Car: 1984 190D 2.2L

I was in the engine bay today replacing a worn engine shock. Upon removal of the plastic intake to get additional working space I made an interesting discovery. There was a broken clear vacuum line that was sticking out of a bundle of lines (image 1). The bundle works its way from the center of the engine to the driver’s side fender (image 2) right next to the glow plug relay where it then connects into a rubber 3-way (image 3). The 3-way contains two black lines, one of which looks like it travels into the cabin because I lost it right before the fuse box.

Anyone have any idea where the clear line should be connected, if this clear vacuum line is of any importance and what the black vacuum lines are?

Attached Thumbnails

     

I've got an '84 190D 5-speed.

On my car, next to the glow plug relay as shown in your picture #3, there's no 3-way tee. Just a straight inline coupler.

However, the clear line that is found near the glow plug relay goes into a black shell along with a brown line. The black shell loops down toward the starter, and then comes back up under the intake manifold (like in your first picture).

The clear line from there comes out of the black shell and goes into a sensor screwed into the metal housing on the engine just back of where the upper radiator hose connects. On my car this metal housing holds two sensors; the clear one goes into a blue sensor that has 2 vacuum ports on it.

I can take pictures for you tomorrow if this doesn't make sense...

__________________

1989 250TD Wagon 5-speed, 160,000mi ::: Dark gray metallic / black cloth
1984 190D-2.2 5-speed, 287,000mi ::: Silver-blue metallic / black MB-tex ::: SOLD

That would be awesome

I found that blue sensor you were talking about and it didn't make sense. One of the lines that I trailed (in red) looked fine. It traveled into another line, which then goes into a metal circular device on the firewall that has to deal with the brakes. The other vacuum port on the blue sensor though just revolves back into itself with a 3-way.

This engine was installed after my other one developed some problems. It was of the same year, but the new engine came from a stick shift 190D (mine's an auto). When I look at the pics I have of the old engine for the automatic, it doesn't show this loop and considering your car is a manual and it doesn't have a loop suggests something is wrong here obviously. Either someone didn't know how to hook up the vacuum system or someone is hiding a fault made.

Any help from anyone would be fantastic. Right now the broken clear vacuum line is a dead end and I am considering just removing it to make the 3-way by the glow plug an inline coupler.

Attached Thumbnails

   

Attached are some photos. I've arbitrarily numbered the lines, and I'll refer to white and clear lines interchangeably.

Coming from the fuse box area and then proceeding past the glow plug relay are 2 lines, a brown/blue one (Line 1) and a white one (Line 2). These enter a black shell and proceed up near the back of the IP as shown in photo A.

There, the black shell ends. The brown/blue (Line 1) goes off into the top of the IP.

A red/white line (Line 3) from the back of the IP is routed into another black shell along with the white one (Line 2) and they both travel in this shell under the intake manifold over to a blue sensor/switch thing screwed into the metal bracket that the upper rad hose connects to (Photo B). The white line (Line 2) ends here. The red/white one has a T at the sensor; it continues out of the T and runs down to a switch/sensor in the cylinder head between cyilnders 1 & 2.

Out of this switch/sensor, a white line (Line 5, photo B) runs over to a T that is on the giant vacuum line between the vacuum pump and the brake booster.

There's also a white line that comes out of the firewall beside the brake booster and runs into the top of the vacuum pump (Line 4, photo B).

It was hard to see some of these lines, so if anyone sees an error in what I've written, let me know.

Attached Thumbnails

     

__________________

1989 250TD Wagon 5-speed, 160,000mi ::: Dark gray metallic / black cloth
1984 190D-2.2 5-speed, 287,000mi ::: Silver-blue metallic / black MB-tex ::: SOLD

I should also mention that my engine is the standard version (USA Federal) that does not have the vacuum-operated EGR emission controls on it. If you've got a California engine, this would change the vacuum line layout.

EDIT: Attached is another photo with the intake manifold removed. You can see all of the vacuum lines in this picture.

Attached Thumbnails

 

__________________

1989 250TD Wagon 5-speed, 160,000mi ::: Dark gray metallic / black cloth
1984 190D-2.2 5-speed, 287,000mi ::: Silver-blue metallic / black MB-tex ::: SOLD