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I got some codes popping up on my Leonardo diagnostic tool that has me baffled, first started several weeks ago shortly after refueling at a station that I wasn't familiar with. The car went into limp mode so we drove it home right away, I got home cleared the codes and the car started right up fine, I was thinking the fuel I got at the station was poor quality so we drove the car till I got down to 1/4 tank then added a fuel from a known good station and a can of seafoam. Car starts and runs rough for about 20 seconds when cold then like a light switch runs perfect but I'm still seeing codes pop up after a cold start. After car warms up it will start with no problems and run normal till it sits overnight then same thing happens the next morning. The first picture is from when it went into limp mode, the second what I get now after cold start, but it runs fine afterwards. Crazy
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Discussion Starter #2
Sound generator is deleted so it isn't that, I got a feeling one of the fuel sensors is damaged. Any ideas or people who have experienced something similar?
 

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Driveline Dampener... is the most likely issue. (I have not looked at your car, so I cannot give you an absolute that this is the issue.)


Read all about it here...


and

and

and
 

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Check your coils and plugs, unless you have any metal noises then it shouldnt be the DLD

DLD is NOT a common failure. A friend of mine used to run the track fleet and replaced like 2 after many track days.
 

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I have read all or most of the posts on this issue with misfire on 5678 and started checking everything related to this except for dropping the started and looking at the dampener. I seriously can't see the DLD being bad, first I would hear some metallic noise which I don't second why would this only happen after sitting for the night, after the car is warm I can drive it anywhere runs perfect and starts perfect with no issues till it sits overnight. I did pull the coils on 5 and 8 the coils that get most with water when driving in rain or washing and examined them closely and they look fine, looked down in at the plugs with a camera and the plug well looks clean and new. If it were plugs and coils I would say it would do it all the time or heavy load which it doesn't. It has to be something to do with temperature of the engine controlling some emissions device or the fuel draining out of the fuel rail or oil draining down from capillaries overnight causing something in the vvt of cams to be off till oil pressure puts them back in place. I'm still leaning toward the fuel quality sensor being bad or off. Car has 19k miles.

I had a 348 ferrari that had a bad o-ring around the flywheel area which leaked this special grease called kubar or something like that, the grease was used to dampen the flywheel something like Mclaren does with its flywheel, well when the grease leaked out and the engine was warm it caused a miss trigger on one of position sensors which caused a hot start problem so I see where it could be something not apparent to what is happening.

Thanks for your input!
 

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Lets make it clear guys, the DLD makes a Rattle sound on start. If you dont have any rattles, its not DLD failure, its as simple as that, also it only happens mainly on heavily tracked cars.. Even then its rare.Its a simple wheel with springs that absorbs shock from the drivetrain, when the springs come loose, then you have an issue.

e that this is the issue.)
 

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ive actually just noticed one of the codes that I didnt see before, the fuel trims on the ecu have maxed out, basically the ecu has a window of fuel adjustment (normally for part throttle only) the lambda sensors sniff the exhaust stream to monitor the amount of air that is in the exhaust gasses, if there is too much air, the ecu will try and compensate and add fuel to keep as close as it can get to lambda 1.0 (14.7) AFR which is what all manufacturers target as it is a cross of good power/good fuel consumption and emissions.. You have exceeded the limit of the ecus self adjustment so this is telling me you might have an airleak/boost, check your ISG and boost pipes too.

Also I see the fuel rail has issues, so possibly the engine isnt getting enough fuel either. post your long term fuel trims and you will be able to tell from that if it is too rich or too lean

Also you are not meant to be using any extra fuel additives, this could effect the fuel system, not in a constructive way..
 

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ive actually just noticed one of the codes that I didnt see before, the fuel trims on the ecu have maxed out, basically the ecu has a window of fuel adjustment (normally for part throttle only) the lambda sensors sniff the exhaust stream to monitor the amount of air that is in the exhaust gasses, if there is too much air, the ecu will try and compensate and add fuel to keep as close as it can get to lambda 1.0 (14.7) AFR which is what all manufacturers target as it is a cross of good power/good fuel consumption and emissions.. You have exceeded the limit of the ecus self adjustment so this is telling me you might have an airleak/boost, check your ISG and boost pipes too.

Also I see the fuel rail has issues, so possibly the engine isnt getting enough fuel either. post your long term fuel trims and you will be able to tell from that if it is too rich or too lean

Also you are not meant to be using any extra fuel additives, this could effect the fuel system, not in a constructive way..
This all started after filling up at a old service station in a little town in southwest Missouri, shortly after fill up it went into limp mode. I suspect bad fuel because the cold start popping in the morning is getting better as drive the car more, or the self learning of the ECU is dialing in some values that is helping out. I did a 20k service on the car and while all the panels where off I checked every hose and connection for the intake and they were all tight. I also pulled a couple coils 5 and 8 the ones that get most the water on them and they were fine and no signs of arcing or corrosion, plug wells were spotless clean. The sound generator is blocked off and removed, the mechanical speaker had no holes or signs of wear so I doubt it was that.

It would nice to know the normal values of the fuel pressure sensor and the fuel additive adaptive sensors, I have the workshop manual it came with the diagnostic tool but has no values noted on anything, just how to remove and reinstall components.

You say your car does the same thing? Have you possibly gotten poor fuel at anytime resent?
 

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Discussion Starter #10
I will put the diagnostic tool and see if I can read those values for long term fuel trims.
 

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Values of fuel pressure should be LESS than 700 Kpa as quoted by Mclaren themselves that is using their mds system though...Not sure how other diagnostics would read out
 

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Since it's repeatable after sitting overnight, try turning the ignition on (not starting or in accessory, fully on) waiting for 3 seconds, then turning it off, ignition back on, ignition off, then ignition back on a 3rd time. Then start it and see if you get the same result.

