E36 328is Crazy high fuel consumption
Discussion
vsonix said:
When taking off hard in second gear, does the car feel heavy/sluggish until you hit around 3.5k revs whereupon all of a sudden it feels like a lead weight's been thrown out the window as the car suddenly finds its power and surges forward?
My 728i does this to a certain extent, wondering if I have a problem now! Fuel consumption is certainly normal though and it will happily trundle along at 85 pulling 2500rpm though, but once it hits 3500rpm its noticeably quicker, thoughts? Might see if I can upload a video in the next day or 2 and see if people think it's normal.
Edited by E38Ross on Monday 30th April 16:08
E38Ross said:
vsonix said:
When taking off hard in second gear, does the car feel heavy/sluggish until you hit around 3.5k revs whereupon all of a sudden it feels like a lead weight's been thrown out the window as the car suddenly finds its power and surges forward?
My 728i does this to a certain extent, wondering if I have a problem now! Fuel consumption is certainly normal though and it will happily trundle along at 85 pulling 2500rpm though, but once it hits 3500rpm its noticeably quicker, thoughts? Might see if I can upload a video in the next day or 2 and see if people think it's normal.
Edited by E38Ross on Monday 30th April 16:08
If you have a sin
The inlet manifold boosts power at the lower revs at the expense of higher engine speed performance.
At about 3500-ish RPMs there is a switch over from closed loop 14.7:1 AFRs to about 12-12.5:1 AFRs (richer for more power)
The 328 will have 2 lambda sensors, both pre-cat and in each exhaust manifold, so one covers 1-3, the other covers 4-6.
There isn't any secondary post cat lambdas on Euro 328s.
At about 3500-ish RPMs there is a switch over from closed loop 14.7:1 AFRs to about 12-12.5:1 AFRs (richer for more power)
The 328 will have 2 lambda sensors, both pre-cat and in each exhaust manifold, so one covers 1-3, the other covers 4-6.
There isn't any secondary post cat lambdas on Euro 328s.
tali1 said:
heebeegeetee said:
I'm surprised at some of the figures on this thread, 'cos according to the 328 owners who post on the anti-diesel threads they all do 40 mpg all the time.
It's not just a 328 thing - every apparently thirsty 6/8/12 cylinder petrol gets near diesel levels of mpg.And old cars which are matching their 25 yrs newer counterparts.Go figure
Frances The Mute said:
E38Ross said:
vsonix said:
When taking off hard in second gear, does the car feel heavy/sluggish until you hit around 3.5k revs whereupon all of a sudden it feels like a lead weight's been thrown out the window as the car suddenly finds its power and surges forward?
My 728i does this to a certain extent, wondering if I have a problem now! Fuel consumption is certainly normal though and it will happily trundle along at 85 pulling 2500rpm though, but once it hits 3500rpm its noticeably quicker, thoughts? Might see if I can upload a video in the next day or 2 and see if people think it's normal.
Edited by E38Ross on Monday 30th April 16:08
If you have a sin
half tempted to go out later this evening and do a short video, flooring it from standstill in 2nd gear up to well past 3500rpm and upload it here and see whether people think it's normal.
thing which makes me think it IS normal is it'll sit happily at low rpm without any issues really and mpg is fantastic when on a run. OBC can show around 40mpg on a long run cruising at 70 (indicated) if i reset the computer when the engine is hot and already on the motorway.
vsonix said:
tali1 said:
heebeegeetee said:
I'm surprised at some of the figures on this thread, 'cos according to the 328 owners who post on the anti-diesel threads they all do 40 mpg all the time.
It's not just a 328 thing - every apparently thirsty 6/8/12 cylinder petrol gets near diesel levels of mpg.And old cars which are matching their 25 yrs newer counterparts.Go figure
I could get 48-72 mpg on a dual carriageway stretch with my 2.0 litre Mondeo auto BUT it would always average 16 mpg .In heavy traffic the OBC would drop 0.1 mpg.... every minute.
(And that with a car with fully recon, run in engine with brand new cat convertor)
Well I've changed the sensor and although its early days I have noticed an improvement! The obc figures are fluctuating so I am waitibg at least a week to see if there is a real change. I am also considering an ecu reset after a week of 'normal' driving.
Interesting to see the experiances of others in the community.
Interesting to see the experiances of others in the community.
