The Top DSM Community on the Web

For 1990-1999 Mitsubishi Eclipse, Eagle Talon, Plymouth Laser, and Galant VR-4 Owners. Log in to remove most ads.

Please Support JNZ Tuning
Please Support STM Tuned

Do I have crank walk? Or something else?

This site may earn a commission from merchant
affiliate links, including eBay, Amazon, and others.

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

RussianEclipse

10+ Year Contributor
38
0
Sep 25, 2012
Walnutport, Pennsylvania
Alright I know the whole idea behind crank walk and I have read up about how it happens and such. But I can't tell if mine has it. Going to work one morning I went to make a left turn up a hill and my 95 GST acted weird I had power but as I shifted to third at the top of the hill I lost all power. Think I ripped one of my intercooler pipes off again I pulled over and looked. No they were all on. So I go to start the car and just cranks. Left the car in a parking lot and went to work. Came back i tryed to figure it out. Nothing was visibly wrong. Checked the codes and I had my usually e vap fault. And a multiple mis fire and a running to rich fault. So I was lost. Got the car home and me and my mechanic ripped in to the car checked all sensors. They were good by test. So we go to physically look at the crank sensor and as we removed the cover the sensor was torn to shreds by smashing against the crank. And the crank pulley was almost falling off. (Loose and when we put it one we made sure it was tight) I got the crank walk idea into my head. So we got to work taking out the motor and trans. Got it out and took off the oil pan and my buddy used a spoon bar and went to see if the crank would move at all and he said he could feel it move a bit but only thru the bar not see it move. So I thought that had to be crank walk. Plus that's what I had read, left turn, no power, scrapping sound from block, moving crank. But my car has 84,xxx miles on it. And is the classic dsm pain but I love it. When I bought it she needed a lot of work took about three months. Rebuilt head all new valves and such. All new everything but coolant temp sensor and and power steering pump. (No joke my entire bay besides what I mentioned and block and trans is new) and all work done correctly. Now I can't get the feeling that it's not crank walk cause I had just put 1,050 miles on the whole new setup and no problems besides a never ending boost leak. And besides this problem I had no signs besides sometimes for the past week it felt like I would build up all this power and it couldn't go any where like a boost leak or pipe disconnected. So does anyone know a for sure sign I have CW or is it something else that I can just fix. I plan on building the motor since it is out but if it's CW I'm gonna buy and build a full 6 bolt. But if I don't have to and I can use my new head and just build the block that would be great. And questions that are just useless like is there fuel or spark yes all sensors were fine but the crank sensor which was destroyed. I honestly have a feeling te crank pulley might be bad and it didn't stay tightened and started to slid and bash the sensor.
 
So you knew that the crank sensor was bad so you pulled the entire motor??? Why not just get a new one?Only way to know if you do have a thrust bearing failure would be to check it. You said you "mechanic" did. Doesnt sound like it to me..

This is crankwalk. I was going to put this motor in my buddys car until I noticed this, he bought it used.

[ame=http://www.youtube.com/watch?v=02apraf5pNc]6 bolt confirmed thrust beating failure - YouTube[/ame]
 
No I pulled the motor cause I was planning on building it. And the crank sensor was literally torn to pieces behind the pulley. The pulley had almost come off. And all we had checked was to see if there was any play in the crank it self and he said he would only feel a slight movement with the bar we were using. That's why I asked to see what a for sure way to check was. And he is a certified mecnahic and does this for a living at a high end import shop. He doesn't have much experience with DSMs so he wasn't sure how much play the crank had from factory cause the movement was so little you could even see it.
 
hey man, the best way to know if you have cw is to use a dial indicator on a magnetic stand and place it on the snout of the crankshaft (pulley side) and push the crank all the way to one side and zero the dial indicator. from there push the crank forward and back a few times ending with forward. taking a measurement each time and use the largest reading you get as your reading and compare it to factory specifications. if your reading is more than what is specified by manufacture then you have cw if not then something else is tearing your crank sensor up. 2g 4g63 engines are famous for crank walk. the 6bolt swap does solve this issue nicely. one reason the 7 bolt 2g motors get crank walk is from using a heavy duty clutch pressure plate with a single clutch disc. with all the clutch disengaging and engaging it puts a lot of load and stress on the thrust bearing, thrust bearing is what keeps the crank from walking, and when the bearing cant take it no more this is when crank walk happens (the thrust bearing fails and gets chewed up).

on another note it be a good idea to check up and down play to see if any exists, i do this sometimes to be sure that the crank isn't moving around more than one direction in its main caps.

as for the crank senor, i know some sensors are adjustable on gap clearance between the reluctor wheel and the sensor pick-up (not that familiar with the 4g63's sensors). most manufactures specify .010" but some specify more or less than that. if there is a clearance specification i check with the manufacture (if the sensor cap clearance is adjustable).
 
If you have the motor pulled (could have just checked crank endplay while still in car) just look at the thrust bearing. If it's chewed up then yeah it's cw. If the end play is like in the video then yeah its CW. If the crank was moving that much then the crank trigger plate was getting into the crank sensor and probably is what destroyed the crank sensor.

Check crank end play. spec is .002" to .007".
 
2g 4g63 engines are famous for crank walk.
1)the 6bolt swap does solve this issue nicely.

2) one reason the 7 bolt 2g motors get crank walk is from using a heavy duty clutch pressure plate with a single clutch disc. with all the clutch disengaging and engaging it puts a lot of load and stress on the thrust bearing

1) Oh really? That video I posted in my first response IS a 6 bolt.. Any engine with a crankshaft can walk.

2) So a 6 bolt with a heavy clutch isnt putting the same load on the crankshaft as on a 7 bolt?
 
1) Oh really? That video I posted in my first response IS a 6 bolt.. Any engine with a crankshaft can walk.

2) So a 6 bolt with a heavy clutch isnt putting the same load on the crankshaft as on a 7 bolt?

yes any engine can get crank walk, but the 6 bolt doesn't get it as much as the 7 bolt is what i was getting at.
 
Support Vendors who Support the DSM Community
Boosted Fabrication ECM Tuning ExtremePSI Fuel Injector Clinic Innovation Products Jacks Transmissions JNZ Tuning Kiggly Racing Morrison Fabrications MyMitsubishiStore.com RixRacing RockAuto RTM Racing STM Tuned

Latest posts

Build Thread Updates

Vendor Updates

Latest Classifieds

Back
Top