# Misfire help and advice please.



## Hunt4freedom (Jan 28, 2021)

Well not so much... ANYONE HELP.

Getting a P0302 misfire, I am afraid its a piston on a car I have only owned 1 week!

So it did the trick for one day with the bars leak engine restore, and its right back doing the same symptoms. CEL is not flashing, first the stabiltrak light will come on. Then the CEL will come on. This is what I know for sure.
1. Injector was changed by dealer
2.Plugs were changed
3. Coil Was changed.
4. Bars leak and engine restore added to oil
5. Last oil change done wrong weight put in it, they used 0w20
6. High Octane gas put in
7. Seafoam added to fuel
8. Water remover ISOheat added to the fuel
9. Car is only getting about 29 MPG avg
10. Start stop mode is not working
11. Dealer did a compression check and they said it was low but within specs.

So I know its getting spark and fuel and has compression, I did not find a vacuum leak. I am kinda lost and am now thinking I will need to replace the engine, does anyone have any ideas? How can I look at Cylinder 2 and determine the condition of the piston? Any thoughts would be great!


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## Johnny B (Jun 4, 2019)

Well checking the bore and cylinder is really easy with an endoscope. You can get one that will attach to a device or get a standalone unit, both option can be gotten for cheap ($20-60). I found one option for you that seems to be good enough for most jobs. 

USB Endoscope for Otg Android Phone, Computer, 5.5 mm Borescope Inspection Snake Camera Waterproof with Micro USB, Type C, 16.4FT Semi-rigid Cord with 6 LED Lights, Compatible with Windows PC, MacBook: Amazon.com: Industrial & Scientific

While your checking the cylinder recheck the spark plug, both the condition and for the proper gap. Make sure the coil spring is in place. Also, and I hate to say this, but ensure someone didn't put the di-electric grease on the spark plug terminal. If everything looks good, swap the plug with another one from different cylinder as see if the misfire follows the plug.

If you pull the spark plug and it is beat up, you probably have major issues with that cylinder.


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## Hunt4freedom (Jan 28, 2021)

Johnny B said:


> Well checking the bore and cylinder is really easy with an endoscope. You can get one that will attach to a device or get a standalone unit, both option can be gotten for cheap ($20-60). I found one option for you that seems to be good enough for most jobs.
> 
> USB Endoscope for Otg Android Phone, Computer, 5.5 mm Borescope Inspection Snake Camera Waterproof with Micro USB, Type C, 16.4FT Semi-rigid Cord with 6 LED Lights, Compatible with Windows PC, MacBook: Amazon.com: Industrial & Scientific
> 
> ...


Thank you, I am going to do my own pressure check on the cylinders tomorrow and I will report my findings, My OBD reader is showing it is definitely running rich and you can smell it also. Well if it is the engine the dealership will replace it, I will just buy the motor and they will cover the labor and chemicals. 

Normally you would not do this type of thing with a car you just bought, but I fell in love with the car, its the premier model fully loaded! 

With this Misfire if you start the car from cold, it does not act up until it comes to full operating temp. Now as I stated they did run the wrong weight oil, my experience says no BUT could this have anything to do with the mis?


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

How many threads do you need on the same topic?


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## Hunt4freedom (Jan 28, 2021)

Well I can close this one, haha didn't realize it. This is my first time in any type of forum. My apologies.


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## Johnny B (Jun 4, 2019)

I was going to say something earlier but....you need to stop putting all those "chemicals" in your car. If I were you, I'd change my oil immediately. Get 5W-30 GF-6A rated oil, and new filter.
I doubt the oil is causing the misfires, but having the wrong oil and that other crap in your oil could cause permeant damage. If your car gets through this, put 5W-30 GF-6A rated oil in your engine. And nothing else, ever. I mean never ever. On that note, stop putting stuff in your gas too. Keep using premium, but if you really think you're getting water with it change gas stations.

Here is the deal, your engine is very new. And assuming the compression check was done properly, I would next check the intake manifold for leaks. Specifically where the block and manifold meet.

It's to bad this is happening, I really like my car too. But being honest *ALL* of those parts that were changed could have been tested. I'm not a profession mechanic, but I do fix machinery for a living. And these guys are what I call "Easter egging" the problem  Don't blame the car for peoples ignorance.


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

A GF6a oil isn't specific enough, it should also be Dexos1gen2 
Running 0w20 isn't gonna cause permanent damage though in the way it seems you're implying


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## Hunt4freedom (Jan 28, 2021)

Thanks guys
@Johnny B I didn't put the fuel additives in there the car lot did, I put the Bars leak in but I don't normally add anything to my oil. It was a hail mary test. I know with the direct injection motors basically the fuel cleaners don't really do anything. Is it possible the valve has gunk on it? Maybe a proper injection cleaning? 

@Ma v e n what oils carry that rating, I was going to change the oil tomorrow anyways. I do appreciate all your input on this.


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

Many oils do. Mobil 1, Castrol Edge black bottle, Pennzoil Ultra, Walmart SuperTech High Mileage, Shell Gas Truck, etc.... Look for the Dexos1 logo on a 5w30 oil.