OptiManc said:
Well I've changed the sensor and although its early days I have noticed an improvement! The obc figures are fluctuating so I am waitibg at least a week to see if there is a real change. I am also considering an ecu reset after a week of 'normal' driving.
Interesting to see the experiances of others in the community.
I think I remember reading or hearing somewhere CPU reset after CPS change is a good thing, but can't remember where. Ah yeah, it was at a meet I was at the other day, chap said "after changing the sensor you must remember to also do X which many people don't". Can't remember what X was exactly but it might have been resetting the ECU. Not very helpful I'm afraid lolInteresting to see the experiances of others in the community.
vsonix said:
I think I remember reading or hearing somewhere CPU reset after CPS change is a good thing, but can't remember where. Ah yeah, it was at a meet I was at the other day, chap said "after changing the sensor you must remember to also do X which many people don't". Can't remember what X was exactly but it might have been resetting the ECU. Not very helpful I'm afraid lol
On the contrary, it’s given me some confidence, I may even do the reset sooner, the price at the pump went up today so the sooner the savings start the better!Well it has been a good number of days since i changed the cam sensor and 2 days later i reset the ECU by disconnecting the battery for a short while.
Verdict, i think the problem has been resolved partly. performance has recovered, now its great from standstill, doesn’t seem or sound laboured and is prompt as it used to be around a year ago. However, fuel consumption has improved also but still fluctuates. My driving style has changed since the issue became apparent, so i rely on the Range on the OBC, and that seems be to more stable than counting down the miles like a stopwatch like it used to. However, it is temporal so i think the problem is only half resolved. I am going to change the o2 sensors too (after pay day) and monitor again.
Like for like driving with the issue and now partially resolved, i would summarise to say we're nearly there.
Thank you to everyone for their contribution, knowledge sharing and support in this thread, your input has been very much appreciated.
I'll update again after changing the o2 sensors.
Verdict, i think the problem has been resolved partly. performance has recovered, now its great from standstill, doesn’t seem or sound laboured and is prompt as it used to be around a year ago. However, fuel consumption has improved also but still fluctuates. My driving style has changed since the issue became apparent, so i rely on the Range on the OBC, and that seems be to more stable than counting down the miles like a stopwatch like it used to. However, it is temporal so i think the problem is only half resolved. I am going to change the o2 sensors too (after pay day) and monitor again.
Like for like driving with the issue and now partially resolved, i would summarise to say we're nearly there.
Thank you to everyone for their contribution, knowledge sharing and support in this thread, your input has been very much appreciated.
I'll update again after changing the o2 sensors.
FWIW I replaced a faulty exhaust camshaft sensor on my Z3 3.0 with the M54 engine. I reset the ECU using INPA software and cable (same as I used to find the fault in the first place). There were no lights on the dash to warn of this sensor issue either (despite 83 recorded error codes for it). It was the only error code recorded on the car, apart from a one off code for the throttle switch/pot. INPA records the number of times the error occurs, so it's easier to spot a one off glitch verses a regular problem. Plus you can clear the codes and check again after a drive to see if codes reoccur quickly as my camshaft sensor code did (3 errors in one afternoon).
Like you I've found the car feels much more lively (especially in higher gears, so less need to change down unless really motoring). I've seen a small increase in mpg, but I've been using the extra power. Reseting the OBC and driving less briskly soon sees it reading around 32mpg, which I don't think is bad for a 3 litre.
I read another thing on a Z3 forums about how some BMWs seem to lose power as the service lights mean that the car is near to needing a service. Some claim that doing nothing more than reseting the lights brings the performance back up to scratch. Haven't tried this myself as I haven't had the car long and still have 4 lights on the SI at the moment, but I'll keep an eye on the mpg figures as it approaches the service to see if mine 'drops off'.
Like you I've found the car feels much more lively (especially in higher gears, so less need to change down unless really motoring). I've seen a small increase in mpg, but I've been using the extra power. Reseting the OBC and driving less briskly soon sees it reading around 32mpg, which I don't think is bad for a 3 litre.
I read another thing on a Z3 forums about how some BMWs seem to lose power as the service lights mean that the car is near to needing a service. Some claim that doing nothing more than reseting the lights brings the performance back up to scratch. Haven't tried this myself as I haven't had the car long and still have 4 lights on the SI at the moment, but I'll keep an eye on the mpg figures as it approaches the service to see if mine 'drops off'.
steve_bmw said:
I remember you posting about simular issues a few months back, did you get the the bottom of your mpg problem??
