Improve 3.0si Response

[kern417]

Going on 2 years with my 2010 3.0si and the performance is killing me. I didn't think it would matter much since it's just a daily driver and I wanted the N/A reliability over the turbo/V8 maintenance, but now I'm starting to reconsider.

Is there anything I can do to improve the throttle response? Right now it feels like there's a rubber band between the pedal and the throttle body. It's completely dead until >50% throttle, and even then it doesn't really begin going until 2k+ rpm. It's to the point that i'm extremely hesitant to pull out into traffic at times because the car can barely get out of it's own way, especially if there's a hill.

Also, sometimes I feel the entire drivetrain jolt under me when braking hard. I'm thinking motor/trans mounts or bushings might be going out. Would that help give a more direct feel with the throttle? And how could I diagnose if the bushings are bad?

I bought the car at 70k and just crossed 85k. I'm not sure about the previous owners maintenance, but I have a new intake filter ordered in case it's just dirty, but not sure that will help. I've also replaced spark plugs less than 5k ago. I have no problem doing the maintenance/upgrades myself, but I need some low end torque if it's going to stick around in spring. Any tips are appreciated. Like I said, i have other performance-oriented cars so I don't need a rocket ship. Just something that moves when I tell it to

[Spyro235]

Originally Posted by kern417

Going on 2 years with my 2010 3.0si and the performance is killing me. I didn't think it would matter much since it's just a daily driver and I wanted the N/A reliability over the turbo/V8 maintenance, but now I'm starting to reconsider.

Is there anything I can do to improve the throttle response? Right now it feels like there's a rubber band between the pedal and the throttle body. It's completely dead until >50% throttle, and even then it doesn't really begin going until 2k+ rpm. It's to the point that i'm extremely hesitant to pull out into traffic at times because the car can barely get out of it's own way, especially if there's a hill.

Also, sometimes I feel the entire drivetrain jolt under me when braking hard. I'm thinking motor/trans mounts or bushings might be going out. Would that help give a more direct feel with the throttle? And how could I diagnose if the bushings are bad?

I bought the car at 70k and just crossed 85k. I'm not sure about the previous owners maintenance, but I have a new intake filter ordered in case it's just dirty, but not sure that will help. I've also replaced spark plugs less than 5k ago. I have no problem doing the maintenance/upgrades myself, but I need some low end torque if it's going to stick around in spring. Any tips are appreciated. Like I said, i have other performance-oriented cars so I don't need a rocket ship. Just something that moves when I tell it to

So, a few things. Unfortunately, the n52 is a great motor, just slow when hauling 5k lbs. there’s not much to do to change the performance, without immense cost. You’re better of selling and getting a diesel or v8. Being I have a diesel, if you can delete it, I highly recommend one. That motor doesn’t make much power under 2k rpm, so that’s not going to change much.

However there is one big thing you should do before you just sell it- tune the transmission! I’m pretty sure xhp can tune your trans, but I highly, HIGHLY recommend messaging Rod Sutphin on facebook and asking if he can help you. I have rod’s Tune in my x5d, and it transformed the way the vehicle performed and handled and responded. Night and day. Throttle response and trans behavior GREATLY changes how the car FEELS compared to your inputs, and stock trans tuning from bmw, for the diesel at least, was super sloppy/slushy. That’s my main advice. For 250 total, it’s worth a shot before you sell the vehicle.

As far as the clunk during heavy braking, is it right before you stop?Like, braking down from 20-10ish? Could be the transfercase gear getting stripped out, mine did the same thing and the new transfercase actuator gear solved it no issue.

[kern417]

Originally Posted by Spyro235

So, a few things. Unfortunately, the n52 is a great motor, just slow when hauling 5k lbs. there’s not much to do to change the performance, without immense cost. You’re better of selling and getting a diesel or v8. Being I have a diesel, if you can delete it, I highly recommend one. That motor doesn’t make much power under 2k rpm, so that’s not going to change much.

