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New Poject, oh boy (bought 06 m5 non-running)

57K views 490 replies 32 participants last post by  desmo01 
#1 ·
Hello, and happy corona virus everyone.

As part of my typical day to day foolishness, I bought a new project (yeah, not needed) 06 SMG M5. Had it shipped from CA and it just showed today.

Black/black...and the fun part, it doesn't start.

It cranks fine, coughs a bit, then just keeps cranking. Seems like it needs fuel, but I could be wrong.

I did synch the CAS/DME and it is not the problem. Will add pics soon.

Any ideas on where to start are most welcome!
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#2 ·
My crystal ball is telling me it's gonna be catastrophic - someone clearly had it apart before (both airboxes were taken out, jump point cover missing, coil packs missing pull handles, the middle clip between the cabin filter housing is gone etc) and didn't like what they found. I'd boroscope every cylinder as the first order of biz.

Fortunately CL is full of $6-8K engines these days.
 
#13 · (Edited)
Check engine ground and the fuel pump relay in glovebox and the 6 or so relays/fuses in ECU box under passenger air filter? Theres only one small ground On the passenger side which can go bad really easily especially if there is any power steering fluid leaks. Its kind of hard to see from top

Due to age and possible high mileage, i would stArt from the relays, fuses, and then move on to checking the engine harness. Someone was already fiddling with it as i can see from the pictures around the fuel injector plugs etc

Just to be on safe side, i would bolt an extra ground wire from the chassis jumpstart ground bolt to the engine block (theres existing ground point Bolts under the plastic cover where the engine harness plugs into and crankshaft sensors are).
 
#14 ·
I'd check spark or coil impulse with an oscope. If the engine is indeed turning over, it is either lack of spark or fuel. I believe in this generation of controller security, the DME/CAS handshake already occurred and would not allow continued crank, if the modules and key failed handshake. That would also set a code for sure, whereas starting your car with 10 defective coils may not generate any code. Also check to make sure the ionic modules are there and hooked up. When you buy non running cars, alot of times parts are missing, ask me how I know...
 
#16 ·
Tried brake clean on start, no joy..will try that again when I remove airbox. If DME/CAS don't synch, it will just crank. Had that happen on my 08. I do have an oscope and current probe so I'll check firing of coils. Didn't see fuel pressure data in INPA, so what's best way to check that? I do have a fuel gauge that's set up for my Ducati, could adapt that I would guess. Ionic modules are there/hooked up. I did go through rear fusebox and continuity check all fuses (good). Not sure what relay is in rear fuse box but didn't mess with that. Battery is low (40% on charger) but car cranks ok.
 
#18 ·
There is no schrader valve so your gauge won’t be of much use. It’s a returnless system with a pressure transducer on the line. I’ve never looked but there should be a procedure to view fuel pressure.

I doubt that anyone would sell an M5 for cheap because of a simple thing like low or bad fuel, blown fuse, dead or low battery, etc. Maybe he’s gonna be lucky though, it could be there are no spark plugs?
 
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