HHR SS Miss Fire

[ss#4]

long story short dealer put new injectors in and still has issue with a miss fire on Cylinder #3, P0303. Now the GM Techline is saying a valve must be hanging on #3 causing a the missfire. This only occurs at start up after it has sat for 8 to 12 hours in sub 30 deg weather, but at start up the temp has been anywhere from 15 to 35 deg. So any how I find it really hard to believe that a sticky valve is causing an issue only at start up. no issues any other time. I am just a little nervious for the dealer to put a new head on this. I am concerned I will now have more issues with the items they have to remove to get to it for instance intake leaks, Turbo issues...... Has anyone else had or heard of this? thanks

[consultIII]

there is a tsb for this concern. misfire cold due to compression loss from sticking valve believed to be from fuel contamination. the injector's probably failed the afit test from the same fuel contamination and hense their replacement.

good policy to address this known cause first. sounds like the dealer is doing a good job.

If you don't agree with the diagnosis your only option (if its warranty) is to dealer shop. If its customer pay open your wallet and get a second opinion.

not saying that your doing this but its interesting how when its warranty people want the smallest stuff fixed at all costs but when its customer pay they can live with it. I'd probably be the same way if I put out $30 G for a new car.

[ss#4]

Do you have the TSB? My concern is I will be keeping the car well after the warranty is up and I don't want to deal with a poor repair latter when it is on my time. meaning long term effects of a crappy job of replacing a head affecting the bottom end of a otherwise good motor.

[MBRSUB]

What was the result of this, did you have the head replaced and did it solve the problem?
I have a 2010 HHR SS with a similar problem, misfire on cylinder 2 once which set the check engine light. It also hesitates sometimes until warm after cold start up. Seems it is more likely a incorrect mixture setting during cold start up. Doesn't happen every time from start up.
Dealer has said that it needs the head replaced under warranty and has ordered one.
I am nervous to let him do such major work without a more permanent problem.
Any suggestions?

[ss#4]

I hope your issue is not mine. my symtom was only the #3 cylinder misfire at cold start if the ambient temperature was below 30deg. Which is very common from October to May in Northern Michigan.

So after I went through the foolish dealership dance of a "computer glitch" and poor fuel. they swapped around plugs and coils. Then started changing parts, fuel injectors, head, then the valve springs (separate repair from the heads boneheads), then computer and ultimately the motor last January. I did go just short of a year until 2 weeks ago when the light went on again. this time the codes were for 2,3&4 misfire and a bus bar disconnection. took it and since it was warm 40s no current issue. of course.

Now as an automotive engineer myself and part time at home mechanic some of the stragegy was plain foolish. Insist that if they are replacing the head not to just swap in the components from the original. please use mine as a reference and any dealership can get the info. Mine has been "serviced" at Williams Chevrolet in Traverse City, MI. at the end of the day on the head they went back in and replaced the components, plain foolishness. Also note my clutch would no longer disengage consistantly after the motor was swapped. HUH. Yes your gut feeling is very good about them doing a good job. Plain and simple a flat rate mechanic will only do the best job he can in the fastest time possible. and anyone saying differently is not willing to admit failure or is truly extraordinary.

Hind sight. Contact the GM Customer now before the repair so when or if there is still an issue it is documented. if you have a problem contact the Better Business Bureau then GM Customer Service then the dealership. they have 3 changes to fix the issue at least in Michigan. Otherwise it falls into a Lemon Law, but you have to notify them in writing for a last and final chance to fix it. I am a very loyal GM customer and failed to believe I could get a bad car from them but it does happen. obviously I am on a thin cord with mine, but will only replace it with another GM product, foriegn cars belong somewhere other than my drive way. hope this helps

[GMCustomerService]

Originally Posted by MBRSUB

What was the result of this, did you have the head replaced and did it solve the problem?
I have a 2010 HHR SS with a similar problem, misfire on cylinder 2 once which set the check engine light. It also hesitates sometimes until warm after cold start up. Seems it is more likely a incorrect mixture setting during cold start up. Doesn't happen every time from start up.
Dealer has said that it needs the head replaced under warranty and has ordered one.
I am nervous to let him do such major work without a more permanent problem.
Any suggestions?

If I can be of assistance in working with you and your dealership towards resolving this concern, please send me a private message with more information (including your name and VIN, as well as your dealership's name). I'd be happy to get a case set up.

Sarah
GM Customer Service

[MBRSUB]

Thank you very much for the update with your HHR SS cold starting problem, sorry to hear that you are still experiencing the problem after all the work done.
What year is your SS?
The reason I ask is that I have 2!! One 2008 and one 2010. I also like GM, have a 95 GMC 6.5LTD suburban from new, great vehicle v little problems nearly 200K miles.
Any way---- the 2008 starts and runs perfectly also seems to have more get up and go. The 2010 is more fuel efficient (a little) and I just wondered if GM changed the ECU firmware to lean it out to get more miles.
So my 2010 has misfired once, but in the 30 to 60 degree cold start, hesitates until warmed up, feels like not rich enough fuel mixture. When very cold like today 20 deg, starts and runs just fine.
I suspect my problem may be a firmware issue or a lazy temperature sensor.
After your experience I am convinced its not the binding valves and certainly will not let them any where near to replacing the head.
Thank you for your comments

[MBRSUB]

So I exchanged many emails with GM Customer service with no real solution other than work through the dealer.
So being a weekend mechanic I bought some new spark plugs and examined the plugs and ignition coils myself focusing on #2. There was no evidence that the dealer had taken it apart to check anything.
I found nothing wrong, all plug gaps measure in tolerance .030 to .035. So I replaced #2 plug with a new one, and set all plugs to .032. Followed shop manual instructions for refitting ie dielectric grease and correct torque.
Fixed the problem, no missfire, and car goes much better. Been a week now!
Conclusion is the #2 spark plug was marginally bad.
My concern is with the dealer jumping to must replace the cylinder head.
I have informed GM customer service and going to dealer tomorrow!

