Advice sought: 1st time startup after 3 years of sitting

[ramonajim]

Gustav is a 1972 280SE 4.5. He was running fine-ish* whenever he was called on up until 3-4 years back when taking care of Darling Wife's Ma and then father-in-law became enough of a handful that car-related projects became limited to "keep the necessary ones moving."

Gustav has worked his way up to Number 2 on my ToDo list.... so I'm starting to noodle the details involved in getting him back into circulation.

Beyond the obvious re-connect (and likely recharge/possibly replace) the battery, what steps are prudent with 3-4 year old gas & oil?

Possibly noteworthy items:

• Pertronix ignition was installed ~ 10 years ago
• Fuel relay is assumed to need replacing (see definition of fine-ish, below )
• Tires will be replaced before road trips ensue (plenty of tread, but they're pushing 10 years old at this point).

*Fine-ish:

• We were getting occasional missing at highway speeds back before Gustav was parked.
• Had one instance where he wasn't starting - no fuel. Based solely on conversation with a fellow MB fan, we suspected the fuel relay - a couple quick taps on said relay and he started right up.

[Sugar Bear]

280SE 4.5 Nice car!!!

It is very important to confirm that the engine turns freely i.e., not stuck/seized from sitting. If it is free, then change the oil, fresh gasoline, battery etc. should be good.

If it does not turn freely, stop. Do not try to free it with the starter, pull the plugs and put some light oil in the cylinders and wait for it to free.

Good luck and keep us posted!!!

[ramonajim]

I suppose I should 'fess up about my fear over the "fresh gas" piece of this.

Makes perfect sense. But - not knowing what is involved in getting the old gas out has me concerned over this step. Catching and dealing with 10 or more gallons of fuel I'm not currently set up for.

Three+ years in Maryland weather (actual hot/cold cycles). Gas is maybe an issue? Definitely an issue?

Guess I'm hoping for a nudge in either the "pfft - go for it" or the "you're gonna hate yourself if you don't take the time to do it right" direction.

Opinions welcome!

[joshhol]

Gas is likely an issue. Did you add a storage additive prior to parking it? If not, Play it safe and drain it, or tow it to a shop just to have the fuel drained.

If the fuel is ethanol based (should say ethanol contaminated) then it has likely absorbed a fair amount of water over those alternating weather cycles. It may have phase separated.

Do you really want to run gummed up water laden fuel through your expensive Mercedes Benz engine?

[meltedpanda]

I second that , I would drain or get it drained , you will be sorry if you don't. Id pull plugs and see if the engine will turn by hand. Drain oil , check radiator , look for rotten rubber hoses, connections ect. Brake hoses should be checked, brake function ect. If she starts drive short distance or let run, then observe for any leaks , smoke ext.... good luck , pictures

[ramonajim]

You guys are no fun

I appreciate the nudge towards doing it right. Got a shopping cart queued up with likely bits.

Open question in my mind is removal of the drain plug/fuel strainer. I'm finding a few older posts about a 22MM allen wrench and/or using the back end of a spark plug socket.

Assuming at this point I'll siphon out as much fuel (fuel/water/sludge) mixture as possible, then get the beast up in the air and start working on the plug.

Any pointers for tools/techniques for strainer removal?

[Mike D]

You could undo the fuel line, attach a length of hose, jumper the relay, fill a gallon gas can and add it to one of your other vehicles to run out. Continue this until the tank is empty. The diluted "bad" gas won't be much of a factor in your other cars. I wouldn't put any more than a gallon of the old stuff per tank.

You get some benefit from the old gas and you don't have to worry about disposal. I'm presuming you are planning on replacing the fuel filter anyway, yes?

Use a paint strainer to catch any particles. The strainer will also tell you the condition of the fuel in the car.

p.s., I just realized the irony of my signature line in reference to this.

[meltedpanda]

Mike, I agree that could be done -BUT- be careful of sparks and connections on your jumper to the fuel system . Even old gas likes to explode ...

on the drain plug, once again -buy the right socket and do it correctly , the allen socket fitted to a 3/4 inch drive or half inch with a breaker bar will get it loose, spray it with PB blaster or such , tap the edges, wait and repeat . I have never had issue with removal

[Adriel]

If me, and I am paranoid, I do at least one soaking of the rings with SiliKroil, if not six times, gently turning over after each soak.

Also, while the tank was empty, just make easy and replace the fuel filter.

Hope this helps, from fellow M110 owner.

[rocky raccoon]

Caution is good but gee whiz people it has only been three years. Not like this is a 30yo barn find.

[Mike D]

Yeah but surely you don't think we're going to let Jim get away with letting his Benz sit idle without punishing him do ya?

[lorainfurniture]

I would just dump fresh gas in, charge battery. When car starts, (hopefully no mice chewed wires) proceed to Italian tune up

[Tomguy]

Been there, done that with a 4.5. I changed the oil and put fresh gas in. Took the valve covers off, put some oil on each cam lobe and tower. Took the plugs out, put a few drops in each cylinder.
Disconnected the fuel system (the "Other wire" on the + terminal at the battery), the coil +, and then cranked it until it built oil pressure.
Stopped cranking for about a minute, then cranked for a good solid minute. Stopped for 3 minutes.

Reconnected the fuel + coil. Cranked. It fired right up. Be prepared to have your neighbors potentially call the fire department, if you have any. Even without adding oil, if it was outside, 4 years of dust, dirt, moisture, and potentially rodent pee/poo on your engine, exhaust, etc - not to mention the oil that's oozed out, was already on the outside but found its way "Downstream", etc all burns off in a smokeshow guaranteed to last at least 10 minutes.

That being said, the gas tank was completely empty before sitting, and I STILL wound up with a frozen injector. So take that with a grain of salt. You may want to disconnect the lines at the injectors, and pull the rails / injectors, and just spray them really well inside with some "Carb and throttle body cleaner".

Now, this was about 20 years ago the car was put aside to sit, in the elements, for 4 years or so. Fast-forward to a few years back, when I went to sell it. The car had a half tank of gas. It ran great when parked (had rust, collision damage, etc but ran fine). Only sat about 2 years without running. It would not run. It would fire, but would not stay running. That's because of ethanol in the gas, most likely. The gas smelled terrible and was about the color of urine. After a long walk on a hot day. So I am unsure if you're going to get away with not draining the tank.

[ScooterABC]

Originally Posted by meltedpanda

on the drain plug, once again -buy the right socket and do it correctly , the allen socket fitted to a 3/4 inch drive or half inch with a breaker bar will get it loose, spray it with PB blaster or such , tap the edges, wait and repeat . I have never had issue with removal

I've never had a problem with inserting a spark plug socket in backwards and inserting the drive extension into the spark plug side of the socket. I think I've done this to replace the screen on maybe 4 cars now...