# 2018 Cruze 1.4 Spark knock continues and slight misfire, no CEL or codes stored



## BluezCruze2018 (Aug 10, 2018)

For the past few months my car has been at the Dealership multiple times for LSPI, Spark knock, and an intermittent misfire (hiccup) under load or when I ease into the throttle on a hill. The dealership had my car for over a month, apparently did all kinds of tests, had a tac case on it too. “Could not duplicate concern at this time” written on repair order #4. As of today, I’m still experiencing Spark knock under load or light acceleration, along with a loud pinging under heavy acceleration. I’ve switched to Mobile 1 synthetic oil, and it doesn’t matter what grade of fuel I use either. The longer I drive the worse it gets. Also I’ve been experiencing rough idle/surging immediately after I refill the car. I don’t top off the fuel tank either and when the pump stops I close the gas cap. Once I restart the car it idles rough and starts surging. Once I put it in gear and drive off, it runs normally after that. What should I do? I’m getting to the point of wanting GM to buy this car back. I’ve got 14,800 miles and it’s been in the shop longer than I’ve owned it.


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## Ma v e n (Oct 8, 2018)

There's an updated engine calibration to reduce likelihood of piston damage from LSPI. It typically only gets installed on cars that get pistons, but it may help you if it hasn't been updated yet. Document 5080870 in GM Service Information mentions the availability of the calibration. It's worth asking about.

Additionally you should check your air filter and make sure it's properly locked in place and it's bracket isn't warped or otherwise damaged.


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## jblackburn (Apr 14, 2012)

Your symptoms of a hard start and rough idle after filling up suggest a bad EVAP purge valve - a super common failure on the 1st gen 1.4/1.8.


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## Slayinit (Jan 8, 2013)

My '18 1.4 stutters and sputters throughout the RPM range during acceleration. I think it's just how they're tuned. It's likely constantly adjusting for ideal fuel economy depending on throttle position, engine and ambient air temperature, fuel quality, load, etc.

Pretty annoying and it is likely especially pronounced with a manual transmission. But I think it's normal. My '13 Accord 6MT is the same but to a lesser degree. 

Using premium (91+ octane) lessens the severity of the surging for me. Anecdotal? Sure. YMMV.


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## Fadclt (Jan 9, 2018)

I get an lspi event at around 50 mph low rpm and increasing throttle without downshifting. Now lately I get it all the time. Running 93 octane changed air filter. It was knocking before I changed air filter. No CEL. Dealership stated they cant do anything unless a light comes on or it blows up. Nice customer service GM.


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## Ma v e n (Oct 8, 2018)

Fadclt said:


> I get an lspi event at around 50 mph low rpm and increasing throttle without downshifting. Now lately I get it all the time. Running 93 octane changed air filter. It was knocking before I changed air filter. No CEL. Dealership stated they cant do anything unless a light comes on or it blows up. Nice customer service GM.


Dealership just being lazy. If they can duplicate the concern they are likely to be able to diagnose it and repair it, getting g paid by GM to do so. They probably just have no clue what to look at since there's no code , sign of a lazy/crappy tech, especially if the concern is easily replicable. That would mean they could log the event with the scan tool and send it to GM for diagnostic assistance as well. It's laziness or ineptitude if the problem is easily duplicated. Poor customer service to boot. Trying another dealership possible?


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## Fadclt (Jan 9, 2018)

I took the tech for a ride and he heard it and said I dont know what it is. Service manager said GM wont pay to check the pistons for damage. I kinda stuck because there is so many dealers around here that if you didnt buy the car from them they wont look at it. I'm going to have to try and call GM directly. That's a whole bunch of fun!


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