Car is a 2014 wagon 4 matic with the 157 motor.
I have times where the car sits in the garage for weeks without being driven.
On my 97 Porsche 911, I take out the fuel pump relay and crank the starter until the pressure gauge climbs.
Is there a way to do that with the AMG?
I saw a short video of a obviously home made relay with a push button on top, for engaging the starter to crank without firing. Relay was in the engine bay fusebox.
Unfortunately, I couldn't find the source of this device.
I'd like to get the oil back up to the heads and journals before starting.
Thank you for any advice.
Ed

 

Have you tried keeping the pedal fully to the floor as you crank? In some vehicles this disables the ignition, it will only crank while oil pressure builds up.

 

How about a pre-oiler or accumulator? The latter is much cheaper but you have to use it manually and pay attention when doing it, but very doable. I bought one ages ago and I think they $100? So I'd rekon $200 now. Moroso Oil Accumulator.
The preoilers back them were like $500, so I never looked into them, but just push a button and in a few seconds you have oil pressure I never understood why they didn't put them on cars, especially expensive ones. Then when I got older I learned about business, which boils down to one thing; profits.

Another thought is Lucas oil stabilizer. It help keep oil on the parts so cold starts are better lubed. I use it on everything that takes oil, even my generators. Well, not 2-strokes, but otherwise everything.
Then there's moly or tungsten disulfide, which I put on parts when building an eng if you really want it to work, but you can add to the oil to get some bennies. Some is better than 0.
I wouldn't bother cranking w/o starting, there is very little load on the eng at idle. Well, I should say there wasn't before the EPA stepped in. They increased load a lot for emissions but it's still not too bad. I adjusted mine so it's old school, low idle and load, and doesn't wake up my neighbors. That noise was the main reason I did it. But that is an option if you really want

For the starter bypass, there's a relay somewhere that you simply energize with 12V from a little push button. Just have to find it. You can put that inside the car if you want, and even wire it so it can't engage if the ign is On. Sorry I don't know where that relay is, but I'd imagine it's in the front fuse box? Someone here knows, just hope they see this and reply. I'd say trace the wire from the starter but I'm sure it disappears into the loom.

 

I have not had to practiced pre-oiling crank. It sounds good to pump oil before starting the engine. At least the crank bearings.

I guess you can use any piece of wire to jump this relay. It only involves fairly low Amperage, right?
The starter internal relay activates the starter own 900A contactor relay.

 

The most I've seen a starter relay draw is 3A, which is the old school Ford ones. I'd imagine the relay is built into the starter and that's fed by a generic little 1" black cube relay, no doubt in the fuse box. Those only takes a few mA to trigger so you can use a teeny weeny little push button.
Just have to find that little 1" relay, assuming that's how they did it. I assume because that makes sense and it's how I've done it when making something, but with MB you never know, it might have some complicated and expensive module to be an On/Off switch.

 

Here's mine. Ignore the "N", that was a note to self. M is the starter

 

Great! Now it's tempting to pre-lube unused engines after winter.


Are the chassis computers going to sense the car as getting stolen ? ?


Engine is going to pump up block galleries to crank and up to head favorites.
Thing is the cylinders are still dry until 25Psi opens up squirters with enough oil volume.

So crank a little but not too long

 

IMO, step one, get rid of the solenoid....

 

Thank you for the info about the starter relay. I'm going to take a closer look at that. Sounds like the push button would just make a connection to jump the starter. Should be easy to do.
Btw, I unplugged a few months ago and I like the feedback I get from the motor.

 

Not an MB video, but oil priming and listen to the comment about idle oil pressure late in the video

 

Unfortunately all the suggestions here are just going to be educated guesses at best.
While engine oiling especially at startup is critical, in my opinion, other a nitrogen filled pre-oiler, there is no avoiding it.
In fact I would say that preventing ignition is actually going to be more harmful than allowing it to start. Especially if you're still allowing fuel to go in there.
But even if you're able to disable both fuel and ignition, you're still subjecting the engine to compression, which is putting the load stresses on all the crank and rod bearings. Except you're doing it at 250 RPM where the oil pressure would most likely be insufficient to provide any pressure needed to prevent bearing on metal contact.
I built quite a few engines, both Auto and aviation. The only way to do a proper oil priming is with no compression, in other words we would leave the spark plugs out and turn the motor over. Only then there's essentially no stresses in the motor, and you can properly fill all the oil galleys and bearings with adequate oil.
So in my experience the safest thing to do is just start started normally, what did idle normally for a minute, and then drive it very conservatively below 3,000 RPM until it's warmed up, and then give it hell LOL
​​​​Also if you think of the oil system, and the way it was designed, though it's not like all the oil drains out of all the galleys and the pump. Some of the residual stuff May drain out of the bearings, but it's still in the crank galleys and all the motor galleys, as soon as that car fires up it has full oil pressure within one or two seconds.

 

If using the button on the relay the engine won't even know anything is happening. So no fuel, no nothing. Seems reasonable to me, if cranking is the way he wants to do it.
If it were me, especially if after a winder like Cali mentioned, then I'd do pre-oiler. It could be a super simple setup, like use a cordless drill to power it. No need for a fancy high $ setup for once in a while use.

 

Simple pre oiler with a drill? Please elaborate this simple plan.

 

Suck from the pan via a tube, to little pump that's driven by a drill, pump the output into the oil filter housing.

 

Just dump it into the housing? Is there a threaded port in the housing?

 

I have something like this in mind.
external pump via drill motor will not create oil pressure.

 

Just be careful with using non-MB relays. Check all connection, numbering, resistance, wiring details. You do not want a relay to ground your FrontSAM ($$$).

There are horror stories with the Air Compressor for the Airmatic blowing up FrontSAM. Here is the summary from MasterLou (he mention R, ML , and GL class but ...)

 

specially the "flyback diode" that protects the F-SAM from seing the voltage spike when interupting the coil.
It's hard to test which relay has a resistor, which has a diode and which has none.
Use your favorite multimeter to ohm around the coil both directions.

 

Eck; did you really say an external pump using a drill will not create oil pressure? I literally do things like this for a living, fyi, but am open to your theory how it would not work.

Actuating the relay some other way changes nothing in how that flyback resistor works. You could swap the resistor out for a diode to make it work better, but if it really bothers you/anyone then bypass the relay.
I still think it's a waste of time to crank for pressure. Let me put this into your brain: If the pump has to suck air at first, because the oil drained out of the tube, then cranking will take more revolutions to get oil pressure than if you started it. So cranking could be worse than starting it.
A pre-oiler or accumulator is the answer, imo.

 

Where are you pumping this oil to? Where does the drill pump outlet go?

 

cdk: Post 14

 

What sort of adapter goes to the oil filter housing to pressurize the oil system? Just dumping it into the filter housing does nothing to pressurize anything. Might as well put it into the valve cover.

 

Once again, like I said about. I don't recommend this. It's completely a pointless endeavor.
But if you are determined to do this, you would pump it into the place where you would put an oil pressure sensor. There is a 6 mm Allen plug on the oil pump housing.
That's where the factory says you can hook up a mechanical oil pressure gauge, meaning that is in the pressurized side of the system. So if you were able to hook up a pump to that port, and pump oil in, you would prime the motor

 

Thank you kenneyd, this makes sense, although too much of an inconvenience to get it all set up.
I'm probably going for the oem starter relay and incorporate a switch to only crank.
Popp the hood, switch the relay, crank for a while and put the stock relay back.

 

That would work well.