I just purchased this car, and it shows no open recalls, so i'm assuming it was replaced at some point. I found another thread where a user had replaced theirs 4 times.
Sky runs rough and/or Won't Crank unless i disconnect/reconnect the battery
21 - 40 of 76 Posts
So i went out to take the care for a ride yesterday, got in it around noon put the key in turned it to the on position, all the proper lights came on, no clicking. I turned it to the "start" position and, once again, nothing. When i parked it 2 days prior it was running normally. So I had to take a different car. I went out later in the day put the key in and tried to start it. This time it turned over immediately and started. Unfortunately (or fortunately) , now it was running the way it did prior to my last battery disconnect/reconnect. I was going to test just disconnecting/reconnecting the battery, but it was very windy here, and I didn't want to risk it with the hood up and doors open in that wind. I took a video of the way the engine was running at this time. Note the drop in RPMs (though this time they weren't dropping quite as much as they did the last time). In the middle of the video I pressed on the accelerator just to show it doesn't matter the rpms, it regularly just cuts out when it's operating like this. You can see the check engine light flashing, but no stored codes:
Here's what it acts like when it starts and isn't running normally.
JohnWR, Today at lunch time i confirmed the Sky was still running rough, dropping RPMs every few seconds and I did my battery disconnect, wait 10 minutes, reconnect test. The results were, as I expected at this point, the car started and ran normally after this. Because I already purchased a new ignition switch, i'm going to replace that this weekend, but it doesn't seem like that could be the issue. Do you have any other ideas at this point? This is a super frustrating issue. I don't seem to have any major voltage drops with the car running i'm only seeing .030 Volts when set to the 2 volt setting.
Joined
·
2,025 Posts
I'm the furthest thing from an expert, but...
If this were a Redline, it sounds like maybe a bad/dirty MAF sensor. Disconnecting the battery would reset its internal tables to the "default", so it would probably run okay for a little while until it starts compensating for bad data from the MAF.
Unfortunately, you say this is a base Sky. I don't really know if the LE5 engine has any sort of similar behavior.
Just a thought.
If this were a Redline, it sounds like maybe a bad/dirty MAF sensor. Disconnecting the battery would reset its internal tables to the "default", so it would probably run okay for a little while until it starts compensating for bad data from the MAF.
Unfortunately, you say this is a base Sky. I don't really know if the LE5 engine has any sort of similar behavior.
Just a thought.
Thanks for the response, I appreciate all attempts to help me with this.
Today, with the car running normally (I checked before I started the ignition switch replacement) I replaced the ignition switch. Immediately upon restarting the car, it was exhibiting the same bad behavior engine light flashing, rpms dropping over and over. I hooked up my PC and my OBD II monitor, still no codes. At your suggestion, I disconnected the battery to "reset" the tables again, and disconnected the MAF. Car started up and ran normally. One thing I did confirm with this test however, is the car's computer is capable setting Codes and my OBD II reader can indeed read them (i was starting to have my doubts). I got the P0102 pending code that I should have with that disconnected. I reconnected the MAF and let it run for a while. I have attached the diagnostic report from that session, though I'm not sure that's helpful since the car was running fine for the duration of this test when the monitor was hooked up to it.
The fact that it consistently works after a battery disconnect/reconnect kind of leads me away from an issue with a ground/relay/fuse. Because it seems like something does need "reset". Any ideas on what can interfere with cranking and/or running normally, but upon losing power, resets itself? I'm kind of at a total loss.
Did you try to start after disconnecting the maf sensor? That will force it to use the manifold air density circuit. If works ok then, the maf sensor is probably bad. Expect a code to be set because of the disconnection. Or if the problem started after a tune, the tune might be the problem. I have seen other problems due to bad temp sensors.
I should have done that, but no. I disconnected/reconnected the battery, then disconnected the MAF, then started it. I was only thinking of testing to see if I would get a code for the MAF if it wasn't functional and I did. I am assuming that if the MAF is causing my issue, i would have had a code, but my reasoning could be off on that?
It may depend on how far out of range it is. It may be marginal.
