Mercedes W113 230SL warm running device (WRD) P3Z or warm running device thermostat

This is a detailed video showing the restoration of the warm running device (WRD) on a 1965 Mercedes 230 SL. The video goes on to explain exactly how this device regulates both the fuel and the airflow as the engine warms up to temperature. If your Mercedes Pagoda W113 has a rough idle or difficulty starting when cold, this video might give you some ideas on how to fix the problem. The WRD is often mislabeled as the cold start valve (CSV) but the latter is a different part of the car covered in a later video.

[@user-us7jc6om7c]

Great job. The detail you provided explains how all the parts work together. I hope you do more videos on the 230SL. I’m in the middle of my rolling restoration of a ‘66 230SL.

[@MikesMercsandothercars]

Good luck with your restoration - such nice cars! I must admit, my 230SL has been so reliable over the years that I have very little work on it. However....the old girl is starting to show her age and need s a bit of TLC. First stop will be a minor tune up and then spruce up the fuel delivery system. Mike

[@savneo]

Excellent clear explanation, well done to you. 👍👍

[@MikesMercsandothercars]

Thanks! Mike

[@Nilfaultfound22]

Always amazing! Will you give us a reminder when the film is out so we can see the car in action?

[@MikesMercsandothercars]

Not sure - but I'll let you know. Mike

[@pistonnerd]

Over £500 for a thermostat 😳 Great content, Mike!

[@MikesMercsandothercars]

Yes...£600 including tax is eyewateringly expensive but as they say 'The Lord giveth and the Lord Taketh way' I figured that as the film company had just paid out to use the car, it was time to reinvest some of the proceeds. Imagine if you needed to replace the housing...that costs thousands if you can get one!! Mike

[@pistonnerd]

@@MikesMercsandothercarssmart move investing in the Pagoda, it's a real beaut!

[@MikesMercsandothercars]

@@pistonnerd Seem to remember I paid £14k all those years ago. It has been a super reliable car. Mike

[@cav4290]

Great video. The backside of hood (bonnet - for you other there :) and the engine bay should be in body color - seems like someone used a black rattle can and sprayed it over.

[@MikesMercsandothercars]

Yes you are right...that has always bothered me. At some stage I need to repaint the Pagoda...but that is quite far down my list of priorities. First I need to finish the red 107....get rid of the gold 450SL parts car...and get my ramp back in use. How is the Ferrari project going? Mike

[@mauropis1]

This is the warm running device . The cold start valve is another thing . Located in the intake manifold .

[@MikesMercsandothercars]

Thanks for your comment - yes you are right, this is the warm up regulator, or warm up device. Some people also call it the cold start valve.....although technically, the cold start valve is really the cold start injector/solenoid. Strangely enough, my Pagoda decided not to start yesterday..Mike

[@mauropis1]

I have a 250sl w113 and recently I had my injection pump overhauled in Germany and I got a culture around that 😅. The warm running device helps to lean the mixture when the coolant temperature reach around 60 Celsius . The cold start valve has a needle inside and a spring . I had to replace the needle because was letting fuel inside the engine all the time . This is a very bad condition because the engine run very rich . Cold start basically gives a squirt of fuel to help to turn on the engine . There is a solenoid and a thermo time switch which is a probe that sense the coolant temp and you will have more fuel squirt or less in relation to the coolant temp . Back in the 60s was genius, now mechanics get crazy to see such old technology.

[@MikesMercsandothercars]

@@mauropis1 Thanks for your comment Who did you use to over haul the injection pump and what did it cost? I am currently restoring a 1975 D Jetronic 280SL. It is amazing to compare that car with my 1980 Fiat 238 van. The van looks (and drives!) like a vehicle from the 1950's whereas the SL still looks and feels quite modern despite being much older. It just illustrates to m,e how far ahead Mercedes were in their engineering. Now lets se if I can get my Pagoda running! Mike

[@rome288]

Awesome video… as always. I hope you do an R107 cold start valve video because mine does not work and a used one on eBay is $700. The R107 valve only regulates air bypassing the throttle so I am able to manually cold start my car by bypassing the valve and holding the throttle for a while during coils start. I hope you know of a way to repair vs. replace. I like the dark blue color on that W113.

[@MikesMercsandothercars]

Hi - thanks for your comment. Can you send me a picture of your cold start valve on the car? Mike