306oc - Peugeot 306 Owners Club & Forum
306 hdi only 37 mpg? - Printable Version

+- 306oc - Peugeot 306 Owners Club & Forum (https://www.306oc.co.uk/forum)
+-- Forum: Engines (https://www.306oc.co.uk/forum/forumdisplay.php?fid=16)
+--- Forum: DW10 HDi section (https://www.306oc.co.uk/forum/forumdisplay.php?fid=10)
+--- Thread: 306 hdi only 37 mpg? (/showthread.php?tid=19155)



306 hdi only 37 mpg? - scfc_151 - 26-11-2013

I have a 2001 2.0 hdi with 213,000 miles

The mpg is only 37 average. This is services every 6000 miles so the air and fuel filter is clean. It doesnt feel down on power and runs well.

Is there any reason it could be so low? Im not heavy footed, the brakes arent binding and tyre pressures fine.

Would a plannet peugeot diagnostic tell me anything if I could find one anywhere near Stoke on Trent?

Many thanks


RE: 306 hdi only 37 mpg? - Jonny81191 - 26-11-2013

That is a bit low, are you doing lots of short journeys?


RE: 306 hdi only 37 mpg? - scfc_151 - 26-11-2013

Yeah they are short journeys to be honest but I used to get around 45mpg with town driving

I was wondering about a diesel leak off test for the injectors


RE: 306 hdi only 37 mpg? - Jonny81191 - 26-11-2013

So you've had the car a while and it's suddenly dropped?

Is this over a couple of tanks?

Yeah a leak off test certainly wouldn't hurt.


RE: 306 hdi only 37 mpg? - Poodle - 26-11-2013

Does she rev easily under load? When does she come on boost?


RE: 306 hdi only 37 mpg? - scfc_151 - 26-11-2013

I wouldnt say suddenly dropped this is over a while but when I speak to the mechanic all I get is "well it is winter they do use more".
I understand that but even people hammering them get above 40mpg!

Its revs easily enough turbo comes in about 2700?


RE: 306 hdi only 37 mpg? - Toms306 - 26-11-2013

The EGR is probably stuck open if it's not already blanked.

Tbh to get mpg that bad it's gotta be a mixture of things.


RE: 306 hdi only 37 mpg? - Dum-Dum - 26-11-2013

37mpg is impressively low lol. On your short journeys when does the car warm up by?


RE: 306 hdi only 37 mpg? - scfc_151 - 26-11-2013

With regards to the egr i did try to blank it off but could barely get my hand to it. I did disconnect the solenoid and blank tge vac pipes for a while but made no difference.

The main use is to and from work at the min which is only about 3.5 miles each way so it barely gets warm. I was considering swapping to a small petrol but a new baby boy means I wanted to keep a bigger car and obviously money constraints mean I need to keep it on the road for a while


RE: 306 hdi only 37 mpg? - Jonny81191 - 27-11-2013

Turbo comes in at 2700rpm? On a stock hdi? I'd be looking for a boost leak. Like a really big boost leak Big Grin


RE: 306 hdi only 37 mpg? - Poodle - 27-11-2013

Yeah, boost leak could be the problem, or the maf. I was actually thinking it might be a blocked cat at that kind of mileage.


RE: 306 hdi only 37 mpg? - scfc_151 - 27-11-2013

The cat was replaced about 18 months ago and a genuine maf sensor about 2 years ago.

Sorry with regards to the turbo I was getting my wires crossed. I was thinking about when somebody was talking about injector tick some time ago. It kicks in at about 2300.

How would I check for a boost leak and where should I look? Ive looked at the turbo before its difficult to access really and I couldnt see any splits in pipework.

Just one point I dont know if is related to anything atall. When the temperature drops below 6 degrees outside when. I apply the brake the revs drop to the point where it feels its going to stall but never does and revs come back when I take my foot of the brake. When the car warms up it seems to to away. I know this might have nothing to do with it but ive posted this on other forums and still dont have an answer.