The original manifestation of the issue was a "no crank" condition. I.e. I put the key in the ignition, I turn it to the Start position, and nothing. However, at that time, if i just held the key in the start position for a while, it eventually turned over and started and then stalled. So that's what began my "adventure". I cleaned up the main ground contact and reconnected the battery and voila, it started and ran fine for a few days. The next time i had an issue, it would start and then run rough, i.e. rpm drop (if you watch the video i shared in post 22 you can see the rpms dropping over and over) and it was hardly drivable. Sometimes when the issue recurs I get a no crank, sometimes it turns over fine, starts, and then runs with the rpms cutting out over and over. The consistent thing is, so far, every time I disconnect the battery for a few minutes and reconnect, it starts and runs normally for a period of time.
Thanks, I read through that post. I guess you linked that due to the OnStar issues reported there? I did a little research and it seems that I cannot just disconnect the OnStar module, because there is communication that links the BCM to the ECM. Though I think it is a possible cause, so I'll need to figure out how to bridge the comm wires.
I did check the voltage during the last episode while the car was running. The voltage was dropping to around 12V during the RPM drop and back to 13.7 as the RPMs recovered. I know losing RPMs will cause a voltage drop, but I think the fact that it goes below the battery voltage could mean there is a temporary short? This is the strangest car issue I have ever dealt with, but at least I'm learning. 🤷♂️
Joined
·
1,140 Posts
Now that your battery is replaced with some piece of mind for you- the reset with no codes thrown is concerning.
Sounds like a bare wire grounding out the system. Is the fuse box secure?
The ECM loose? NO miss fires of any kind?
Not a fuel issue or maybe the MAF as a problem. Not the TB either as the car does run smoothly. Nothing in the motor making weird noises, like a timing chain slipping.
I think this comes back to an electrical issue here- ignition, starter, alternator, maybe the ECM or BCM factor default parameters after the battery reset. Even the dealer guys would be scratching their heads over this one.
Computers of today's car world- when they go bad and leave you stranded. This sort of sounds like Limp mode cutting the engine power off before real damage is done but it is not a blown hose off the intake like in the turbo model.
IF this problem is not electrical or fuel related it might be a corruption in the software. We have had owners here replace their ECM for reasons. I doubt yours is gone, but then again... tracing electrical gremlins is never a fun job.
Every wire, every relay or module, every drain on the battery, bring more frustration to the owner. Having patience is the key here- our community will figure this one out.
Throwing new parts at it is never a good thing for your bottom line in the big picture. It's not visible to the naked eye test, nor is it showing up on your meter or CEL flashing, nor is the fuel an issue. It's not a neutral safety switch problem either. Why after 15 minutes of normal operations does it do this. Why not an hour later or every other day? Cutting out of the power is not running rough imho. That would throw certain codes- make loud ass popping noise from the exhaust. Stumbles when pressing the accelerator hard. That would tell me something.
When it gets warmed up during travel this happens.
The hard starting when cold has me back to the MAF and ECM here. Clean connections to both of these sensors or recheck your starter, the connections to the alternator, and since you replaced your ignition the list of culprits is getting smaller for you. Let us know how things go as you continue this adventure.
LAC
Sounds like a bare wire grounding out the system. Is the fuse box secure?
The ECM loose? NO miss fires of any kind?
Not a fuel issue or maybe the MAF as a problem. Not the TB either as the car does run smoothly. Nothing in the motor making weird noises, like a timing chain slipping.
I think this comes back to an electrical issue here- ignition, starter, alternator, maybe the ECM or BCM factor default parameters after the battery reset. Even the dealer guys would be scratching their heads over this one.
Computers of today's car world- when they go bad and leave you stranded. This sort of sounds like Limp mode cutting the engine power off before real damage is done but it is not a blown hose off the intake like in the turbo model.
IF this problem is not electrical or fuel related it might be a corruption in the software. We have had owners here replace their ECM for reasons. I doubt yours is gone, but then again... tracing electrical gremlins is never a fun job.
Every wire, every relay or module, every drain on the battery, bring more frustration to the owner. Having patience is the key here- our community will figure this one out.
Throwing new parts at it is never a good thing for your bottom line in the big picture. It's not visible to the naked eye test, nor is it showing up on your meter or CEL flashing, nor is the fuel an issue. It's not a neutral safety switch problem either. Why after 15 minutes of normal operations does it do this. Why not an hour later or every other day? Cutting out of the power is not running rough imho. That would throw certain codes- make loud ass popping noise from the exhaust. Stumbles when pressing the accelerator hard. That would tell me something.
When it gets warmed up during travel this happens.
