When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Misfire Cylinder #1, brand new coils and spark plugs. Please help!
Hey guys, my 2011 E350 got 140k miles and it's been giving me misfires on several cylinders. Given, the high mileage, I decided to just replaced all 6 cylinders with new Delphi coils and Bosch OE plugs. Now I'm only getting misfire #1 and the engine idles rough on start up with code P0301. What else could it be? Any help is greatly appreciated.
2015 SL400 (M276 Turbo), 2014 C350 Sport (M276 NA), 2004 SL500 (M113), 2004 Audi TT225 (BEA)
Did you also replace the spark plug boots with the coils? You have the M272 engine, right? Two other things to check would be the compression on cylinder 1 and the fuel injector on cylinder 1. The good news is that if it's a leaky injector, they are relatively cheap in comparison to a GDI injector.
Is the P0301 code the only code? What about fuel trims for cylinder 1?
wait, don't the coils come with new boots? I didn't reuse the boots.
yes, M272 engine.
How do I check the compression and fuel injector and fuel trims for cylinder 1.
P0301 is the only code.
wait, don't the coils come with new boots? I didn't reuse the boots.
yes, M272 engine.
How do I check the compression and fuel injector and fuel trims for cylinder 1.
P0301 is the only code.
swap coils first, and see if the misfire follows and if not check that plug and move it and see if it follows. this will rule out of bad new part.
swap coils first, and see if the misfire follows and if not check that plug and move it and see if it follows. this will rule out of bad new part.
first swap current parts between positions, and avoid introducing new variables in the diagnostic. Even when swapping you may fix (poor contact), or damage/disturb working parts. Always minimize number of variables. New parts does not mean good parts.
2015 SL400 (M276 Turbo), 2014 C350 Sport (M276 NA), 2004 SL500 (M113), 2004 Audi TT225 (BEA)
Originally Posted by GOPHIMBO
wait, don't the coils come with new boots? I didn't reuse the boots.
yes, M272 engine.
How do I check the compression and fuel injector and fuel trims for cylinder 1.
P0301 is the only code.
There are a couple of ways to check compression. One way is with XENTRY. It sets the engine to not start while you crank it and then measures and compares the speed of each cylinder. If they are all relatively close in rpm of each other and at around 200 rpm, then compression is good. If cylinder 1 spins much faster, say 30 rpm faster, that means there is less resistance, and the cylinder is not sealing well. You have low compression on that cylinder, which will cause a misfire.
The other way is to get a compression test kit. There are lots of YouTube videos showing how to do it. Cylinder compression should be around 150 psi +/-25 psi, but all cylinders should be close to each other.
Testing the fuel injector is easiest done by moving it to another cylinder. I said easiest, not easy. Still, you are working with a traditional, non-GDI fuel system, so replacing all the fuel injectors with matched and balance injectors is an option. Did that on my 2004 SL500 and the car actually ran better with better gas mileage.
Lastly, you will need a scan tool that will show your LTFT overall. (It's an OBD standard so you may be able to do it with a generic scanner, but generic scanners are usually a waste of money on a Mercedes.) If Bank 1, where cylinder 1 resides, is significantly different from Bank 2, then you know you may have a bad injector. If the trims are a negative value greater than 10%, you have a problem. If the trims are within +/-10%, you're probably OK.
All the other recommendations are good first steps in trying to isolate the problem.
As mentioned above, new doesn’t mean without fault. I had one faulty new plug out of 8, brand new in Bosch box. I bought another new plug and solved that mystery. I also believe we sometimes wiggle/reseat a wire connection and resolve issues.
It sounds like the issue might extend beyond the coils and spark plugs you’ve already replaced. Possible causes for a persistent misfire in cylinder #1 could include a leaking or faulty fuel injector, a vacuum leak around that cylinder, or even an issue with the compression such as worn piston rings or valve seats given the high mileage. Additionally, wiring problems or a malfunctioning ignition control module specific to cylinder #1 could be contributing to the rough idle and persistent misfire. I recommend scanning the vehicle for fault codes using the engine control unit (ECU) as well as other related modules like the fuel injector control module and the ignition control module. There should be fault codes stored in one or more of these control modules related to your issue. You might need to take it to a mechanic, but if you want to figure this out yourself, getting a full system scanner like youcanic’s full system scanner is ideal for diagnosing all systems comprehensively. Just be careful to use a full system scanner, or if you use a generic fault scanner such as the Innova 3100, you might not see all fault codes. Have you already checked the fuel pressure and injector operation for cylinder #1?
