texterted

Got a pending code, P0128.

Coolant Thermostat (Coolant temperature below thermostat regulating temperature).

Seeing as this thermostat and the coolant temperature sensor are contained within the same unit. I've gone and purchased it from my dealer. Typically they fail below the thermostat and allow coolant to bypass the thermostat. Thus generating the code, as it takes longer for the engine to reach normal operating temperature.

Has anyone got any hints or tips for the fitting process on my rare v8 diesel, please?

My VIN WDC1641282A449850

Plutoe

See attached

texterted

Awesome, cheers Plutoe!

I don't suppose you have access to the data sheet I'm wondering if there some bleed screw I need to know about.
Thanks very much.

Maj. Dundee

Here it is.

texterted

Thanks Major Dundee!

I wanted that one too... I just didn't know it. Nice to see, thanks.

No, the one I want is the istrunctions AR20.00-P-1142-04A referred to in that document Plutoe posted for me.... about bleeding the cooling system.

Maj. Dundee

Here it is.

texterted

Awesome, thanks Maj, new vacuum filler ordered!

Maj. Dundee

Do you intend to replace all the fluid or just the fluid lost during repair? What color is your present fluid?

texterted

I was going to get as much out as I could, it's a kind of amber colour. I'm assuming it's the original factory coolant.

Maj. Dundee

Here are the instructions for drain and fill. You do not have the equipment to do this, so remove the reservoir cap and drain the coolant by attaching the appropriate size hose to the fitting. Then proceed with replacing the thermostat.

Then fill with Zerex G05 which is amber in color via the reservoir but not to the top. Then wait until the level recedes and fill again until it no longer recedes. With the cap still off, start the eng. and watch the level. If it goes down add coolant while the eng. is still running. When it stops receding, squeeze the upper radiator hose a few times to purge air pockets.

Shut off eng. if it overflows and replace cap. Then let it cool down and check the level and add as required.

texterted

That's brilliant, thanks very much Major!

texterted

I got this done today, no real problems. I put about 8ltrs of G-05 (mixed 50/50 with de-ionised water) in the system. I cleared the code and will have to see if it comes back, fingers crossed it doesn't!

Thanks for all your help guys!

texterted

I was wrong about this! The Temp sensor is a separate unit. The sensor in the thermostat housing is actually a heater! I suspect that this was what had failed on mine.

I also note that Mercedes have revised the design of the unit. Designated with a letter B at the end of the part number, instead of the A that mine had.

I've still not had the code come back, so more fingers crossed!