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MB 300SD starting problems

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Rudolf Diesel

I could use the help of someone familiar with the MB diesels. My FIL has an '83 300SD, it has a 5 cylinder turbo diesel in it. If the thing sits more than a day or two below freezing it will not start. Is not starting at 30* normal? If it sits below 0 long enough to cool off completely it will not start. Plugging in the block heater for 4 hours or so will get it warm enough to start. It had all new glow plugs put in a couple of months ago at the MB dealer. Is there anything to check? How would I go about seeing if one or more of the glow plugs has failed? The car has about 130K miles on it and is in perfect shape other than needing a generator in the trunk :eek: Once started it runs good, good power and economy, with no problems till it gets cold again. All fuel is treated with PS Supplement too. Thanks for any help.
 
Starting Problem

Fella at work used to have problems starting his MB in cold weather if it was not plugged in, used to drive him nuts that my CTD would start every time, sometimes his wouldn't even if it was plugged in. Bigger battery helped a bit and cycling the glow plugs several times (3-5 minutes) usualy works. Used to have the same problem with the company flat bed truck (Volvo :mad: POS) even if it was parked indoors. Driver was too lazy to wait for the glow plugs to finish cycling. Winter front also helps with starting, keeps the cold wind out.

Neil:)
 
you can check the glow plugs using a digital(thats what i use) multimeter by removing the connecter plug from the glow plus relay it is mounted on the driver side fender opposite the injection pump (rectangular black box) when the plug is removed you will see numbers 1 thru 5 they represent the respective glow plugs, connect one probe of the multimeter to ground and using the other you can check them one by one all readings should be very close if not then the glow plug is bad. another thing that can cause hard starting in cold weather is the valves ,if there is not enough clearance then they dont close they way they should and as a result there is loss of compression which leads to hard starting. more than likely if the glow plugs were replaced as you said they were then chances are that they are ok but still they can go bad. besides these two condition the other can be timing.

hope that it helps

p. s. - dont used the starting fluid at all.
 
Thanks B Gill, I will do a little digging to see of the glow plugs are good. If they are it sounds like it needs a trip to the doctor. :eek: I will do the valve adjustment if I can come up with the settings, that should be a piece of cake as there is a ton of room under the hood. Timing I won't mess with. Thanks again.
 
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