Terrible Fuel Mileage--Power Steering Related?

rothwem · 08-02-2019, 08:55 AM

Like the title states, I’ve been getting awful gas mileage. I get ~15 around town and ~22 on the highway. I’ve got no codes showing, but I’ve also got another issue that I’m wondering if its related. My power steering reservoir is leaking and covered in power steering fluid, and if I turn the wheel while the car is stopped, it bogs the engine. This tells me that maybe the power steering pump is putting too much strain on the motor? Could this be also related to my poor mileage?

3002 tii · 08-04-2019, 02:30 PM

Re poor mileage when was last time you cleaned your Vanos solenoids?

335xirookie · 08-04-2019, 02:45 PM

Quote:

Originally Posted by rothwem

Like the title states, I’ve been getting awful gas mileage. I get ~15 around town and ~22 on the highway. I’ve got no codes showing, but I’ve also got another issue that I’m wondering if its related. My power steering reservoir is leaking and covered in power steering fluid, and if I turn the wheel while the car is stopped, it bogs the engine. This tells me that maybe the power steering pump is putting too much strain on the motor? Could this be also related to my poor mileage?

following...I get same milage and I did plugs gapped at 25,vanos are new,coils are new. mhd stage 1 with dci...

rothwem · 08-05-2019, 08:05 AM

Quote:

Originally Posted by 3002 tii

Re poor mileage when was last time you cleaned your Vanos solenoids?

The exhaust side was bad (threw a code), and I replaced it a couple months ago. I didn't touch the intake side, maybe I'll try cleaning it to see if it helps things out.

Nickco43 · 08-08-2019, 12:49 AM

Quote:

Originally Posted by rothwem

Like the title states, I’ve been getting awful gas mileage. I get ~15 around town and ~22 on the highway. I’ve got no codes showing, but I’ve also got another issue that I’m wondering if its related. My power steering reservoir is leaking and covered in power steering fluid, and if I turn the wheel while the car is stopped, it bogs the engine. This tells me that maybe the power steering pump is putting too much strain on the motor? Could this be also related to my poor mileage?

I get 13 MPG. Your MPG is good.

Phyrexia · 08-08-2019, 01:45 PM

A healthy N52 should be greatly exceeding 22mpg on the highway. 30+mpg.

Phyrexia · 08-08-2019, 01:47 PM

Quote:

Originally Posted by 335xirookie

following...I get same milage and I did plugs gapped at 25,vanos are new,coils are new. mhd stage 1 with dci...

This is the N/A Forum. Nobody's got MHD here. There are like two folks with turbos here.

AlisoBob · 08-09-2019, 08:02 PM

My daughters E90 was getting terrible mileage, until the DISA valves finally quit completly.

After I swapped them out, it's like a totally different car. 19+ city. 30+ highway.

https://www.e90post.com/forums/showthread.php?t=1619542

rothwem · 08-12-2019, 07:05 AM

Quote:

Originally Posted by AlisoBob

My daughters E90 was getting terrible mileage, until the DISA valves finally quit completly.[/url]

I'm fairly certain there's no DISA valves on my car, its a stock 328i with no 3 stage manifold. Do you mean Vanos solenoids?

Quote:

Originally Posted by Phyrexia

A healthy N52 should be greatly exceeding 22mpg on the highway. 30+mpg.

Yep. It also smells super rich at startup, but I've got no codes, not even BMW specific ones. I wasn't able to work on it this weekend, but this week, the plan is to try monitoring the O2 sensors while idling. Apparently its rare for them to both go bad at once, so if you see a huge difference between the voltages, there's probably a bad one.

If everything there looks normal, I'm going to try pulling the intake Vanos solenoid and blasting it out with some carb cleaner.

335xirookie · 08-17-2019, 08:20 PM

Quote:

Originally Posted by Phyrexia

Quote:

Originally Posted by 335xirookie

following...I get same milage and I did plugs gapped at 25,vanos are new,coils are new. mhd stage 1 with dci...

This is the N/A Forum. Nobody's got MHD here. There are like two folks with turbos here.

I consider myself informed... Back to forced induction I go...

Fritzer · 08-19-2019, 11:43 PM

Quote:

Originally Posted by Phyrexia

A healthy N52 should be greatly exceeding 22mpg on the highway. 30+mpg.

wat

rothwem · 08-20-2019, 08:34 AM

Figured I'd update a bit.

I pulled the intake vanos solenoid and cleaned it off with MAF cleaner
I changed the air filter
I replaced the serpentine belt, tensioner and idler pulley.

The vanos solenoid wasn't THAT dirty, but I sprayed it off anyways.

The air filter was fairly dirty, but not THAT bad. I do drive on gravel roads a lot though, my favorite place to take my dog for a walk and a swim is down a ~1 mile gravel road and we're there probably every other day.

With the serpentine belt change, the engine no longer lugs when I turn the steering wheel, which is cool. I replaced it because I had the o-ring on my oil filter cap leak a startling amount of oil onto the belt, and I figured it was only a matter of time before it started breaking down. It was surprisingly easy to change too, it was a ~30 minute job from start to finish.