However there is one big thing you should do before you just sell it- tune the transmission! I’m pretty sure xhp can tune your trans, but I highly, HIGHLY recommend messaging Rod Sutphin on facebook and asking if he can help you. I have rod’s Tune in my x5d, and it transformed the way the vehicle performed and handled and responded. Night and day. Throttle response and trans behavior GREATLY changes how the car FEELS compared to your inputs, and stock trans tuning from bmw, for the diesel at least, was super sloppy/slushy. That’s my main advice. For 250 total, it’s worth a shot before you sell the vehicle.

As far as the clunk during heavy braking, is it right before you stop?Like, braking down from 20-10ish? Could be the transfercase gear getting stripped out, mine did the same thing and the new transfercase actuator gear solved it no issue.

Thanks, I'll check that out. I actually started paying attention to how long it forces the revs to stay below 1500 and it's frustrating for sure. That might help wake it up. It just seems like 50% throttle only opens the throttle plate like 10%. I wish I had a sport mode to increase the sensitivity like on my F32. I honestly think an N55 would tickle my pickle but a diesel would be nice obviously. I just don't have any experience with them so somewhat intimidating.

Regarding the drivetrain, it's when I slam on the brakes. The speed doesn't matter much, but it's more pronounced from higher speeds. Usually happens if I'm doing 50 or so and a light turns yellow, so the person in front of me slams on their brakes and I have to respond accordingly. I literally have to stomp on it though, normal heavy braking doesn't always cause it. The feeling is like if your luggage flew forward from the trunk and hit your backseat, except I feel it under the car. Like everything shifts in the drivetrain when I slam on it. I was thinking of doing bushings and a trans/diff service since I'm not sure if/when it was done and the car is high in mileage. *Hopefully* It's not a hardware issue. That's past my comfort level of repairs do DIY. I just don't want to keep shooting in the dark if there's a way to diagnose bushing and mount failures by measuring the flex or something?

[Spyro235]

Originally Posted by kern417

Thanks, I'll check that out. I actually started paying attention to how long it forces the revs to stay below 1500 and it's frustrating for sure. That might help wake it up. It just seems like 50% throttle only opens the throttle plate like 10%. I wish I had a sport mode to increase the sensitivity like on my F32. I honestly think an N55 would tickle my pickle but a diesel would be nice obviously. I just don't have any experience with them so somewhat intimidating.

Regarding the drivetrain, it's when I slam on the brakes. The speed doesn't matter much, but it's more pronounced from higher speeds. Usually happens if I'm doing 50 or so and a light turns yellow, so the person in front of me slams on their brakes and I have to respond accordingly. I literally have to stomp on it though, normal heavy braking doesn't always cause it. The feeling is like if your luggage flew forward from the trunk and hit your backseat, except I feel it under the car. Like everything shifts in the drivetrain when I slam on it. I was thinking of doing bushings and a trans/diff service since I'm not sure if/when it was done and the car is high in mileage. *Hopefully* It's not a hardware issue. That's past my comfort level of repairs do DIY. I just don't want to keep shooting in the dark if there's a way to diagnose bushing and mount failures by measuring the flex or something?

An n55 would probably be just fine! It’a A good bump above to n52. Personally, I knew I wanted more than the n55 and I wanted the gas mileage of the diesel. The diesel is very low stress- climbing any hill in a high gear, etc.

About the bump- I’d suggest seeing if you can visually check out your motor mounts, and the big rubber bushing in the transfercase support. That one acts like the trans mount.
Other than that, I’d suggest the rear differential bushings? But, I’d suggest trying to diagnose before throwing all these parts at it! Not TOTALLY sure how though.

[Huz-Z]

Having an E85 Z4 with an N52 (which has been bulletproof since I bought it in 2009), and also an E70 X5 with the N55 for the last 3 years, and knowing that the reliability of the N52 is vastly superior to the N55 (my X5 is in the shop right now as I type this with a VANOS failure; the high pressure fuel system died in September - two major engine issues in 3 months - and the transfer case packed it in back in July - thank God for extended warranty); I think I would be more than happy to keep the N52.

