Weird car troubles
January 15, 2018 7:00 AM Subscribe
I have a 2004 Mazda3 hatchback with just under 50,000 miles on it. Lately, it has been giving me a real headache with starting issues and a check engine light, and so far my mechanic has not been able to fix the problems permanently. I'm gonna list all the problems I've had in the last year or so even though they might not all be related, in the off chance that it gives anyone some ideas.
1. Air conditioning, probably unrelated to my chief concerns at this time. Here is my previous question. Since then the A/C has died completely but as it was the end of summer and I am not made of money, I haven't taken it back in for this issue specifically (although, see below).
2. Last winter, the car wouldn't start on a very cold day (single digit temps) after being driven a short distance and sitting for about an hour. A jump from a friend couldn't get it started either. Luckily, we were close to an auto parts store and were able to buy a new battery and install it. Strangely, after installing the new battery the car still wouldn't start until our friend who was helping us whacked at the alternator with his wrench. No kidding, it started right up. We thought "huh, weird, friend must have some Fonzie powers" and attributed it to the cold, an old battery, and our driving habits (infrequent, short trips).
3. About 2 months ago, the check engine light came on. We avoided longer trips and highway speeds (which are pretty much outside of our normal driving anyway) until we had a chance bring it in to the mechanic.
3. A few weeks after the check engine light came on but before we had a chance to get it checked out, my boyfriend took the car on a short trip (a couple miles) and it wouldn't start when it was time to go home. It was cold outside, but not that cold - about 40 degrees or so. After several attempts to start he jiggled the shifter and it started right up, and worked fine thereafter. Check engine light was still on, so we finally brought it in to the mechanic.
4. Mechanic said the check engine light indicated the thermostat needed to be replaced, so he replaced that. Said the battery was a little low and recharged it, but that it checked out fine. While the car was there I told them about the A/C being totally out, so they did another refrigerant replacement+dye thing. Mechanic says regarding the A/C we must be missing a leak somewhere, but it's winter and I'm not exactly running the A/C a bunch right now so it's hard to test, and it's hard for me to take the time to keep bringing the car in to look for leaks.
5. The check engine light came back on about a week or two ago.
6. Saturday afternoon, the car wouldn't start. It was pretty cold - in the teens - but my bf had just driven it for a short errand earlier that morning. I have a battery charger so we let that charge for 6 hours at 8 amps, but it still wouldn't start even after the display on the charger said the battery was fully charged... until my bf jiggled the shifter and then it started right up. He turned it off and started it right up again. We let it run for about 15 minutes but by then our plans had been cancelled so we haven't driven it since then.
Ok so the shifter thing is super weird and honestly I'm inclined to think it's unrelated. Or that maybe something wasn't aligned properly, like some sort of safety feature where it won't start if it's not fully in Park. But the car was definitely *trying* to start - with the hood up, I could hear clicking and humming like it was trying to turn over and just couldn't.
Really it had all the symptoms of a low battery (but not totally dead, as the radio/lights/etc worked), except that charging said battery did not help until the shifter jiggle. Also reminded me of the time last year that a jump followed by a brand new battery could not start our car until our friend whacked the alternator. But I also realize how illogical that sounds so I'm fine dismissing those things as oddities.
A friend is coming over today with a code reader to see if it's still throwing the same thermostat code as before or if it's something different. Would love some ideas to toss out to the mechanic for when I bring this thing back in.
1. Air conditioning, probably unrelated to my chief concerns at this time. Here is my previous question. Since then the A/C has died completely but as it was the end of summer and I am not made of money, I haven't taken it back in for this issue specifically (although, see below).
2. Last winter, the car wouldn't start on a very cold day (single digit temps) after being driven a short distance and sitting for about an hour. A jump from a friend couldn't get it started either. Luckily, we were close to an auto parts store and were able to buy a new battery and install it. Strangely, after installing the new battery the car still wouldn't start until our friend who was helping us whacked at the alternator with his wrench. No kidding, it started right up. We thought "huh, weird, friend must have some Fonzie powers" and attributed it to the cold, an old battery, and our driving habits (infrequent, short trips).
3. About 2 months ago, the check engine light came on. We avoided longer trips and highway speeds (which are pretty much outside of our normal driving anyway) until we had a chance bring it in to the mechanic.