Anyways, now I just need to drive it to see if it makes a difference.

hassmaschine · 08-20-2019, 11:17 AM

Quote:

Originally Posted by Fritzer

wat

yes - well, assuming it's not an AT/AWD.

my *average* is like 25 - highway driving is always 30-35. city is like 21. But that will depend on if you drive in a big city where you spend most of your time idling and not moving. Highway mileage is what it is.

rothwem · 08-20-2019, 03:22 PM

Quote:

Originally Posted by hassmaschine

yes - well, assuming it's not an AT/AWD.

my *average* is like 25 - highway driving is always 30-35. city is like 21. But that will depend on if you drive in a big city where you spend most of your time idling and not moving. Highway mileage is what it is.

Lawdamercy, please don't let this turn into one of those stupid threads where everyone posts how great or awful their personal MPGs are.

rothwem · 09-03-2019, 02:02 PM

Well so after I changed the air filter and vanos solenoids, I'm at a 19.2 mpg average for 100% in town driving, not too shabby. I'd say that's a healthy improvement from 15.XX.

So yeah, if your mileage is terrible, try changing your air filter and cleaning your vanos solenoids. I wish I had done one at a time to isolate which one it was, but they both needed doing I think.

08-02-2019, 08:55 AM	#1
rothwem Major 473 Rep 1,191 Posts Drives: 2009 BMW 328i Wagon Join Date: Apr 2009 Location: Asheville, NC iTrader: (0) Garage List 2009 BMW 328i [0.00]	Terrible Fuel Mileage--Power Steering Related? Like the title states, I’ve been getting awful gas mileage. I get ~15 around town and ~22 on the highway. I’ve got no codes showing, but I’ve also got another issue that I’m wondering if its related. My power steering reservoir is leaking and covered in power steering fluid, and if I turn the wheel while the car is stopped, it bogs the engine. This tells me that maybe the power steering pump is putting too much strain on the motor? Could this be also related to my poor mileage?
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08-04-2019, 02:30 PM	#2
3002 tii Lieutenant General 2280 Rep 12,565 Posts Drives: Z4 M, X5, GX460 Join Date: Apr 2008 Location: CT iTrader: (99) Garage List F15 X5 xDrive35i [8.75] E86 Z4 M [10.00] F10 550i (Retired) [9.17] F25 X3 xDrive35i (R ... [9.43] E82 135is (Retired) [9.50] E85 Z4 M (Retired) [9.41] E90 328i xDrive (Re ... [9.25] E86 Z4 3.0si (Retired) [9.20]	Re poor mileage when was last time you cleaned your Vanos solenoids? __________________ Follow for latest mods
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08-08-2019, 01:45 PM	#6
Phyrexia Resident Pedant 503 Rep 792 Posts Drives: '15 335i 8AT Join Date: Nov 2017 Location: Limbo iTrader: (1)	A healthy N52 should be greatly exceeding 22mpg on the highway. 30+mpg. __________________ '15 F30 335i 8AT Estoril II/Black (12.218 @ 114.94mph) MHD Stage 2+ 93 / XHP Stage 3 / M-Goodies / K&N Filter / ER CP / CSF IC / NGK 97506 / ER DP / Michelin A/S 3+
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08-09-2019, 08:02 PM	#8
AlisoBob Enlisted Member 25 Rep 35 Posts Drives: 2008 328i Join Date: Aug 2016 Location: Aliso Viejo Calif. iTrader: (0)	My daughters E90 was getting terrible mileage, until the DISA valves finally quit completly. After I swapped them out, it's like a totally different car. 19+ city. 30+ highway. https://www.e90post.com/forums/showthread.php?t=1619542
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08-20-2019, 08:34 AM	#12
rothwem Major 473 Rep 1,191 Posts Drives: 2009 BMW 328i Wagon Join Date: Apr 2009 Location: Asheville, NC iTrader: (0) Garage List 2009 BMW 328i [0.00]	Figured I'd update a bit. I pulled the intake vanos solenoid and cleaned it off with MAF cleaner I changed the air filter I replaced the serpentine belt, tensioner and idler pulley. The vanos solenoid wasn't THAT dirty, but I sprayed it off anyways. The air filter was fairly dirty, but not THAT bad. I do drive on gravel roads a lot though, my favorite place to take my dog for a walk and a swim is down a ~1 mile gravel road and we're there probably every other day. With the serpentine belt change, the engine no longer lugs when I turn the steering wheel, which is cool. I replaced it because I had the o-ring on my oil filter cap leak a startling amount of oil onto the belt, and I figured it was only a matter of time before it started breaking down. It was surprisingly easy to change too, it was a ~30 minute job from start to finish. Anyways, now I just need to drive it to see if it makes a difference.
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09-03-2019, 02:02 PM	#15
rothwem Major 473 Rep 1,191 Posts Drives: 2009 BMW 328i Wagon Join Date: Apr 2009 Location: Asheville, NC iTrader: (0) Garage List 2009 BMW 328i [0.00]	Well so after I changed the air filter and vanos solenoids, I'm at a 19.2 mpg average for 100% in town driving, not too shabby. I'd say that's a healthy improvement from 15.XX. So yeah, if your mileage is terrible, try changing your air filter and cleaning your vanos solenoids. I wish I had done one at a time to isolate which one it was, but they both needed doing I think.
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