To start off i bought Monark glow plugs from Mercedessource.com 2 months back. the plugs were made in germany and they said were suppose to be better quality then bosch. THE MONARK PLUGS ARE STRAIGHT UP GARBAGE. 4 of the plugs were burned out and only one of the plugs was working. But the plug that was working only heated up towards the bottom INSTEAD of the top were its suppose to.


I removed all plugs scrubbed and reamed all holes to remove the carbon buildup and replaced with all new original Bosch plugs. i havent driven car in couple days and temperature was same when the car was having problems starting.

THE car started right up without any hesitation on the first try. so i will stress to stick with the original parts on these cars and not with aftermarket.. especially the glow plugs.

The bosch plugs rock! I have seen autolight glow plugs the official glow plug of nascar I kid you not fail in 1 month

Just ask FI how great the bosch plugs are!!! He has drained his battery a couple of time by accidentally leaving them on and they still work even with a couple hours of constantly glowing

Beru is the best as per my experience followed by BOSCH.

I was happy with the Monarks but I did have one burn out prematurely.
Now the replacement for that one is showing signs of stress - the insulation is starting to pancake around the post. So I'm going to put the Bosch plugs back in.

Other monark products seem to be great though. the GP relay is working well and I love the hand primer pump - feels much more solid than the factory unit.

-Christian

PS - did Bosch update their GP design? I have a set of the original '85 GPs with 54K miles on them. They look good.

(02-17-2010 12:11 AM)Syncro_G Wrote:  ..
PS - did Bosch update their GP design? I have a set of the original '85 GPs with 54K miles on them. They look good.

For the 616/617, there are two Bosch designs.

Part number 0 250 201 001 - 11.5 v
   
   


Part number 0 250 201 039 - 11 V
   
   


The 0 250 201 039 is what is typically sold.
I believe the 0 250 201 001 is not manufactured any more. Just "new old stock" is left. I have found the 0 250 201 001 last a much longer time compared to the 0 250 201 039.




.

I recently pulled the monarks and am now running Bosch

several were in great shape after the few thousand miles of use but I had to swap a few that in succession, kept burning out.

word has it monark had a "bad robot" in the assembly line that they have since fixed.
That doesn't make a whole lot of sense to me because from what I observed, the problem looked like it was from using insulators with too low a melting point.

But given 4 of the 7 monark plugs I went through were fine, it does look to have been a batch problem.

At this point I have no reason to go back but down the line, they may be a good option again.