Monark versus Bosch glow plugs in 1984 300DT?
 

Bosch Duratherms are the best imo

I pulled some 8 month old Monark pencil plugs and replaced them with French made Bosch plugs. Two of the Monarks had already failed.

Sent from my Galaxy Note 3

I also used monarks and one failed after 1 Year and I live in S California where the Glow Plugs don't get near the workout they do in cold areas. Do not use Autolite as the tips swell up on them.

On the internet French made Bosch Plugs are in the range of 8-10 dollars each.

Also get a Glow Plug Reamer or look up one of the other methods of cleaning out the Carbon from the holes so you get the max life out of the new Glow Plugs.

i've had beru fail too. just go with the bosch.

Bosch is best.

Bosch Glow Plugs are certainly cheaper, easier to find and entirly adequate.

Things like carbon build up on the Glow Plugs, worn out Injector Nozzles and other issues that effect the proper burning of Fuel in the Precombustion Chamber all effect the longivity of the Glow Plugs.

Every bad glow plug I have pulled from my two 300D's where Bosch, as I recall, but don't know the history of them. I have installed various ones since. Some ~$8 ea ones I bought on ebay are still fine after maybe 2 years. I recall a 3-letter name (KYB or such), and bought as a pack of ~10. I need to start logging each glow plug I change w/ cyl number.

Re reaming the holes, I just used a standard metric tap, but only a few times since there was negligible carbon. When I have had the injectors out, I don't see any carbon build-up in the pre-chambers. I also look down each w/ the glow plugs on to insure they are glowing at the tips.

NGK

Is it a stationwagon TD? What is a DT?

DT = a Diesel Engine with a Big Turbo. ;)



Charlie