3. A few weeks after the check engine light came on but before we had a chance to get it checked out, my boyfriend took the car on a short trip (a couple miles) and it wouldn't start when it was time to go home. It was cold outside, but not that cold - about 40 degrees or so. After several attempts to start he jiggled the shifter and it started right up, and worked fine thereafter. Check engine light was still on, so we finally brought it in to the mechanic.
4. Mechanic said the check engine light indicated the thermostat needed to be replaced, so he replaced that. Said the battery was a little low and recharged it, but that it checked out fine. While the car was there I told them about the A/C being totally out, so they did another refrigerant replacement+dye thing. Mechanic says regarding the A/C we must be missing a leak somewhere, but it's winter and I'm not exactly running the A/C a bunch right now so it's hard to test, and it's hard for me to take the time to keep bringing the car in to look for leaks.
5. The check engine light came back on about a week or two ago.
6. Saturday afternoon, the car wouldn't start. It was pretty cold - in the teens - but my bf had just driven it for a short errand earlier that morning. I have a battery charger so we let that charge for 6 hours at 8 amps, but it still wouldn't start even after the display on the charger said the battery was fully charged... until my bf jiggled the shifter and then it started right up. He turned it off and started it right up again. We let it run for about 15 minutes but by then our plans had been cancelled so we haven't driven it since then.
Ok so the shifter thing is super weird and honestly I'm inclined to think it's unrelated. Or that maybe something wasn't aligned properly, like some sort of safety feature where it won't start if it's not fully in Park. But the car was definitely *trying* to start - with the hood up, I could hear clicking and humming like it was trying to turn over and just couldn't.
Really it had all the symptoms of a low battery (but not totally dead, as the radio/lights/etc worked), except that charging said battery did not help until the shifter jiggle. Also reminded me of the time last year that a jump followed by a brand new battery could not start our car until our friend whacked the alternator. But I also realize how illogical that sounds so I'm fine dismissing those things as oddities.
A friend is coming over today with a code reader to see if it's still throwing the same thermostat code as before or if it's something different. Would love some ideas to toss out to the mechanic for when I bring this thing back in.
When you say it had all the symptoms of a dead battery, you don't say what happened when you actually turned the key. Did it make noise like it was trying to start?
posted by dbx at 7:55 AM on January 15, 2018
posted by dbx at 7:55 AM on January 15, 2018
But the car was definitely *trying* to start - with the hood up, I could hear clicking and humming like it was trying to turn over and just couldn't.
posted by under_petticoat_rule at 8:01 AM on January 15, 2018
posted by under_petticoat_rule at 8:01 AM on January 15, 2018
I had a car once that required the same alternator whacking - IIRC it was getting stuck and not turning, meaning the battery wasn't charging when the engine was running. Definitely check the alternator, seems likely you need a new one. A stuck alternator won't charge the battery while the engine's running, and possibly has knock-on effects (I once had a car where the alternator belt also ran the water pump, so the engine overheated when the alternator seized).
posted by EndsOfInvention at 8:01 AM on January 15, 2018
posted by EndsOfInvention at 8:01 AM on January 15, 2018
Sounds like you need a new mechanic. :-) Yep, get the code read, then if there's an auto supply place(like Advance Auto, Pep Boys) they can tell you more about whats going on. Also they can check out your battery and alternator. IMHO I think its the alternator and the belts, that would also as EndsOfInvention said involve the water pump too. If not you could possibly have a short/bad ground in your electrical system.
posted by PJMoore at 8:14 AM on January 15, 2018
posted by PJMoore at 8:14 AM on January 15, 2018
There are several symptoms here - the alternator definitely sounds like a problem based on the description, and it would explain why you're having problems with the charging system.
The shifter-thing sounds like a faulty sensor somewhere - however, it could be indirectly related to your charging system problem - depends on how the car is wired.
Example: there is a well-known (and hated) issue on 2007 Chrysler products (Jeeps, especially) where, when the battery gets low or isn't charging, you start getting all kinds of weird behavior, like the power locks triggering automatically, and windshield wipers spontaneously operating - up to and including the engine just dying because of a sensor issue that isn't adequately powered.
If the alternator isn't functioning right, it's not charging the battery properly, which could lead to strange electrical gremlins and sensor issues.
It's a relatively straightforward thing to fix and shouldn't be terribly expensive. You could probably get someone to do it for beer money if you supplied the parts, which you can get at any decent chain auto parts store.
Your mechanic's success in troubleshooting is directly proportional to his or her ability to duplicate the problem. If something only happens intermittently, it's much harder to fix.
