91TSi FWD
20+ Year Contributor
- 617
- 3
- Jan 26, 2003
-
Edmonton,
OK, ever since I became a member at this site Ive seen post after post of people wondering about crankwalk. By now you could use the search topic, type in crankwalk, and somewhere in there youll most likely find your answer. What I'm trying to do here is to get peoples opinion on this thread. Please look it over and add/or edit what you think is wrong or what should be added. My goal here is to come up with a post that everyone can be pointed to. Please, no B.S.
Crankwalk...
Crankwalk reffers to a crankshaft which moves an excessive amount inside the engine.
Many 2G owners have experienced walking crankshafts. This happens because the crankshaft does not fit in the bearings proporly. Crankwalk is also known as thrust bearing failure. the bearing fails and allows the crank to "walk". A walking crankshaft will not harm the crankshaft itself, but the movement can place excessive or uneven loads on the bearings, causing premature failiure.
When the crankshaft "walks", it pushes the backplate into the crank sensor causing it to fail (literally, it tears through the crankshaft angle sensor). This problem usually manifests itself as a ticking noise coming from the timing belt area, as the sensor is literally and slowly ground away by the crankshaft. Any such noise should be investigated right away to prevent serious problems. If you have taken apart your car to replace the crank sensor, look to see if there are plastic shavings on the trigger plate, where the plate has actually contacted the sensor itself. If your crank sensor has suddenly failed, the chances that the sensor has done so on its own are low. To replace the sensor alone is a short term fix, if your crankshaft is walking. Getting to the crank sensor is a lengthy process since the timing belt and all else has to come off.
Other causes of crankwalk include the 2g oil injectors. They clog, causing a lack of oil on the bearings and thus, the bearings warp and allow the crank to "walk". Also, it has been stated that a higher pressure clutch application, especialy the 2600, accelerates the process if you are going to get it. However, let it be known that there is no solid proof as of yet that a strong pressure plate causes crankwalk because of the relatively common occurence in stock cars.
The crankshafts in many of the 1G DSMs have a larger rod and fit more proporly inside the bearings. The six-bolt motors are not nearly as suseptable to get crankwalk as the later 7-bolts. The 6-bolt engines were produced between March, 1989 and the third week of May, 1992. May 1992 to the first week of May, 1994 have 7-bolt motors in the 1G DSMs. All 2G DSMs have the 7-bolt engine. Even though the Spyder has a 2.4L SOHC engine it can still crankwalk, as with the 1.8L 1G. Note that any engine can get crankwalk, even big V8s.
If you want a temporary fix for crankwalk, you can contact Mitsubishi as they have made bearings which propory fit the crankshft. Matching the bearings is tricky and requires exact information about when the crankshaft was manufactured, which may be determined by color markings on the crankshaft itself. The 2G factory manual includes information on how to match crankshafts to bearings.
There is no real way to tell if you car is experiencing crankwalk, symtoms are usully difficult to diagnose untill major damage occures. Some symptoms are that when you are turning a left corner the clutch will often stickdown, this is often a sign of crankwalk. Other symptoms include rough or poor clutch engagement, inconsistant engagement height, ticking noises, difficult shifting, and variing pedal height or pressure. Another symptom is having the engine RPM decrease significantly when the clutch pedal is depressed. As you add more and more horsepower to your engine, the greater chance you have of getting crankwalk.
Also, there is no recall as of yet on the crankshafts.
for more info on crankwalk, check out these sites.
- http://www.magnusmotorsports.com/crankwalktheory.htm
- http://members.shaw.ca/costall/1000Q/
- http://www.vfaq.com
- http://www.nx2k.com/eclipse/crank_walk.htm
Or go somewhere like google and do a search for crankwalk.
Crankwalk...
Crankwalk reffers to a crankshaft which moves an excessive amount inside the engine.
Many 2G owners have experienced walking crankshafts. This happens because the crankshaft does not fit in the bearings proporly. Crankwalk is also known as thrust bearing failure. the bearing fails and allows the crank to "walk". A walking crankshaft will not harm the crankshaft itself, but the movement can place excessive or uneven loads on the bearings, causing premature failiure.
When the crankshaft "walks", it pushes the backplate into the crank sensor causing it to fail (literally, it tears through the crankshaft angle sensor). This problem usually manifests itself as a ticking noise coming from the timing belt area, as the sensor is literally and slowly ground away by the crankshaft. Any such noise should be investigated right away to prevent serious problems. If you have taken apart your car to replace the crank sensor, look to see if there are plastic shavings on the trigger plate, where the plate has actually contacted the sensor itself. If your crank sensor has suddenly failed, the chances that the sensor has done so on its own are low. To replace the sensor alone is a short term fix, if your crankshaft is walking. Getting to the crank sensor is a lengthy process since the timing belt and all else has to come off.
Other causes of crankwalk include the 2g oil injectors. They clog, causing a lack of oil on the bearings and thus, the bearings warp and allow the crank to "walk". Also, it has been stated that a higher pressure clutch application, especialy the 2600, accelerates the process if you are going to get it. However, let it be known that there is no solid proof as of yet that a strong pressure plate causes crankwalk because of the relatively common occurence in stock cars.
The crankshafts in many of the 1G DSMs have a larger rod and fit more proporly inside the bearings. The six-bolt motors are not nearly as suseptable to get crankwalk as the later 7-bolts. The 6-bolt engines were produced between March, 1989 and the third week of May, 1992. May 1992 to the first week of May, 1994 have 7-bolt motors in the 1G DSMs. All 2G DSMs have the 7-bolt engine. Even though the Spyder has a 2.4L SOHC engine it can still crankwalk, as with the 1.8L 1G. Note that any engine can get crankwalk, even big V8s.
If you want a temporary fix for crankwalk, you can contact Mitsubishi as they have made bearings which propory fit the crankshft. Matching the bearings is tricky and requires exact information about when the crankshaft was manufactured, which may be determined by color markings on the crankshaft itself. The 2G factory manual includes information on how to match crankshafts to bearings.
There is no real way to tell if you car is experiencing crankwalk, symtoms are usully difficult to diagnose untill major damage occures. Some symptoms are that when you are turning a left corner the clutch will often stickdown, this is often a sign of crankwalk. Other symptoms include rough or poor clutch engagement, inconsistant engagement height, ticking noises, difficult shifting, and variing pedal height or pressure. Another symptom is having the engine RPM decrease significantly when the clutch pedal is depressed. As you add more and more horsepower to your engine, the greater chance you have of getting crankwalk.
Also, there is no recall as of yet on the crankshafts.
for more info on crankwalk, check out these sites.
- http://www.magnusmotorsports.com/crankwalktheory.htm
- http://members.shaw.ca/costall/1000Q/
- http://www.vfaq.com
- http://www.nx2k.com/eclipse/crank_walk.htm
Or go somewhere like google and do a search for crankwalk.
Thanks. I've added your information to the origianl post.
Its about a different crank and bearing design, along with the other changed mentioned. When a 7 bolt is new, or hasnt walked and has 150k miles on it, the crank fits in the bearings just fine. Some walk, some dont. Why that is is the real mystery.
