (I've got a million :)), what is this in this picture? http://www.lewiscomputerservices.com/DSC02572.gif
The reason I ask, is that there's supposed to be a vacuum line hooked up to it. If I connect it, I get flaring in the transmission. If I don't connect it, I get hard shifts. I'll take the hard shifts over the flaring, but I want to try to fix it.

Thanks!!!
Have you tried a forum search? The archive has a wealth of information.

Welcome, to take advantage of all the forum features, please re visit the 'Welcome to the Forum' tutorial sticky on top of the W126 page, as well as the two DIY stickies.
It will show how to search the forum (3 words min.), and has a link to the Russian MB site where you can run a VIN#.
Cheers
 

Attachments

·
Registered
1986 300SDL 311,500
Joined
·
287 Posts
I've read that bypassing the EGR vacuum stuff with boost power, but hamper fuel economy on the highway... Have you noticed any difference on either point since you've done away with your EGR?

Also, do you happen to have the contact info for this fellow you bought the kit from? Do you know if he has them available for W123 OM617s (I'm not sure that they're any different for W126s, but just in case).

TIA
I don't remember exactly what my mileage was pre-removal, but my w126 OM603 is delivering around 25 or 26 mpg, a tad less if I floor it at every light. That's acceptable to me, so I haven't experimented with reinstalling the EGR to see if it goes up any... but as I recall, it didn't make much difference.

I bought it from Brian Carlton over at mercedesshop.com - and I have no idea if he's got the 617 kit or not. Mine's a 603 so I didn't ask about the other. I suspect the exhaust systems are completely different and it would take a different block-off plate to fill the gap left by the EGR.

I didn't notice a significant power increase, but I suspect my EGR was malfunctioning before I removed it, and therefore may not have been hampering power as much as a functional one might do. Removing my ALDA has produced a marked increase in power, far more than the EGR ever could have robbed.
 
1 - 5 of 5 Posts
Top