EdS320

Use CAUTION when working on your engine around the plastic vacuum tubing, it can break if bent or moved.

A Warning for your information:

I was cleaning up my 1996 S320 engine compartment and wiping gunk off some engine parts at the front of the engine next to the front plastic cover, when I accidentally and unknown to me I wiped and broke a brittle vacuum tube going to the EGR valve. This caused the check engine light to come on and caused me many day's of grief to track down the problem.

The vacuum tubing used on Mercedes is plastic and not rubber like on other makes. So over time the heat from the engine will cause it to become stiff, hard and as brittle as glass. So if you should you try to, or accidentally bend or move to much, it will break in two. Especially the 2 tubing's going over the top of the engine next to the spark plugs and coils {under the top cover} and where they come out from under the top cover at the front of the engine. The tubing will not bend but break, so don't even test it if it looks yellow and not white. You may never know you broke it because it will stay in position and not separate because it is stiff. I just replaced my tubing for about $12 {for 3 meters of tubing you cut to length} with OEM vacuum tubing from an MB dealer. You will see the white {or yellow if old & brittle} plastic vacuum tubing around the engine area. If you chose to replace it. Do one section at a time, the plastic tubing pushes into rubber hose connector's that attach to the components it's going to. Or be aware and leave it be, and get some tubing next time you are at your dealer and keep it available.

mleskovar

speedybenz

I just broke some today removing my intake manifold. Like you said it was very brittle.

Jeff

Raul J. Carrasq

I have an S320 1994, and my engine light kept coming on, however in recent days I took it to the dealer and they told me that it was the EGR valve. I am going to check this to see if the light goes out. Do you just take out the old and replace with the new one or is ther e anything else involved in doingt this?Thank you.

Raul J. Carrasq

My Cruise control stopped working the other day. This is an S320 1994. It is of my understanding the cruise control works with the vacum system. Could one of this hoses be broken and that it's not working?

bamberger_1

to fix the broken vacuum lines you dont need to replace the whole line. Just slide a piece of rubber hose (hardware store!) of the suitable size over the to ends, and it works again. Cut it long enough (~2-3 inches) so it wont come off again

EdS320

Yes that will work. That's what I did to get me going until I replaced the whole length of tubing. Only problem is, that the old plastic vacuum tubing kept breaking each time I tried to insert a splice section of rubber tube, so my splice of rubber tube was 18 inches long before I was able to get it...

John_Collins

If the rubber tubing is soft, it could collapse under pressure. Best to replace the plastic tubing with MB material.

Just last week I changed plugs on my 99 SL600 and when I attempted to move one tube out of the way it was so brittle it broke. Before I finished the job I had broken three lines. I bought 5 meters of the stuff from a local dealer for $10 and replaced every piece of it I could find.

silveroldie

Can you tell me where all the vacuum lines attach to the engine? A squirrel or rat ate one of mine and I don't know where it came from. The engine starts, runs fine for 2 or three seconds, then starts to choke off and finally stops after about 6 seconds. The vacuum lilne in question is about 1/4 inch, stiff black plastic and has about 1inch radius turn about one inch from the end. It appears to go into something rather than around something.

mleskovar

Car model/year/engine/transmission? Where did you find the piece? What are the ID and OD?