Loss of power.

[Mikeyang]

I was recently out with some other guys on a run through the Scottish hills and noticed I was struggling to keep up with other cars with considerably less power than what a stage 2 f10 m5 has. So I done some dragy runs and it turns out I’m doing 100-200kph in over 8 seconds when it should be 6-7 there abouts. I have a stage 2 map from a reputable mapper, eventuri intakes and decats. I did runs before all the modifications and the times seem to match the standard figures very closely so I’m definitely losing power.

I noticed occasionally I’ll get surges of power almost like a pulse of power when loading up the car.

I’ve done some logs the car will occasionally hit 1.5 bar boost pressure but seems to be very sporadic and not always and sometimes no where near. I’ve checked all the accessible areas where boost could leak everything’s tight. I’ve ordered new boost pressure solenoids, has anyone fitted these before and are they common to fail on the m5 I’ve not seen much about it when doing a google search.

Thanks in advance.

[AnotherM]

Originally Posted by Mikeyang

I was recently out with some other guys on a run through the Scottish hills and noticed I was struggling to keep up with other cars with considerably less power than what a stage 2 f10 m5 has. So I done some dragy runs and it turns out I’m doing 100-200kph in over 8 seconds when it should be 6-7 there abouts. I have a stage 2 map from a reputable mapper, eventuri intakes and decats. I did runs before all the modifications and the times seem to match the standard figures very closely so I’m definitely loosing power.

I noticed occasionally I’ll get surges of power almost like a pulse of power when loading up the car.

I’ve done some logs the car will occasionally hit 1.5 bar boost pressure but seems to be very sporadic and not always and sometimes no where near. I’ve checked all the accessible areas where boost could leak everything’s tight. I’ve ordered new boost pressure solenoids, has anyone fitted these before and are they common to fail on the m5 I’ve not seen much about it when doing a google search.

Thanks in advance.

Have you hooked up a scanner to measure knock? It sounds like your car is retarding the timing.

Can you flash back to stock and see if it fixes it?

[Mikeyang]

Voltages across the knock sensors all are consistent.

[AnotherM]

What tool are you using to monitor the Knock sensors?

I would hook the scanner up and watch knock, timing, and all AF values. Somewhere your DME is seeing an issue.

I dont think you have a boost leak. The DME would see that the pressure is not consistent and throw a cell. I had a boost leak in bank 1 charge pipe and i got a cel right away. It was babk 1 rich value beyond threashold.

[Mikeyang]

Originally Posted by AnotherM

What tool are you using to monitor the Knock sensors?

I would hook the scanner up and watch knock, timing, and all AF values. Somewhere your DME is seeing an issue.

I dont think you have a boost leak. The DME would see that the pressure is not consistent and throw a cell. I had a boost leak in bank 1 charge pipe and i got a cel right away. It was babk 1 rich value beyond threashold.

I’m just using bimmerlink.

I’m hoping it’s the boost solenoids to be honest.

I loaded the car up tonight in 6th I’ll upload the pics the boost fluctuates a considerable amount.

[AnotherM]

Originally Posted by Mikeyang

I’m just using bimmerlink.

I’m hoping it’s the boost solenoids to be honest.

I loaded the car up tonight in 6th I’ll upload the pics the boost fluctuates a considerable amount.

If that doesnt resolve your problem. I would plug a good scanner in and watch your ambient pressures. My scanner allows me to monitor ambient pressure in multiple locations on each bank. It would help you narrow down where the issue is.

You are definitely not holding consistent boost which sounds more like a WGA or solenoid issue than anything, but without monitoring the car to see which bank or where the pressure is dropping, you may be looking for a long time. I would Order a foxwell nt510 or comparable scanner if i were you.

Good luck bro,

[Mikeyang]

Well solenoids didn’t fix the problem

[kjdeion21]

Originally Posted by Mikeyang

I was recently out with some other guys on a run through the Scottish hills and noticed I was struggling to keep up with other cars with considerably less power than what a stage 2 f10 m5 has. So I done some dragy runs and it turns out I’m doing 100-200kph in over 8 seconds when it should be 6-7 there abouts. I have a stage 2 map from a reputable mapper, eventuri intakes and decats. I did runs before all the modifications and the times seem to match the standard figures very closely so I’m definitely losing power.

I noticed occasionally I’ll get surges of power almost like a pulse of power when loading up the car.

I’ve done some logs the car will occasionally hit 1.5 bar boost pressure but seems to be very sporadic and not always and sometimes no where near. I’ve checked all the accessible areas where boost could leak everything’s tight. I’ve ordered new boost pressure solenoids, has anyone fitted these before and are they common to fail on the m5 I’ve not seen much about it when doing a google search.

Thanks in advance.

Hey Sir, you almost describe the exact same situation I’m having I ran out of stage two tune I am fully StraightPiped with Catless downpipes resonator delete and muffler delete… I have cold air intake and a JB4 stage 2 tune and I’m able to read my maps and everything and I’ve also been running on octane booster and race fuel in the higher maps and my throttle response is unbelievable I’ve been getting 27 pounds of boost 22 to 27 pounds of boost I barely touch the gas pedal and it goes into boost… I just recently filled up my gas tank and since then my car is running below stock even in the correct map we’ve checked the timing everybody’s telling me I could have a boost leak as the highest boost I go in is eight psi and that’s a WOT but I’ve checked all obvious areas I have all new intercooler lines from when I bought the car and none of my charge pipes or anything from the normal spots look to be having an issue … when I did all this to my car all the modifications I changed out all the coils all the plugs and a few other things in the engine but I’ve also checked everywhere that I’ve touched and made sure that there’s no issues with any of the lines that I played with when I take them took everything apart, I don’t get it because they talked about a vacuum line being missing from my mufflers but it’s fully straight piped and it would’ve happened 7/8 months ago when I installed the straight pipes… Would my car let me know if I’m running on wastegate pressure or if I have my boost control solenoid‘s or my boost control modules or my wastegate was messed up? Please help were you able to get your solved?