Engine Malfunction after Velos tune

[OllieX5M]

Sorry for the delay just been busy. So I replaced the map sensors all 4 and also swapped out the boost solenoids. Man the car if def feeling better and getting more boost but popped a code after the 3rd or 4th pull and in limp mode completely. Turn car of and on and it’s back to normal. 310B codes gone which means the maps sensors / boost Pressure solenoids fixed that. Now I’m getting 2ABC Boost Pressure sensor electric which my mechanic stated he usually sees this with a bad tune.... All sensors are on properly, brand new factory bmw sensors. And sometimes it will throw 30FC, but not every time boost pressure to low, no leaks of any kind after another inspection of all vacuum lines which are all new too. I’m removing velos tune almost certain the car will drive fine. I’ll keep you guys posted.

[pdX5M]

Originally Posted by OllieX5M

Sorry for the delay just been busy. So I replaced the map sensors all 4 and also swapped out the boost solenoids. Man the car if def feeling better and getting more boost but popped a code after the 3rd or 4th pull and in limp mode completely. Turn car of and on and it’s back to normal. 310B codes gone which means the maps sensors / boost Pressure solenoids fixed that. Now I’m getting 2ABC Boost Pressure sensor electric which my mechanic stated he usually sees this with a bad tune.... All sensors are on properly, brand new factory bmw sensors. And sometimes it will throw 30FC, but not every time boost pressure to low, no leaks of any kind after another inspection of all vacuum lines which are all new too. I’m removing velos tune almost certain the car will drive fine. I’ll keep you guys posted.

I don't think it's a bad tune that's throwing the codes. I've been running Velos for 15k now without issue. Any tune will certainly expose underlying issues though.

[OllieX5M]

We will find out after I remove it. I have changed all 3 vent lines, air ducts, all 4 sensors, all vacuum lines, all coils, all spark plugs, both pneumatic boost solenoids. Not sure what else could be cause these limp modes especially when the car nails it on 1 and 2nd gear with no issue. As soon as I go full power on 3/4/5 limp mode....

[Sophisticated Redneck]

Originally Posted by OllieX5M

We will find out after I remove it. I have changed all 3 vent lines, air ducts, all 4 sensors, all vacuum lines, all coils, all spark plugs, both pneumatic boost solenoids. Not sure what else could be cause these limp modes especially when the car nails it on 1 and 2nd gear with no issue. As soon as I go full power on 3/4/5 limp mode....

Have you checked your waste gates and vacuum pump? If wastegates are worn out, you will get low boost codes, they can be adjusted somewhat by tightening up the actuator arm.

I would also have your mechanic check the vacuum pump and make sure it's pulling enough vacuum.

Another possibility is a failed gas tank vent valve or the plastic line. It connects to the lower Intake on bank 2. It will leak boost into the gas tank if it fails. Again it's only on bank 2 so codes for low boost will only be on bank 2 if it is causing it.

If all those check out, I had to repair a leaking failed seam on my lower Intake that looks like it was a manufacturing defect. The M uses the same lower intakes. If yours has the same defect, you can see it on the bank 1 lower Intake just below where it connects to the throttle body. You can see the separation in the plastic as compared to the bank two lower Intake. Plastic epoxy will fix it and save you from having to pull the engine to replace if yours has it too. Keep us posted how it all works out

[OllieX5M]

Finally! the issues are gone once the tune has been removed. I really pushed the car to double confirm. 1-4 full wot shift right at or before redline and no codes no lights down shifting at high rpm nothing. Cars running strong on Stock tune. Not even considering putting the tune back on at all i dont miss the lights or codes... you cant even get full use the car without a light showing makes no sense.
Only issue was the cold start after the stock tune was put on ran rough and had a light but not code. Cleared everything with Carley turned off car turned right back on no issues. Even at idol i had this blip here and there thats gone too. Problem fixed car is running as it should although i might change to factory spark plugs if the cold becomes an issue due to the step colder plugged which at gapped to .022...

[OllieX5M]

Originally Posted by Sophisticated Redneck

Have you checked your waste gates and vacuum pump? If wastegates are worn out, you will get low boost codes, they can be adjusted somewhat by tightening up the actuator arm.

I would also have your mechanic check the vacuum pump and make sure it's pulling enough vacuum.

Another possibility is a failed gas tank vent valve or the plastic line. It connects to the lower Intake on bank 2. It will leak boost into the gas tank if it fails. Again it's only on bank 2 so codes for low boost will only be on bank 2 if it is causing it.

If all those check out, I had to repair a leaking failed seam on my lower Intake that looks like it was a manufacturing defect. The M uses the same lower intakes. If yours has the same defect, you can see it on the bank 1 lower Intake just below where it connects to the throttle body. You can see the separation in the plastic as compared to the bank two lower Intake. Plastic epoxy will fix it and save you from having to pull the engine to replace if yours has it too. Keep us posted how it all works out

I appreciate the info and will keep this in mind in the future, but everything is working on stock tune and will keep it that way. This is the wifes car which i need running right hauling my kids around in it. I drive an e46 m3 as my daily and have an m5 in the garage for summer.