Holden Cruze Eats Fuel

3228 Views 41 Replies 15 Participants Last post by davidtranlds, 1 mo ago

davidtranlds

Discussion Starter · 4 mo ago

Hi guys

So, recently purchased Holden Cruze 2012 SRi-V JH Series II, 1.4L turbo petrol, second hand.

It's advertised to have a combined fuel economy of 6.9L/100km (34mpg)

However, it's currently running at 10L/100km

The car itself drives smooth (except when shifting gears - details will be in another thread), no misfiring (that I can hear), pinging, knocking, etc.

Wheels are pumped to the right pressure, brakes aren't dragging, I mostly do highway/freeway drives, which range from 70km/h to 100km/h (44mph to 60mph).

Been like that since the day I got it.

Any ideas what I can diagnose to see what could be causing it to eat so much fuel?

Thanks

21 - 40 of 42 Posts

davidtranlds

Discussion Starter · #21 · 4 mo ago

Thanks guys. I definitely understand that second cars may never be perfect. It is due for it's next maintenance in the next 2000km.
I am booking in a date with a mechanic soon.

For me, it's more to better understand what's going on, as I don't want to just take the word of the mechanic - A B C are the problems, X Y Z are the costs, and pay for something that I shouldn't have needed to in the end.

So going through the standard OBD readings has been good, to get a better idea that it's running within spec.
But the really bad fuel economy, yeah, I know 6.9L is market BS, but surely it wouldn't be as bad as 9L (or 10L previously), because that's really bad marketing then.

So far I've checked the air filter - dusty, could do with a replacement.
Main thing was some sand/dirt/leaves inside the container thing that sits under the filter... So I took it out and cleaned it up.

Watching videos online, the MAF sensor they all talk about, and location, and how to get it out, seems different to mine, so still trying to figure that one out.
Also need to pick up some of that CRC cleaner or whatever it is so I can spray it clean when I do locate it.

I haven't checked sparks yet, will definitely need to take a look so I can get before photos so I can compare to post-service.

Yep, unfortunately we have dodgy mechanics too, and even the mechanic I thought I could trust, my wife's car came back a corner from the rear back light housing thing broken off and simply glued back on (and not even straight)... And they didn't say anything... Basically got away with it because I didn't notice until a week later... I also can't accuse them because I have really bad memory to be honest - might have happened from the mechanic before our usual one (but I'm pretty sure it only there after going to our usual one) so yeah...

As for the fuel, 91 octane definitely isn't enough? Manual says to run on 91 octane, and 95 if we like.

See less See more

grs1961

· #22 · 4 mo ago

davidtranlds said:
As for the fuel, 91 octane definitely isn't enough? Manual says to run on 91 octane, and 95 if we like.

Yes, the 1.4 can run on 91, but it's designed to work on 95 or higher.

It takes a few tanks of 95 to re-learn.

RBalym

· #23 · 4 mo ago

davidtranlds said:
Hi guys

So, recently purchased Holden Cruze 2012 SRi-V JH Series II, 1.4L turbo petrol, second hand.

It's advertised to have a combined fuel economy of 6.9L/100km (34mpg)

However, it's currently running at 10L/100km

The car itself drives smooth (except when shifting gears - details will be in another thread), no misfiring (that I can hear), pinging, knocking, etc.

Wheels are pumped to the right pressure, brakes aren't dragging, I mostly do highway/freeway drives, which range from 70km/h to 100km/h (44mph to 60mph).

Been like that since the day I got it.

Any ideas what I can diagnose to see what could be causing it to eat so much fuel?

Thanks

My son has the same car year and model and I have been driving it after he bought it a couple of months ago and I have been driving it to make sure its ok, I checked his economy and it was the 10L/100K's so I reset everything on it that could be reset and now its 6.8L/100K's , Might pay to reset it including average speed and see how you go

davidtranlds

Discussion Starter · #24 · 3 mo ago (Edited)

2

First time I reset it, it was 10L/100km still.
After a long time, and sorting out the LTFT issue, it's gone down to 9L/100km.

Here's the air filter.

Hood Motor vehicle Automotive design Auto part Office equipment

Spark plugs from left to right

Household hardware Gas Engineering Auto part Metal

I also noticed some of the carbon build up lingering around the chambers these sparks sit in - not a lot, just a little here and there.

Mechanic is booked for this Wednesday - we'll see how things go.

That aside, so far I've added Nulon Petrol Injector Cleaner and Penrite EGR & CAT Clean+.
I had an old bottle of Wynn's 100000km additive of sort which I used also.

Any other recommendations I might be able to use after the service for a general clean/maintenance/upkeep sort of thing?

See less See more

skildude

· #25 · 3 mo ago

The plugs look really good. The air filter needs changing. The air filter won't harm your mileage as the vehicle automatically adjusts the fuel/air ratio to maximize combustion.

Couple of dumb questions.
No codes or engine light on?
Do you smell gas/petrol if you walk around the car or lift the hood after driving?
Drive at 60 MPH or whatever the KPH is(around 11000kph I think) what RPMs are you seeing. should be around 2k
perhaps your tranny needs a service?

davidtranlds

Discussion Starter · #26 · 3 mo ago

There used to be an engine light and that was the P0171 but was resolved when the dealership replaced the purge value (apparently has different proper name that I can't remember now).

