symbiosis

Newby here. Lurker for awhile (Hate to make this my first post) & avid toyota supporter/driver for most of my adult life. But I had to register as I'm scratching my head (& soon the bottom of my wallet) on this one.

Yesterday my wife drove our 98 4runner ltd down freeway ~65mph, lost power...RPMs bouncing around...then a clanging & she pulled off the road....engine dead
Just got the word from the mechanic that it threw a rod (looks like it blasted out a fist-size part of the lower block near the starter) & needs the engine replaced.

background;
Got it ~1yr ago @100K from a local dealer?.twas a local trade in....in near-immaculate condition/well maintained....I suspect the 4wd/locking diff & other functionalities went unused in it's first 6+ years. I've used 4wd numerous times tooling around local mountain roads. Other than that, the ~25k I've put on it was all mellow driving (w/routine oil changes.) Have had no problems whatsoever w/it leading up to this. Up til yesterday, the engine has always sounded & run great (I'd occasionally find an inadvertently pushed ECT or O/D button but for mere moments.) ?.have really loved this rig.

my question:
What in the world could have caused this????
Looks like this is a highly reliable engine -that this kind of thing should NOT happen to.
I know 130K miles/8yrs isn?t new, past warrenty, etc (& I basically got a ?thanks for sharing? from a Toyota experience program phone call/inquiry) but my curiosity is peaked. I?ve never had anything major like this happen. Is there something I could have /should have done differently? Something I missed? Or should I just say oh well & play the part of the bad-defect rod part lottery winner?

Looks like I?m gonna be out at least $4+K . but almost more distressing is that my decades long confidence & advocacy for Toyota is shaken. I work in a line of business that advocates for adoption of their quality processes & have never had reason not to spout their praises. Really torn up here. Any insights appreciated.
Thanks.

Forrest Gump 9

usually bad gas, detonation, spun the bearing, seized the rod, and punch a hole out the side of the block.

Ringmaster

Stick or Automatic?

wjwerdna

(sorry no useful info from me here, but welcome to posting at yotatech )

sorry to hear about that, but with the odds, whew, I guess the rest of us are ok

SoiledGreen98

Yea i haven't heard of that happening before. I have like 145,000 on mine and no problems yet. Sorry it happened to you Look on the bright side, you get a brand new motor. Now you get another 9 or 10 years, at least, with no problems

symbiosis

Automatic

fg-bad gas? wouldn't I hear/have some other telltale sign (rattling/knocking/?) or could it be that sudden?

Finelygotone

My guess on this is if you had no unusual symptoms of the bearing going south (ie. Oil pressure loss, knocking, etc.) it is probably not from bad gas/detonation in this NA motor (it's not supercharged, right?). Probably was due to a sudden (and sustained) loss in oil pressure - failed oil pump or drive, plugged pick up or oil filter, etc.. Which cylinder was it on? My guess is that it was one of the cylinders the furthest from where oil pressurizes the crank - maybe 5 or 6....
Unfotunately, if your wife is not anal about checking the guages, the small idiot light and the guage could have shown a loss of pressure for the small amount of time that the motor needed to grenade at 65 mph and she just did not notice....

Has the mechanic torn the oil pump down or looked at the pick up/filtration system?

964runnerKY

Did you just have the oil changed? A friend has a 98 and theirs did the same thing but I think the dealer left the oil plug off and they replaced the motor for free.

gpcollen1

The oil plug off would be hard to imagine but not tightened all the way and it worked itself out is a definite possibility.

Just recently heard of a really good mechanic night tightening the plug all the way. It took approximately 100 miles for it to work itself out. The guy driving his car said he pulled off the exit ramp immediately upon seeing the oil light and hearing the ticking and by the time he stopped the engine was done.

