107sl Oil cooler

[max9888]

Does anyone know the cheapest place to get an oil cooler for a 1981 107 500sl?
Are they easy to fit?
All help much appreciated

 

[Myros]

I once fitted a cooler to my BMW, back in the 80s

it was a PACET, thermostatically controlled, all the kit including adapter plate and hoses. You could google them.
Are you sure you need one? Are you running hot, frying your oil.

After I fitted the oil rad to my BMW, I fitted an oil temp gauge. The oil never got over 90 celsius in about 10 years. The rad sprang a leak, so I took it off and just ran the outlet hose to the inlet side of the adapter plate. The oil temp gauge still never showed more than 90 celsius. If I'd fitted that first, I would have saved over a hundred quid and a lot of work.

I can't say I've seen our 500 running hot yet, and we've schlepped it up the Alps and back down again, and blatted up the autobahns the far side of 100mph for hours.

 

[max9888]

It is certainly running hot, 4 hours in the sun with the heater on full to keep the temp down!
The cooler has a leak on the bottom and is finished I think.
Also do you know how to adjust the idle speed?
Thanks

 

[Myros]

yes and no

you can fiddle with the co adjustment a bit just to fine tune it, but the idle is electronically set up from an idle control unit. There is also an idle control valve which does it's job while the engine is warming up. They can go as well. Describe your sympoms a bit more and we'll have ago.

The oil cooler you are talking about is I think stuck on the side of the coolant rad. You might have to replace the whole shebang, even though they should unbolt. You'll find it probably gives up the ghost entirely as you try and undo the pipes and fittings

 

[max9888]

Thanks for that. That is right about the cooler.
When the car is hot it will not idle, it just cuts out, the previous owner said he had it adjusted down to improve fuel economy. does this sound likely?

 

[Myros]

sounds like shinola to me

as we both know there is no such thing as economy with a 500. I can't help but laugh every time I look at the instruments to see that little needle in the red zone, again.
If you are spanner happy, I think an allen key/hex bar can be slid into the rubber grommet on the air filter housing, and pushed gently down, engage with the co adjuster, you then twiddle it a bit to get the desired idle. You should do this with a co meter attached to the exhaust, which is how my mechanic did it. I can't remember the dia of the hex bar, but it's about 3mm.
The idle should stand at 750 in p or n with the engine fully warmed, and 500 in D, same criteria. plus or minus 100 on the high side and 50 on the low side.

Have a look at this schematic

http://www.detali.ru/cat/oem_mb2.as...&L=765.701&CT=F&cat=048&SID=50&SGR=015&SGN=01

 

[max9888]

The co meter is just to check the emissions...right?
I saw another thread showing how to adjust the idle speed by going under the drivers footwell is that a wise thing to be fiddling with.http://forums.mercedesclub.org.uk/showthread.php?t=3137&highlight=107
The schematic is for the oil cooler I take it.
Thanks for all this it is much appreciated.

 

[Myros]

Max

unless you are our Malcolm and an electronic genius, these things just get replaced, and are expensive. I paid £100 for a breakers idle control valve, and MB wanted about £400 for a new one. The idle control units, as per the pic, are similar.
First things first, get down to a good garage and have the team run a tune up diagnosis on your motor. All they might have to do is set the co back into range and you might be spared all the grief. I think that's the only adjustment the previous owner could have done.
Economy on a 500 SL, what was he thinking?

 

[Myros]

Max

I forgot to mention, the cooler in the picture is for the auto transmission fluid, not for the engine oil.

 

[max9888]

Thanks for that, not being the electronic genius I will take it to my mechanic!
Why oh why buy a 500 and then look for fuel economy!