50,000 miles on a Mazda 3 isn't much - they're really good cars - seems like if you can get these little issues sorted out you should be good to go for quite a while.
posted by Thistledown at 8:20 AM on January 15, 2018 [3 favorites]
The shifter-thing sounds like a faulty sensor somewhere - however, it could be indirectly related to your charging system problem - depends on how the car is wired.
Example: there is a well-known (and hated) issue on 2007 Chrysler products (Jeeps, especially) where, when the battery gets low or isn't charging, you start getting all kinds of weird behavior, like the power locks triggering automatically, and windshield wipers spontaneously operating - up to and including the engine just dying because of a sensor issue that isn't adequately powered.
If the alternator isn't functioning right, it's not charging the battery properly, which could lead to strange electrical gremlins and sensor issues.
It's a relatively straightforward thing to fix and shouldn't be terribly expensive. You could probably get someone to do it for beer money if you supplied the parts, which you can get at any decent chain auto parts store.
Your mechanic's success in troubleshooting is directly proportional to his or her ability to duplicate the problem. If something only happens intermittently, it's much harder to fix.
50,000 miles on a Mazda 3 isn't much - they're really good cars - seems like if you can get these little issues sorted out you should be good to go for quite a while.
posted by Thistledown at 8:20 AM on January 15, 2018 [3 favorites]
You haven't really spelled out your symptoms clearly enough. Normally, when starting a car, it cranks (the nur-nur-nur sound of the starter motor spinning the engine as you hold the key in the start position) and then it fires (the engine catches and runs with the key in the on position.) You keep addressing things like the car isn't cranking (i.e. the battery and the alternator) but then you say that the car "clicks and hums like it's trying to turn over." I'm not sure if that means that the car was cranking and wouldn't fire or if you just mean the the car makes some noise when you try to start it, like the click of the starter solenoid.
If it's not cranking, the park/neutral safety switch may be flaky. You can also try starting it in Neutral to see if that makes any difference, it should be able to start in either position.
If it's cranking and won't fire, I'd suspect the coolant temperature sensor or connections to it. This might also explain the 'thermostat stuck open low coolant temp" code. Basically, the coolant temp sensor works like a choke on an old fashioned car. If the car thinks it is cold (due to the bad sensor) it will make the mixture rich and flood the car. This can cause the won't start after a short trip complaint (assuming that the car cranks normally, but will not fire.)
posted by Larry David Syndrome at 8:28 AM on January 15, 2018
If it's not cranking, the park/neutral safety switch may be flaky. You can also try starting it in Neutral to see if that makes any difference, it should be able to start in either position.
If it's cranking and won't fire, I'd suspect the coolant temperature sensor or connections to it. This might also explain the 'thermostat stuck open low coolant temp" code. Basically, the coolant temp sensor works like a choke on an old fashioned car. If the car thinks it is cold (due to the bad sensor) it will make the mixture rich and flood the car. This can cause the won't start after a short trip complaint (assuming that the car cranks normally, but will not fire.)
posted by Larry David Syndrome at 8:28 AM on January 15, 2018
Response by poster: To clarify, I hear clicking but no cranking. (It started normally this morning, so I can't replicate the issue or record the noises.)
posted by misskaz at 8:48 AM on January 15, 2018
posted by misskaz at 8:48 AM on January 15, 2018
Strangely, after installing the new battery the car still wouldn't start until our friend who was helping us whacked at the alternator with his wrench.
My 2007 Mazda3 Hatchback died in the middle of a parking lot one day and it was because it needed a new alternator. I was lucky that I had just turned into the parking lot.
Another time, same vehicle, engine would not turn despite several attempts. Called AAA. The tow truck driver stepped on the gas and turned the key and the engine started right up. From then on if the car wouldn't start I did the same thing. I don't remember why this worked, just that it did.
Check engine light: one time it simply would not go away. Turned out it had something to do with the gas cap. I had it replaced and the light went away. I was told the Check Engine light on these cars is very easily triggered.
All of this and a couple other things started happening right after the warranty expired, about three years and 40,000 miles in.
posted by Crystal Fox at 8:51 AM on January 15, 2018
My 2007 Mazda3 Hatchback died in the middle of a parking lot one day and it was because it needed a new alternator. I was lucky that I had just turned into the parking lot.
Another time, same vehicle, engine would not turn despite several attempts. Called AAA. The tow truck driver stepped on the gas and turned the key and the engine started right up. From then on if the car wouldn't start I did the same thing. I don't remember why this worked, just that it did.
