Chevrolet Cruze Forums banner

1 - 10 of 10 Posts

·
Registered
Joined
·
37 Posts
Discussion Starter #1
2015 cruze. 4500 kms, k and n filter, Trifecta tuned, manual transmission.

Seam to get a weird/slight misfire at idle with AC on. No engine codes, it's just rough enough to be bothered by it. If I give it a little Rev it seams to smooth out sometimes. And when I turn off the AC it seams to go away completely. I just started using AC in the past week, got the car in December never used AC till now.

People will ask "did it happen before the tune?" I'll say I don't know because I did not use AC till this week.
 

·
Registered
Joined
·
43 Posts
Yeah I would like more information on what other people's Cruzes do with the A/C on also. I have a 2012 Cruze, Manual and I wouldnt call it a misfire but the revs are slightly unsteady. Oscillating/reving up & down at idle +/- 300 rpm by itself. Similarly if u give it a bit of gas, it will smooth out for a second then eventually the revs drop back down and then repeats the cycle. When I turn off the A/C it goes away, I cant remember if it did this before the tune or not. But I don't think it is normal for a car and I doubt the automatic trans cruze does it. I just attributed it to the motors small displacement struggling to turn the A/C lol (until u rev that 1.4 and then she stops struggling lol).
 

·
Administrator
Joined
·
25,603 Posts
A/C doesn't impact my 2012 ECO MT idle. I'm stock tune but with NGK BRK7E vPower copper spark plugs.
 

·
Moderator
Joined
·
2,168 Posts
The AC doesn't affect the idle on my completely stock engine '14 1.4L turbo manual 1LT, idle is smooth and steady and I don't feel any oscillation or vibrations unless I'm REALLY paying attention but even then it's barely enough vibration to know the engine is running. Do you have a CEL? What kind of gas are you running?
 

·
Registered
Joined
·
43 Posts
Ill have to see if it does it burning various grades of gas. I can hear it because of the revs increasing and decreasing slightly (300 rpms is a little bit more than one notch on the rev meter). When driving I don't notice it though.
 

·
Administrator
Joined
·
25,603 Posts
Ill have to see if it does it burning various grades of gas. I can hear it because of the revs increasing and decreasing slightly (300 rpms is a little bit more than one notch on the rev meter). When driving I don't notice it though.
This type of idle fluctuation is a symptom of a vacuum leak. In the next week or two you'll probably get a CEL and the code will be P0171. When this happens you'll need the PCV valve/camshaft cover replaced.
 

·
Administrator, Resident Tater Salad
Joined
·
17,002 Posts
Stock tune - my idle gets a little rougher, but does NOT ever hunt up and down in any way. 2012 LT MT
 

·
Registered
Joined
·
206 Posts
2015 cruze. 4500 kms, k and n filter, Trifecta tuned, manual transmission.

Seam to get a weird/slight misfire at idle with AC on. No engine codes, it's just rough enough to be bothered by it. If I give it a little Rev it seams to smooth out sometimes. And when I turn off the AC it seams to go away completely. I just started using AC in the past week, got the car in December never used AC till now.

People will ask "did it happen before the tune?" I'll say I don't know because I did not use AC till this week.
I've got a 2013 1.4t cruze, I installed 42lb injectors and stiffened the front transmission mount. The NVH with A/C on at idle was bad, all I did was increase idle speed to something like 911 rpm and is much improved; note, this is the idle speed with the A/C on. With A/C off I am idling in the 800's. I thought my issue was partially the injector swap, but your post says otherwise.
 

·
Registered
Joined
·
43 Posts
It could be a vacuum leak, I have replaced the PCV re-circulation hose previously. I believe they told me it was clogged and caused oil to pool in the intake. But your saying its the actual PCV valve?
 
1 - 10 of 10 Posts
Top