E36 328is Crazy high fuel consumption

E36 328is Crazy high fuel consumption

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Discussion

E38Ross

34,946 posts

211 months

Monday 28th May 2012
quotequote all
how many miles did you get from that tank? guessing around the 220 mark?

that is truly shocking!

Johnboy Mac

2,666 posts

177 months

Monday 28th May 2012
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Wow, 16.3 not good at all but it's the correct figure so there's a fault for sure. Next time when carrying a mpg check, avoid running out fuel as there's no need, just use the trip meter i.e brim the tank, rest the trip, do 150-200 miles and brim the tank gain. Hope, the new coolant temp.sensor does the trick, it's very possible it will.

E30M3SE

8,465 posts

195 months

Monday 28th May 2012
quotequote all
OptiManc said:
isnt that the coolant temp sensor?
No, that is the air temp sensor.

The coolant temp sensor, there are 2, one that runs the electric fan for the A/C, it's located in the side of the radiator, the one you want is in the side of the head,



part# 14 in this diagram.

Look at this also.


ETA;
if you've already got the air temp sensor then change it, it's the easiest of the lot to change.

Edited by E30M3SE on Monday 28th May 14:47

OptiManc

Original Poster:

156 posts

237 months

Monday 28th May 2012
quotequote all
E38Ross said:
how many miles did you get from that tank? guessing around the 220 mark?

that is truly shocking!
209 and 198...when i filled up at first it said +340 that soon sort itself out! :s

OptiManc

Original Poster:

156 posts

237 months

Monday 28th May 2012
quotequote all
Johnboy Mac said:
Wow, 16.3 not good at all but it's the correct figure so there's a fault for sure. Next time when carrying a mpg check, avoid running out fuel as there's no need, just use the trip meter i.e brim the tank, rest the trip, do 150-200 miles and brim the tank gain. Hope, the new coolant temp.sensor does the trick, it's very possible it will.
Thanks Johnboy, i did the empty tank to ensure there isn’t any fuel lingering around inside and the computer making an incorrect assumption of fuel volume. And also at the request of others being so very helpful on this thread.

OptiManc

Original Poster:

156 posts

237 months

Monday 28th May 2012
quotequote all
E30M3SE said:
No, that is the air temp sensor.

The coolant temp sensor, there are 2, one that runs the electric fan for the A/C, it's located in the side of the radiator, the one you want is in the side of the head,



part# 14 in this diagram.

Look at this also.

ETA;
if you've already got the air temp sensor then change it, it's the easiest of the lot to change.

Edited by E30M3SE on Monday 28th May 14:47
Nice one E30M3SE! Very nice link, where do you find this lot?
OK, will change air temp sensor first of the shop can get it in today otherwise i'll either wait or attempt the coolant sensor today.

OptiManc

Original Poster:

156 posts

237 months

Tuesday 29th May 2012
quotequote all
Tried to post this last night but the forum was down.

Checked the coil packs on advise of a mechanic but they appear clean.

Have now bought an Air Temp Sensor and Coolant Temp Sensor (so many sensors!) and plan to install Air sensor first tonight and trial it for a week if it seems stable.

I will be resetting the ECU post installation the only way i know which is to disconnect the battery for a while, is that enough?

Brake switch is playing up now but can sort that easily.

OptiManc

Original Poster:

156 posts

237 months

Wednesday 30th May 2012
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Manged to get the air sensor in this morning, was very tricky and had to remove a fair few parts to get to it.

Early signs (after 2 starts and 18.4 miles) that there is some stability, however this is what happened with the MAFF and the Cam Shaft sensor so i'm not holding my breath.

Will keep you posted...

vsonix

3,858 posts

162 months

Thursday 31st May 2012
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hmmm I've had a thought...

The fact that once a sensor is replaced there is an improvement follwed by a decline again makes me wonder if it might be something to do with the ECU... I'm wondering maybe if the car previously had some other intake/M50 manifold/exhaust or similar engine mods, was remapped to take advantage but then original bits put back but ECU left with the remap that is trying to do things that are no longer possible and causing over-fuelling etc. You said you reset the ECU but I'm not sure if that would clear any remapping or not.

OptiManc

Original Poster:

156 posts

237 months

Thursday 31st May 2012
quotequote all
vsonix said:
hmmm I've had a thought...

The fact that once a sensor is replaced there is an improvement follwed by a decline again makes me wonder if it might be something to do with the ECU... I'm wondering maybe if the car previously had some other intake/M50 manifold/exhaust or similar engine mods, was remapped to take advantage but then original bits put back but ECU left with the remap that is trying to do things that are no longer possible and causing over-fuelling etc. You said you reset the ECU but I'm not sure if that would clear any remapping or not.
I thought that too, however the mechanic and previous owner (second owner from new) confirmed no such mods have been made banghead. However, the ECU update/flash by the mechanic in Jan/Feb this year would have flushed out any remapps.