The hard starting when cold has me back to the MAF and ECM here. Clean connections to both of these sensors or recheck your starter, the connections to the alternator, and since you replaced your ignition the list of culprits is getting smaller for you. Let us know how things go as you continue this adventure.
LAC
Thank you so much for the details and the encouragement!
A couple points of clarification here: The temperature of the engine doesn't seem to matter. I've had it run fine be up to operating temperature, park it, then five minutes later give me a no-crank, requiring the battery to be disconnected/reconnected. I've also had it run fine up to operating temp, park it, then five minutes later - it starts right up and and runs fine again. I've had it sit overnight (last night for instance) and I come out in the morning and it starts fine (I went for a drive and filled it with gas this morning). I've also had the opposite issue, it sits overnight, I go to start it and runs like it does in the video I shared - I.e. it seems to crank fine, but then I'm getting that complete power loss on regular intervals with the rpms dropping (and as I noted in the last post, when this is happening the voltage drops to 12V every time the rpms cut out). When this happens the relays under the hood for the fuel pump and Crank/Run chatter cyclically - coinciding with the total RPM drop. So to me that indicates an issue in the ignition system, because it seems like everything needed to run the car is losing electrical power at once - but I'm an armature and out of my depth here.
I agree, I'm done "throwing parts" at it. I need to find the actual cause. The fuse box in the car (the BCM) seems solid and secure. The fuse box under the hood also seems secure and the wiring looks good to me, i.e. no evidence of excessive corrosion, or wear on any of the wiring harnesses that are visible. The ECM is installed and looks/feels ok as well. Connectors seem seated securely.
One other thing to note, the previous owner told me he recently replaced the PCM, because he had a code that indicated there was a communications problem. Though he told me it never ran poorly for him. I have all of the paperwork for everything he did to the car including the PCM - it came from "https://www.fs1inc.com/" with a lifetime warranty. And i have the receipt for the dealership he took it to for a "Crank variation relearn". After purchasing it from him in June, I and no issues with it for several months and about 1000 Miles. I even took it to a mechanic to do a once over and to get a 2nd opinion on the condition. They told me there was some noise in the drive train, a little engine noise (both of which I was aware of already), but unless I was planning on racing it, they weren't concerned.
Joined
·
1,140 Posts
(1) When this happens the relays under the hood for the fuel pump and Crank/Run chatter cyclically
(2) the dealership he took it to for a "Crank variation relearn".
(3) I even took it to a mechanic to do a once over.
Here are 3 options or solutions maybe to your problem.
Lifetime warranty- u don't say? We just might put that line to the test here?
The drive train chatter- loose universal joints> rear end fluid been changed out?
The big difference in my car after changing out the Trans fluid is... night and day.
No sluggish shifts from 1st to 2nd. No hard downshifting. MPG went up too.
As a preventive maintenance measure I changed out the diff fluid & additive.
Never a way ward sound or unusual noise ever.
Engine chatter- they never offered to say what they thought was the chattering noise inside?
Yeah it might be hard to asses this what might be the causes. Lifters, timing chain guides
valve springs, or any combination thereof. No I don't intend to track my car either but when I do push it- I expect it to perform. Twice on my recent trip to the beach- I punched it into ticket territory. 105 just to merge from an entrance ramp, and 87-ish to make an exit ramp.
U don't want any- cutting out of the power during these tests.
With the battery now eliminated from the equation- the ignition if replaced has been checked off the list- grounding points checked, connections to the major components checked, fuses and boxes checked, it's back to these modules again. The problem is intermittent. IF one of these modules or relays was bad- the problem would be consistent.. but that doesn't seem to be the case here. It could be a communication problem as there was some evidence of this before with the pervious owner.
Communication or re-learn error, corruption of this is still only part- as the car works when it wants to not ever time you need it to. I would call your mechanic back- maybe the dealer too and see if they can offer any suggestions to your problem? IF they want a closer look- a visit might be in your near future but this might relieve your stress but also funds from your wallet too. IF either one is stumped by this intermittent problem of yours- without throwing more parts at the problem you will have all winter to find what they couldn't find. IF you solve it on your own- then return the call to the dealer or mechanic and tell them. Their response back would be interesting for our community should any one else have this same problem in the future.
John is pretty good with our electrical systems- Robo & TS too. I have not seen this issue over on the Solstice forum before but I might have missed that thread.
LAC
(2) the dealership he took it to for a "Crank variation relearn".
