Timing belt not broken, but cam won't turn? - Mitsubishi Forum - Mitsubishi Enthusiast Forums

2nd Generation This includes all Eclipses, and Talons built from 1995-1999
Sponsored by:
Sponsored by:

Thread Tools Search this Thread
Old 06-14-2007, 09:48 PM
Thread Starter
Join Date: Jun 2007
Posts: 3
Default Timing belt not broken, but cam won't turn?

This is a new one for me. My 97 Spyderw/stock 4g64engine was running fine but would not restart after shutdown. It makes that sickening sound they make when the timing belt breaks. I removed the oil cap to see if the rockers were moving when the the engine turned over and they were not. Great! The belt broke while starting. No bent valves. I then pulled the timing cover to find the timing belt tight and intact. I cranked it over again and the engine turns over and thealternator and power steering pump belts are turning with the crankbut the timing belt and camare not moving.Anyone have any idea what has happened?
Reply With Quote
Old 06-15-2007, 02:00 AM
Join Date: Apr 2007
Posts: 232
Default RE: Timing belt not broken, but cam won't turn?

sounds like maybe bearings may have siezed up or a rod is broke somewhere in there.
Reply With Quote
Old 06-15-2007, 04:21 AM
Senior Member
Join Date: Nov 2006
Location: Colorado Springs, CO.
Posts: 3,430
Default RE: Timing belt not broken, but cam won't turn?

This doesn't make any sense.
Your crank spins but not the cams? You say there's no bent valves...how do you know this? Did you remove them?
If the crank is moving the pulley to move the accessory belts, then your belt is loose or there's something in the head that is keeping the cams from moving. So, is it the cams, lifters, or valves that are locked?

What were you doing with your car, btw? Did you rev your motor too high (float)?
Reply With Quote
Old 06-18-2007, 09:16 PM
Thread Starter
Join Date: Jun 2007
Posts: 3
Default RE: Timing belt not broken, but cam won't turn?

I am hoping there are no bent valves. I have not pulled the head yet. I assumed the valves were not bent because the engine was running fine whenit was shut off. After sitting for an hour it would not restart.The crank rotates freely and the bottom end sounds intact. The timing belt is as tight as a new belt installation. Could the key be sheared on the crank sprocket or stripped from the belt?I dont have enough experience with a 4g64 or any other Mitsubishi engine to diagnose what happened. All my experience has been with big blocks and small blocks.
Reply With Quote
Old 07-16-2017, 12:16 PM
Junior Member
Join Date: Jul 2017
Posts: 8
Default 39 year backyard mechanic

Either a guide pin broke between the pulley and the shaft of crank or cam or the belt is missing teeth and just spinning or the cam broke close to the pulley.
You have to set the timing again with a new belt being certain that both intake and exhaust rockers on no1 cylinder is loose as it's in the compression strap me and not the intake strike or 180^ out.
If you have interference engine be preosr d for damaged valves.
Reply With Quote
Old 07-20-2017, 11:29 PM
mxmikie's Avatar
Senior Member
Join Date: Sep 2005
Location: Bouse,az
Posts: 1,049

your timing belt teeth have striped off the belt at the crankshaft remove the belt and you will see
Reply With Quote

Related Topics
Thread Thread Starter Forum Replies Last Post
Intermittent starting, cranks but won't turn over phatmatt Mitsubishi Endeavor 1 07-16-2017 12:27 PM
broken timing belt on 96 mirage 1.5 89baja Mitsubishi Mirage 4 09-29-2011 09:08 PM
Broken Timing Belt mhorn0817 Mitsubishi Galant 0 04-25-2011 07:07 PM
Cam timing/timing belt change on VR4 engine 8000RPMS Mitsubishi 3000GT 2 08-30-2007 05:49 AM
no reverse lights and turn signal won't turn off dornstar 2nd Generation 5 05-22-2006 04:58 PM

belt, broke, broken, cams, camshaft, crankshaft, eclipse, mitsubishi, moving, reason, spin, spins, timing, turn, turning

Thread Tools Search this Thread
Search this Thread:

Advanced Search

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

Featured Sponsors
Vendor Directory

All times are GMT -5. The time now is 10:35 AM.

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.