Hello,
Had the car in the shop and my mechanic said I am starting to get a slow leak from my bock heater on the 300SDL. He said I can find an oem block heater and change it myself. What size wrench do I need to get the block heater off? And is there anything I should consider before starting?
Thanks,
A

__________________
1987 300SDL
187,000 miles

I'd say the main thing to consider is why the mechanic passed off the job to you
There are lots of threads on here regarding the difficulty of removing the block plug to install a heater. I'm guessing that removing the heater itself is not much easier. It may be easier because the metals are different, but if you're the kind of person that takes the car to a shop for difficult jobs, I'd be passing the job back to the mechanic or buying some JB Weld.
Sorry, I can't help on the socket size.

__________________
1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

Thanks for the reply. He actually was going to do the job but said it was not that difficult of a job. So I said I would give it a try first before allowing him to do it and save me a few quarters.
A

__________________
1987 300SDL
187,000 miles

46 or 47mm.

Thanks, for the info NJ300sdl. Does anyone know if you can cut the cord and put a socket over the block heater?
A

__________________
1987 300SDL
187,000 miles

I'm pretty sure the electric cord is removable without cutting it.

__________________
1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

Just pull it. You might want to do a search on how difficult it (easy?) it is to pull the block heater though, before even trying it.

__________________
1987 300TD
1984 300D
755,000 KM and going strong
BC Canada

my car had 260K+ on it when I removed the block heater - it's brass / bronze material sealed with an O-ring. I was able to remove it with a 3/4" drive ratchet and socket - as I recall it was 1 13/16" socket (or there abouts - 46mmish)

With the long 3/4" ratchet and a good push after applying Kroil penetrant and waiting a half hour or so - it came right out.

It's a good opportunity to flush the cooling system - as you'll have to drain it to replace the heater - or get wet when you remove it!

The new heater I got does an amazing job - even the cylinder head was warm after having it plugged in a few hours.

__________________
95 E300 Diesel 265k and counting