# 2012 Cruze Diesel reduced power and sluggish acceleration



## I_Am_Weasel (11 mo ago)

Oh boy where do i even start, so i apologize right from the get-go, i'm going to be opening quite a few topics related to various issues i'm experiencing, so you're going to be seeing a lot of me, like it or not... I'm the sad sad owner of a 2012 Cruze Gen 1 Diesel EU version with 163 Hp manual 6 speed and for the past few years i've had nothing but problems with it, i'm trying to patch it up so it's relatively presentable to sell. First problem on the list and the worst so far is related to reduced power and bad acceleration: the whole car feels like it's really underpowered below 2000 rpm, you have to rev it like a gas-powered car to get it going and sometimes when it's really hot outside, the acceleration behaves almost like it has a dead zone up until 2000ish rpm when it suddenly jumps into life and jerks forward due to what i believe is the turbocharger kicking in. Honestly, i don't consider it safe to drive around town anymore, as i've had a couple of situations where i tried to run a yellow light, gave it some throttle and literally nothing happened, so i ended up braking aggressively not to run a red light, almost getting rear-ended in the process. Ironically it seems to run ok...ish at speeds above 55 mph, i have no problem overtaking, although you can definately feel that it's lacking the 163 Hp it's supposed to have. There is no engine check light on, turbocharger was tested last year and it's delivering excellent boost, it's not burning oil or the oil level rising over time, only the now famous ABS and StabiliTrak lights are on, which i didn't even get close to fixing. To make matters worse there is no Chevrolet dealership in the EU anymore, so i'm at the mercy of second-hand mechanics, which are really bad here. I'm trying to get a general idea of what could be wrong before i start throwing money at it. Don't hesitate to ask any questions!


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## Detrious (Jul 5, 2017)

I don't know how different that engine is to the one we have in the states but it sounds like maybe you have a plugged up MAP sensor. It reads boost pressure in the intake and uses that data to tell the engine how much fuel it needs. If it can't get a good reading it won't deliver enough fuel. It might be that once the engine gets to 2000rpm it's making enough boost to actually read despite a blockage. I would start there, on our US engines it is located on the intake manifold, on top to the left of center. There's some good threads about it on here. 

For the stablitrack and abs lights replace your negative cable from the battery to the chassis, that usually takes care if it unless you actually do have a problem with them.


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## Detrious (Jul 5, 2017)

https://www.euspares.co.uk/parts-catalog/sensor-intake-manifold-pressure-15024/chevrolet/cruze/cruze-j300/24449-2-0-vcdi



I think that's the right vehicle and engine. We have the Fiat designed diesel over here, at least for the 2.0L, and I'm pretty sure you all have the VM Motori version. I do not know how different they really are though.


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## I_Am_Weasel (11 mo ago)

Detrious said:


> I don't know how different that engine is to the one we have in the states but it sounds like maybe you have a plugged up MAP sensor. It reads boost pressure in the intake and uses that data to tell the engine how much fuel it needs. If it can't get a good reading it won't deliver enough fuel. It might be that once the engine gets to 2000rpm it's making enough boost to actually read despite a blockage. I would start there, on our US engines it is located on the intake manifold, on top to the left of center. There's some good threads about it on here.
> 
> For the stablitrack and abs lights replace your negative cable from the battery to the chassis, that usually takes care if it unless you actually do have a problem with them.


Thanks for your reply, the engine code is Z20D1 which i know is used in one variant or another in all 2.0 applications so layout is the same, only the 1.7 is a different engine. I'll have a look tonight after this **** heat wave calms down, i have a leftover spray of sensor cleaner here somewhere.


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## I_Am_Weasel (11 mo ago)

Detrious said:


> https://www.euspares.co.uk/parts-catalog/sensor-intake-manifold-pressure-15024/chevrolet/cruze/cruze-j300/24449-2-0-vcdi
> 
> 
> 
> I think that's the right vehicle and engine. We have the Fiat designed diesel over here, at least for the 2.0L, and I'm pretty sure you all have the VM Motori version. I do not know how different they really are though.


