1966 250SE power steering pipes and oil cooler
 

250SE coupe with 280SE engine under restoration

On my power steering box there are 3 pipes I know 2 are oil in from the pump and out to the tank the 3rd pipe has been puzzling me until I offered up the inlet air manifold I could then see that the bends in the pipe align it with a connection on the manifold, can anyone tell me what this pipe is for please.

It also seems to have a permanent damp patch on the rubber section of this 3rd pipe although the car is not yet running, there are no visible splits but I think it may have become porous is this detrimental?

Next question.
Although my car is a 250SE coupe it has been fitted in the 70's with a 280SE engine and auto box, I know the 280 engine has an oil cooler next to the radiator, my car has the original radiator and my engine has been fitted with the 250 oil filter arrangement and oil heater tank below the engine mounting, again is this detremental to this engine?
I have the 280SE oil filter block etc., and pipes BUT NOT THE 280 OIL COOLER RADIATOR, I could fit an after market oil cooler if this is the way to go.

Anyone know why the 250 had the heater and the 280 had the cooler?

Any advise appreciated

Cliff Kent

Third pipe goes to an hydraulic throttle advance on the intake manifold which only existed on the 250SE engine. S.O.L

block it off or get a different steering box.

I have never seen one on a 250 or 280 but they were common on the M189 3.0 liter engine . What is first 6 digits of the chassis number of that coupe? ( not the USA VIN) :)

Oh,and that thing on 250 engine is in fact a water/oil heat exchanger for cooing the engine oil. Both the 280 and the 250 have a thermostat for the cooler so you need to run one or the other. I would be running the 280's radiator mounted oil cooler and filter arrangement . They all use the same oil filter though. The water /oil exchanger are a leaky damn thing and you would be better off without it.

Im not sure if the 280 rad with integeral oil cooler will fit my car (if I can find one), is the 280 rad the same overall width?

I would be tempted to use the 280 filter block and pipes and find an aftermarket oil cooler that will fit somewhere, does that sound reasonable?

Will post the chassis number later

i have a spare oil cooler that clips on the rad, u can have if u find a rad. i think the parts yard here has a few at $100. pm me for contact info

It depends on your chassis number if one will fit . There are three different front panel arrangements where the radiator sits. the 300 and the 220 used the same size radiator as an example ,but with different locations for the top hose neck. You can mount the factory Air/oil cooler down in front of the radiator if your chassis is an early one. A pair of new flex hoses and some brackets are al that is needed to mount one. AMG,in the 70's mounted them down the front ,just above the bumper and in front of the grill. The japanese do the same on their comical conversions. ;):)
http://ll.speedhunters.com/u/f/eagam.../nym/one12.jpg

I found someone at a show last week with a 71 280SE saloon and took some photos of the engine for pipe routing etc, just had a look and that has the oil cooler on the side of the radiator but its difficult to tell if the front panel is different to mine.

I wont have the chassis number until tomorrow evening as the car is at my daughters house, what I think is the chassis number starts 111.

I can get an after market oil cooler at a reasonable price and did think I would fit it a little more descretley than the one shown in the photo!!!
Also there is the offer of the original one located in Florida which I could rig up below and in front of the main rad if my front panel wont accept the proper configuration.

Where is the oil thermostat located? does this control the flow to the cooler?

Will post the chassis number tomorrow also can you help with paint code? I will list what I think maybe the paint number as well just incase.

Thanks

the thermo is in the oil filter adaptor housing on the side of the block. it's a simple little device but if an attempt is made to block off the oil cooler and run an engine without it, the oil pressure is diverted straight to the bearings etc with out going to the filter.
Paint codes are on the option plate with 3 digits and either G or H next to them (g=glasurit and H=herbert.) All of the colours are easily available from any paint supplier. The original type cooler is lifted from the car with the radiator .

I think the early tall grid 280 radiator + oil cooler will fit your 250.

But honestly, with nowadays oils quality and speed limitations I doubt you need an oil cooler. I would rather focus on having a radiator in good shape so that you don't overheat in traffic jams, and on a smaller rear end ratio that will give you a more relaxed cruising on highways, lowering rpm and be less demanding on the engine. An oil cooler may have been relevant in the sixties as oils were loosing their lubricating properties at much lower temperatures than today and because these cars were supposed to be able to go at full speed all day long on German Autobahns with a tall rear end ratio. Not really the use we have of these cars nowadays, and removing the oil cooler is one less thing to go wrong under the hood.

that is the point i am making above. A lot of guys have simply blanked off the oil cooler .Sometime later,sooner than later, the engine wears out rather quickly because there is no oil filtering. The cooler is really only working when the engine temp is 90C.
The lubricating oil is part of the engines cooling and it is necessary .

Well, I guess one needs to study the oil circuit before blanking it off. I would use a 230 oil filter housing that has no fitting for the oil cooler. I would also see where are the different valves and what they do. I went through that process when I removed the oil coolong system from my 5.0L M117.

I think an oil cooler is not always relevant. A good example are the US W126 500 and 560 versions. None of them were fitted with an oil cooler while the euro versions had one. Difference is that euro models were prone to some use on German Autobahns.

My chassis number is 111 021 22 083312 I have no idea how to decode this and am quite confused re the different chassis types W108, W110, W111 etc

Have tried to see if the chassis number of the saloon I saw the other week is visible in my photos but it isnt, all I know is that it is a 1971 car.

Found the paint code it is 332 G

Can you tell from this chassis number if the later radiator with oil cooler will fit?

Since when? There is no thermostat in the oil cooler system for a 250 or a 280 and I've been running a water/oil cooler for years without any problems. I'm sure they do leak from time to time but then so do the air/ oil coolers. In fact, they're more prone to leaking due to rusting and over half I've looked at are junk.

that is why I said they are leaky things and the Air/oil cooler is better. The thermostat is a small spring device in the filter adaptor housing. It doesn't look like a thermostat but it is. We are discussing an engine in the UK here BTW and USA versions,as GGR points out,weren't fitted with coolers. Which is strange considering the high temps in part of the USA. :)