No funny smells around the car, I don't believe there are any leaks, everything looks dry at the moment.

I'll see where the RPM sits on my way to work

davidtranlds

Discussion Starter · #27 · 3 mo ago

RPMs whilst driving at 100km/h is about 1800-1900

davidtranlds

Discussion Starter · #28 · 3 mo ago

So, the mechanic noticed the wheels looked a little big and they were.

Car is spec'd to use 215 / 50 / 17, and the wheels currently on it are 215 / 55 / 17.

Using an online calculator, it was a 21mm difference in diameter, which is illegal (max difference here is 15mm).

So he called the dealership and they said they'll change it over.

So when I get the car back tomorrow, will have to bring it over to the dealership.

Hopefully this car service, along with user the correctly sized wheels, will improve fuel economy...

Reactions: 1

skildude

· #29 · 3 mo ago

The mm difference will make a bit of a difference since the ECU calculates the speed and mileage from the correct tires and wheels being on the vehicle. The RPMs seem in the ballpark for the speed. This will likely change a bit with different tires maybe 2 MPH on the speedo. Lets hope the mechanic finds something simple that will make a difference.

davidtranlds

Discussion Starter · #30 · 3 mo ago (Edited)

Alright, wheels finally changed over, took forever for the dealership to organise time for me.

I've definitely noticed it drives a little sharper on turns, and I think the engine isn't revving as hard (only marginally less).

But definitely positive signs.

During the mechanics inspection, he said the sparks are gapped too wide.
He also found a number of leaks.

So now we're looking into a warranty claim to get all the leaks sorted, then he'll do the service.

I might just go out and regap the sparks in the meantime, what should the gap be?
How many mm?

EDIT:
Just found a post here that says a 1.4T is 0.033" - 0.037"
So thats 0.84-0.94mm
That seems quite small?

See less See more

skildude

· #31 · 3 mo ago

You're better off just changing them out. New platinum, Iridium, and other good plugs are factory gapped and don't need you to touch them for the next 100k miles.
If the gap has changed they are worn. The plugs do wear as they age.

Cruzing12

· #32 · 3 mo ago

Tire diameter eh!

Was thinking about this and came back to say your battery could be on the way out... Probably not 10L/100km bad. But 1-1.5L/100km.

As a 1.8l owner I average about 7.2L/100km driving a mix of city and country road. Running 87

davidtranlds

Discussion Starter · #33 · 3 mo ago

skildude said:
You're better off just changing them out. New platinum, Iridium, and other good plugs are factory gapped and don't need you to touch them for the next 100k miles.
If the gap has changed they are worn. The plugs do wear as they age.

That would be plan when we do the service.
Just thought I could regap for the time being as shops are generally closed when I'm available, or I have other matters to tend to, so when I can organise the service, get it all done then and there too.

Are the gaps that small though?

Cruzing12 said:
Was thinking about this and came back to say your battery could be on the way out... Probably not 10L/100km bad. But 1-1.5L/100km.

I didn't think battery could affect fuel, but did watch a video about it recently.

Funny thing is, battery did die last week, 100% flat, or around there, and had to jump start it.

Cruzing12

· #34 · 3 mo ago

davidtranlds said:
That would be plan when we do the service.
Just thought I could regap for the time being as shops are generally closed when I'm available, or I have other matters to tend to, so when I can organise the service, get it all done then and there too.

Are the gaps that small though?

I didn't think battery could affect fuel, but did watch a video about it recently.

Funny thing is, battery did die last week, 100% flat, or around there, and had to jump start it.

Yeah buddy, a dead battery makes the alternator work harder making the engine work harder... Again I don't know by how much.

skildude

· #35 · 3 mo ago

The plugs aren't like old fat tip ones. Even checking the gap can push the tip further down. Best to wait and have them changed outright.

davidtranlds

Discussion Starter · #36 · 3 mo ago

Thanks for the info Cruzing and skildude

Hopefully can get the warranty repairs sorted soon

davidtranlds

Discussion Starter · #37 · 2 mo ago

So previously taking about the battery

I noticed when I have the AC on, the fans are a little stronger when idle compared to when driving.
I can't remember if it happens without AC also, Will have to try

Nevertheless, once i come to a stop, i notice the fans have a bit more power, Andy once i start driving, they weaken a bit.

Is this normal, or a sign of a weak battery?

Cruzing12

· #38 · 2 mo ago

Another theory to present is a vacuum leak.

It can raise your typical average consumption by 1-2L per 100km. May not even set a code.

Cruzing12

· #39 · 2 mo ago

davidtranlds said:
So previously taking about the battery

I noticed when I have the AC on, the fans are a little stronger when idle compared to when driving.
I can't remember if it happens without AC also, Will have to try

Nevertheless, once i come to a stop, i notice the fans have a bit more power, Andy once i start driving, they weaken a bit.

Is this normal, or a sign of a weak battery?

The system seems to run in a dynamic mode, upping the voltage when needed, and lowering it to conserve fuel. Over time it just doesn't charge the battery completely.

davidtranlds

Discussion Starter · #40 · 2 mo ago

A vacuum leak but no code, definitely something to check again then

Gonna have to get that smoke test done

As for the fans blowing stronger when idle, and weaker when driving, you're saying not an issue then?

21 - 40 of 42 Posts