Pagoda SL Group

W113 Pagoda SL Group => Drive train, fuel, suspension, steering & brakes => Topic started by: dpreston Virginia on February 10, 2024, 23:05:18

Title: Warm Running Device
Post by: dpreston Virginia on February 10, 2024, 23:05:18
My 69 280SL has been running rich and quickly fouls the spark plugs. I have gone through the linkage tour, check cold start valve (working perfect), replaced injectors and now I removed the Warm Running Device. It was thoroughly stuck.
I have cleaned it and hit it with PB blaster, then grease I have finally gotten it to move by hand but not to allow it to move freely enough for the plunger to move it. Do I need to take it completely apart? If so how do I do that or how to I free it up?
Photos show the movement I can pushing the valve open and close.

Thanks for any help to fix my WRD.
David Preston
Title: Re: Warm Running Device
Post by: rwmastel on February 11, 2024, 01:33:02
You're a Full Member, anything in the Tech Manual?
Title: Re: Warm Running Device
Post by: dpreston Virginia on February 11, 2024, 02:11:07
Not how to take it apart and get it working.
Title: Re: Warm Running Device
Post by: Pawel66 on February 11, 2024, 10:30:53
I think taking it apart is, basically, unscrewing two screws and parts you get are shown here: https://www.sl113.org/wiki/Engine/WarmRunningDevice

How to get it working - I think it is about freeing the valve if it is stuck, making sure that the thermostat is working and then adjusting it with two types of shims. Technical Manual covers all if it in essence.

As for freeing up the valve:

https://www.sl113.org/forums/index.php?topic=14134.msg96068#msg96068

https://www.sl113.org/forums/index.php?topic=14271.msg97165#msg97165

As for checking if the thermostat is working, e.g. here:

https://www.sl113.org/forums/index.php?topic=30847.0

Use a pot or kettle, thermometer and measure extention of the thermostat pin

AS for adjusting:

Oval shims regulate fuel mixture during warm up - more shims, richer mixture.
Round shims regulate time when WRD is working (depends on temperature) - more shims means longer work of WRD.

Search on the forum will point to a lot more materials.
Title: Re: Warm Running Device
Post by: Pinder on February 11, 2024, 16:32:51
I found this video to be a good explaination

https://www.youtube.com/watch?v=F6sxlOFmoYw
Title: Re: Warm Running Device
Post by: dpreston Virginia on February 11, 2024, 19:49:47
What a great how to video! Thanks for sharing!
Title: Re: Warm Running Device
Post by: Pinder on February 11, 2024, 21:13:33
To free up the mechanism reemove the air filter, (should screw off) and spray your favoirte WD40 or equivelant to free it up so it moves smoothly, sea foam etc spray it every hole.
Title: Re: Warm Running Device
Post by: Pawel66 on February 11, 2024, 21:53:01
Maybe also:
- during the kettle test, you can just blow through the device to see if the thermostat is closing the air

- when you are putting it back together, it is good to apply some sealant between thermostat and its housing; the sticking of the air valve comes often from coolant dripping down there where the valve is and leaves residue that makes the valve and plunger stuck
Title: Re: Warm Running Device
Post by: dpreston Virginia on February 12, 2024, 19:37:35
Took the valve completely apart and lightly sanded the inside of the body and the valve. Then added some grease. Reinstalled and the car is running well.

Thanks for all the help especially Joe Alexander. What a great community.
Title: Re: Warm Running Device
Post by: rwmastel on February 12, 2024, 20:32:18
dpreston,

That's great!  Good work.  I have two questions.

... lightly sanded the inside of the body and the valve.
Why?

Then added some grease.
Where?
Title: Re: Warm Running Device
Post by: dpreston Virginia on February 12, 2024, 20:41:30
I sanded the air valve and air valve housing with 800 grit paper. And then put grease in the housing to ensure smooth easy movement.

David


Photo of these parts are in technical manual at: https://www.sl113.org/wiki/Engine/WarmRunningDevice
Title: Re: Warm Running Device
Post by: rwmastel on February 12, 2024, 20:45:52
But, nothing moves in the hosing.  It's just a place for the thermostat to sit and be affected by water temperature.
Title: Re: Warm Running Device
Post by: rwmastel on February 12, 2024, 20:46:49
Oh, you meant air valve housing.  Duh!  Sorry.