RexSeven
RexSeven UberDork
2/6/14 7:26 p.m.

Anyone ever hear of a car just suddenly developing excessive crankshaft endplay? My sister's 2004 Hyundai Elantra started burning oil early this morning and the low oil light came on. I took a quick look at it and it looked like oil blew out all over the firewall. She brought it into her shop. They looked at it and said the crankshaft was shifting side-to-side while the engine was running. Has anyone ever heard of this happening? What would cause such excessive endplay? Bad thrust washer? It has only 96K miles and already needs a new engine.

Streetwiseguy
Streetwiseguy UberDork
2/6/14 8:32 p.m.

I doubt it suddenly developed end play, but I bet it suddenly got to the point where it started moving enough to spray oil all over the place. If it really is end play, and not a problem with the front pulley, it will have a thrust bearing worn out, and likely the crank face worn as well. Time for an overhaul or a used engine, I'm afraid.

codrus
codrus HalfDork
2/6/14 11:42 p.m.

If it were a Miata engine, then I'd say it sounds like the thrust bearing just fell out into the oil pan. Dunno if Hyundai engines have the same design or not.

z31maniac
z31maniac UltimaDork
2/6/14 11:50 p.m.
codrus wrote: If it were a Miata engine, then I'd say it sounds like the thrust bearing just fell out into the oil pan. Dunno if Hyundai engines have the same design or not.

Side note, how does that happen? We just dealt with that for a friend's MSM engine, done by a professional builder?

RexSeven
RexSeven UberDork
2/7/14 3:43 a.m.
Streetwiseguy wrote: I doubt it suddenly developed end play, but I bet it suddenly got to the point where it started moving enough to spray oil all over the place. If it really is end play, and not a problem with the front pulley, it will have a thrust bearing worn out, and likely the crank face worn as well. Time for an overhaul or a used engine, I'm afraid.

Yeesh. Another dead car is the last thing we need right now.

Knurled
Knurled PowerDork
2/7/14 1:28 p.m.
RexSeven wrote: Anyone ever hear of a car just suddenly developing excessive crankshaft endplay? My sister's 2004 Hyundai Elantra started burning oil early this morning and the low oil light came on. I took a quick look at it and it looked like oil blew out all over the firewall. She brought it into her shop. They looked at it and said the crankshaft was shifting side-to-side while the engine was running. Has anyone ever heard of this happening? What would cause such excessive endplay? Bad thrust washer? It has only 96K miles and already needs a new engine.

Chrysler 2.4s are bad for this - the thrust bearing dies, then I assume the next process is that oil gets between the pump and front seal and when you push in the clutch, it hydraulically forces the seal out. Then the oil leakage can be measured in blocks per quart.

codrus
codrus HalfDork
2/7/14 4:35 p.m.
z31maniac wrote:
codrus wrote: If it were a Miata engine, then I'd say it sounds like the thrust bearing just fell out into the oil pan. Dunno if Hyundai engines have the same design or not.

Side note, how does that happen? We just dealt with that for a friend's MSM engine, done by a professional builder?

Miata engines have two half-circle thrust bearings that sit in a grooves in a main cap (one on either side of the crank), matching up with the bottom 180 degrees of the crank. For some reason not entirely clear to me, if the thrust bearing is too thin to start with, then it wears much faster than it normally would. This lets the crank rub against the block and the other main caps, machining them down and filling the oil with metal particles. These result in massive amounts of wear on the rest of the engine. At some point, the gap between the thrust bearing and the crank becomes larger than the thickness of the bearing, and it falls out into the oil pan (sometimes bouncing around the crankcase in the process). Now the crank has something like a quarter to half an inch of endplay, which is huge and can break rods. The engine is junk anyway -- by the time someone notices what's happened, the metal particles have trashed everything.

A small number of 99s were installed with too-small a thrust bearing from the factory, and there was a TSB on it, but it's a general design failure of the BP and happens (at a lower rate) with all of them. I took apart a 94 engine which had failed for that reason. This is why FM recommends installing a clutch-interlock override when adding a higher-pressure clutch to a turbo car (with no oil pressure at startup, having the clutch pushed in maximizes the thrust bearing wear).

I don't know what it is that's different about the Mazda design that makes it more susceptible to this problem than other engines.

http://www.miata.net/solo/99miatathrustbearingfailure.html

Sorry for the Miata tangent in a non-Miata thread. :-)

Knurled
Knurled PowerDork
2/7/14 4:37 p.m.
codrus wrote: I don't know what it is that's different about the Mazda design that makes it more susceptible to this problem than other engines.

Nothing much... anything with multipiece thrust bearings can drop them.

93gsxturbo
93gsxturbo Dork
2/7/14 8:26 p.m.

Are you sure its not a Mitsubishi? Because it just crankwalked.

belteshazzar
belteshazzar UberDork
2/7/14 8:34 p.m.

My integra did this once

Kenny_McCormic
Kenny_McCormic UberDork
2/7/14 9:30 p.m.

In reply to 93gsxturbo:

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