Yes that is the right part, i remember taking a pic of it for a price investigation and it was a Bosch sensor, for some reason at least here, you cannot find that exact one, it was either replaced with a different code part that's identical or discontinued.


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## Aussie (Sep 16, 2012)

I think I have the same engine in my Australian Holden Cruze. 2012 Holden Cruze diesel, has the fuel filter been changed? I have only 92K km on mine and have owned it from new and have never had any issues apart from the occasional DPF light which cleared with a short 2,000rpm drive.


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## I_Am_Weasel (11 mo ago)

Aussie said:


> I think I have the same engine in my Australian Holden Cruze. 2012 Holden Cruze diesel, has the fuel filter been changed? I have only 92K km on mine and have owned it from new and have never had any issues apart from the occasional DPF light which cleared with a short 2,000rpm drive.


Yes that is the exact same engine, same layout and everything except yours is right-side drive. I changed the fuel filter about 5000 km ago on a suspicion that it was causing issues but no change whatsoever. Question: is your engine vibrating excessively at idle, i know these are diesel engines and it kinda comes with the territory but i can't shake the feeling this it's vibrating more than it should, i feel it through the whole car, some days is worse than others. Another thing, have you noticed any weird "resonance" at 1500 rpm, another weird quirk i discovered 2 years after i bought it, is that while revving it stationary, the whole car shakes really bad but only in a very narrow 50 - 100 rpm range around 1500 rpm, besides that it's smooth across the rev range... i think it's possessed or something.


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## I_Am_Weasel (11 mo ago)

I_Am_Weasel said:


> Thanks for your reply, the engine code is Z20D1 which i know is used in one variant or another in all 2.0 applications so layout is the same, only the 1.7 is a different engine. I'll have a look tonight after this **** heat wave calms down, i have a leftover spray of sensor cleaner here somewhere.


The MAP sensor was indeed dirty but nothing too shocking, i've seen some horror story pics with them in way worse conditions. Regardless, i sprayed the hell out of it with some sensor cleaner, left it to dry for about 30 mins and it seems to make no difference at all, i can fool myself that it's running a little better but i guess that would be placebo. I'll try to source a new MAP sensor online in case this one is fried or uncalibrated, they are relatively cheap, something like 20 bucks/euros but i have a feeling it's not going to change much...


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## Aussie (Sep 16, 2012)

I_Am_Weasel said:


> Yes that is the exact same engine, same layout and everything except yours is right-side drive. I changed the fuel filter about 5000 km ago on a suspicion that it was causing issues but no change whatsoever. Question: is your engine vibrating excessively at idle, i know these are diesel engines and it kinda comes with the territory but i can't shake the feeling this it's vibrating more than it should, i feel it through the whole car, some days is worse than others. Another thing, have you noticed any weird "resonance" at 1500 rpm, another weird quirk i discovered 2 years after i bought it, is that while revving it stationary, the whole car shakes really bad but only in a very narrow 50 - 100 rpm range around 1500 rpm, besides that it's smooth across the rev range... i think it's possessed or something.


I have never had any issues with the engine. A few months ago I had an issue, after driving through deep water in a heavy rainstorm, the engine kept going to reduced power then coming good again. This repeated every few seconds. I managed to get home OK and rang roadside assistance who came out and put a scan tool on it. Scan came up accelerator and brake not compatible. I took a picture and then he cleared the code for me and car has been perfect ever since. Maybe this code clearing can help with your problem?


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## Aussie (Sep 16, 2012)

I_Am_Weasel said:


> Yes that is the exact same engine, same layout and everything except yours is right-side drive. I changed the fuel filter about 5000 km ago on a suspicion that it was causing issues but no change whatsoever. Question: is your engine vibrating excessively at idle, i know these are diesel engines and it kinda comes with the territory but i can't shake the feeling this it's vibrating more than it should, i feel it through the whole car, some days is worse than others. Another thing, have you noticed any weird "resonance" at 1500 rpm, another weird quirk i discovered 2 years after i bought it, is that while revving it stationary, the whole car shakes really bad but only in a very narrow 50 - 100 rpm range around 1500 rpm, besides that it's smooth across the rev range... i think it's possessed or something.


