|
|
 Timing belt snapped on '00
#1074630
10/06/14 03:03 PM
|
Joined: Jan 2005
Posts: 899
OP
Rock Warrior
|
Am I screwed? Valve damage?
|
|
|
Re: Timing belt snapped on '00
[Re: Fujisawa_Rob]
#1074631
10/06/14 03:53 PM
|
Joined: Dec 2006
Posts: 163
Wheeler
|
From AGCO automotive website: Mitsubishi 3.8L Interference
|
|
|
Re: Timing belt snapped on '00
[Re: Fujisawa_Rob]
#1074632
10/06/14 07:28 PM
|
Joined: Feb 2002
Posts: 1,410
Body Damage is Cool
|
Am I screwed? Valve damage? The 3.5 engine is an interference engine, BUT if you're lucky there may not be any damage. Any loud metal against metal sounds? <img src="/forums/images/graemlins/confused.gif" alt="" />
98 Gen 2.5
05 Pontiac GTO
91 Corvette ZR-1
2011 Kia Sorento (wifey mobile)
Clarkdale, AZ
|
|
|
Re: Timing belt snapped on '00
[Re: Fujisawa_Rob]
#1074633
10/07/14 11:07 PM
|
Joined: Mar 2005
Posts: 1,006
Body Damage is Cool
|
I had a interference Honda engine snap a timing belt. Bent a couple of valves but nothing else. Replaced two valves and on the road again.
You'll only know if you remove the head. Compression test first would be good idea.
92 Montero LS 3.0L V6 Auto, Stock, Original owner, 185,800K miles
|
|
|
Re: Timing belt snapped on '00
[Re: pcc]
#1074634
10/08/14 02:24 AM
|
Joined: Jan 2001
Posts: 13,649
Web Wheeler
|
I would not do a compression test. A valve may be stuck extended, and you could do more damage. What speed was the engine at when the belt broke? This will give you an idea of how much damamge was done.
Ultimately, you'll have to pull at least one head, probably both, before you know what it's going to cost.
Not responsible for advice not taken...
|
|
|
Re: Timing belt snapped on '00
[Re: fasteddy]
#1074635
10/08/14 11:44 AM
|
Joined: Dec 2006
Posts: 163
Wheeler
|
Could he loosen the cams, replace the belt, THEN do compression test?
|
|
|
Re: Timing belt snapped on '00
[Re: cheesegrater]
#1074636
10/08/14 07:13 PM
|
Joined: Jan 2001
Posts: 13,649
Web Wheeler
|
Possible, with great care. You have to rotate the motor so all pistons are below tdc, then rotate the cams by hand to be sure all valves are fully closing (very slim possibility they will). If you get very lucky, then you could put on a new belt and check compression. The problem is that a bent vavle will usually not fully close. A bent valve is the most probable result of a broken belt, followed by piston and head damage. Valves are steel. Pistons are aluminum. You can get piston damage ranging from just dents to broken piston crowns.
Not responsible for advice not taken...
|
|
|
Re: Timing belt snapped on '00
[Re: fasteddy]
#1074637
10/08/14 09:23 PM
|
Joined: Dec 2006
Posts: 163
Wheeler
|
I also just had a thought that maybe by loosening the cams and relieving the lobe pressure, one could detect a bent valve since it would not return to fully closed position.
Last edited by cheesegrater; 10/08/14 11:22 PM.
|
|
|
Re: Timing belt snapped on '00
[Re: cheesegrater]
#1074638
10/08/14 10:58 PM
|
Joined: Jan 2001
Posts: 13,649
Web Wheeler
|
You don't need to loosen the cams. Just rotate the crank so no piston is at tdc, then rotate the cam sprocket. You don't have to drop the piston much. Valve lift is under 3/4" max, even with the rocker ratio being over 1.
Not responsible for advice not taken...
|
|
|
Re: Timing belt snapped on '00
[Re: pcc]
#1074639
10/27/14 08:10 PM
|
Joined: Jan 2005
Posts: 899
OP
Rock Warrior
|
Sorry for the delay, never got notifications of replies.
I'm in the process of pulling the heads, which of course means removing the whole top end. Kind of a pain. I'll know soon how bad the damage is. If I have valve damage, I might just go pull a set of j/y heads.
It snapped while driving, doing about 45. I had no idea what had happened, it just wouldn't restart. Now I know what a sudden compression loss feels like.
|
|
|
|
