Can a crankshaft break?
October 6, 2016 1:52 PM Subscribe
I think my mechanic is full of crap and I need a new one. Took my car in for an oil leak, after telling me I needed to pay 550 for a new seal, they're telling me crankshaft is 'broken' and it may be cheaper to get a new engine.
I am not car stupid, but I am also not super car smart. The first time I took my car in, they misdiagnosed the oil leak as a transmission leak. The second time, they said they had to replace a seal (I should have asked what seal, but I did not. I will find out when I talk to these bozos next.) Now that they have replaced the seal, they're saying it's not the seal, that the crankshaft is broken, and that's why it's leaking oil.
While this shop used to be trustworthy, I think I definitely need a new shop. But in the meantime, can a crankshaft break? Wouldn't I notice more than oil? Why wouldn't a seal stop the oil from leaking, even if the crankshaft was broken?
A quick google search tells me the crankshaft is essentially one of the hardest things in the engine to break. It also tells me it does all the effing work in an engine, so I think I would notice if it was broken.
What questions should I be asking about this? Can I get out of paying the $550 if it didn't fix the problem and/or if they are scamming me? I have a wedding coming up in 6 months, I don't have the money to throw away on a POS mechanic.
I am not car stupid, but I am also not super car smart. The first time I took my car in, they misdiagnosed the oil leak as a transmission leak. The second time, they said they had to replace a seal (I should have asked what seal, but I did not. I will find out when I talk to these bozos next.) Now that they have replaced the seal, they're saying it's not the seal, that the crankshaft is broken, and that's why it's leaking oil.
While this shop used to be trustworthy, I think I definitely need a new shop. But in the meantime, can a crankshaft break? Wouldn't I notice more than oil? Why wouldn't a seal stop the oil from leaking, even if the crankshaft was broken?
A quick google search tells me the crankshaft is essentially one of the hardest things in the engine to break. It also tells me it does all the effing work in an engine, so I think I would notice if it was broken.
What questions should I be asking about this? Can I get out of paying the $550 if it didn't fix the problem and/or if they are scamming me? I have a wedding coming up in 6 months, I don't have the money to throw away on a POS mechanic.
Of course a crankshaft can break. One possibility is that some of the counter weight has broken off and that's causing the shaft to wobble. That wobble is causing the main seal to go out. (I'm assuming the main seal is what they replaced.)
If you're asking, yes it's too early to judge these guys to be "POS bozos" not knowing any more than you do.
posted by humboldt32 at 2:09 PM on October 6, 2016 [5 favorites]
If you're asking, yes it's too early to judge these guys to be "POS bozos" not knowing any more than you do.
posted by humboldt32 at 2:09 PM on October 6, 2016 [5 favorites]
It's not impossible and it's also easy enough for them to email you a smartphone photo of it.
posted by mattamatic at 2:13 PM on October 6, 2016 [1 favorite]
posted by mattamatic at 2:13 PM on October 6, 2016 [1 favorite]
Yes, this was how my first car died. Sorry!
posted by PaulaSchultz at 2:27 PM on October 6, 2016 [1 favorite]
posted by PaulaSchultz at 2:27 PM on October 6, 2016 [1 favorite]
Response by poster: Hey all, thank you for the quick responses. I think next time I'll do some deep breathing before making an askmefi, I didn't use the most positive language.
If I can ask a followup, if my car is running okay now with an apparent cracked crankshaft, is there any way to guess how long til it finally kicks the bucket (assuming I keep putting oil in it)?
posted by motioncityshakespeare at 2:57 PM on October 6, 2016
If I can ask a followup, if my car is running okay now with an apparent cracked crankshaft, is there any way to guess how long til it finally kicks the bucket (assuming I keep putting oil in it)?
posted by motioncityshakespeare at 2:57 PM on October 6, 2016
Impossible to say.
