Afterglow rated glow plugs for OM603? - PeachParts Mercedes-Benz Forum

Jeremy5848 · #1 12-08-2008, 01:15 PM

Now that my '87 has afterglow (see the DIY here), I wondered whether I should use afterglow-rated glow plugs. However, I can't find any listed in any of the Internet stores. The only mention of special plugs is in some threads in this forum talking about installing an afterglow relay and new plugs in OM61x engines using a Bosch kit. Nothing mentioned for the OM60x engines.

Jeremy

awsrock · #2 12-08-2008, 02:32 PM

I could be wrong, but aren't the new Bosch duraterms ok for afterglow use? I think they redesigned their standard glow plugs to be able to handle afterglows..I don't think you need to get anything special.
BUT, let's wait and see what others say

babymog · #3 12-08-2008, 03:53 PM

If you have the later angled-injection head (not the original #14), you already have them, the originals won't fit.

Otherwise, I'd look into whether the 602T glow-plugs will fit, all US-bound 602 turbos had afterglow.

Jeremy5848 · #4 12-08-2008, 04:48 PM

I have a #14 head; it is not the original thanks to a PO but it is nonetheless a #14. Neither my mechanic not the dealer had anything other than stock glow plugs listed for my car. The mechanic didn't know about the Bosch afterglow relay kit available for the 61x engines; the dealer didn't even know what 'afterglow' was – had to explain it to him. It seems that the folks who really know these cars are here on this forum!

The plugs in the car now are Bosch Duraterm 80006 (the Bosch part number is 0 250 201 039). Perhaps they are already "afterglow rated." Didn't later W124 diesels, e.g., the 300D 2.5 with the OM602 engine, come with an afterglow relay?

Jeremy

babymog · #5 12-08-2008, 05:00 PM

Yes.

All US-bound 602 turbo cars had afterglow.

That includes the '87 190D 2.5 turbo. I suggest finding the part number for the '87 190D 2.5 Turbo glow-plugs as the head design is similar, compare them physically to the glow-plugs in your car. If they are the same length/reach and same diameter/pitch thread, you're golden. I'm not sure if the 300D 2.5Turbo head is the angled-injection type like the '90s 603s, if so the thread is different and they (purposely) will not fit the earlier head.

vox_incognita · #6 12-08-2008, 05:51 PM

If you do a search with the kit part number 0 250 201 953,you`ll see that it uses your plugs:
Fast Glow Plug Kit
With Post-Glow
(Glow plugs remain active
up to 3 minutes after
starting. Provides better
performance during cold
starting conditions.)
Contains:
(4) 0-250-201-039 Plugs
(1) 0-281-003-096 Relay
(1) Set of Instructions

...much easier to tell what is what with Beru designations -a GV(MJ) plug would not tolerate afterglow,a GN will ..A cross-reference with the number shows a GN plug...Those Duraterm 0-250-201-039 work flawlessly in regular type of relays also..

I cannot confirm however whether ALL Duraterm line Bosch plugs tolerate afterglow.

Jeremy5848 · #7 12-08-2008, 08:33 PM

OK, thanks guys. The 1987 190D Turbo takes the Bosch 80006 glow plug, same as mine. so looks like what I have is OK for afterglow.

Bio300TDTdriver · #8 12-08-2008, 10:51 PM

Those are afterglow rated, I think. See this thread for Dave's write up.

Jeremy5848 · #9 12-08-2008, 11:56 PM

Quote:

Originally Posted by Bio300TDTdriver

Those are afterglow rated, I think. See this thread for Dave's write up.

I must be losing it . . . I remember that thread now, even contributed to it, oh well.

The most interesting comment that Dave makes is that "afterglow rated" plugs are designed for the 13.5 volts that is present in a running engine, whereas "normal" plugs are rated at 11.5 volts because the load tends to drag the battery down. However, the glow plug in a running engine is already hot and the combustion makes it even hotter, and so it draws less current.

At 11.5 volts, the initial current rush for a 0.5 ohm cold glow plug is about 20 Amps. As the glow plug heats, the resistance rises and the current goes down. Once the engine is running, the voltage goes up to 12.5 volts but the resistance of the glow plug has increased to more than 5 ohms so the current is only 2 Amps or so.

With my afterglow mod, the speed of my cold engine increases noticeably when the relay clicks off after 30 seconds. The glow plugs must be putting a ferocious load on the alternator, hence a drag on the engine. No smoke seen yet!

I'll have to watch more carefully, see if I can put a number on the RPM change.

Jeremy

88300D · #10 12-09-2008, 09:32 PM

http://www.bosch.com.au/content/language1/downloads/Glow_plug__Contents_New_layout.pdf

This may help