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Hi everyone,
I have a 2013 C250. I recently swapped and replaced a like for like engine because the previous owner seized the previous engine. Swapped it with a similar year and almost same mileage (108k).
The car turns on but the engine doesn’t crank.
I used my foxwell obd scanner to clear all the codes and nothing obvious appears with the engine and tranny.
Do I need to have the dealership or an indy register the ECU to the new engine? Or it it a simple starter issue?
thanks for your replies
Last edited by freddieb; Aug 23, 2024 at 12:45 AM.
Reason: More info in body
2015 SL400 (M276 Turbo), 2014 C350 Sport (M276 NA), 2004 SL500 (M113), 2004 Audi TT225 (BEA)
So, there is absolutely no crank? I would start with replacing the starter. When you remove the old one, apply 12V to it directly and see if it spins. There is also the old test to hit it with a hammer while someone tries to start the car, but that only works if the car starts. Then you know it's a bad starter. You also want to check to see if the starter is getting 12V when trying to start the car.
If that doesn't work, then take it to the dealer.
Which Foxwell scanner do you have? Is it the one specifically for Mercedes?
Thanks for the replies, everyone. Responses are below:
To clarify, there is no crank at all. After I replaced the starter, it turns over but stops after about 2 or 3 revolutions,(probably because the system knows not to continue cranking)??.
>I would start with replacing the starter. When you remove the old one, apply 12V to it directly and see if it spins. I had the starter tested at my local parts store and they confirmed the starter was bad. So I ordered a part and now the car cranks but now doesn't turn over.
>Just curious, do you hear the fuel pump turning on, do you have fuel pressure? You should be able to see fuel pressure on the Foxwell scanner.
There is fuel pressure. I tested the schrader valve near the driver side bottom of the engine. Fuel spurted out all over my shirt.
>Is the battery good, tested and/or charged?
New battery. I also charged the battery and it measured at 12.7v just before cranking it.
>Did you replace the ecu with the replacement engine, or did you install your old ecu?
I used the old ECU. I am going to ask the guy that I bought the engine from, to see if I can test his ECU (if he still has it)
I also have the Foxwell NT809BT version.
Lastly, there is compression in the first cylinder (gauge goes up to around 30 psi) before the system stops cranking completely.
I do it again and same thing happens. The system stops cranking after around 3 revolutions.
Any other suggestions before I enlist the help of an indy or dealer?
You have a "crank, no start" with replacement engine swap using your original ECU.
The battery and starter are good.
--- You do have some fuel pressure so let's double-check your spark...
pull a coil + plug to witness spark during crank.
--- Also let's make sure the MAIN GND STRAP at tranny was reconnected during swap - (I know 800Amp cranking current uses main GND) - Just check crusty main GND
--- If nothing else turns up... scrutinize ECU data with a capable scanner.
Last edited by CaliBenzDriver; Sep 1, 2024 at 04:11 PM.
You have a "crank, no start" with replacement engine swap using your original ECU.
The battery and starter are good.
--- You do have some fuel pressure so let's double-check your spark...
pull a coil + plug to witness spark during crank.
>I double checked fuel pressure and pressure test was at 60+ psi
** I do NOT have spark. I tested the ignition wire and ignition coils with a tester and there is no spark.**
I checked fuses 19 and 27 and both were good.
--- Also let's make sure the MAIN GND STRAP at tranny was reconnected during swap - (I know 800Amp cranking current uses main GND) - Just check crusty main GND
> Yes, double checked that ground strap was connected to tranny
--- If nothing else turns up... scrutinize ECU data with a capable scanner.
> I had a friend of a friend who works for Mercedes and he brought his $30k Mercedes scanner and tested it. He reinitaited the systems to ensure all were syncing up. The only thing that came back was an outside temp sensor and one other thing that wasn’t related to the starting issue.
He thought because the cranking was somewhat slow, the non OEM starter might be a possible culprit but unlikely. He told me to check for spark on the first cylinder with the plug in. And there is no spark.