posted by humboldt32 at 3:21 PM on October 6, 2016 [1 favorite]
posted by humboldt32 at 3:21 PM on October 6, 2016 [1 favorite]
What may be going on is that the crankshaft is not actually cracked, but it's worn or grooved where it contacts the seal, so the new seal won't seal against it. Depending on the car, it may be possible to have a repair sleeve fitted over the worn part of the crank so that the seal has something to seal against.
posted by zombiedance at 3:22 PM on October 6, 2016
posted by zombiedance at 3:22 PM on October 6, 2016
You really need to get a better understanding of what is wrong, because calling something "broken" is uselessly vague. If possible, get the mechanic to stand under the car with you and show you the problem. If that's not feasible, then it might help if you have a mechanically savvy friend talk to them on your behalf and insist on a clear explanation of the problem. If neither of those options work, then seek a second opinion from another shop.
posted by jon1270 at 4:01 PM on October 6, 2016
posted by jon1270 at 4:01 PM on October 6, 2016
>I think my mechanic is full of crap and I need a new one.
Regardless of whatever else is true or not, that right there is sufficient reason to change mechanics.
If your crankshaft was broken, you would notice more than leaking oil.
There would be noises, and vibration.
Could they have said broken crankshaft harmonic balancer, rather than broken crankshaft?
What year and make is the car?
I'm guessing it has a manual transmission?
How many miles?
Did you buy it new?
Has the car seen bad treatment (low oil, overheating, etc)?
Any other symptoms other than leaking oil?
How much is it leaking?
Do you keep putting oil into the engine?
How often do you check the oil?
What was the lowest you ever saw the oil?
Do you have an oil pressure gauge or an oil pressure warning light?
What does the gauge read, or has the warning light ever come on?
What did they do to fix the "transmission leak"? How much did it cost?
How much did it cost to replace the seal?
posted by the Real Dan at 4:07 PM on October 6, 2016 [1 favorite]
Regardless of whatever else is true or not, that right there is sufficient reason to change mechanics.
If your crankshaft was broken, you would notice more than leaking oil.
There would be noises, and vibration.
Could they have said broken crankshaft harmonic balancer, rather than broken crankshaft?
What year and make is the car?
I'm guessing it has a manual transmission?
How many miles?
Did you buy it new?
Has the car seen bad treatment (low oil, overheating, etc)?
Any other symptoms other than leaking oil?
How much is it leaking?
Do you keep putting oil into the engine?
How often do you check the oil?
What was the lowest you ever saw the oil?
Do you have an oil pressure gauge or an oil pressure warning light?
What does the gauge read, or has the warning light ever come on?
What did they do to fix the "transmission leak"? How much did it cost?
How much did it cost to replace the seal?
posted by the Real Dan at 4:07 PM on October 6, 2016 [1 favorite]
Broken crankshaft aside, you shouldn't be able to get out of the $550 seal replacement. Going to a mechanic is like going to the doctor. You go through the most obvious and likely tests to treat the most common maladies. If that doesn't work, you dig in deeper.
Did they drop the oil pan to inspect the crank? Are there pictures?
posted by hwyengr at 8:32 AM on October 7, 2016 [2 favorites]
Did they drop the oil pan to inspect the crank? Are there pictures?
posted by hwyengr at 8:32 AM on October 7, 2016 [2 favorites]
Response by poster: the Real Dan, here are the answers I know:
Could they have said broken crankshaft harmonic balancer, rather than broken crankshaft?
They definitely didn't say broken crankshaft harmonic balancer. But, they didn't give me specifics. They said that it was leaking because of a broken crankshaft, and that they wouldn't know what was broken about the crankshaft without pulling it apart, and that that would be the same labor cost as just replacing the crankshaft, $1800.
What year and make is the car?
It's a 2005 Chevy Cobalt
I'm guessing it has a manual transmission?
It's an automatic
How many miles?
Around 140k
Did you buy it new?
I bout it used, I think I bought it in 2011 or so
Has the car seen bad treatment (low oil, overheating, etc)?
It hasn't, except for the oil leak that it has now. I noticed the oil leak after I drove to Chicago and back, which was an 11 hour trip both ways. When I got back, the oil light came on when I turned sharp corners, but no other times.