I'm going to fit the coolant sensor this bank holiday weekend weather permitting, after that if it doesnt solve the problem I'll have to seriously reconsider our future together frown

vsonix

3,858 posts

162 months

Thursday 31st May 2012
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probably get a new engine for £400 on ebay...

OptiManc

Original Poster:

156 posts

237 months

Saturday 2nd June 2012
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The air sensor replacement made no difference, coolant temp sensor went in eventually, very tricky position but its in and no difference so far.

Took it into BM Tec in Manchester to diagnose and clear fault codes, no codes to clear mind you. Anyway, they diagnosed it thoroughly and were as baffled as I and perhaps all us on this thread are. They did however say it was the "sweetest" sound engine they'd had in.

Tomorrow (sunday 3rd June) I'll be installing the O2 sensors, after that if the fault is not solved, with a heavy heart I'll have to call it a day...or hold it in parc ferme until I am able try something else.

E38Ross

34,946 posts

211 months

Saturday 2nd June 2012
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so you mean they didn't diagnose it? surprised an indy couldn't do it! really weird as to why it's getting that poor mpg! my much heavier, automatic 728i gets around twice that mpg! 150 miles cruise yesterday sat at 70mph saw the trip computer read 38.1mpg from a cold start!

OptiManc

Original Poster:

156 posts

237 months

Saturday 2nd June 2012
quotequote all
E38Ross said:
so you mean they didn't diagnose it? surprised an indy couldn't do it! really weird as to why it's getting that poor mpg! my much heavier, automatic 728i gets around twice that mpg! 150 miles cruise yesterday sat at 70mph saw the trip computer read 38.1mpg from a cold start!
Thanks for rubbing it E38ROSS! driving
Correct, they werent able to diagnose it, but they tried for sure.

Danny and I had a chat about his E46 M3, then i looked at Danny and Andy despondently before nursing home my E36

E38Ross

34,946 posts

211 months

Saturday 2nd June 2012
quotequote all
OptiManc said:
E38Ross said:
so you mean they didn't diagnose it? surprised an indy couldn't do it! really weird as to why it's getting that poor mpg! my much heavier, automatic 728i gets around twice that mpg! 150 miles cruise yesterday sat at 70mph saw the trip computer read 38.1mpg from a cold start!
Thanks for rubbing it E38ROSS! driving
Correct, they werent able to diagnose it, but they tried for sure.

Danny and I had a chat about his E46 M3, then i looked at Danny and Andy despondently before nursing home my E36
hehe sorry mate. that's rotten luck they couldn't diagnose!

it's not running on 50k mile old oil is it? hehe

really, really strange....more so by the fact it's running smoothly still.

OptiManc

Original Poster:

156 posts

237 months

Saturday 2nd June 2012
quotequote all
E38Ross said:
hehe sorry mate. that's rotten luck they couldn't diagnose!

it's not running on 50k mile old oil is it? hehe

really, really strange....more so by the fact it's running smoothly still.
Let you off.
Nope, oil has been changed 3 times in total, 5w-30 Edge now and plugs have been changed 3 times too, Bosch and now NGK, platinum.

OldGermanHeaps

3,801 posts

177 months

Saturday 2nd June 2012
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Binding brake or driveline issue? fuel return line with an intermittant kink? just throwing out guesses now. did the garage hook up a scan tool and take it for a drive watching live values?

Daniel1

2,931 posts

197 months

Sunday 3rd June 2012
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The amount you would start saving in fuel you could probably replace the engine?

E30M3SE

8,465 posts

195 months

Sunday 3rd June 2012
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OldGermanHeaps said:
Binding brake or driveline issue? fuel return line with an intermittant kink? just throwing out guesses now. did the garage hook up a scan tool and take it for a drive watching live values?
Valid point, but I think the OP said the has had recent inspection II, so would assume this it not occuring, but may be the OP could re-check this.




Edited by E30M3SE on Sunday 3rd June 16:27

OptiManc

Original Poster:

156 posts

237 months

Sunday 3rd June 2012
quotequote all
E30M3SE said:
Valid point, but I think the OP said the has had recent inspection II, so would assume this it not occuring, but may be the OP could re-check this.




Edited by E30M3SE on Sunday 3rd June 16:27
Correct. Brakes have been checked and theyre working correctly and not binding. Fuel lining also in tip top working order. I wish it were something this simple.

I have '92 320i coupe in the garage, fired that up today, considering getting that back on the road while a solution for the 328ise comes about. Still sounds great!