> I had a friend of a friend who works for Mercedes and he brought his $30k Mercedes scanner and tested it. He reinitaited the systems to ensure all were syncing up. The only thing that came back was an outside temp sensor and one other thing that wasn’t related to the starting issue.
He thought because the cranking was somewhat slow, the non OEM starter might be a possible culprit but unlikely. He told me to check for spark on the first cylinder with the plug in. And there is no spark.
Any other ideas??
Ok, you have a well defined NO SPARK on a replacement engine using original chassis ECU.
At this stage we ignore drive authorization with your own ECU.
Top suspect becomes crank sensor.
Don't guess use your own scanner to read ECU faults
Ok, you have a well defined NO SPARK on a replacement engine using original chassis ECU.
At this stage we ignore drive authorization with your own ECU.
Top suspect becomes crank sensor.
Don't guess use your own scanner to read ECU faults
i thought I’d update this thread
I changed out the CPS with a new one from FCP Euro. Instead of cranking only 3 or 4 times, it now cranks around 8 times. But still doesn’t turn over.
My Mercedes mechanic friend pulled a wiring diagram and said there's a relay responsible for the ignition coils in the front sam (circuit 87). I found were 2 at location O, Engine circuit 87 relay, and R, Chassis circuit 87 relay.
i tested the relays. Both are good. On the relays, I activated 1 and 2 using a car battery and got about 75ohms, 3 and 5 showed continuity. So I suspect they’re good.
For kicks over the weekend. I took apart the electrical system on the bad engine. And compared all the connections to make sure everything was connected. And all looks connected.
Any other ideas? Is there an ignition control module on this car that I could possibly test? I hope I’m getting close.. any other suggestions are most welcome!!
2015 SL400 (M276 Turbo), 2014 C350 Sport (M276 NA), 2004 SL500 (M113), 2004 Audi TT225 (BEA)
Originally Posted by freddieb
...Lastly, there is compression in the first cylinder (gauge goes up to around 30 psi) before the system stops cranking completely.
I do it again and same thing happens. The system stops cranking after around 3 revolutions.
30 psi is insufficient for combustion. You should be seeing around 150 psi +/-25 psi. If cylinder 1 has only 30 psi, you have a big problem. Sounds like time for another engine. You've been scammed.
2015 SL400 (M276 Turbo), 2014 C350 Sport (M276 NA), 2004 SL500 (M113), 2004 Audi TT225 (BEA)
By "big problem" I mean a blown head gasket or worse, a cracked head or block. Double check and make sure you are measuring compression correctly. Are you losing coolant? Do you have oil in your coolant or coolant in your oil?
By "big problem" I mean a blown head gasket or worse, a cracked head or block. Double check and make sure you are measuring compression correctly. Are you losing coolant? Do you have oil in your coolant or coolant in your oil?
Thanks, JettaRed.
i went back and re-tested the compression after putting in a new CPS. The old CPS only allowed the engine to turn around 3-4 times, not enough to give a good reading I thought. I put in a new CPS and it now turns around 8 times. Here are the results;
Cylinder 1-4: 50,60,80,25.
“****!”
i asked the guy who sold me the engine and he said it was running before the accident. But the car had been sitting for 3 years!! The guy was kind enough to refund my money back. But before I take the engine out again. I thought I’d do this in the video. He put Seafoam in his bmw with low compression and it worked!
2015 SL400 (M276 Turbo), 2014 C350 Sport (M276 NA), 2004 SL500 (M113), 2004 Audi TT225 (BEA)
You can try the seafoam, but I don't trust this guy's methodology. I suspect his initial readings on cylinders 1 and 3 were bad to begin with. Also, seafoam is not going to "seal rings". Again, you need to be seeing around 150 psi. The engine will not run with 60 psi, or even 80 psi. There is something mechanically wrong with your engine. It's doubtful you have bent valves because you would have even lower compression, but if they are not seating well, or if you have a cracked head, or really bad (broken) rings, or a blown head gasket, you will not get to the psi you need for combustion. You might want to put a scope into each cylinder to see what the pistons, valves, and cylinder walls look like. Here is an excellent scope for automotive inspections.
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