Any other symptoms other than leaking oil?
No other symptoms that I noticed, there are no noticeable noises, there is no grinding.
How much is it leaking?
I can't tell, I've only noticed it a few times. Sometimes I will check the oil after two or three weeks, and it's fine. Others, like a recent 3 hour trip (each way), it was empty when I got home.
Do you keep putting oil into the engine? How often do you check the oil? What was the lowest you ever saw the oil?
I put oil whenever it's low. It seems to be all or nothing, it will go from around 4 or 5 quarts to empty. I check every few weeks, or after a trip of decent length (such as the 3 hour trip recently). The lowest I've seen it was essentially empty, and that was after both the Chicago trip and the 3 hour trip.
Do you have an oil pressure gauge or an oil pressure warning light? What does the gauge read, or has the warning light ever come on?
I don't have a gauge, but there is a warning light. Like I said above, when it's low it will sometimes come on in the middle of sharp turns, but that's it.
What did they do to fix the "transmission leak"? How much did it cost? How much did it cost to replace the seal?
They replaced the rear main seal, but also told me it wouldn't fix the "real" problem. It cost 550, 47 for parts and the rest was labor.
What they showed me was essentially this. The mechanic had a bolt in the bottom hole, and when he unscrewed the bolt, oil leaked out. He also turned the crankshaft manually, and when it turned so that a whole without a bolt in it was on the bottom, oil started leaking again. He said that the oil shouldn't come out, and that that was the problem.
posted by motioncityshakespeare at 6:43 PM on October 10, 2016
Could they have said broken crankshaft harmonic balancer, rather than broken crankshaft?
They definitely didn't say broken crankshaft harmonic balancer. But, they didn't give me specifics. They said that it was leaking because of a broken crankshaft, and that they wouldn't know what was broken about the crankshaft without pulling it apart, and that that would be the same labor cost as just replacing the crankshaft, $1800.
What year and make is the car?
It's a 2005 Chevy Cobalt
I'm guessing it has a manual transmission?
It's an automatic
How many miles?
Around 140k
Did you buy it new?
I bout it used, I think I bought it in 2011 or so
Has the car seen bad treatment (low oil, overheating, etc)?
It hasn't, except for the oil leak that it has now. I noticed the oil leak after I drove to Chicago and back, which was an 11 hour trip both ways. When I got back, the oil light came on when I turned sharp corners, but no other times.
Any other symptoms other than leaking oil?
No other symptoms that I noticed, there are no noticeable noises, there is no grinding.
How much is it leaking?
I can't tell, I've only noticed it a few times. Sometimes I will check the oil after two or three weeks, and it's fine. Others, like a recent 3 hour trip (each way), it was empty when I got home.
Do you keep putting oil into the engine? How often do you check the oil? What was the lowest you ever saw the oil?
I put oil whenever it's low. It seems to be all or nothing, it will go from around 4 or 5 quarts to empty. I check every few weeks, or after a trip of decent length (such as the 3 hour trip recently). The lowest I've seen it was essentially empty, and that was after both the Chicago trip and the 3 hour trip.
Do you have an oil pressure gauge or an oil pressure warning light? What does the gauge read, or has the warning light ever come on?
I don't have a gauge, but there is a warning light. Like I said above, when it's low it will sometimes come on in the middle of sharp turns, but that's it.
What did they do to fix the "transmission leak"? How much did it cost? How much did it cost to replace the seal?
They replaced the rear main seal, but also told me it wouldn't fix the "real" problem. It cost 550, 47 for parts and the rest was labor.
