1993 Crank Pulley Wobble - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


General Miata Chat A place to talk about anything Miata

Reply
 
 
 
LinkBack Thread Tools
Old 05-18-2008, 10:52 PM   #1
Junior Member
Thread Starter
iTrader: (3)
 
Join Date: Oct 2007
Location: Fremont, CA
Posts: 173
Total Cats: 0
Default 1993 Crank Pulley Wobble

Hi everyone,

I depowered my rack last week, and my buddy noticed that my crank pulley has a wobble to it.

My best attempt to explain the wobble:
There is 1.5-2 mm dfference between the lowest and highest points around the circumference of the crank pulley at idle.

I read the articles about the weak crank keyways on the 90-91.5 miata on miata.net, but mines is a 93. I also verified that I have the long-nose crank. Is there still a chance that my keyway is busted?

I will check torques on the bolt tomorrow. Is there anything else I should look into?
rippledabs is offline   Reply With Quote
Old 05-18-2008, 11:12 PM   #2
Senior Member
iTrader: (4)
 
Join Date: Aug 2007
Location: Guam (U.S Terr.)
Posts: 786
Total Cats: -2
Default

I think you got it down. Just be careful when you check those bolts. Because the head snap off easy. My neighbor snapped two of those bolts while trying to torque them to spec.
*Its a lot of fun drilling them out*
mike_671 is offline   Reply With Quote
Old 05-19-2008, 05:33 AM   #3
AFM Crusader
iTrader: (18)
 
olderguy's Avatar
 
Join Date: Oct 2004
Location: Wayne, NJ
Posts: 4,437
Total Cats: 84
Default

The long nose crank is also susceptable to "crank wobble". I've seen two and repaired one with the locktite fix. See MNet garage for details.
olderguy is offline   Reply With Quote
Old 05-19-2008, 09:46 AM   #4
Elite Member
iTrader: (30)
 
Join Date: Aug 2007
Location: Va Beach
Posts: 7,282
Total Cats: 0
Default

I had the same problem with my 92 (also a long nose). I repaired it according to the locktite instructions and it has been fine for a year now and mine was pretty bad.



__________________
Best Car Insurance | Auto Protection Today | FREE Trade-In Quote
levnubhin is offline   Reply With Quote
Old 05-19-2008, 12:10 PM   #5
Junior Member
Thread Starter
iTrader: (3)
 
Join Date: Oct 2007
Location: Fremont, CA
Posts: 173
Total Cats: 0
Default

Quote:
Originally Posted by levnubhin View Post
I had the same problem with my 92 (also a long nose). I repaired it according to the locktite instructions and it has been fine for a year now and mine was pretty bad.
Did you hear a metallic rattle noise at idle?
rippledabs is offline   Reply With Quote
Old 05-19-2008, 12:13 PM   #6
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,809
Total Cats: 1,780
Default

that's what min looks like, but mine makes deadly bird chirping noises.
Braineack is offline   Reply With Quote
Old 05-19-2008, 12:38 PM   #7
Elite Member
iTrader: (30)
 
Join Date: Aug 2007
Location: Va Beach
Posts: 7,282
Total Cats: 0
Default

Cant recall it making any noises. It was a year ago.
__________________
Best Car Insurance | Auto Protection Today | FREE Trade-In Quote
levnubhin is offline   Reply With Quote
Old 05-19-2008, 01:01 PM   #8
Elite Member
iTrader: (2)
 
Join Date: Jun 2006
Location: ABQ, NM
Posts: 1,850
Total Cats: -8
Default

I've seen 1.8s with pulley wobble. Also check the 4 bolts that hold the pulleys together. I've seen thoes little ******* shear right off.
BenR is offline   Reply With Quote
Old 05-20-2008, 10:39 AM   #9
Junior Member
Thread Starter
iTrader: (3)
 
Join Date: Oct 2007
Location: Fremont, CA
Posts: 173
Total Cats: 0
Default

Is it possible to check the key just by removing the big 21mm Bolt?

I may be able to see the keyway / key, to see any damages, using a dental mirror.

Last edited by rippledabs; 05-20-2008 at 11:24 AM.
rippledabs is offline   Reply With Quote
Old 05-26-2008, 06:05 PM   #10
Junior Member
iTrader: (1)
 
Join Date: May 2008
Location: NJ
Posts: 146
Total Cats: 0
Default

i noticed this on a 99 my buddy was looking to purchase a few months ago.

as far as i know the car is still for sale and about $2000 less than when we went to look at it.
ChairFaceChippendale is offline   Reply With Quote
Old 05-26-2008, 06:11 PM   #11
Newb
 
Join Date: Dec 2006
Location: U.K
Posts: 15
Total Cats: 0
Default

My crank pulley fell off on the way home from work a few weeks ago,it was my own fault as i had done a key way/wood ruff key repair a week or so before and although had used a thread lock when torquing up the crank bolt i had failed to fit a new crank bolt and i believe the old bolt had stretched.
dave_v is offline   Reply With Quote
Old 05-26-2008, 07:15 PM   #12
Junior Member
iTrader: (1)
 
Join Date: May 2008
Location: NJ
Posts: 146
Total Cats: 0
Default

yeah i'm under the impression that no matter what car/engine you're working on the crank pulley bolt is one time use. even if not it's worth the extra few dollars in that "while you're in there" kind of way.
ChairFaceChippendale is offline   Reply With Quote
Old 05-26-2008, 07:17 PM   #13
Senior Member
iTrader: (2)
 
SamS's Avatar
 
Join Date: Jun 2006
Location: Wisconsin
Posts: 1,251
Total Cats: 7
Default

I had 2 bolts shear off randomly a couple years ago, definitely made the pulley wobble.
SamS is offline   Reply With Quote
Old 07-19-2008, 11:53 PM   #14
Junior Member
 
Join Date: May 2007
Location: NC
Posts: 246
Total Cats: 0
Default

Keyway struck in my 00. About 1/8" play at front of keyway and the keyway on the inside of the cam pulley was also worn so replaced cam pully, welded keyway gap on the crank (to fill the excessive room) and ground it back to spec, new key fits nice and tight and I will be locktighting the whole thing tomorrow thoroughly. I too had a strange noise coming from the crank and I suspect it was this play in the bottom cam pulley. Yes I know welding your crank is not ideal since it anneals the metal etc (but the motor has 145K on it so I'm not too worried, by the time it's a problem I'll be into a new motor). Welding fix is a PITA (mostly all the sanding and grinding after the fact) but at least you know you will never have to do it again .... ever.
mtncrvr is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
TunerStudio timining issue - 90 Miata 1.6 Turbo spec1sef MEGAsquirt 28 05-09-2017 08:03 AM
Need help - Stock Balancer and Fastforward overlay pulleys Frank_and_Beans Supercharger Discussion 13 09-12-2016 09:17 PM
Missing/knock at idle, can someone point me in the right direction? Mikel MEGAsquirt 4 09-28-2015 05:46 PM
Got bad Crank Angle Sensor and Random Misfire codes, but runs fine. Greasyman General Miata Chat 2 09-28-2015 11:44 AM
So this fell out of my engine, identify? 1993z32 Engine Performance 11 09-05-2015 12:18 AM


Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 10:40 PM.