I had my 7-bolt built back in 2005 with a mitsubishi 4g64 crank, eagle rods and wiseco pistons. The engine was refreshed with new bearings and rings in 2010. I don't put many miles on it (less than 1k/year). The only reason I had it refreshed is because I had the engine out anyway, so I figured it couldn't hurt.

Anyway, here's the issue: I noticed a clicking when pushing in the clutch that I couldn't resolve, even when changing every piece of the clutch system, including the throwout bearing. I took a look at the crankshaft position sensor and it looked like the sensing plate had been rubbing against it. I noticed the plate itself was slightly bent, so I ordered a new plate and sensor. It still made the clicking sound. Two hundred miles later, I'm out cruising and push in the clutch to shift and the car shuts off and has to be towed home. I get a malfunctioning crankshaft position sensor code. The new stuff has the same scuffs from rubbing as the old stuff. That's the only "testing" I have done so far since I don't have a digital caliper to measure travel, but I plan to get one soon.

My questions are: How likely is it that this is your run-of-the-mill crankwalk, or is it more likely due to poor machining during the refresh? Since the sensor went first, is it possible to fix my engine, or is it toast? If I fix it, would it probably happen again? If it's possible to fix it, what will need to be done to get it working again?

Thanks for reading this novel guys.

Sounds like when my 96 GST walked from back in 2003. Not sure about the block being toast though
But I wouldn't use it again

Hard to say, really. It is possible that the machine work was not done right; unfortunately, I don't think you could really tell at this point if it was or not.

Definitely sounds crank-walk-ish with the rubbing issues, though. You can fix it with the machine work, but I'd be hesitant to use the same block since it's already been machined, and failed. But that's just me and I'm weird.

Sorry cannot really offer any other advise at this point. The measurements you plan on doing will shed more light into this.

Good luck!!

You need to look at your crank and thrust surfaces to see if its just the bearing worn down or the crank is damaged. Or worse the block. Being as you don't drive it alot, do you have the clutch switch unplugged?

Yes, the clutch switch has been disabled since 2005. Would it make a difference regarding whether or not to rebuild if it were the bearing or crank that's damaged? Obviously, if it's the block I won't, but if it's the crank could I just get a new crank?

Hit the harmonic balancer towards the trans, then pry under it with a screwdriver. If it noticeably moves you have crankwalk.

nicknorth11 said:

Yes, the clutch switch has been disabled since 2005. Would it make a difference regarding whether or not to rebuild if it were the bearing or crank that's damaged? Obviously, if it's the block I won't, but if it's the crank could I just get a new crank?

Click to expand...

Yes if its the bearing or crank you can just replace them.

I had a 6 bolt stroker walk on me after bad machine work in 200 miles! The crank was fixed and re assembled it walked in 1 mile!! IMO once an engine walks that block and crank are junk!

has anyone ever thought, aside from poor machining, of looking at how the thrust bearing gets its oil?

i cant recall where it was, but i read an article aiming at the 2g oil squirters being partially to blame for the crank-walk issue.

6 bolts would be different. i think its due to their design personally (e.g.- 1g vs 2g).

anyway, id be checking out other stuff than the "hard parts".

edit: magnus. durr, heres the thread clicky

Get a dial indicator, pry bar and a buddy. Put dial indicator against HB with engine off of coarse. Push, pry the crank back towards tranny, zero out indicator. Pry, push back the opposite way. I'm pretty sure more than .008 runout indicates your thrush bearings are toast. I don't have my shop manual in front of me to be sure.
Improper seating of the thrush bearing at final torquing is also a failure point.
Your buddy is there to laugh at you and help you pull the motor.

Pretty much.

.002-.007 standard. .0098 is the limit

Thanks. I haven't had time to pull the engine yet, but a quick visual of the oil was good. It looked brand new without a spec of metal. So far so good. I'll keep the thread updated as a make progress.

What machine work was done? If it was a simple refresh, then there likely wasn't any machining performed that would have led to a thrust bearing failure. If that is indeed the problem, I would lean more towards clearances or assembly.

Yeah, it was just a refresh. I guess assembly error makes more sense. Hopefully it's not totally screwed because the shop made a stupid mistake. I'm pretty anxious to get this thing out. Hopefully I'll have time soon.