Hi folks, I'm new to this forum but need a little guidance on an apparentglow glug problem. Any help is greatly appreciated!

The car is a 1980 240 D (non turbo). Last night she was a little hard to start - it took 3 tries before the engine started and stayed running. Before I got out of the driveway and into the street, the glow plug light began flashing. The owners manual tells me that this indicates the glow plug system is not functioning properly and to take the car to the MB dealer. I'd rather not do that if I can help it.

I suspect it is a bad glow plug relay.

I also own a 2000 Ford F250 powerstroke diesel and am familiar with the replacement of its glow plug relay. This system is different on the MB.

My question(s):

1) is there a way to test the relay?

2) is it necessary to replace the glow plugs and relay together?

3) if you had to buy a replacement relay or other parts, where would you buy them? and what is a reasonable price for these parts?

For what it's worth, this engine is about 6 years old and was a replacement from MB in Stutgart, not rebuilt. It has approx. 60K miles on it. The car has just under 500,000 kilometers, but still looks and drives like a new one.

Thanks for all input.... John

1964 MBZ 190C (5.0 & C4 from 71 Mustang)
1977 Lincoln Town Car (black beauty)
1980 MBZ 240D 4 speed
1993 Mazda MX3 GS (27K)
2000 Ford F250 Powerstoke

 

https://www.autohausaz.com

is a good sourse i just bought the new improved kit from them...It includes a new relay that keeps the plug hot longer. and 4 plugs (bosch)..I recommend staying with Bosch plugs

If your glow plug light is flashing it means that one or more plugs are bad......check your metal fuse in your relay box as well...not sure about 80 but if you dont have the newer relay box that includes the fuse then your fuse box is on the fire wall next to the end of the engine...the relay is on the front left fender near the headlight

Dieselgiant.com has some good DIY with pictorial walk thrus for free ......on relays and plug testing or you can order a cd from them to get the expanded..the free walk thrus on most of there stuff has done me well...great info on that web site..there prices on parts are not always the best but they do provide info and that is worth a few bucks

60K on a new engine...your just getting to the end of your break in..sweet...keep the dead bugs off you rear window..they tend to catch up with 240s...LOL

It may be getting time to adjust your valves as well...check dieselgiant for that as well. I bought their tools, got a valve cover gasket and a full CD for about 70 bucks...I did 3 valve jobs so far so i have more than paid for what i bought. I had never done one...it was rather easy once I viewed the Video

ever think of run veggie oil in that thing? I have 3 cars on it

Good luck

Pierre
82 300SD veggie converted 250000
78 300D Veggie converted 178000
84 300SD...runnin a 5050 mix...she will be converted soon as well 165000

 

Thanks for the great info. Now I have a good idea of how to proceed....

Re: veggie oil....

Glad you asked!!! That's the main reason I bought this car a little over a year ago from the original owners. I've been making my own biodiesel for almost 3 years for the F250. At this point it is just about honestly painful to me anytime I actually have to go and pay for fuel at the pump. The Ford has been just wonderful, but it's huge, and my 2nd car was the Lincoln which is not much smaller. I have owned many older Benzes over the years, and had heard they actually are very well suited to run on alternative fuels because of their simplicity. So I was kind of interested when a customer of mine (I'm a bartender, he details cars professionally) told me his long-time customer wanted to let go of this one. They had it serviced at the MB dealer every 5000 kilometers, and I have every reciept for every time the hood was opened from 1980 to now. Incuding all the documentation that came with the new engine from Stutgart.

I thought it would get 35 or so miles per gallon, and I could make less biodiesel. I guess maybe I get to make a little less, but the 240 only gets maybe 28 - 30 for me, and you are right about slow! I find that I still drive the F250 a lot since it actually gets almost 20 mpg and is a lot more comfortable and much, much faster....

I have also burned kerosene mixed with biodiesel and a little dino diesel when we had a lot of kerosene left over after last years heating season. The car did'nt miss a beat.

Boy did I get off on a tangent there,, sorry,, In hindsight I may have been better off going with the conversion to veggie oil. I decided to brew my own bio though, because it really is not that hard to do, and I can put into any vehicle in any ratio I want to. Sometimes it is a hassle though, like now when the tank is almost empty and I'm just starting a batch of fuel, so I won't have any for a couple of days at least. I have cultivated a couple of wonderful sources for my used veggie oil though, and think it would be very easy to run either of my diesels on this oil.....

May make the conversion at some point since I do plan to keep both of these ones for a long time!!

 

Hi, I too have a simular issue with my 83 300SD. For the last week or so I have noticed that the glow plug light on the dash would not come on turning the key. I tried it a few more times and it worked for a while. Now it doesnt work at all. I can get it started but not too easy since its in the 40s here at 0500 when I go to work.

I looked at the relay and the strip fuse is fine and no corrosion I can see. Odd part is that the plug timer still clicks off in about 15 seconds or so. Ill check out diesel giant and see what they have though I have to sayI dont have that much expeience with voltmeters. But, Ill give it a shot.

I have the newer non-inline plugs. Having this style would one going out effect all of them like the older loop type? If so is there a sequence to follow?

Any help would be apprecatied. Cheers Chris

 

Even one malfunctioning glowplug in cold morning weather causes your type of trouble. If I may suggest for you to use the Search function in this forum you will find an absolute ton of information on this very subject, including how totest relays for malfunctions and how to ohm test glowplugs with a multimeter. You'll also find replacement part numbers and good sources for buying them by using Search.

 

Johnathebar - I had exactly the same problem you are describing; very hard to start, once it did start it was pretty darn noicy and after the car started, the glow plug lightwould flash.
Took the car to my indy and he diagnosed the problem as a bad glow plug. He replace it andnow she starts and purrs like a kitten...

 

John,
I also have a 240d bought third hand, which I have been baselining, going over system by system to start a good maintenance baseline. I replaced all glow plugs after hard starting became continuous. I hooked each one up to a 12V battery chager on 10 amp charge. Only one lit. Then I replaced all 4. The others had been original- 260000 km on all of them!

I cleaned all the wires between the glow plug relay and the individual plugs.

Besides glow plugs, the BIGGEST improvement came by replacing the battery (-) ground cable. I have two ground cables now, both coming from the battery. One to the engline block, one to the frame. Now in 10 degree weather, with a wait about 25 seconds, she starts on the FIRST try with a slightly longer hold on the starter.

Also: CHECK your OIL viscosity. I am using 5W40; thinner does make a difference in winter.
strelnik

 

Just did this replacement over Holiday. Glow Plugs 1 and 4 were bad and the relay light on the dash would not come on. In Houston, this is not a big deal since we really don't have winter; I had this issue since July. Itgot into the 40's and I had to lean on the starter to get it going. I tested resistance and found the plugs that offended. I am clean start in 40's now. Some recommend changing all plugs at once.

 

I also am in the sameboat as John,

New to the forum. I'malso new to MBz: 84 300sd, and new to diesel.


I do not see any glow plug light on the dash when I turn the key. I fiqured the gplugs are bad, so I ordered 5plugs and a new relay. It has the block heater, and the previous owner just plugged it in all the time in the winter here in Buffalo. The car runs good once it gets started, and restarts nicely when its warmed up. I have not recieved my repair manual in the mail yet, I don't have a clue yet where the relay is located. Can someone let me know where the relay is hid?

thanks

EDIT: I replaced all the plugs, then the gp light came on with the key. Then I replaced the factory gp relay with a new bosch "fast" relay kit. The car starts fine in the 35 degree weather now