Author Topic: Some questions in my 280S's engine bay  (Read 264 times)

3l33ter

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Some questions in my 280S's engine bay
« on: 03 November 2021, 12:04 PM »
Here's a picture of the area above the distributor.

There is a plastic tube coming up from the front of the engine block, near the crank pulley. It is broken and just sticking out in the air above the distributor (green arrow). When I drive the car, it squirts a little oil out onto stuff. What is that tube and where is it supposed to route to?

As you can see, my radiator leaks. Is there a source for new ones? Should I get this one repaired?

I have two ports on my air filter housing that aren't connected to anything (yellow arrows). What hoses do I need to buy and where do they route to?

The car starts and runs just fine...
'75 280S
'77 6.9
'82 300TD

daantjie

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Re: Some questions in my 280S's engine bay
« Reply #1 on: 03 November 2021, 02:49 PM »
Crankcase breather hose?
Daniel
1977 450 SEL 6.9 - Astralsilber

UTn_boy

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Re: Some questions in my 280S's engine bay
« Reply #2 on: 03 November 2021, 03:38 PM »
The two connections on the air filter housing are supposed to connect to a diverter valve located under the front of the intake manifold, somewhat behind the secondary air injection pump.  However, I notice that the belt is missing off of the air pump.  Due to the belt being missing, the air pump has probably seized up, or the system has been disabled.  It all has to do with emissions, and it was a joke of a system even when it was new.  It literally crammed air into the exhaust to displace unburned hydrocarbons so it would pass U.S. emission standards at the time.  It was claimed that the it aided the thermal reactor (pre catalytic converter name) in cutting down on emissions, but it was all a rouse.  You can either put everything back like it was, leave it as is, or finish removing the emissions related items under the hood and find a Euro style air filter housing that does not have these two extra hose connection on it.  However, this may involve replacing the entire exhaust system if you want to do it right.  While an expensive feat, the engine will run and breath a hell of a lot better. 
1966 250se coupe`, black/dark green leather
1970 600 midnight blue/parchment leather
1971 300sel 6.3, papyrus white/dark red leather
1971 280sel Black/black leather
1973 300sel 4.5, silver blue metallic/blue leather
1976 280s astral silver/blue MB Tex

3l33ter

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Re: Some questions in my 280S's engine bay
« Reply #3 on: 04 November 2021, 04:48 PM »
Aha! I did notice exhaust coming out of one of the ports, and with what you said about the air pump, I suppose it is the port that was supposed to send fresh air into the exhaust. With the air pump disabled, exhaust was flowing back through it.

OK I'll try to eradicate the smog crap when I have time.

What about the oil tube? I can't figure out what it could possibly be for.
'75 280S
'77 6.9
'82 300TD

UTn_boy

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Re: Some questions in my 280S's engine bay
« Reply #4 on: 04 November 2021, 08:11 PM »
I didn't touch on the black tube because Daantjie correctly called it out.  It's a crank case breather hose.  It has nothing to do with oiling.  Though, when the engines becomes worn and blowby increases this tube will allow oil vapor to escape from it if it's unhooked.  It's supposed to connect to a line that runs to the back of the car to a pressure relief valve tied into the fuel tank vapor system.  The line it connects to should run up the left side of the car, under the steering gear box, and up the left front frame rail.  Why anyone would disconnect this is beyond me, but the plastic does become brittle with age, so maybe it broke.  Hard to say without the car in front of me. 
1966 250se coupe`, black/dark green leather
1970 600 midnight blue/parchment leather
1971 300sel 6.3, papyrus white/dark red leather
1971 280sel Black/black leather
1973 300sel 4.5, silver blue metallic/blue leather
1976 280s astral silver/blue MB Tex

3l33ter

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Re: Some questions in my 280S's engine bay
« Reply #5 on: 05 November 2021, 02:12 AM »
Oh daantjie I thought you were talking about the ports on the air filter. So if this little tube is just a breather vent, is it OK to cap it? I don't see any other lines in the engine bay that look like the remnant or the other end of this broken line, but I'll look down under the steering box and the frame rail.
'75 280S
'77 6.9
'82 300TD

UTn_boy

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Re: Some questions in my 280S's engine bay
« Reply #6 on: 06 November 2021, 08:08 AM »
I have two U.S. model 280S cars here where I'm at to look at and compare to.  Neither of them have this plastic crankcase breather hose.  For now I have to assume that someone has replaced the engine from an early W114 280.  The W114 models with the M-110 had this hose.   
1966 250se coupe`, black/dark green leather
1970 600 midnight blue/parchment leather
1971 300sel 6.3, papyrus white/dark red leather
1971 280sel Black/black leather
1973 300sel 4.5, silver blue metallic/blue leather
1976 280s astral silver/blue MB Tex

3l33ter

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Re: Some questions in my 280S's engine bay
« Reply #7 on: 07 November 2021, 10:43 PM »
I have a California-spec '74 280 W114 and it doesn't have the plastic tube. Hmm

Well I capped it on the 280S, and so far so good. Thanks guys!
'75 280S
'77 6.9
'82 300TD

UTn_boy

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Re: Some questions in my 280S's engine bay
« Reply #8 on: 08 November 2021, 06:41 PM »
A California spec W114 280 would not have had this tube from 1974.  Only the 1972 and 1973 federal models would have. 
1966 250se coupe`, black/dark green leather
1970 600 midnight blue/parchment leather
1971 300sel 6.3, papyrus white/dark red leather
1971 280sel Black/black leather
1973 300sel 4.5, silver blue metallic/blue leather
1976 280s astral silver/blue MB Tex

Taha

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Re: Some questions in my 280S's engine bay
« Reply #9 on: 11 November 2021, 03:25 PM »
May I ask what is that box with 3 connected hoses beside the radiator? Also I don't see the oil cooler in this photo. Is this a Euro/Us difference? thank you.
1978 280S

Randys01

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Re: Some questions in my 280S's engine bay
« Reply #10 on: 11 November 2021, 06:19 PM »
That's the charcoal cannister for capturing fuel fumes. Not every variant was fitted with an oil cooler.........eg Euro 6.9's have an oil cooler but Aust ones don't?....go figure?

3l33ter

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Re: Some questions in my 280S's engine bay
« Reply #11 on: 15 November 2021, 11:47 AM »
Yes, the thing with 3 hoses is the charcoal canister.

My 280S and my 6.9 both have no oil cooler. I haven't seen many w116s at the junkyards but they didn't have oil coolers either.
'75 280S
'77 6.9
'82 300TD