I forgot to mention, I have the 6T45 automatic transmission and the only time the engine is a little rough is when it is doing a DPF burn. The engine also idles 100rpm higher during the burn and sounds just a little different.


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## Kjartan.a.j. (Dec 24, 2019)

Hi Weasel

Cannot claim to have any golden pointers to throw at you, but have you considered the DPF being the culprit?
My thought is it may be too full to clear itself though passive burn cycles.
The sluggishness and shaking/resonance you mention are _very_ similar to symptoms I had with a 1.7 DCI Corsa when the DPF was completely plugged - car was almost constantly trying to regen but filter was too far gone.
You don't mention the mileage of the car, but I know it regens in the crappy old fashion of injection excess diesel into the cylinders post injection to raise exhaust temps, thereby burning off soot in the DPF (my old Corsa worked the same way).
The only way you can know for sure if it's plugged is getting a scantool capable of reason the pressure drop across the DPF (though I cannot tell you how much is acceptable, mine is hollowed out long ago).
Alternatively you can try 1-2 cans of: MOTIP Turbo & EGR Cleaner in 500ml Aerosol - great stuff that's non-flammable and harmless to the engine, I use it about once a year.
If you take the front part of the DPF heat shield off and unscrew the lambda sensor you can spray directly onto the catalytic converter, which is the upper part of the DPF filter housing (both are fitted in the big steel cannister in front of the engine).
It'll clean the converter first and seep into the DPF afterwards, with any luck that'll clear the soot if it's not baked in too hard.
Cheap remedy if it works, but even if not it can _only_ help the engine.

_Edit_'
I have the exact same car as you and Aussie for the past 4 years, 2012 J305 Cruze Z20D1 manual.
I had it chipped, EGR disabled and DPF hollowed at 25K miles though,so never had problems with either.
Engine is a gem imho, apart from the complete lack of turbo pressure below 1800 that you also mention.
I believe this problem is only amplified by restricted filter - later turbo spooling and general sluggishness.


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## I_Am_Weasel (11 mo ago)

Kjartan.a.j. said:


> Hi Weasel
> 
> Cannot claim to have any golden pointers to throw at you, but have you considered the DPF being the culprit?
> My thought is it may be too full to clear itself though passive burn cycles.
> ...


On the contrary, this might actually be the golden pointer, i never mentioned that it does very frequent regens, so much so that it does them every 100 miles or so, even if i drive it mostly out of town. The car only has 60k miles so the DPF shouldn't be that clogged up but then again, with the atrocious quality of diesel fuel here, i can't say that i'm surprised. I've been caught up with work for the past few weeks, so i didn't have time to look for a mechanic that won't try to instantly rip you off but i'll most definitely be looking into this.

Many thanks


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## Kjartan.a.j. (Dec 24, 2019)

Well assuming the DPF is the problem and you're not scared of a little hands-on work, you could take the cannister off and remove the DPF part of the filter.
It does take some work unless you open and reweld the cannister, but it can be done from the exhaust side with a spade drill and patience - you'll wanna leave the catalytic converter part intact otherwise car will smell like a 1975 Ferguson tractor.
By keeping the original cannister you'll never have any MOT issues and assuming the engine is doing good exhaust gas won't smell any worse.

You'll of course have to rewrite the ECU to ignore DPF pressure differences, but several companies offer this service.
I ordered mine from a company in Britain, SA-Tuning.
600£ bought their handheld tuner with stage 1 map (200hp/440nm), EGR delete (just unplug the EGR) & DPF delete (software only, still gotta remove the filter part).
It's not "cheap" but considering what you get (and the future troubles you avoid) it was a no-brainer for me.

Since ours is a completely different engine from the 2.0 diesel in the US and it doesn't suffer from the oil pick-up seal problem I'd say this investment is worth it.
Only done 100k miles in mine but I reckon it'll serve for years to come, the Z20D1 is really built like a tank.


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