None of that turbo charged shit - just plain old naturally aspirated reliability. Perhaps not as thrilling as a working N55 to be sure, but not nearly as terrifying either when the N55's evil little engine alarm light decides, as it very likely will, that its time to brighten your day, spike your blood pressure and threaten your bank account.

Just sayin'.

[kern417]

Originally Posted by Huz-Z

Having an E85 Z4 with an N52 (which has been bulletproof since I bought it in 2009), and also an E70 X5 with the N55 for the last 3 years, and knowing that the reliability of the N52 is vastly superior to the N55 (my X5 is in the shop right now as I type this with a VANOS failure; the high pressure fuel system died in September - two major engine issues in 3 months - and the transfer case packed it in back in July - thank God for extended warranty); I think I would be more than happy to keep the N52.

None of that turbo charged shit - just plain old naturally aspirated reliability. Perhaps not as thrilling as a working N55 to be sure, but not nearly as terrifying either when the N55's evil little engine alarm light decides, as it very likely will, that its time to brighten your day, spike your blood pressure and threaten your bank account.

Just sayin'.

Thanks, but like I said, I'm not worried about the reliability. Try towing another Z4 with your Z4 and see how it handles it The weight differential is bad and I'm sure the throttle mapping isn't lending me any favors. The car is dead below 2k, and it won't get moving unless i floor it most of the time. If it was in a track car, sure. But I can't daily drive a car that struggles to pass a ford focus.

I do my own labor and repairs for the most part, so a hpfp isn't a huge issue. I've already had to replace every gasket on the cylinder head it seems, and there's still a few small leaks somewhere. So even the N/A engines aren't bullet proof. I'll pay $1000 a year to get an extra 100 ft lbs of torque.

I also think the 6-speed trans vs newer 8speed is contributing to the sluggish behavior. That paired with the N55 would make a world of difference.

[Huz-Z]

Originally Posted by kern417

Thanks, but like I said, I'm not worried about the reliability. Try towing another Z4 with your Z4 and see how it handles it The weight differential is bad and I'm sure the throttle mapping isn't lending me any favors. The car is dead below 2k, and it won't get moving unless i floor it most of the time. If it was in a track car, sure. But I can't daily drive a car that struggles to pass a ford focus.

I do my own labor and repairs for the most part, so a hpfp isn't a huge issue. I've already had to replace every gasket on the cylinder head it seems, and there's still a few small leaks somewhere. So even the N/A engines aren't bullet proof. I'll pay $1000 a year to get an extra 100 ft lbs of torque.

I also think the 6-speed trans vs newer 8speed is contributing to the sluggish behavior. That paired with the N55 would make a world of difference.

Ah okay! It seems then that you are well equipped if you do run into issues with an N55.

It seems to me that, after hanging out on the E85 Z4 forum for a while now, that there isn't much that can be done to significantly increase the power output of an N52. I presume that your X5 is producing something similar to the 255 hp that my Z4 produces (in that car, the engine is a freakin' joy by the way). Some N52s are detuned to 215 hp (as was the case with the 2006 - 2008 Z4 3.0i); those can be increased to 255 or so with a tune and an intake swap I think. But you probably already have that much power / torque now.

My X5 is a 2012 and its my daily driver, in a town with lots of hills, many pretty steep too. When its working right, its a total pleasure to drive - plenty of guts and sounds great. I'm hoping that I've just hit a statistical anomaly re the recent issues and I'll be in the clear soon, so I can get back to really enjoying my 35i. Avoid the 2012 model year if you can - transfer case issues are common for that year.

[Spyro235]

Originally Posted by Huz-Z

Ah okay! It seems then that you are well equipped if you do run into issues with an N55.

It seems to me that, after hanging out on the E85 Z4 forum for a while now, that there isn't much that can be done to significantly increase the power output of an N52. I presume that your X5 is producing something similar to the 255 hp that my Z4 produces (in that car, the engine is a freakin' joy by the way). Some N52s are detuned to 215 hp (as was the case with the 2006 - 2008 Z4 3.0i); those can be increased to 255 or so with a tune and an intake swap I think. But you probably already have that much power / torque now.

