FREE MAN5

Let me start with some brief history. I have a 2007 S550...I had a starter relay put on last May last may and this past I had my ECU refurbished. I got the ECU back and about 2 weeks later the car started having issues with starting (engine turning over without starting until it would finally start) then one day it wouldn't turn over, now it just clicks 1 time when I turn the key. Refurbished ECU, and both batteries are new. I had the vehicle towed to the mechanic who put the starter on who proceeded to tell me the engine was seized. I had a neighborhood mechanic look at and his thoughts are it's the starter. He tried turning the engine with a breaker bar and it wouldn't budge. My question is would a bad starter cause the engine not to turn?

More context... It didn't seize while driving, and I had a oil change a couple of months prior.

Thank you in advance,

streborx

ECU refurbished? What's this about?

FREE MAN5

Yes, My ECU was bad, so I sent it out to get refurbished.

streborx

What was bad about it, who refurbished it, and what did refurbishment involve?

Jaap

If 2 mechanics cannot turn the engine over there must be some serious problem.
Do you have an endoscope / borescope?
Then remove all the sparkplugs and look into each cilinder.
Look for any strange damage, scratches to the cilinderwall, bent valves, debris in the cilinder etc.

For step2:
Drain the oil and look for metal or shiny particles in the oil

Step 3:
Remove the oilpan and inspect

Step 4:
Remove the valve covers and inspect

Arrie

Not being able to to turn the engine with s breaker bar is very bad sign.

The starter is one thing that is in contact with the flywheel and in theory it could cause engine to seize. Take the starter off and then try to turn engine with a breaker bar.

The other “utilities” run by the belt could do this too so for the test take the belt off too.

streborx

Check your oil level -- hopefully it's at the full level. A jammed starter could be the cause as identified above. Should be easy to remove and check.

JohnLane

"Jammed starter" very unlikely. If a starter has been recently replaced by someone not competent to do so... By all means.... inspect.

OP pull all spark plugs and see if it will turn by hand (breaker bar). If fuel or coolant comes out of a particular hole you have a dead injector, dead ECU (Fail to delivering fuel to one injector anytime power is supplied) or mechanical issue causing coolant to be in a hole.
The don't just seize. Something unpleasant happened.

BOTUS

many chipped AMG engines will nip up in a bore and bend a rod - either they throw so much fuel in it hydraulic locks - or drivers try to put 600bhp on the road on a cold engine before the piston warms to its correct shape...

electrical issues shouldn't cause a seizure (outside leaving an injector wide open or the ignition so far wrong it melts) - starter motors go bad all day long on these so that may give no crank - so follow the posts above about trying to manually turn over and if that's not good, pull plugs and try again....

streborx

A jammed starter does seem unlikely, but with a refurbished ECU about all you can absolutely rule out is the spare tire inflation pressure (lol).

FREE MAN5

I'm back but with not much information, but I have another question. What could cause a vapor lock? and could that seize the engine? I'm asking because I remember having a code describing something about an evaporator leak not long before the engine issues, Thanks in advance.

Ultrakla$$ic

A hydro locked motor would/could be impossible to turn. Lets hope its not that!~

Jaap

Vapor lock and evaporator leak are two completely unrelated things (even though they sound similar).
And no it cannot seize your engine.

Ultrakla$$ic

I would take the starter out of the car and then see if the motor will turn by hand using the crank bolt to spin the motor. If not, then what if the refurbished ECU commanded too much fuel into a/the cylinders and hydro locked the motor?? YIKES!

FREE MAN5

Can this be fixed?

FREE MAN5

This seems like the most likely scenario. Can this be fixed?

Ultrakla$$ic

As long as there wasn't catastrophic damage or even damage to the rotating/moving internal parts.

Now I'm not trying to instill fear or say that your motor is hydro locked, as I'm merely responding to the bit of info you've given and possible causes. Start by removing the starter incase the bendix either grenaded and has the motor in a bind. Then try and spin the motor as it SHOULD spin........may wanna take the spark plugs out too to aid in spinning the motor easily, and scope the cylinders while theyre out. Fuses, relays and even a jacked up ECU will not prevent the motor from spinning over by hand, however, internal damage of any magnitude to the rotating/moving parts could though. Keep us posted.

Me personally I would take the starter and the plugs out and try and turn the motor by hand since you haven't even been able to do that at all since starting this thread. If the motor spins, then you've at least possibly narrowed it down to the starter/bendix. If you take the spark plugs out and gas or water comes out of the empty spark plug holes while spinning the motor then I'd suggest setting the car on fire and collecting the insurance.

BOTUS

best to remove the plugs and see if it will turn - not sure why anyone would want to remove the starter (unless believed to be easier to get at ring gear to turn it over)

looking at the plugs will tell a lot about the condition of things and if any liquid in there it has a chance to get out - an engine that has tried to squash a liquid is likely toast - damaged pistons / rings, smashed little ends, bent rods and these days a twisted engine block are all normal disasters...