2015 SL400 (M276 Turbo), 2014 C350 Sport (M276 NA), 2004 SL500 (M113), 2004 Audi TT225 (BEA)
Originally Posted by tepelena
It sounds like the issue might extend beyond the coils and spark plugs you’ve already replaced. Possible causes for a persistent misfire in cylinder #1 could include a leaking or faulty fuel injector, a vacuum leak around that cylinder, or even an issue with the compression such as worn piston rings or valve seats given the high mileage. Additionally, wiring problems or a malfunctioning ignition control module specific to cylinder #1 could be contributing to the rough idle and persistent misfire. I recommend scanning the vehicle for fault codes using the engine control unit (ECU) as well as other related modules like the fuel injector control module and the ignition control module. There should be fault codes stored in one or more of these control modules related to your issue. You might need to take it to a mechanic, but if you want to figure this out yourself, getting a full system scanner like youcanic’s full system scanner is ideal for diagnosing all systems comprehensively. Just be careful to use a full system scanner, or if you use a generic fault scanner such as the Innova 3100, you might not see all fault codes. Have you already checked the fuel pressure and injector operation for cylinder #1?
You're pretty much repeating what has already been said. However, what is a "vacuum leak around that cylinder" mean? Can you provide clarification? Also, what is a "malfunctioning ignition control module specific to cylinder #1"? I was unaware of such a device. What is the control module designation? I'd like to look it up in XENTRY to see if there is a test for it.
You're pretty much repeating what has already been said. However, what is a "vacuum leak around that cylinder" mean? Can you provide clarification? Also, what is a "malfunctioning ignition control module specific to cylinder #1"? I was unaware of such a device. What is the control module designation? I'd like to look it up in XENTRY to see if there is a test for it.
@JettaRed , I could only guess he is referring to the ECU controller for the specific injector, say -> the pin at the ECU connector is not sending the correct signal because of something internal.
I have seen that the injection controller is damaged on the internal side of ECU on other brands.
I picked the best looking plug from the old set and swap out that new one. Idling much better, no CEL and no misfires. I'm gonna drive it for a few days to be sure. So far it look promising! Quality control issues from Bosch i guess.
As mentioned above, new doesn’t mean without fault. I had one faulty new plug out of 8, brand new in Bosch box. I bought another new plug and solved that mystery. I also believe we sometimes wiggle/reseat a wire connection and resolve issues.
I think you might be right on this one. I picked the best looking plug from the old set and swap out that new one. Idling much better, no CEL and no misfires. I'm gonna drive it for a few days to be sure. So far it look promising! Quality control issues from Bosch i guess.Thanks man!!
Happened with my Durango with the 3.6L V6 engine just a month ago:
I got the misfire on cylinder #2 with rough idle. Clearing the code it ran just a few hours fine, but problem returned.
- Replaced the spark plug but no help.
- Moved the cam shaft adjustor magnets between the banks with no help.
Did a little research and found out about the VVT solenoid problem. This engine has this solenoid for each bank and after replacing it on the bank for cylinder #2 the problem went away.
So, as the VVT solenoid is for the whole bank of cylinders and the error code was only misfire on cylinder #2 it could be that this code does not mean only cylinder #2 just because this VVT solenoid works all the cylinders in the same bank.
So, in this MB case perhaps the problem is with the camshaft adjustor magnets especially is the problem comes back.
I don't know if MB engines have that VVT solenoid...?
Happened with my Durango with the 3.6L V6 engine just a month ago:
I got the misfire on cylinder #2 with rough idle. Clearing the code it ran just a few hours fine, but problem returned.
- Replaced the spark plug but no help.
- Moved the cam shaft adjustor magnets between the banks with no help.
Did a little research and found out about the VVT solenoid problem. This engine has this solenoid for each bank and after replacing it on the bank for cylinder #2 the problem went away.
So, as the VVT solenoid is for the whole bank of cylinders and the error code was only misfire on cylinder #2 it could be that this code does not mean only cylinder #2 just because this VVT solenoid works all the cylinders in the same bank.
So, in this MB case perhaps the problem is with the camshaft adjustor magnets especially is the problem comes back.
I don't know if MB engines have that VVT solenoid...?
Yeah, your Dodge is using a slightly different version of the same Bosch system. Perhaps more robust with less parts.
the M276/8 use 4x independent VVT Gears positioned by 4x oil solenoids and 4x Camshaft sensors.
The variable camshat timing works based on available oil pressure... so clean + cooled oil is essential to reliably position camshafts based on pre-learned maps.
Does your Durango feature a variable oil pump as well?
Last edited by CaliBenzDriver; 10-06-2024 at 05:26 PM.
These are not cam shaft solenoids what I am talking about. These are cam shaft adjustor magnets that the MB engine has as well as the Dodge engine, but the Dodge engine also has VVT cam shaft solenoid that looks like picture below. That is what was broken in my Dodge causing cylinder #2 misfire. As the same cam shaft works valves for all cylinders in the same bank the misfire could have been in any of the three cylinders, but it calls it only for cylinder #2, which is the first one in front on driver side.
