What are these bits on my 380SL

[300sdToronto]

We've been trying to sort out the "plumbing" of our vac system from a very blurry vacuum diagram for the 1982 380SL. we're learning about the engine as we stumble along and have a couple of questions about the attached picture.

Is item #1 the "warm up compensator", item no. 6 in the 380Sl shop manual vac diagram?

Is item #2 the "check valve", item no. 44 in the shop manual vac diagram, or the sinisterly named "orifice", item no. 9 in the shop manual vac diagram?

Finally, where the blankety-blank is the temperature switch for the aux fan? I need to test it.........

Thanks much for anyone who actually knows where stuff is on the 116 engine.

[JPMOSE]

#1 is the Warm Up Regulator

#2 I could not figure out what this exact check valve is for..it looks like A1168000378 (replaced by A0011401760) which is used for multiple applications, such as Thermo Valve; Warm Up Regulator. You may just have to follow the vacuum lines from source to what ever stems off of the Check valve to see.

The switch for the Aux Fan should be one of two switches on the thermostat housing. One switch is for the Temperature Gauge, while the other is a 100C switch for the Aux Fan. Remove the connector and jump the wires on the connector...the Aux Fan should run.

[AZreGuy]

to clarify "Jump" should mean touch to ground, not hot. do not do until you are for sure. even though touching to ground will not damage as for hot??

[JPMOSE]

On the Aux Fan Temp Switch the switch closes at 100C. If the connector has two wires on the switch, bridging the wires is the same as closing the switch and will not cause any electrical problems.

[abiby]

Looking at your pic, the aux fan switch should be to the left of the oil dipstick while the temp gauge sender should be to the right.

[300sdToronto]

Thanks. All the parts sites show the aux fan switch as a single connector item so I presume this shorts the connection to ground. I will test asap.

On to vac. I am trying to identify which check valves should be where. No one carries a green and white one any longer, as fitted to my car. The parts site show a white and black and a blue and black valve. I've attached a vac diagram. It shows one check valve connected between the vac ports of the warm up compensator (regulator) and another check valve connected between the intake manifold and the switchover valve. I need to know part numbers and which way round they need to be connected. I appear to be missing the one that goes to the switchover valve.

See diagram .....
Attached Thumbnails

[300sdToronto]

Sorry guys, still trying to make sense of the vac diagram.

Is the part in the first picture, next to the coil, the 2 way vac valve?

Is the part in the second picture - on inner fender inside engine compartment, behind headlights, driver's side the lamda control unit or what? I am referring to the metal box, half hidden, with vac and electrical connections.

thanks muchly......

[cushjbc]

Ritchie

I looked at the electronic troubleshooting manual for an 82 380SL. On page 208, there are 2 pictures. The first one depicts what you have asked. Mercedes-Benz calls the item next to your coil a switchover valve solenoid. If it has two vacuum hoses attached (ignition advance application), it is commonly called a two-way valve; three vacuum hoses (climate control), it is called a three-way valve. Bottom line, a condition happens, this valve transmits a vacuum source somewhere.

The second picture is your ignition switching unit, commonly called "switchgear". Yours is several generations newer in advancement toward solid state ignition than the one on my car so I'll just call it a clock and not attempt to build it.

PM me and I can send you what I'm looking at.

[JPMOSE]

You need to subscribe (it's free) to the EPC so you can look up part numbers. With three classics, I'd be lost without it! Here is the site:

EPC-net Online


Even though it is free, they still ask for a credit card number....but it is never charged...so don't let that alarm you.

Using your shop manual illustration, along with the photos in the EPC, one can easily determine the part number. The information is invaluable.

Sometimes, just doing a google search with the part number only will reveal on-line vendors that sell that part with illustrations. Some of the vacuum valves have substituted to new part numbers

[300sdToronto]

Thanks for all the tips and I'll look at EPC. I have spent some happy times at the Kelowna MB dealership looking at parts diagrams .......

There is just so much MORE plumbing on the 380SL than my 300SD. The SD's engine compartment looks positively barren after you've spent a few hours trying to follow things in the SL and undo that expletive deleted fastener that is hidden under multiple layers of brackets, vac and electrical cables, assorted intake manifolds, etc. etc.

[300sdToronto]

One more thing off the list - tested the aux fan. It works.

the connector is indeed to the left of the dipstick on the thermostat housing. Grounded the connector and the fan starts up.

I'll probably order a new temp sensor as it will be hard to test.

[horangiin]

I know this is an old post, but could someone direct me to where I could find that green "check-valve" called orifice? Read somewhere it is a strainer. Does not seem to be same as the newer blue and white check valves being sold as replacement parts.

[okyoureabeast]

Hey Horangiin. I'm familiar with what you're talking about.

It's actually not a check valve but basically a small filter that prevents gunk from entering into the system. I broke the old style one and discovered what looked like cheese cloth on the inside. The part number above is incorrect. I have a spare in my cave of wonders. Let me check what the number is and post it here.

I had to buy mine from the dealer. However pelican should have them available here.

In all honesty, you might not even need it. If yours broke, I would put it onto the wish list for the next big parts order. Just bypass for the time being.

[horangiin]

Thanks for the reply. Thought I was going crazy since everyone is pointing me to the check valves. I broke mine opening it up since it appear to be blocked on both ends. Did see some filtering elements and what appears to be just paper and not rubber flap. Couldn't find any replacement part num.

[okyoureabeast]

Sadly, I found the part but don't have the number. The replacements are much tinier.

Take it into the dealer. They might actually have it in stock for you.