Jacked up car tried to start it and now it won't start even on ground. - PeachParts Mercedes-Benz Forum

mbzjag8090 · #1 10-16-2011, 08:02 PM

I jacked up the front of the car to try and get rid of air in coolant. I tried to start it when it was jacked up. It wouldn't start so I lowered it and now it won't start on the ground? Please help. Thanks.

layback40 · #2 10-16-2011, 08:23 PM

Quote:

Originally Posted by mbzjag8090

I jacked up the front of the car to try and get rid of air in coolant. I tried to start it when it was jacked up. It wouldn't start so I lowered it and now it won't start on the ground? Please help. Thanks.

It sounds like air in the fuel system. I assume it is still able to crank.
Have you done anything to the fuel system lately?

mbzjag8090 · #3 10-16-2011, 08:28 PM

Nothing. It was closer to starting when I first jacked it up. Now it hardly turns over when turning the key. Could raising the car somehow lead to air in the fuel system?

mbzjag8090 · #4 10-16-2011, 08:28 PM

Also... it was starting normally before I jacked it up.

layback40 · #5 10-16-2011, 08:35 PM

Quote:

Originally Posted by mbzjag8090

Nothing. It was closer to starting when I first jacked it up. Now it hardly turns over when turning the key. Could raising the car somehow lead to air in the fuel system?

If you had an pocket of air in the fuel system, it could have moved when you jacked the car up. Does it crank strong?

mbzjag8090 · #6 10-16-2011, 08:37 PM

It did crank strong the first time when it was up but no now it is not cranking strong.

layback40 · #7 10-16-2011, 08:51 PM

Quote:

Originally Posted by mbzjag8090

It did crank strong the first time when it was up but no now it is not cranking strong.

The battery is going flat. Needs a charge to get it going.

Skippy · #8 10-16-2011, 08:55 PM

Yup. Recharge your battery, bleed the fuel system, and it should be good to go.

mbzjag8090 · #9 10-16-2011, 08:59 PM

Ok, I've got a battery charger I'll hook up tonight. Why would the battery get drained by trying to start the car with it jacked up? Thanks for your help...you seem confident it is this simple which is good news for me.

mbzjag8090 · #10 10-16-2011, 09:03 PM

You are saying it is going flat from trying to start it? That surprises me because I have only tried to start it maybe 4-5 times. So you both think it is the air in the lines which is the problem? I'll bleed the air via the plastic screw pump. When will I know when to stop pumping the thing? Thanks

bustedbenz · #11 10-17-2011, 11:01 AM

Quote:

Originally Posted by mbzjag8090

You are saying it is going flat from trying to start it? That surprises me because I have only tried to start it maybe 4-5 times. So you both think it is the air in the lines which is the problem? I'll bleed the air via the plastic screw pump. When will I know when to stop pumping the thing? Thanks

Jacking the car up didn't drain a battery by itself. My suspicion would be that the battery was already in marginal condition (if it's more than 3-4 years old, it's suspect; if it has ever been "Deep cycled" -- run completely dead due to headlights being left on, etc, it's also compromised) and so it didn't take much cranking to use what capacity it had left. Starting is the highest amperage requirement that will ever be placed on a battery.

If you listen carefully, you will hear a relief valve opening inside the engine when the pump has done all it is going to do -- sounds sort of like a squeezing, squirting noise -- it's hard to describe but you'll notice it. It may not take long at all for this to happen -- 15-30 pumps at most -- because the pump does not bleed the entire fuel system. If the air is in the metal lines themselves going to each injector, the pump will be ineffective at bleeding because it doesn't push fuel that far.

If this is the case, then the only options for bleeding the system are either extended cranking intervals (30-45 seconds at a time, 5-10 minute cool down period in between, maximum of 2-3 attempts) or else what most people would do -- loosening the fuel line nuts one at a time, cranking until fuel comes out the line, and then retightening.

bustedbenz · #12 10-17-2011, 11:03 AM

Forget what I said about extended cranking for bleeding the system ------ this not only works but is factory recommended for the 603 engine (86 and newer) but isn't likely to be as effective on a 617. It might work but it's a lot of wear and tear on the starter for an engine that wasn't designed the same way as the one they recommended that procedure for.

I ran my 603 completely dry on the side of the road one time and after rescue fuel was brought to me, cranked it for about 55 seconds with my foot on the floor until the thing was going. Starter survived the experience, but I won't be responsible if somebody else's dies. The thinking at the time was that with every few seconds that went by, the engine seemed to be getting a little more momentum and a few more cylinders hitting here and there, and it was better to keep that momentum going at the starter's expense rather than to "lose ground" by waiting for a cool down.

Stretch · #13 10-17-2011, 12:31 PM

Quote:

Originally Posted by mbzjag8090

You are saying it is going flat from trying to start it? That surprises me because I have only tried to start it maybe 4-5 times. So you both think it is the air in the lines which is the problem? I'll bleed the air via the plastic screw pump. When will I know when to stop pumping the thing? Thanks

You'll hear a slight change in sound as the fuel gets pushed back along the return line. If the pump leaks diesel then you will probably be wasting your time trying to do it this way...

mbzjag8090 · #14 10-17-2011, 01:53 PM

Thanks. This morning I went out and it started. I did charge the battery. The air bubble must have moved overnight.

vstech · #15 10-17-2011, 02:20 PM

lets move the cooling system question to a new thread!
I'll move it for you!