Steve,I have only just resolved my MPG/Power problem. Turned out the CAT was blocked. I would normally associate a blocked CAT as reducing power the same amount across the whole of the Rev range but mine was definitely picking up after 3k. Anyway CAT changed and it drives much much better and MPG is ok now, though I need to do a ECU reset as recently (long story) I temporarily had two dodgy second hand lambdas in. Oh also I changed my 323i CAT for a 328i section, definitely worth it!
OldSkoolRS said:
FWIW I replaced a faulty exhaust camshaft sensor on my Z3 3.0 with the M54 engine. I reset the ECU using INPA software and cable (same as I used to find the fault in the first place). There were no lights on the dash to warn of this sensor issue either (despite 83 recorded error codes for it). It was the only error code recorded on the car, apart from a one off code for the throttle switch/pot. INPA records the number of times the error occurs, so it's easier to spot a one off glitch verses a regular problem. Plus you can clear the codes and check again after a drive to see if codes reoccur quickly as my camshaft sensor code did (3 errors in one afternoon).
Like you I've found the car feels much more lively (especially in higher gears, so less need to change down unless really moice lightstoring). I've seen a small increase in mpg, but I've been using the extra power. Reseting the OBC and driving less briskly soon sees it reading around 32mpg, which I don't think is bad for a 3 litre.
I read another thing on a Z3 forums about how some BMWs seem to lose power as the service lights mean that the car is near to needing a service. Some claim that doing nothing more than reseting the lights brings the performance back up to scratch. Haven't tried this myself as I haven't had the car long and still have 4 lights on the SI at the moment, but I'll keep an eye on the mpg figures as it approaches the service to see if mine 'drops off'.
I've heard the same about service lights so i tried it when the issue first vecame apparent but it didnt make any difference. Like you I've found the car feels much more lively (especially in higher gears, so less need to change down unless really moice lightstoring). I've seen a small increase in mpg, but I've been using the extra power. Reseting the OBC and driving less briskly soon sees it reading around 32mpg, which I don't think is bad for a 3 litre.
I read another thing on a Z3 forums about how some BMWs seem to lose power as the service lights mean that the car is near to needing a service. Some claim that doing nothing more than reseting the lights brings the performance back up to scratch. Haven't tried this myself as I haven't had the car long and still have 4 lights on the SI at the moment, but I'll keep an eye on the mpg figures as it approaches the service to see if mine 'drops off'.
I'll lookinto getting own software and cable now, perhaps with its age and milage its worth having a set.
E38Ross said:
Frances The Mute said:
E38Ross said:
vsonix said:
When taking off hard in second gear, does the car feel heavy/sluggish until you hit around 3.5k revs whereupon all of a sudden it feels like a lead weight's been thrown out the window as the car suddenly finds its power and surges forward?
My 728i does this to a certain extent, wondering if I have a problem now! Fuel consumption is certainly normal though and it will happily trundle along at 85 pulling 2500rpm though, but once it hits 3500rpm its noticeably quicker, thoughts? Might see if I can upload a video in the next day or 2 and see if people think it's normal.
Edited by E38Ross on Monday 30th April 16:08
If you have a sin
half tempted to go out later this evening and do a short video, flooring it from standstill in 2nd gear up to well past 3500rpm and upload it here and see whether people think it's normal.
thing which makes me think it IS normal is it'll sit happily at low rpm without any issues really and mpg is fantastic when on a run. OBC can show around 40mpg on a long run cruising at 70 (indicated) if i reset the computer when the engine is hot and already on the motorway.
It was upposed to say that if you have the earlier single vanos lump (up to march 1997 if memory serves) you can swap the manifold out.
Other than that, yes. It is normal.
Frances The Mute said:
Not too sure what happened to the rest of my post....
It was upposed to say that if you have the earlier single vanos lump (up to march 1997 if memory serves) you can swap the manifold out.
Other than that, yes. It is normal.
Unless it's an M3, all 6 cylinder E36's had single VANOS until the end of its production in 1999.It was upposed to say that if you have the earlier single vanos lump (up to march 1997 if memory serves) you can swap the manifold out.
Other than that, yes. It is normal.
Dual Vanos for the standard 3series 6 cylinders came in with the E46.
There's slightly more involved with the M50 manifold mod than just swapping them over too. Certain versions of the M50 manifold are not suitable for the conversion.
Best person to contact is Alpina527 - he probably knows more about the mod than anyone else in this country.
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