[RocketRaccoon]

Hello, hope everybody is doing well. I'm going to reanimate this topic because my 2007 HHR just got Cyl#1 misfire code and Check Engine light... Also, it's lacking (some) power. What I did: new oil, air filter, 4 NGK spark plugs (I like NGK). After driving from friend's garage (who flipped this car and I bought this car), I got 28.7 mpg at 60 mpg on 5-th/manual tran. And... Check Engine light went off! No more Check Engine light! AutoZone lady advised me to add Lukas and I did. Also, I added Heat to remove moisture.



I'm new to Chevy. Here's my driving experience: 1st-strong, 2nd-wea, 3rd-okay, 4-th kinda okay, 5-th is 5th. I do like driving fast though, my RPMs are sky-rocking 4500. If I shift between 2000-3000, it don't have any power. And if I drive 'normally' or like a normal person, it gets 27,5-27,7 mpg in the city of Anchorage, AK.
Questions:

1) is this normal for this car or

2) I should I do anything to this car or just leave it as is? Is there anything that can be done? I mean, if this car just a piece of crap at 108,000 miles?
What "advisors" advised to do:
- (possibly) coils $150
- possibly injectors $150
- possibly wires $160
- cat convertor $120
- camshaft position sensor $70
- O2 sensor $45 (AutoZone//Amazon prices)

I'm hesitating to schedule an appointment with a local dealer (only 1 in town) due to my past (and bad) experience with MB dealer (car was stolen this is the reason why I got a 'new car').
Any help will be appreciated.

[RocketRaccoon]

Originally Posted by RocketRaccoon

Hello, hope everybody is doing well. I'm going to reanimate this topic because my 2007 HHR just got Cyl#1 misfire code and Check Engine light... Also, it's lacking (some) power. What I did: new oil, air filter, 4 NGK spark plugs (I like NGK). After driving from friend's garage (who flipped this car and I bought this car), I got 28.7 mpg at 60 mpg on 5-th/manual tran. And... Check Engine light went off! No more Check Engine light! AutoZone lady advised me to add Lukas and I did. Also, I added Heat to remove moisture.



I'm new to Chevy. Here's my driving experience: 1st-strong, 2nd-wea, 3rd-okay, 4-th kinda okay, 5-th is 5th. I do like driving fast though, my RPMs are sky-rocking 4500. If I shift between 2000-3000, it don't have any power. And if I drive 'normally' or like a normal person, it gets 27,5-27,7 mpg in the city of Anchorage, AK.
Questions:

1) is this normal for this car or

2) I should I do anything to this car or just leave it as is? Is there anything that can be done? I mean, if this car just a piece of crap at 108,000 miles?
What "advisors" advised to do:
- (possibly) coils $150
- possibly injectors $150
- possibly wires $160
- cat convertor $120
- camshaft position sensor $70
- O2 sensor $45 (AutoZone//Amazon prices)

I'm hesitating to schedule an appointment with a local dealer (only 1 in town) due to my past (and bad) experience with MB dealer (car was stolen this is the reason why I got a 'new car').
Any help will be appreciated.

UPDATEs:

1) I visited Chevy dealer and explained to them that this is my first Chevy and all above + I won't accept any "recommendation" to change a head. What Chevy dealer said: "HHR was a cheap car ... don't expect much from it... they (4 cyl) cars are all like this...maybe Cruze it bit better". This was free advice from a dealer. If I want an official thing, I'd pay $140. (Probably my last American car at this point).
2) Checked codes for free @ AutoZone! This time the code is P0300 - "too many random cylinder misfires ...". Just in case, I did reset the codes with AutoZone's $20 diagnostic tool.
3) Driving experience: gas 28.1 mpg in mixed cycle (HWY speed was 75mpg and up; I was hopping that Check Engine light will go On but it didn't).

MEANWHILE: I cancelled my order with fuel injectors.Will enjoy the weather, sunshine, and COVID. Not going to do anything with a car! It looks to me that Chevy labor and parts are the same as any Japanese car. They (Chevy) break a lot. Imagine buying parts for a V8 engine! Mucho dinero... Why buy Chevy? Exactly... never again!

P.S. Dealer checked my remote control for HHR. Buttons are hard to press and I though I should buy a new remote (online $13 for pair). Dealer said, new remote will be the same... it's 'normal'. God, I miss my Mercedes! Programming fee...will be around $50! (turn the key and hold a button) + one remote $100.

This was like a self - help session. lol?