Also, have you ever looked at the spark plugs? You may have fouled some or in less than great shape.
 

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Since it's repeatable after sitting overnight, try turning the ignition on (not starting or in accessory, fully on) waiting for 3 seconds, then turning it off, ignition back on, ignition off, then ignition back on a 3rd time. Then start it and see if you get the same result.

Also, have you ever looked at the spark plugs? You may have fouled some or in less than great shape.
No but its strange that it runs perfect after 20 seconds of popping, like someone turned a switch on and its perfect all day long till it sits over night. It does seem to be getting better now I have run a tank of gas and sea foam through it, no more codes but still pops on cold start from over night.
 

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No but its strange that it runs perfect after 20 seconds of popping, like someone turned a switch on and its perfect all day long till it sits over night. It does seem to be getting better now I have run a tank of gas and sea foam through it, no more codes but still pops on cold start from over night.
It's bangs and pops, not sputters or skips?
 

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It's bangs and pops, not sputters or skips?
Rpm up and down runs rough sputters and pops then bam after 20 seconds it's runs perfect all day, starts perfect even if it sits for 8 hours but over night it comes back. If it were plugs I would think it would do it all the time or at WOT but it doesn't. Crazy.

I've enjoyed watching your videos by the way.
 

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Lets make it clear guys, the DLD makes a Rattle sound on start. If you dont have any rattles, its not DLD failure, its as simple as that, also it only happens mainly on heavily tracked cars.. Even then its rare.Its a simple wheel with springs that absorbs shock from the drivetrain, when the springs come loose, then you have an issue.
Well, I never tracked my car and it didn't rattle, and McLaren HQ themselves diagnosed my misfires and CEL issues as being due to the DLD. They replaced it and voila, problem solved.

That said, I don't remember my car making a bunch of pops and sputters.
 

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Well, I never tracked my car and it didn't rattle, and McLaren HQ themselves diagnosed my misfires and CEL issues as being due to the DLD. They replaced it and voila, problem solved.

That said, I don't remember my car making a bunch of pops and sputters.
Then why would it only do it after sitting all night long and then clear up after 20 seconds and be perfect full throttle idle and starting. If the drive line dampener was damaged I would think I'd hear a noise all the time a mechanical problem that would be evident. I have no unusual noises during a cold start after sitting all night long just the popping and uneven idle for about 20 seconds. Did your car do the same thing?
 

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Rpm up and down runs rough sputters and pops then bam after 20 seconds it's runs perfect all day, starts perfect even if it sits for 8 hours but over night it comes back. If it were plugs I would think it would do it all the time or at WOT but it doesn't. Crazy.

I've enjoyed watching your videos by the way.
The pops, bangs, sputters, RPM surges, etc I suspect are a result of running rich, borderline flooding the cylinder possibly. This leads me to one of 4 conclusions (but note this particular subject I'm not an expert on, so accept it as food for thought). A) Spark plugs aren't quite up to par and can't burn all the fuel, which is less of a problem later because it's learned what it needs to do to adjust fuel. B) An oxygen sensor is malfunctioning, perhaps the heater isn't working and running for 20 seconds gets it warm enough to work properly. C) Perhaps the DLD or a sensor is not reporting correct data initially, throwing off the fuel mix. D) Your ISG has a small leak allowing unmetered air into the engine and it's having a hard time decifering what to do initially.

20 seconds sounds like the normal time in a cold start where the turbos chill out, which tells me there typically is a different fuel map in that time.

Then why would it only do it after sitting all night long and then clear up after 20 seconds and be perfect full throttle idle and starting. If the drive line dampener was damaged I would think I'd hear a noise all the time a mechanical problem that would be evident. I have no unusual noises during a cold start after sitting all night long just the popping and uneven idle for about 20 seconds. Did your car do the same thing?
It's possible it's temperature related. 8 hrs during the day ambient air temperature may be equal or higher, 8 hrs at night is likely lower. A lower temperature would have a different air density, which changes things.
 

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as per the mclaren guidelines please check the following:

1. connectors going to all/effected plug for corrosion or coming loose.
2. Check value of fuel rail pressure is within spec. (guna have to visit dealer for that one) above 700kpa
3. Check all plugs into the coils for water corrosion/loose connection
4. Check for hydrocarbons in coolant (to check for coolant leaks into cylinder, for example water)
5. Check for all air leaks, ISG, boost piping.
6. Check plugs, to be honest, I would say no 2 is most important on your list given the codes you have

Also check ground point (26) rear left side of the car on chassis. This is the official process a per mclaren for these codes.

As you have an adaptation error, it looks to me that you have a fuelling issue, but you need to read out the fuel adaptations to see which end of the scale you are on being rich or lean. You can purchase an ELM reader, Wifi model if you have IOS, Bluetooth if you are running android on your phone, then get dash command, you can read off the fuel trims using that.

I am having a few silly misfire issues, I am pretty convinced its a very small leak from the ISG, I have now unplugged it as a trial to see how the car responds, so far so good but its only been a few days. as its unplugged the flap inside that is used to control the amount of air to it, remains closed, so that should stop the leak if I have one, my isg hasnt been changed in 27kkms ! I might block it off I might not, I havent decided yet.
 

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To be clear, the DLD issue isn't something that happens 24/7. Mine was sporadic to the point that they thought they fixed it, no CEL anymore, and then when I went to pick the car up it happened right when I turned it on even though it didn't happen all day before that. At that time he could hear what sounded like misfiring a little. It is a vibration from the DLD that causes the sensors to think it's a misfire. It can make a little noise, but it wasn't loud bangs, sputters, or pops and erratic RPM.

I don't think the DLD would make the RPM erratic, so that sounds like something else.
 
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