My X5 is a 2012 and its my daily driver, in a town with lots of hills, many pretty steep too. When its working right, its a total pleasure to drive - plenty of guts and sounds great. I'm hoping that I've just hit a statistical anomaly re the recent issues and I'll be in the clear soon, so I can get back to really enjoying my 35i. Avoid the 2012 model year if you can - transfer case issues are common for that year.

Transfercase issues are RAMPANT throughout all xdrive systems- X3's and X5's and 3 series seem to get hit the harderst. In reality, the failure that happens 99% of the time is that the actuator motor gear strips out. The actuator motor worm gear is metal, and the gear it mates with is a type of plastic. I JUST had this issue on mine (about time, at over 240k) after beating my car up offroad for a day. $22 on amazon prime, and an hour and a half of subframe lowering (not removing all the way), and it's good as new. I also went ahead and changed the fluid in it, and ran the adaptations required when new fluid is put in. Easy fix, should it ever happen to you out of warranty.

My dash didn't show any lights, but I got horrible shuddering when applying throttle and turning, in addition to a jerk when coming to a stop.

As for reliability, I personally considder the n55 a reliable rig, considering ti's power output. The n55 and the v8's get the 8 speed, while the m57 35d kept the 6 speed. I LOVE my diesel, most of all for it's super unstressed driving especially in hilly areas. It NEVER reaches 3k rpm unles I'm purposely hammering the throttle... it just makes gobs of power even at 1200 rpm.

[kern417]

Originally Posted by Huz-Z

Ah okay! It seems then that you are well equipped if you do run into issues with an N55.

It seems to me that, after hanging out on the E85 Z4 forum for a while now, that there isn't much that can be done to significantly increase the power output of an N52. I presume that your X5 is producing something similar to the 255 hp that my Z4 produces (in that car, the engine is a freakin' joy by the way). Some N52s are detuned to 215 hp (as was the case with the 2006 - 2008 Z4 3.0i); those can be increased to 255 or so with a tune and an intake swap I think. But you probably already have that much power / torque now.

My X5 is a 2012 and its my daily driver, in a town with lots of hills, many pretty steep too. When its working right, its a total pleasure to drive - plenty of guts and sounds great. I'm hoping that I've just hit a statistical anomaly re the recent issues and I'll be in the clear soon, so I can get back to really enjoying my 35i. Avoid the 2012 model year if you can - transfer case issues are common for that year.

Originally Posted by Spyro235

Transfercase issues are RAMPANT throughout all xdrive systems- X3's and X5's and 3 series seem to get hit the harderst. In reality, the failure that happens 99% of the time is that the actuator motor gear strips out. The actuator motor worm gear is metal, and the gear it mates with is a type of plastic. I JUST had this issue on mine (about time, at over 240k) after beating my car up offroad for a day. $22 on amazon prime, and an hour and a half of subframe lowering (not removing all the way), and it's good as new. I also went ahead and changed the fluid in it, and ran the adaptations required when new fluid is put in. Easy fix, should it ever happen to you out of warranty.

My dash didn't show any lights, but I got horrible shuddering when applying throttle and turning, in addition to a jerk when coming to a stop.

As for reliability, I personally considder the n55 a reliable rig, considering ti's power output. The n55 and the v8's get the 8 speed, while the m57 35d kept the 6 speed. I LOVE my diesel, most of all for it's super unstressed driving especially in hilly areas. It NEVER reaches 3k rpm unles I'm purposely hammering the throttle... it just makes gobs of power even at 1200 rpm.

thanks i'll keep an eye on that. I don't think it's the transfer case since normal driving is fine. I'll just have to find some time to get under the car and inspect all the bushings. and do a trans/diff service. Even though technically they're "lifetime" right? I can't even find a fuel filter to replace on this thing.