Of KIAS and crankshafts -- and an acceleration stutter in my KIA

Hi, Car Talk Community

I live in Morocco and drive a 2011 KIA Carens (called Rondo in the USA) seven-seater that I love. Except when the crankshaft breaks. This has now happened twice – once in 2013 and now in 2015. I’ve seen online that other KIAs have had crankshaft pulley bolt issues. The one we got in 2013 was from a junkyard, by the way. I am wondering if I need to ditch this car after we get it fixed, getting as much money as possible out of it or if there is any other advice you can give me about how to keep this from happening again.

And while I am at it, the car has a kind of stutter that it does when accelerating at higher speeds, especially after it’s been on the highway for a day. It does a little chug-chug between 100 and 120 km/hour that will go away when you speed up. We replaced the fuel pump twice after we first got the car, but that was clearly NOT the problem. I think I heard Tom and Ray address this on a rerun show earlier this year, but I was driving and couldn’t write anything down. Got any ideas on this one? While the mechanic has the car open, I thought maybe he could fix this one, too.

Thanks for any help you can give.


Is it the bolt that is breaking or the crankshaft ? If it is the bolt, I would try to find an aircraft grade one.

Problesm when accelerating at higher speeds, often that means the engine isn’t able to get the air and gas in as fast as necessary, or get the exhaust gas out quickly enough. So check the engine air filter, fuel filter, fuel pressure (you may have to measure it when driving at that speed), or catalytic converter back pressure.

It’s unusual for a crankshaft or crankshaft bolt to fail unless there was a human caused reason for it. However, I do note that Kia has issued a revised crankshaft bolt so there may be a manufacturing glitch in materials or design that led to this.

This revised bolt would be a dealer item and they can probably tell you the technical reason why the revised bolt was issued.

It’s also possible that with chronic problems that the crankshaft could be damaged to some degree and a revised bolt may not be the final answer to the problem.

The stutter could be due a number of things. Assuming no CEL and no DTCs set, what about the fuel filter? Was that replaced when the fuel pump(s) were changed?
Maybe the stutter is related to a wobbling crankshaft pulley (courtesy of the bolt…) and it’s having an effect on the crank position sensor.

While it is very unusual for a crankshaft to fail, I can report from first-hand knowledge that British Leyland produced a lot of defective crankshafts in the '70s. In fact, a friend of mine had the misfortune to buy an Austin Marina, and while the car was plagued with a huge number of problems, the biggest one was a broken crankshaft when the car was less than 1 year old!

The crankshaft was replaced under warranty, and–guess what?–the replacement crankshaft snapped about 4 months later.

The multi-line dealer from whom my friend had bought that bomb offered him a very generous trade-in for the damaged goods, and he took that offer. That is the good news.

The bad news is that he applied the trade-in to a Plymouth Volare!
While the crankshaft never broke on that Mopar-made lemon, just about everything else about that car was problematic. Luckily, by that time they had moved to Michigan, so the car rusted away in another couple of years, thus ridding him of that problem.

Some people just seem to have the unique ability to gravitate toward highly-flawed vehicle designs.

Interesting post VDC. I wonder, in cars who seem to have crankshafts prone to failure, if the problem is the materials used (alloy percentages) or construction (forged vs cast). Or would it be more likely just that that way it is mounted and is held by the bearings, so the crankshaft is not properly supported. One of the most interesting threads here for me was on how crankshafts are made.

Hmmm. Interesting info abt those Kias. Thanks.