Z4M subtle hesitation after fill-up... bad gas?

RADRACR · 06-18-2019, 10:21 PM

Wife and I went on a 1-hour road trip today. Car drove fine on the way there. Filled up with 91 (the highest around here), and on the way back the car started hesitating during 85mph cruise control. Not enough to move the tach, but definitely noticeable and annoying. Checked codes when we got home; no faults. I'm hoping the coincidence means bad gas? Anyone with this experience? I suppose no other choice but to drive the tank dry and see what happens with next fill?

RossBMWZseries · 06-19-2019, 12:05 AM

That happened to me once. Coming home from the gym with no wallet (or Apple Pay at the time), I was forced to stop at a gas station. My car was used to drinking Shell’s V-Power, but that night I had to pump 91 and probably wasn’t top tier fuel. I managed to find about $0.80 in the car and under the seats. I pumped what I had just to make it home to pick up my wallet. As soon as I started the car, I could tell it didn’t like the new juice; the RPM’s were taking a slight dip at idle and was hesitant when accelerating. Got home, turned the car off hoping it would go back to normal. Negative. Took my wallet, bought Chevron’s Techron and poured it in the tank as it was nearly empty, filled up with V-Power. After two bottles of Techron in two fill ups, all went back to normal, all’s been good since.

RADRACR · 06-19-2019, 12:47 AM

How long did the rough performance last after the first fill up?

I'm going to pick up a bottle of HEET water absorbing additive tomorrow. The fact the car still drove 50 miles makes me think there isn't a dangerous amount of water in there. Will report back.

RossBMWZseries · 06-19-2019, 11:02 AM

I'd say about 2 weeks. Best of luck!

WeekendWarriorz · 06-19-2019, 11:50 AM

If you run the car all the way down to empty then you risk sucking up any dirt/grime that's been sitting at the bottom of the tank for years. Grab a bottle of Chevron Fuel system/fuel injector cleaner and run it with a tank of gas sometime.

StickMon · 06-19-2019, 06:04 PM

Quote:

Originally Posted by WeekendWarriorz

... Grab a bottle of Chevron Fuel system/fuel injector cleaner and run it with a tank of gas sometime.

Or just fill up at Chevron. The Techron's already in it.
Shell just gives you Nitrogen.

gds52 · 06-26-2019, 07:20 PM

Some gas stations carry cheap quality gas, specially the branded store Chains.
There is a famous chain called Wawa around NJ/PA. They do crazy business but their gas sucks. My cars' mileage used to drop drastically whenever filled up there.
I always make sure to fill up from known top-tier gas brands.

06-18-2019, 10:21 PM	#1
RADRACR Captain 84 Rep 924 Posts Drives: '08 Z4 M Coupé // '09 X5 d Join Date: Apr 2010 Location: Sioux Falls, South Dakota iTrader: (2)	Z4M subtle hesitation after fill-up... bad gas? Wife and I went on a 1-hour road trip today. Car drove fine on the way there. Filled up with 91 (the highest around here), and on the way back the car started hesitating during 85mph cruise control. Not enough to move the tach, but definitely noticeable and annoying. Checked codes when we got home; no faults. I'm hoping the coincidence means bad gas? Anyone with this experience? I suppose no other choice but to drive the tank dry and see what happens with next fill? __________________ '08 Z4 ///M Coupé (#1765/1815) — 1 of 68 Sepang Bronze / Black Nappa / Madeira Wood / 1 of 1 this combo 19" Advan RS / AP Racing / Bridgestone RE-11 / Autosolutions SSK / R.E. Diablo / R.E. trans mounts '09 X5 35d — Space Grey / Saddle Brown 20" Forgestar F14 / SCR Delete
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06-19-2019, 12:05 AM	#2
RossBMWZseries Major 224 Rep 1,130 Posts Drives: '11 E92 328i LCI & '06 Z4MR Join Date: Jun 2014 Location: San Juan TX iTrader: (1) Garage List 2006 BMW Z4M Roadster [7.00]	That happened to me once. Coming home from the gym with no wallet (or Apple Pay at the time), I was forced to stop at a gas station. My car was used to drinking Shell’s V-Power, but that night I had to pump 91 and probably wasn’t top tier fuel. I managed to find about $0.80 in the car and under the seats. I pumped what I had just to make it home to pick up my wallet. As soon as I started the car, I could tell it didn’t like the new juice; the RPM’s were taking a slight dip at idle and was hesitant when accelerating. Got home, turned the car off hoping it would go back to normal. Negative. Took my wallet, bought Chevron’s Techron and poured it in the tank as it was nearly empty, filled up with V-Power. After two bottles of Techron in two fill ups, all went back to normal, all’s been good since.
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06-19-2019, 12:47 AM	#3
RADRACR Captain 84 Rep 924 Posts Drives: '08 Z4 M Coupé // '09 X5 d Join Date: Apr 2010 Location: Sioux Falls, South Dakota iTrader: (2)	How long did the rough performance last after the first fill up? I'm going to pick up a bottle of HEET water absorbing additive tomorrow. The fact the car still drove 50 miles makes me think there isn't a dangerous amount of water in there. Will report back. __________________ '08 Z4 ///M Coupé (#1765/1815) — 1 of 68 Sepang Bronze / Black Nappa / Madeira Wood / 1 of 1 this combo 19" Advan RS / AP Racing / Bridgestone RE-11 / Autosolutions SSK / R.E. Diablo / R.E. trans mounts '09 X5 35d — Space Grey / Saddle Brown 20" Forgestar F14 / SCR Delete
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06-19-2019, 11:02 AM	#4
RossBMWZseries Major 224 Rep 1,130 Posts Drives: '11 E92 328i LCI & '06 Z4MR Join Date: Jun 2014 Location: San Juan TX iTrader: (1) Garage List 2006 BMW Z4M Roadster [7.00]	I'd say about 2 weeks. Best of luck! __________________ 2014 BMW X5 Sdrive35i F15 2011 BMW 328i E92 LCI 2006 BMW Z4 M Roadster E85 2013 BMW S1000RR K46 R.I.P. 1998 BMW Z3 Roadster 1.9L E36 SOLD
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06-19-2019, 11:50 AM	#5
WeekendWarriorz Captain 670 Rep 754 Posts Drives: 2006 Z4M Join Date: Jan 2017 Location: Anaheim Hills, CA iTrader: (4)	If you run the car all the way down to empty then you risk sucking up any dirt/grime that's been sitting at the bottom of the tank for years. Grab a bottle of Chevron Fuel system/fuel injector cleaner and run it with a tank of gas sometime. __________________ 2006 Z4 M Roadster Black/Imola Red, FBO VF-Engineering, e85 Flex Fuel-Sold 2012 BMW 135i N55 DCT Alpine White/Coral Red, FBO, TBI, Full e85, JB4 BEF-Sold 2006 Z4 M Roadster Black/Black-Sold 2021 M2 Competition DCT Hockenheim Silver
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06-26-2019, 07:20 PM	#7
gds52 Colonel 886 Rep 2,720 Posts Drives: BMW Z4M Coupe, BMW 328i E93 Co Join Date: Oct 2011 Location: NJ iTrader: (0)	Some gas stations carry cheap quality gas, specially the branded store Chains. There is a famous chain called Wawa around NJ/PA. They do crazy business but their gas sucks. My cars' mileage used to drop drastically whenever filled up there. I always make sure to fill up from known top-tier gas brands.
	Appreciate 0 Quote