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## Hunt4freedom (Jan 28, 2021)

Ma v e n said:


> Many oils do. Mobil 1, Castrol Edge black bottle, Pennzoil Ultra, Walmart SuperTech High Mileage, Shell Gas Truck, etc.... Look for the Dexos1 logo on a 5w30 oil.


Thank you for that, I went and bought Carquest 5w30 and a Purolator filter, I will change in the morning. I also bought a intake cleaner for the valves, I am going to do both and I will let you guys know, if this works great if not the dealer will be putting a engine in. Last ditch attempt. 

After this all bases will have been covered, I will also let you all know the compression ratings after I check them in the morning as well.


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## Johnny B (Jun 4, 2019)

Maven
It's not just the thin oil, it was the bars leak and restore engine added to it. The car is made for 5W-30, and keeping the wrong oil in it. Well GFL with that.
I'm going to have to agree to disagree on the GF6A. How about I go find me a bottle labeled "Dexos1Gen2" at the store. 
GF-6A is the da bomb !!!!


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## Johnny B (Jun 4, 2019)

Hunt4freedom said:


> I didn't put the fuel additives in there the car lot did, I put the Bars leak in but I don't normally add anything to my oil. It was a hail mary test. I know with the direct injection motors basically the fuel cleaners don't really do anything. Is it possible the valve has gunk on it? Maybe a proper injection cleaning?


I hear you dude, just making a point without dancing around it. I've had to stop several mechanics over the years from putting stupid **** in my cars. If I had a nickel for every time one of them tried contaminating my Dex-cool !

Well, it is possible the intake valve not seating is the issue. That could cause a misfire in the cylinder for sure. The injector of course could be it, but you said it was changed!?!? Well, if true it might be bad wiring I guess or a born bad part. The thing is it could be about a dozen different things, and honestly I'm not trusting the people that are doing your work at all.

Back to the oil. Don't sweat it, just buy a major brand name full synthetic 5W-30. Yes, look for the Dexos rating. But here is the deal Dexos is a 10 year old standard, GM made it cause the oil people were slackers. Great job GM !!! Seriously. But today the new hotness is GF-6A, this summer it will be standard but now some of the oil companies haven't gone over. In the reading I have done this standard has been pushed by the whole industry, and might be the savior of DI engines. It could possible be magic


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

I don't disagree that the supplement s are unneeded. There tens of thousands of gen2 Cruzes running around just fine on 0w20. I don't run it in my 2018 that's specd for it, but running it wouldn't cause harm. 


It's easier to find a D1G2 oil than a GF6 oil. 

The car calls for Dexos, not GF6.

GF6 specs are derivative of Dexos, not the other way around.


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## Johnny B (Jun 4, 2019)

In my book rolling the dice and using thinner oil for 0.3 % more mpg isn’t a good strategy.

Page 272 (of the 21017 owner manual)

Viscosity Grade Use *SAE 5W-30* viscosity grade engine oil. Cold Temperature Operation: In an area of extreme cold, where the temperature falls below −29 °C (−20 °F), an SAE 0W-30 oil may be used. An oil of this viscosity grade will provide easier cold starting for the engine at extremely low temperatures. When selecting an oil of the appropriate viscosity grade, it is recommended to select an oil of the correct specification. See “Specification” earlier in this section.

Page 273

*Do not add anything to the oil*. The recommended oils meeting the dexos specification are all that is needed for good performance and engine protection. Engine oil system flushes are not recommended and could cause engine damage not covered by the vehicle warranty.



Ma v e n said:


> GF6 specs are derivative of Dexos, not the other way around.


That is the whole point I was trying to make.


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

It's slightly funny you think the GF6 spec is so much newer than D1G2.

And D1G3 is releasing in September, and has even stricter limits than GF6.

All of this is moot as many many bottles of Gf5 are still on shelves and much of the GF5 product is actually GF6 compliant anyway as they produced it when they could but didn't switch labeling until allowed.


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## Hunt4freedom (Jan 28, 2021)

So guys here it is

Cylinder 1 110psi
cylinder 2 90 psi
cylinder 3 110 psi
cylinder 4 112 psi

SOOO Looks like that cylinder two is the issue here.  Question would a leaking valve be at blame? I know I have asked but with this information maybe a little more input? The dealer I bought it from wants to do a another can of seafoam, my lord I told them that there is no way additives will help. I can see the valves possibly being the issue, again they are doing all these repairs on their dime, I haven't paid anything. What do you guys think? Again car is not burning oil that I have noticed and no smoke that I have noticed!


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## Hunt4freedom (Jan 28, 2021)

Above PSI rating was from the dealer, not myself as I can't find my compression gauge!


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

That engine is damaged. The 20+ psi variance for #2 is too high and the compression across the board is lower than you'll see on a healthy 1.4


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## Hunt4freedom (Jan 28, 2021)

Ma v e n said:


> That engine is damaged. The 20+ psi variance for #2 is too high and the compression across the board is lower than you'll see on a healthy 1.4


Yes sir, just got done texting with the lot I bought the car from. They are going to make it rite. I finally got done convincing them it needs a engine. I found one with 31k on it for $600.00 from a wreck where it was rear ended. I think this is the way they are going to go. I thank you all for your input and I will update or "vent" as needed!


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