What they showed me was essentially this. The mechanic had a bolt in the bottom hole, and when he unscrewed the bolt, oil leaked out. He also turned the crankshaft manually, and when it turned so that a whole without a bolt in it was on the bottom, oil started leaking again. He said that the oil shouldn't come out, and that that was the problem.
posted by motioncityshakespeare at 6:43 PM on October 10, 2016
If you're losing oil to the point that the pressure warning light is coming on in turns, you'd be well served to do the engine swap. Oil starvation is a serious thing. Maybe it's the crankshaft, maybe it's not, but that engine is well on the way to being trash. That is a SERIOUS oil leak.
posted by hwyengr at 8:35 PM on October 12, 2016
posted by hwyengr at 8:35 PM on October 12, 2016
Looking at the photo, maybe you should be getting that money back for the rear main seal job. I agree that oil isn't supposed to come out of those bolt holes, so the internal passageway within the crankshaft that distribute oil to all the bearings (journal) might have cracked. This is bad because you're leaking oil, and you're also not getting good oil pressure to your bearings. Which is bad.
But that photo also shows the rear main seal. They should have seen the oil coming out of the crank when they did that job.
posted by hwyengr at 8:42 PM on October 12, 2016
But that photo also shows the rear main seal. They should have seen the oil coming out of the crank when they did that job.
posted by hwyengr at 8:42 PM on October 12, 2016
Best answer: Change mechanics.
Evaluate your need for reliable transportation, and drive this one until it dies.
Carry oil with you, and check it rather more frequently.
That 1800 dollars they would charge you, plus the 500 they've already shorn off of you would go a long way toward getting another 2005 Chevy Cobalt (shop chicago craigslist for comparables to see what I mean). Repair, at least by these guys, might not be economical.
Does engine oil drip out of the car where you park it, or does engine oil just magically disappear?
That oil warning light coming on on turns could mean that your oil pan was SO LOW that the oil sloshed over to one side so that it couldn't be picked up anymore to pump into your engine while the light was on. Cars remember that you did this to them forever, and they don't like it.
The fact that your engine oil light isn't on all the time is a good sign. Your engine lubrication system is nominally functional, and whatever is wrong (I don't have much confidence in the mechanic's diagnosis) doesn't seem to have wrecked the lubrication system so badly that it cannot maintain oil pressure.
posted by the Real Dan at 5:50 PM on October 15, 2016
Evaluate your need for reliable transportation, and drive this one until it dies.
Carry oil with you, and check it rather more frequently.
That 1800 dollars they would charge you, plus the 500 they've already shorn off of you would go a long way toward getting another 2005 Chevy Cobalt (shop chicago craigslist for comparables to see what I mean). Repair, at least by these guys, might not be economical.
Does engine oil drip out of the car where you park it, or does engine oil just magically disappear?
That oil warning light coming on on turns could mean that your oil pan was SO LOW that the oil sloshed over to one side so that it couldn't be picked up anymore to pump into your engine while the light was on. Cars remember that you did this to them forever, and they don't like it.
The fact that your engine oil light isn't on all the time is a good sign. Your engine lubrication system is nominally functional, and whatever is wrong (I don't have much confidence in the mechanic's diagnosis) doesn't seem to have wrecked the lubrication system so badly that it cannot maintain oil pressure.
posted by the Real Dan at 5:50 PM on October 15, 2016
Response by poster: The Real Dan, thank you for your help. That's my plan for now, drive it til it dies, and keep it alive as long as possible by monitoring the oil situation frequently.
To your last question, if you come back to this thread, the oil seems to magically disappear, most notably after long trips. I've checked it once a week for the past few weeks and it still has 5 quarts (no long drives recently). So I am truly at a loss for where it's losing the oil.
posted by motioncityshakespeare at 3:04 PM on October 23, 2016
To your last question, if you come back to this thread, the oil seems to magically disappear, most notably after long trips. I've checked it once a week for the past few weeks and it still has 5 quarts (no long drives recently). So I am truly at a loss for where it's losing the oil.
posted by motioncityshakespeare at 3:04 PM on October 23, 2016
A 2005 Cobalt with 140k is a goner. New engine not worth it unless you get a junkyard motor and can do it yourself. Installing a new motor will cost more than the car will be worth *with* a new motor.
posted by spitbull at 3:44 AM on December 21, 2016
posted by spitbull at 3:44 AM on December 21, 2016
This thread is closed to new comments.
posted by DirtyOldTown at 1:56 PM on October 6, 2016