I have seen several posts in different forums about this Dodge engine and they all have it as cylinder #2 misfire. I just cannot believe that if the culprit for this problem is this VVT solenoid it causes misfire only in Cylinder #2 when all three cylinders have the same cam shaft that this solenoid adjusts somehow.
I do not know if MB engine has solenoid that does this function.
Yeah, your Dodge is using a slightly different version of the same Bosch system. Perhaps more robust with less parts.
the M276/8 use 4x independent VVT Gears positioned by 4x oil solenoids and 4x Camshaft sensors.
The variable camshat timing works based on available oil pressure... so clean + cooled oil is essential to reliably position camshafts based on pre-learned maps.
Does your Durango feature a variable oil pump as well?
I don't exactly know how our VVT system works but I do know that each bank has only one cam shaft for intake and exhaust. These shafts work for all 3/4 cylinders in the bank. Any adjustment of the cam shaft works for all cylinders in the bank simultaneously.
we understand your point about Durango ECU Misfire code for one cylinder when in fact its not one cylinder but the whole cylinder bank that is affected.
-- You are right about fault codes being MISLEADING... this is so often that one may begin to think "purposely misleading".
Existing codes are misleading and missing codes as well. Some faults are concealed under wrap to be left ignored.
-- Recently I mentioned the "CAN traffic jams" caused by carefully located marginal connections. It detunes no less than both engine + tranny timings.
-- Oil pressure sensor is missing all together, no fault there either.
-- Voltage yoyo is another sweet chaos in charge of X-Mas trees. No warning: all good!
-- Recently we were looking at tranmy module codes saying "solenoid valve fault" when in fact it's bad gearbox K3 clutch controlled by solenoid.
Once you know, you troubleshoot systems before anything else.
Last edited by CaliBenzDriver; 10-06-2024 at 06:46 PM.
These are not cam shaft solenoids what I am talking about. These are cam shaft adjustor magnets that the MB engine has as well as the Dodge engine, but the Dodge engine also has VVT cam shaft solenoid that looks like picture below. That is what was broken in my Dodge causing cylinder #2 misfire. As the same cam shaft works valves for all cylinders in the same bank the misfire could have been in any of the three cylinders, but it calls it only for cylinder #2, which is the first one in front on driver side.
I have seen several posts in different forums about this Dodge engine and they all have it as cylinder #2 misfire. I just cannot believe that if the culprit for this problem is this VVT solenoid it causes misfire only in Cylinder #2 when all three cylinders have the same cam shaft that this solenoid adjusts somehow.
I do not know if MB engine has solenoid that does this function.
Those go in the center of the VVT. Perhaps others can explain how the "camshaft timing solenoid adjusters" interact with the "camshafts timing solenoid pressure valve"
Those go in the center of the VVT. Perhaps others can explain how the "camshaft timing solenoid adjusters" interact with the "camshafts timing solenoid pressure valve"
these parts are the oil valve that the VVT Solenoid are pressing against to drive oil pressure into VVT Gear to rotate its Camshaft position FWD/RWD.
The standard rattle wear items are
-1- the VVT Gear lock pin that suffers from low oil pressure
-2- the chain tensioners that become limp from abnormal oil pressure
-3- when rattle is ignored the camshaft has a loose ring that cause its failure.
-4- CPS sensors quietly leak oil into harness for $10k repair.
Better oiling is thought to prevent these unnecessary failures related to limited oil pressure.
Last edited by CaliBenzDriver; 10-06-2024 at 08:35 PM.
Those go in the center of the VVT. Perhaps others can explain how the "camshaft timing solenoid adjusters" interact with the "camshafts timing solenoid pressure valve"
Could be.
In the Durango engine fix was easy. Part was little over $100 from AutoZone, job was about 30 min that required removing the air filter housing to get to this solenoid.
If the problem is with the other bank solenoid (passenger side) the job is a bit bigger as the intake manifold has to be removed to get to it. It seems still much less than if these need to be changed out in the MB engine, but I do not know for sure. Hopefully never comes up and the most serious issue will be the cam shaft magnets...
So it was a false positive. CEL and multiple misfires returned. cylinder #1, 3, and 5 now. There's low idle and car doesn't seem to want to accelerate from stop. Time to check the fuel injectors? or maybe oxygen sensors?
What DTCs is the car reporting? Are you using XENTRY? Have you done a compression test?
So far the DTCs are P0301 303 305 with my generic ODB scanner.
is Xentry a Mercedes specific scanner? Never heard of it before.
I haven't done compression, you posted a kit from Amazon earlier. do you recommend that or just get the Xentry scanner? Thanks for the help!
10-03-2024, 05:09 PM
first swap current parts between positions, and avoid introducing new variables in the diagnostic. Even when swapping you may fix (poor contact), or damage/disturb working parts. Always minimize number of variables. New parts does not mean good parts.