Check engine light: one time it simply would not go away. Turned out it had something to do with the gas cap. I had it replaced and the light went away. I was told the Check Engine light on these cars is very easily triggered.
All of this and a couple other things started happening right after the warranty expired, about three years and 40,000 miles in.
posted by Crystal Fox at 8:51 AM on January 15, 2018
Ok, so given the additional info (does not crank) the question is "is it not cranking because the battery is dead or something else?" If it sometimes starts after monkeying around with it for a bit, logically you know that the battery didn't just spontaneously recharge itself so it's unlikely that it's the battery or alternator this time. That points more towards the park/ neutral safety interlock switch, an intermittent starter motor (the contacts on the starter solenoid can sometimes get flaky) or bad connections to the battery (are the cables running to the battery terminals clean and secure?) Intermittent problems like this can be hard to solve, you may have to do some process of elimination replacement of parts. Try starting in Neutral the next time the car acts up and see what happens.
posted by Larry David Syndrome at 9:03 AM on January 15, 2018
posted by Larry David Syndrome at 9:03 AM on January 15, 2018
Adding to the alternator choir. Get that replaced first, then, if still some issues, check the starter.
You may need a new battery with the new alternator if it can't be charged via trickle charger.
posted by jillithd at 10:04 AM on January 15, 2018
You may need a new battery with the new alternator if it can't be charged via trickle charger.
posted by jillithd at 10:04 AM on January 15, 2018
Response by poster: In case it matters, friend's code reader showed P0128 which is the same code it was throwing before the mechanic changed the thermostat. Also the car started up fine to run to and from the grocery store, and just now when we had the code reader plugged in.
Also googled around and found this service bulletin for my car make/model/year and this CEL code. Doesn't solve the starting issue but I'm less worried about the CEL.
posted by misskaz at 11:08 AM on January 15, 2018
Also googled around and found this service bulletin for my car make/model/year and this CEL code. Doesn't solve the starting issue but I'm less worried about the CEL.
posted by misskaz at 11:08 AM on January 15, 2018
Have the computer checked. Google for all the symptoms of a failing computer in your make and model of vehicle and see if it matches your list.
posted by jbenben at 11:55 AM on January 15, 2018
posted by jbenben at 11:55 AM on January 15, 2018
+1 check engine light might be related to gas cap. I have had this issue intermittently on 2006 Mazda 5. Can you remember when you got gas and if it was near the times when the check engine light would turn on?
posted by crazycanuck at 12:03 PM on January 15, 2018
posted by crazycanuck at 12:03 PM on January 15, 2018
I replaced the battery on my last car only to still have it STILL not start occasionally, and then found out that there was corroded wiring to the battery. It was worse in wet weather than dry. Might be worth looking into.
posted by jabes at 12:04 PM on January 15, 2018
posted by jabes at 12:04 PM on January 15, 2018
As it happens I just replaced the alternator on my 2001 Forester.
It didn't fail all at once, I estimate it was failing intermittently for about two months. The under voltage caused a bunch of seemingly unrelated symptoms including alarming dashboard lights and a haunted radio. And it was highly weather dependent, because the battery charges and discharges differently at different temperatures.
I tested it by measuring the voltage on the battery terminals with the car off and then again with the car running. A typical battery will have 12.6 volts at rest, and show about 14.5 volts when the alternator is charging it. In my case there was no difference in voltage so I strongly suspected the alternator.
There are a couple of other tests to rule out some alternator adjacent malfunctions, but that was my step one.
posted by Horkus at 12:06 PM on January 15, 2018
It didn't fail all at once, I estimate it was failing intermittently for about two months. The under voltage caused a bunch of seemingly unrelated symptoms including alarming dashboard lights and a haunted radio. And it was highly weather dependent, because the battery charges and discharges differently at different temperatures.
I tested it by measuring the voltage on the battery terminals with the car off and then again with the car running. A typical battery will have 12.6 volts at rest, and show about 14.5 volts when the alternator is charging it. In my case there was no difference in voltage so I strongly suspected the alternator.
There are a couple of other tests to rule out some alternator adjacent malfunctions, but that was my step one.
posted by Horkus at 12:06 PM on January 15, 2018
Your friend definitely whacked the alternator and not the starter motor right? Because when the brushings start to go in the starter this happens and that's one way to fix it temporarily. And it'll work fine intermittently as you describe on the way to total failure.
