One more on the new car. The glow indicator blinks for up to one minute after starting the car. It starts really well when cold.
I took the easy route and changed out all my glow plugs thinking "Oh, that's what everyone says to do" when the indicator starts to blink... WRONG answer dang it!

Geez, that's 10% of my car's value now in new glow plugs...

Still blinking at me... I checked that the relay is providing current to the plugs. Any other reasons why this indicator would blink?

BTW - I have a full set of glow plugs for sale for a 1980 300D...

Thanks in advance...

__________________
'99 S420 - Mommies
'72 280SE 4.5 - looking to breathe life into it
'84 300SD Grey - Sold
'85 300SD Silver - Sold
'78 Ski Nautique

Just a guess, but I had a 91 ECOdiesel Jetta that had a blinking glow plug light that indicated water in the fuel. I bought some diesel conditioner(FPPF) and poured about 8 ounces in the tank. After about 50 miles, the light went off. YMMV.

Regards,
Ed

Thanks EC93, I use conditioner in almost every tank.

Anyone else have any insight into what makes this indicator blink other than glow plugs being bad?

__________________
'99 S420 - Mommies
'72 280SE 4.5 - looking to breathe life into it
'84 300SD Grey - Sold
'85 300SD Silver - Sold
'78 Ski Nautique

Hi there fellas,
No offense jassz...

I was doing a search on this old topic and low and behold here is my original post from months and months ago.

So the 300 has been starting and running a little rough lately so I tested the GPs and found one bad one. Replaced it with new plug thinking that this might actually finally fix the blinking GP indicator light but alas it still blinks after starting.
I have checked all the GPs, reamed all the holes and checked voltage but all is as it should be according to specs.

This light is STILL blinking after startup. I cannot find anything that states what this indicates and it's beginning to piss me off...

Can anyone shed some light onto why the GP Indicator light is still blinking at me?
I guarantee it is not the GPs...

__________________
'99 S420 - Mommies
'72 280SE 4.5 - looking to breathe life into it
'84 300SD Grey - Sold
'85 300SD Silver - Sold
'78 Ski Nautique

Have you checked the condition of the 80A strap fuse that's on the left fender? Maybe a bad connection or failing strap fuse?

I can't imagine it working intermittently this long but, I guess, stranger things have happened.

__________________
Never a dull moment at Berry Hill Farm.

Yeah, that's one of the first things I did was to remove it and make sure there were no hairline cracks in it. I bent it around a little and it survived so back in she went.

The light has always lit for the pre-start. It only blinks after the car has started. The cycling time of the prestart GP indicator gives me an idea that the temp sensor is working properly as it glws for 5 or 10 seconds longer on really cold mornings. So I don't believe this to be the problem either.

When I go throught he CD manual it only troubleshoots based on a "no light" situation not a blinking light.
In other words I'm still stumped...

__________________
'99 S420 - Mommies
'72 280SE 4.5 - looking to breathe life into it
'84 300SD Grey - Sold
'85 300SD Silver - Sold
'78 Ski Nautique

Fisherman,

I am on travel and do not have access to any of my manuals, so I am going to offer a guess without checking into it. So, take this for what it is worth, which is not much.

There is some electrical device responsible for actually shutting the light off after it turns it on. This can be a relay or some small solid state device, connected to some kind of adjustable resistor and capacitor type timing circuit. To me it sounds like this circuit has a component that is wearing out, and the rest of your system is fine.

When the temperature sensing and lamp on timing circuit, an array of small devices goes to shut off the indicator lamp, it seems one of the devices becomes slightly unstable while it is making the transient from the "on" state to the "off" state. As a result, it causes the circuit to be unable to make up its mind, until what ever stored energy (such as in the capacitor) contributing to the instability is bled off. A check of this theory might be to track the length of the instability and see if it (the duration of the blinking of the indicator lamp) tracks with the outside temperature.

If there is a relationship one way or the other it would suggest the ambient temperature sensing and compensating elements are the parts to be suspicous about. If it does not track, or just seems to be getting worse with time, it may be part of the circuit that is not normally affected by the change in temperature. In any case, I think this part of your relay circuit is responsible for the light flickering and blinking. Unless, of course, one of your neighbors installed one of those blinking Christmas tree bulbs in there to drive you nuts. Good luck, Jim

__________________
Own:
1986 Euro 190E 2.3-16 (291,000 miles),
1998 E300D TurboDiesel, 231,000 miles -purchased with 45,000,
1988 300E 5-speed 252,000 miles,
1983 240D 4-speed, purchased w/136,000, now with 222,000 miles.
2009 ML320CDI Bluetec, 89,000 miles

Owned:
1971 220D (250,000 miles plus, sold to father-in-law),
1975 240D (245,000 miles - died of body rot),
1991 350SD (176,560 miles, weakest Benz I have owned),
1999 C230 Sport (45,400 miles),
1982 240D (321,000 miles, put to sleep)

This sounds like one for Gilly!

__________________
1985 300D Turbo ~225k
2000 F350 (Powerstroke) 4X4, SWB, CC, SRW, 6spd ~148k
1999 International 4900, DT466e (250hp/660 ft/lbs), Allison MD3060 ~73k

First, check the condition of the wires to the GPs -- if one is corroded, you will get the blinking lamp.

The GP relay contains current sensors (really reed switches, I think) for all the GPs. If one isn't drawing current, the relay flashes the GP lamp on the dash after starting. If one of these switches are bad, it always flashes even though the GPs work fine.

I'd ignore it unless it starts hard.

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!