300E starting problem sometimes

[austent]

I picked up an '86 300E locally for $1500, one owner, nice MB. Replaced the OVP due to it turning over but not continuing to run; has worked fine but at least twice since replacing the OVP it takes at least three tries before it starts and keeps running; I am thinking it is not maintaining fuel pressure, check valve and filter replaced in '06; the only other odd thing was the fuel gauge going crazy back and forth, I would not think that had any bearing. Any thoughts would be appreciated.

on another note, speaking of bearings; the fan motor was seized; took it out, notched the bearing and housing lip around it, held it tight and were able to work the shaft free; a lot of patience and lubricant got it done.

[psfred]

Several possibilities.

Check the condition of cap and rotor, especially for carbon tracking. If you have much, you need to replace the camshaft seal, it's getting oil into the dizzy.

Failure to start hot can be a bad accumulator.

Replace the fuel pump relay -- a bad relay will not only prevent proper starting, but will also cause stalls while running. Stalling while coming to a stop is a stuck, dirty, or leaking idle control valve.

Check for vacuum leaks, especially the boot between the air meter horn on the fuel distributor and the throttle body. If the clamp at the throttle body is loose and the clamp is almost all the way tight, you need to replace the boot. Do injector seals, injector sleeve seals, and idle control valve hoses at the same time.

Peter

[austent]

Thanks, thought of some of your list and not others. Weather is getting cold, garage is warm so I can give some weekend time to these. David

[raysea390]

austent, i just posted a question about that elec fan then i saw your post. mine works but is making a heck of a racket. is there a way to temporarily disconnect it and how did you lubricate the shaft? what did you use to lubricate it?

[austent]

You know i would think there is a fuse to the fan that would stop it from working though I have no idea which it is since I lost the relay card that was with the car before I had possessed the car even 12 hours; getting to the fan and disconnecting the wires is not that difficult, though involved; first time through expect a couple of hours, make sure you have a place to lay out the parts in order with screws; once the fan was exposed I used a strong pick to hook the hole on the clamp and release it/a large screwdriver to reclamp; what I did was, very carefully with patience, so as not to damage the plastic fan wheels, put the motor in a vise and with the red extension that comes with a can of WD40 sprayed it in and around the bearing; the shaft goes in a bearing which sits in a lipped housing; that did not free the shaft from the bearing, so with a sharpened screw driver I gently notched the bearing housing and the lip so that I could hold the bearing and lip and gently, with vise grips work the shaft back and forth, lubricating as I went until it freed up; someone posted a procedure for removing the plastic fan wheels, but I was not gutsy enough to try; I used to have something called Aerokoil that was great at freeing up parts rusted together, but cannot remember where I got it, think it was mail order from Kentucky; after freeing it up I applied power using a small battery/could use a battery charger, let it run, lubed some more, let it run, then applied some white silicone grease to inhibit corrosion, let it run then reinstalled and it works now; hopefully it will last through the winter; I hope this helps; once I had it out and was working it free I realized that part took me a good hour and a half; go slow, patience and take care of the plastic wheels. David

[Chadahar]

If it is like my w126 1984 380SE, then take out the glove box and you will see a plug to your left and behind and down from the rear of the bolster(the plastic part) and disconnect the fan. the fuse is used for other things besides the fan.
If you do not want to buy a replacement fan, then disassemble the old one and have the commutator recut and peplace the brushes. mine was so far gone that the commutator looked like the grand canyon and was at least 1/16" DEEPER than where the commutator comes out of the armature. I lucked out with an after market fan and it bolted right up.
You do have to take out the bolster, the plastic foot well cover to get to the fan...on a 126.
Hope this helps.

[raysea390]

Thanks austent and charlies84380se - I found the connector to the fan and have disconnected it for now. Its cool enough here that I don't think it would kick on anyway. Too bad it's not easier to get some lubricant on the shaft...

charlies84380se - where did you find that aftermarket fan?