(3) I even took it to a mechanic to do a once over.
Here are 3 options or solutions maybe to your problem.
Lifetime warranty- u don't say? We just might put that line to the test here?
The drive train chatter- loose universal joints> rear end fluid been changed out?
The big difference in my car after changing out the Trans fluid is... night and day.
No sluggish shifts from 1st to 2nd. No hard downshifting. MPG went up too.
As a preventive maintenance measure I changed out the diff fluid & additive.
Never a way ward sound or unusual noise ever.
Engine chatter- they never offered to say what they thought was the chattering noise inside?
Yeah it might be hard to asses this what might be the causes. Lifters, timing chain guides
valve springs, or any combination thereof. No I don't intend to track my car either but when I do push it- I expect it to perform. Twice on my recent trip to the beach- I punched it into ticket territory. 105 just to merge from an entrance ramp, and 87-ish to make an exit ramp.
U don't want any- cutting out of the power during these tests.
With the battery now eliminated from the equation- the ignition if replaced has been checked off the list- grounding points checked, connections to the major components checked, fuses and boxes checked, it's back to these modules again. The problem is intermittent. IF one of these modules or relays was bad- the problem would be consistent.. but that doesn't seem to be the case here. It could be a communication problem as there was some evidence of this before with the pervious owner.
Communication or re-learn error, corruption of this is still only part- as the car works when it wants to not ever time you need it to. I would call your mechanic back- maybe the dealer too and see if they can offer any suggestions to your problem? IF they want a closer look- a visit might be in your near future but this might relieve your stress but also funds from your wallet too. IF either one is stumped by this intermittent problem of yours- without throwing more parts at the problem you will have all winter to find what they couldn't find. IF you solve it on your own- then return the call to the dealer or mechanic and tell them. Their response back would be interesting for our community should any one else have this same problem in the future.
John is pretty good with our electrical systems- Robo & TS too. I have not seen this issue over on the Solstice forum before but I might have missed that thread.
LAC
LAC, First, thanks for the thoughtful post, it is greatly appreciated. To address your points on the mechanical condition of the car, the mechanic I took it to is pretty good and they specialize in "performance" cars, and this is a Base Sky purchased for fun/cruising with the top down with my wife. If he's not concerned with the noises he heard for a "daily" driver , then I'm not either, I got a pretty good deal on this vehicle and it's in really great cosmetic shape. I have no intentions of trying to get to 105mph
. This is a manual transmission, and that seems pretty solid. Additionally, the previous owner just had the diff fluid changed about a year ago. With 4 kids in college currently, I'm not in a position to spend $1000's on getting the car in perfect condition.
Ignition switch has been replaced. I'm trying to check every "major" component in the ignition system, but I haven't gotten to the "check every connection" part - I'm working on it. If I could get it to behave consistently it would be easier to check the issue. The fact that it ALWAYS gets resolved when the battery is disconnected/reconnected does lead me to a possible issue with a module - But I would expect either the inability to talk to the computer through the obd II port, or a code of some sort - which does lead me back to the ignition system
.Also, I'm not sure about that lifetime warranty either, I'm friendly with the individual I purchased the car from, and I do have the warranty paperwork, but I'm still skeptical. Additionally, how can I return it to them, when i don't know if, in fact, it's the source of my issue??? I'm committed to fixing this myself at this point. I agree that it's likely not a Relay issue, though with good internal contacts being necessary for them to function properly, I have read other stories of relays functioning intermittently. I think I'm going to replace that run/crank relay just to eliminate it (I know I said I'm "done throwing parts at it", but those are pretty cheap anyway). One ground point I haven't checked is the frame ground mentioned by several commenters in this thread. I should have checked it when i had the battery out, but didn't. I'll work on that today.
I just wanted to check in and provide a quick update. If you've read all my posts here, you know I changed the ignition switch about 2 weeks ago and immediately had a "no crank" which required me to disconnect/reconnect the battery. Therefore, I assumed the issue was not resolved. However, ever since that time, the issue has not happened again. It has been cranking and starting every time i ask it to. I've driven it on multiple small drives and have started it at least once a day since that time and let it run for a few minutes. I'm cautiously optimistic that the ignition switch was the cause of my problems, but if I have an issue again, I will update this thread. I want to thank everyone who took the time to read my post and offer me suggestions, it was and is truly appreciated.
21 - 40 of 76 Posts
Join the discussion