Cheers


RE: 306 hdi only 37 mpg? - rd070707 - 27-11-2013

I have the exact same issue with the revs dropping when I brake, but again only when cold


RE: 306 hdi only 37 mpg? - scfc_151 - 27-11-2013

(27-11-2013, 10:33 AM)rd070707 Wrote: I have the exact same issue with the revs dropping when I brake, but again only when cold

Really? Well please let me know if you solve it. Ive had mechanics look for leaks etc but no one can explain it


RE: 306 hdi only 37 mpg? - Midnightclub - 27-11-2013

Out of interest, what's your 'normal' running temp?


RE: 306 hdi only 37 mpg? - scfc_151 - 27-11-2013

(27-11-2013, 10:47 AM)Midnightclub Wrote: Out of interest, what's your 'normal' running temp?

Normal running temp is just over 80 degrees


RE: 306 hdi only 37 mpg? - Toms306 - 27-11-2013

(27-11-2013, 10:33 AM)rd070707 Wrote: I have the exact same issue with the revs dropping when I brake, but again only when cold

My estate used to do this.

I just assumed it's because the vac pump puts a bit of load on the engine and obviously engines are less efficient/harder to keep idling when cold. That said, the ECU should be able to deal with it...


RE: 306 hdi only 37 mpg? - rd070707 - 27-11-2013

Yeah it isnt normal, my last hdi didnt do it, it's so annoying trying not to brake hard in the morning lol. Would love to solve it too


RE: 306 hdi only 37 mpg? - Dum-Dum - 27-11-2013

I'd be looking at swapping the glow plugs in the coolant heater to get it to warm up quicker (as well as checking for boost leaks and properly blanking the EGR).


RE: 306 hdi only 37 mpg? - L.J - 09-01-2014

might be worth changing the thermostat?
could be running slightly colder than it should be


RE: 306 hdi only 37 mpg? - Dum-Dum - 09-01-2014

Nah 80*C is absolutely normal for these cars.


RE: 306 hdi only 37 mpg? - scfc_151 - 09-01-2014

I did replace the coolant and thermostat while I was at it to look after it for the winter


RE: 306 hdi only 37 mpg? - C.A.R. - 09-01-2014

When my MAF was left unplugged my MPG dropped to the low 40s. Not quite as low as you're experiencing but it could be a problem?

This, combined with lower ambient temperatures (diesels can lose 10-15% efficiency in the cold winter months in my experienced) might help towards resolving your problem?


RE: 306 hdi only 37 mpg? - scfc_151 - 09-01-2014

(09-01-2014, 09:14 PM)C.A.R. Wrote: When my MAF was left unplugged my MPG dropped to the low 40s. Not quite as low as you're experiencing but it could be a problem?

This, combined with lower ambient temperatures (diesels can lose 10-15% efficiency in the cold winter months in my experienced) might help towards resolving your problem?

The maf was replaced with a genuine one about 2 years ago and gets cleaned every service. I did check the electric connection just incase


RE: 306 hdi only 37 mpg? - Poodle - 10-01-2014

How have you been cleaning the maf? They're relatively fragile, could have been damaged...

Also, 2300 is fairly late for the blower to come on song, another factor pointing to possible maf issues.


RE: 306 hdi only 37 mpg? - scfc_151 - 11-01-2014

(10-01-2014, 03:56 PM)Poodle Wrote: How have you been cleaning the maf? They're relatively fragile, could have been damaged...

Also, 2300 is fairly late for the blower to come on song, another factor pointing to possible maf issues.

Just sprayed with electrical contact cleaner and left so it should be ok


RE: 306 hdi only 37 mpg? - DeeTurbo - 11-01-2014

Some contact cleaners leave a film of lubrication behind that could throw the values it reads. You really should use something that evaporates of leaving nothing behind, eg brake cleaner.


RE: 306 hdi only 37 mpg? - Poodle - 11-01-2014

How long have you had the car? I wonder if it could be the lower temperatures causing higher consumption, my mpg has dropped by 3-4 over the summer-time figures.


RE: 306 hdi only 37 mpg? - scfc_151 - 23-05-2016

(27-11-2013, 11:28 AM)rd070707 Wrote: Yeah it isnt normal, my last hdi didnt do it, it's so annoying trying not to brake hard in the morning lol. Would love to solve it too

Hi sorry to drag up an old thread just wondered if you solved the problem


Thanks