The clicking you were hearing was presumably the relay, the starter wasn't turning. Try tapping it the next time and see if it fixes it. Or just take it apart and see if it's worn.
posted by fshgrl at 12:14 PM on January 15, 2018
The clicking you were hearing was presumably the relay, the starter wasn't turning. Try tapping it the next time and see if it fixes it. Or just take it apart and see if it's worn.
posted by fshgrl at 12:14 PM on January 15, 2018
Hey, my car is having a couple of the same problems yours is, so maybe I can offer some insight:
Last winter, the car wouldn't start on a very cold day (single digit temps) after being driven a short distance and sitting for about an hour. A jump from a friend couldn't get it started either. Luckily, we were close to an auto parts store and were able to buy a new battery and install it. Strangely, after installing the new battery the car still wouldn't start until our friend who was helping us whacked at the alternator with his wrench. No kidding, it started right up.
Are you sure it's not the starter that your friend whacked at? I have a bad starter at the moment and it has these exact symptoms (generally works from a cold start, but if I drive the car and try to start it again before it's gotten cold, I usually have to give the starter a love tap).
Air conditioning, probably unrelated to my chief concerns at this time.
Have you checked the A/C compressor clutch (mine's a Volvo, YMMV)?
posted by neckro23 at 12:19 PM on January 15, 2018
Last winter, the car wouldn't start on a very cold day (single digit temps) after being driven a short distance and sitting for about an hour. A jump from a friend couldn't get it started either. Luckily, we were close to an auto parts store and were able to buy a new battery and install it. Strangely, after installing the new battery the car still wouldn't start until our friend who was helping us whacked at the alternator with his wrench. No kidding, it started right up.
Are you sure it's not the starter that your friend whacked at? I have a bad starter at the moment and it has these exact symptoms (generally works from a cold start, but if I drive the car and try to start it again before it's gotten cold, I usually have to give the starter a love tap).
Air conditioning, probably unrelated to my chief concerns at this time.
Have you checked the A/C compressor clutch (mine's a Volvo, YMMV)?
posted by neckro23 at 12:19 PM on January 15, 2018
Last winter, the car wouldn't start on a very cold day (single digit temps) after being driven a short distance and sitting for about an hour. A jump from a friend couldn't get it started either. Luckily, we were close to an auto parts store and were able to buy a new battery and install it. Strangely, after installing the new battery the car still wouldn't start until our friend who was helping us whacked at the alternator with his wrench. No kidding, it started right up.
He probably hit the solenoid. Hitting the solenoid will sometimes free up the graphite brushes inside if they're binding up due to corrosion (rust). My guess is that you probably need a new solenoid; the tapping trick is a temporary solution and probably no longer is helpful, though it's so simple it's worth a try.
posted by axiom at 3:04 PM on January 15, 2018 [1 favorite]
He probably hit the solenoid. Hitting the solenoid will sometimes free up the graphite brushes inside if they're binding up due to corrosion (rust). My guess is that you probably need a new solenoid; the tapping trick is a temporary solution and probably no longer is helpful, though it's so simple it's worth a try.
posted by axiom at 3:04 PM on January 15, 2018 [1 favorite]
We had an older car that developed alternator problems, replaced it ourselves with the generic auto parts store alternator, and it went bad in less than a year, as did a replacement. Definitely get the OEM or other high-quality part. A car can run without a battery, but it can't run without an alternator.
posted by wnissen at 9:51 AM on January 16, 2018
posted by wnissen at 9:51 AM on January 16, 2018
When a car won't start, but makes the clicking or buzzing sound when you turn the key, here is a handy, cheap and strange technique that works more than half the time: honk the horn a couple times, then try starting it again.
This works because horns are inductors and when you release the horn button it delivers a (cleaning) spark anywhere there is high resistance. This is called back EMF and it might get you out of a jam. If it works there is definitely some corrosion in a battery connection and when you find that you are out of the ditch.
posted by jet_silver at 7:51 PM on January 19, 2018
This works because horns are inductors and when you release the horn button it delivers a (cleaning) spark anywhere there is high resistance. This is called back EMF and it might get you out of a jam. If it works there is definitely some corrosion in a battery connection and when you find that you are out of the ditch.
posted by jet_silver at 7:51 PM on January 19, 2018
This thread is closed to new comments.
posted by belladonna at 7:54 AM on January 15, 2018 [4 favorites]