Crank Walk Questions

[JwAlbers]

i own a '95 Talon Tsi Awd. my car quit running, i took it to the shop, and they said the crank sensor is bad, and its probable that it is because of crankwalk. This is exactly what they wrote on the diagnosis:

Diagnose no start-no spark. Hooked up lab scope to cam and crank sensors and cam sensor worked ok, but crank sensor had no out put. Checked crankshaft end play and it measured around .010". IF crank moved enough to get into sensor that bottom end is trashed. If sensor and ring look ok it might just need a sensor.

Now my question is, if it has enough shaft play to break the sensor, would it be more expensive to fix the shaftplay, or get a different engine? I've already bought another t-25, used, but in good shape. Ive been told that fixing shaftplay means replacing the bearings and crankshaft, but i honestly dont know too much about these cars.

thanks guys,
Jeremy.

 

[95talongirl]

Well, the OE spec for crankshaft endplay is .0020-.0071; the measurement of .010 you got would mean, that... indeed this engine would need to be replaced... or at least the shortblock. The consensus, from what I've read, is that the best way to "fix" a walked engine is to replace it. You could go through and rebuild it, as well... but many people have had the rebuilt engine to the exact same thing again.

Most people opt for the 6 bolt, but I personally have had no troubles with the 7 bolt engine in both of my 95's.

 

[2GRick]

Well, the OE spec for crankshaft endplay is .0020-.0071; the measurement of .010 you got would mean, that... indeed this engine would need to be replaced... or at least the shortblock. The consensus, from what I've read, is that the best way to "fix" a walked engine is to replace it. You could go through and rebuild it, as well... but many people have had the rebuilt engine to the exact same thing again.

Most people opt for the 6 bolt, but I personally have had no troubles with the 7 bolt engine in both of my 95's.

Go to the Magnus website, click on text and read this well written article. There concensus is that a properly set up crank, while no guarantee, seems to fix the problem in the majority of cases. At least thats my take on the article. They have done more hard research and tech on this than just about anyone else.

 

[95talongirl]

Thanks! I remember reading about the oil squirters; but that article was well put together.

And you are right... who knows if those rebuilt crankwalked motors that did it again were actually rebuilt properly.

 

[say4life]

What have you done to prevent crank walk?

 

[2GRick]

What have you done to prevent crank walk?

Nothing yet ! But will have to eventually. Appparently one of the biggest things you can do is to disconnect the clutch interrupt switch. I've only had my GS T for 1000 mi. It was rebuilt 15,000 mi ago but the clutch interrupt switch has only been disconnected for the last 800 or so mi. I've got about .008 end play and will watch it every 2000 k. Spoke with TEM machine in Napa CA ( a true high performance shop). about the issue and he said to watch it carefully. He is a believer in the 4 piece thrust bearing and careful machineing to help the problem. I would recommend that everyone read the Magnus article. It really cuts throught the hot air and rabbit tracks that pervades this issue.

 

[95talongirl]

Yea, I've often thought a better designed thrust bearing would help this as well. Both of the 95's I have are pretty much stock; in the manner that I haven't done anything like the clutch interupt switch. The white car is running a heavier clutch, with a 16g and supporting mods and has been fine for 190,000 miles miles now. about 50k of which are on the heavier clutch, larger turbo, ect. The blue car has about 111,000 miles and is running the stock clutch and turbo and such.

Both of these cars ARE early build 95's... meaning august and april of 1994. Perhaps this might be a reason?