Good Luck!

littlerunner

i think i know the 98 that 964runnerky may be refering to.the drain plug was not left out.it was however a very unfortunate coincidence.but i was able to get toyota to pay for the engine.a rod bolt broke for some reason.the engine still had oil in the pan when it was towed in.if i remember it had about 70,000 miles at the time.thing is,& you guys need to keep this in mind,if he hadn't been a regular service cust at the dealer toyota would not have paid a dime.i was almost as sick about it at the time as the cust because my wife drives a 97 4runner identical to the 98 that gave up.i worried about something happening to it for a long time.after a while though i gave it up to just being a fluke thing.sometimes not all mechanical failures can be explained.good luck-hope it doesn't leave to bad a taste to take you out of toyota

MTL_4runner

Another common one is a double gasket oil filter (that can take a while to spring a leak if the circumstances are right) or forgetting to refill the oil after an oil change (but that will usually toast the motor within about 15-20 minutes of driving). It is possible you had a detonation problem in one cylinder or that one of the rods actually had a flaw in it from manufacturing.

mkgarrison5

on the 2002 tacomas and 4 runners wouldnt the oil light come on??

RustBucket

iTrader: (1)

Perhaps this is just quantum theory at work? I mean, the probability, under normal driving conditions, for a 3.4 to just blow is very very small but it's there. Maybe this particular engine just happened to jump to the far extreme of the probability curve? Our universe is not mechanistic anyway

On a more practical note, maybe it was detonation? Was your wife climbing a steep hill with heavy throttle or anything? Your description doesn't seem like it...

I really think you should call Toyota and ask them what's going on.

MTL_4runner

It might have held and then let go quickly, but yes, the oil light should have come on briefly.

We could really speculate forever, but a teardown when the new engine is installed would solve the mystery.

symbiosis

not supercharged (not modified @ all)
Do my own oil, am quite anal about thightening things & it hadn't been done in a couple thousand miles (it was coming up to that time again.)
There was definitely oil in there (it's splattered all over underneath.)
I asked her about the oil light & wife was pretty adamant she saw nothing (& sounded like she was watching the tach jump around....course it all happened in just a few seconds.)
I think you're right about 5 or 6 (it's further from the front.)
& she was climbing a hill....on the freeway, don't know how hard she was accellerating....she'd been on it for a couple miles at that point.
Should have mechanic look more closely for actual cause & (if justified) give toyota another call.

paddlenbike

iTrader: (1)

Mine had a rod bolt failure at 55,000 miles. I bought it Certified Used and noticed after a week that it sounded unusual at higher RPMs. As it turns out a rod bolt in one of the cylinders broke, bounced off something and went up into the other bank of cylinders and shattered a piston skirt. It was definately like this the day I bought it--the sound was only noticeable over 4000 RPMs. Because the vehicle had a warranty, they had to replace a connecting rod and a piston in a cylinder on the opposite bank. The dealer thought it might have been a metalurgy problem with the rod bolt.

Sorry to hear about your misfortune, it's something I never would expected from Toyota either. They really are stout motors, but every now and then something goes wrong even with the best engineering tolerances.

TheBlueWave

My company is trying to adapt their practices as well and I never like to hear about things like this. I was reading a long term test for a Honda Pilot (CR or Edmunds, can't remember) and that car snapped a timing belt at like 5k miles, leaving the driver and his family stranded. The point is that it can happen to any product, car or not. So much happens inside an engine block we don't know about and can't see. As an engineer I know that every product made in a factory will be just a little different from its "identical" peers, even with super tight tolerances. Good luck in the future, don't give up on Toyota just yet!

964runnerKY

It was one of my dad's 4runner. I talked to the wife and that is what I heard it could have been but never talked with her husband. They have had it for a 3-4 years now and love it. If that is the case I have a lot respect for the local dealer then.

littlerunner

sounds like the same on,white 98-folks take very good care of it.always looks like it just came off the show room floor. i was very happy to be able to help

964runnerKY

Littlerunner,
can you tell me if there is a recall for the rear springs on my 96 4runner. I will pm you the vin if need.
Thanks
Chad