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Registered:
May 2004
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Shredded Timing Belt, 7MGE
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Sun, 01 August 2004 09:36
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Hi all,
Anyone have any ideas why a 7MGE (3.0 litre 24v Cressida) keeps shredding timing belts?
It's eaten 2 recently; inless than 2,000 km!
Robert
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Location:
Bayside Melbourne.
Registered:
May 2003
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Re: Shredded Timing Belt, 7MGE
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Sun, 01 August 2004 10:29
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It's hungry? 
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Location:
Brisbane
Registered:
June 2003
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Re: Shredded Timing Belt, 7MGE
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Sun, 01 August 2004 10:31
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a pulley not being on straight/ too much/ not enough tension on the belt?
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Registered:
May 2004
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Re: Shredded Timing Belt, 7MGE
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Sun, 01 August 2004 11:07
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Thanks for the suggestions
... it can't be hungry, it's had two already 
... Pulleys look correctly aligned, no obvious faults. The tension 'felt' right; <90º twist on longest run, around 100 Hz.
Have checked the basics. Am looking for something that may be specific to the 7MGE; moving tensioner, worn bearing/other parts.
All advice much appreciated. Feel free to suggest the basics, I may have over looked something simple (as often happens).
Thanks
Robert
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Location:
Brisbane
Registered:
June 2003
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Re: Shredded Timing Belt, 7MGE
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Sun, 01 August 2004 11:14
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only thing ther than tension would've been crankshaft pulley movement. but this shouldnt be happening anyway..is your motor in good nic? ie no bangs, knocks or rattles?
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Location:
Lismore, NSW
Registered:
February 2003
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Re: Shredded Timing Belt, 7MGE
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Sun, 01 August 2004 11:17
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Tight camshafts?
Damage sprockets?
Tight oil pump?
Tight Idle pully?
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Registered:
May 2004
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Re: Shredded Timing Belt, 7MGE
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Sun, 01 August 2004 11:22
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When the first one shredded itself, we found the crank pulley was loose and assumed that to be the cause.
This time it's still tight.
Engine is quite tired, tappet noise, bearing noise, blow-by and the usual oil leak suspects. It may well be time to replace the whole thing.
... Is the oil pump driven off the jackshaft?
Robert
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Location:
Brisbane
Registered:
June 2003
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Re: Shredded Timing Belt, 7MGE
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Sun, 01 August 2004 11:23
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oil pump dead? My oil pump bearings were extremely tight fit when i rebuilt my motor..and would've snapped belts had i not have worn in the bearings with a scourer.
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Registered:
May 2004
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Re: Shredded Timing Belt, 7MGE
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Sun, 01 August 2004 11:40
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Are the oil pumps and/or bearings prone to seizure?
Are these engines expensive or difficult to do a full rebuild?
Robert
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Location:
Brisbane
Registered:
June 2003
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Re: Shredded Timing Belt, 7MGE
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Sun, 01 August 2004 11:50
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depends if your head is rooted
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Registered:
May 2004
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Re: Shredded Timing Belt, 7MGE
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Sun, 01 August 2004 12:01
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I suspect that it'll need a proper head job.
Are you implying that the bottom end is cheap and easy, but the head is an expensive nightmare?
Robert
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Location:
Brisbane
Registered:
June 2003
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Re: Shredded Timing Belt, 7MGE
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Sun, 01 August 2004 12:07
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| xl912 wrote on Sun, 01 August 2004 22:01 |
I suspect that it'll need a proper head job.
Are you implying that the bottom end is cheap and easy, but the head is an expensive nightmare?
Robert
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exactly right
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Registered:
May 2004
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Re: Shredded Timing Belt, 7MGE
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Sun, 01 August 2004 12:14
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Bugger.
Thanks for the advice, much appreciated.
regards
Robert
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Location:
Sydney
Registered:
February 2003
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Re: Shredded Timing Belt, 7MGE
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Sun, 01 August 2004 12:19
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| xl912 wrote on Sun, 01 August 2004 22:01 |
I suspect that it'll need a proper head job
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Don't we all
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Registered:
May 2004
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Re: Shredded Timing Belt, 7MGE
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Sun, 01 August 2004 12:21
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| STR8 2.8 wrote on Sun, 01 August 2004 22:19 |
| xl912 wrote on Sun, 01 August 2004 22:01 |
I suspect that it'll need a proper head job
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Don't we all
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Never mind a proper one
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Location:
Melbourne Vic
Registered:
October 2002
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Re: Shredded Timing Belt, 7MGE
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Sun, 01 August 2004 12:40
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umm, with regaurd to your money hungry 7M, have u tried getting a new tensioner & spring. (I know, 2 weeks from japan, still waiting on one), anyhow i would bet its the spring, mine was under tension, and was slapping around under accell, only a matter of time, and it prob would have stripped the belt teeth.
And i got the head completely done up (2 cracks welded, stud hole welded & tapped, valve grind, reseat, valve guides, shims & hot high pressure clean), new hg kit, new injector seals, throttle body gasket, double platinum NGK's and usual coolant, oil & filter change for $1200, car is like new. (all labour done by me thou)
If your bottom end if fucked thou, then prob easier to just get another engine for her.
Pic of my head after reco (Warning: HUGE pic):
http://members.optushome.com.au/cseufert1/IMG_0008 .JPG
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Registered:
May 2004
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Re: Shredded Timing Belt, 7MGE
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Sun, 01 August 2004 12:54
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Thanks. I'll have a look at the tensioner and spring.
Not sure that investing that kind of money in the head is good value for this engine.
As you suggest, it may be more cost effective to replace it.
Robert
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