95 Metro Timing Belt snapped

jdmetro · #1 02-06-2006, 01:26 PM

Some one please tell me what a "free-wheeling" engine design means and does my car have one? I have a 95 geo metro 3cylinder, 1 liter motor. Supposedly if it is a free-wheeling design then there is less likely a chance that the valves were damaged when the timing belt snapped. Unfortunately, the moron tow truck driver had me try to turn the engine over repeated times in an attemot to diagnose the problem. He thought is was a coil pack. It wasn't!! Thanks for your help.

jd

BeoWolfe · #2 02-06-2006, 02:47 PM

Your safe

. In some engines the valves travel down past where the top of the piston hits when its at the peak of its travel. This is usually ok as the timing belt turns the cam to keep the valves up and out of the way when the piston comes up. Now if the timing belt breaks and a valve is hang down where a piston can hit it the you can imagine the horrible things that would happen.

Luckily in the Geo the valves never travel down far enough for the piston to hit it so even with the timing belt broken its safe you can crank the car over til your blue in the face with out hurting anything.

jdmetro · #3 02-06-2006, 04:54 PM

Thanks Beowolfe for the quick response. You sound well informed regarding my timing belt situation. I hope your are right. My mechanic asked me if I was driving at highway speeds when the T-belt snapped. I wasn't going more than 5 mi. per hr. and traveled less than 35 yards. The mechanic said the 95 Geo metro has what's called an interference engine and the valves could bend when a the timing belt breaks. He also stated that I might need a new water pump. Does this sound right? What's with this interference aspect? And why would he be concerned about my travelling speed?
ps. I going to show him your responses. Even though this mech. has been pretty straight with me in the past, it never hurts to let them know someone is always looking over their shoulder. Thx again Beowolfe...jd

frets14 · #4 02-06-2006, 05:26 PM

Hey JD, I just replaced the timing belt and head on my 95 Metro last fall. The head was replaced due to worn out valves. Your mechanic is definitely wrong in this regard. When I replaced the head I had the cam caps a bit too tight and 30 seconds after the car started the cam froze up and the timing belt snapped. I loosened the caps, replaced the belt and the car has been running fine ever since.

unbe · #5 02-06-2006, 05:48 PM

Quote:

Originally Posted by frets14

Hey JD, I just replaced the timing belt and head on my 95 Metro last fall. The head was replaced due to worn out valves. Your mechanic is definitely wrong in this regard. When I replaced the head I had the cam caps a bit too tight and 30 seconds after the car started the cam froze up and the timing belt snapped. I loosened the caps, replaced the belt and the car has been running fine ever since.

Frets
Wouldn't you say this was a too tight cam bearing issue and not an interference issue,I don't see where your drawing your conclusion from.
Unbe

unbe · #6 02-06-2006, 05:56 PM

[quote=jdmetro][b][color=darkolivegreen]Thanks Beowolfe for the quick response. You sound well informed regarding my timing belt situation. I hope your are right. My mechanic asked me if I was driving at highway speeds when the T-belt snapped. I wasn't going more than 5 mi. per hr. and traveled less than 35 yards. The mechanic said the 95 Geo metro has what's called an interference engine and the valves could bend when a the timing belt breaks. He also stated that I might need a new water pump. [i]Does this sound right? What's with this interference aspect?
Non-interference would be the same as what your calling free-wheeling
Unbe
P.S. Its not uncommon for them to recommend a new water pump while they are in there.

jdmetro · #7 02-06-2006, 07:15 PM

Thanks Unbe. Can my mechanic tell if the valves were affected by a visual inspection or will I just have to "wait and see" as he has suggested? Beowolfe, can you also chime in on this interference issue?

frets14 · #8 02-06-2006, 09:38 PM

Unbe,
Replacing the head and having the bearing caps too tight was not the issue. All I was saying is that after the timing belt broke while it was running, all I had to do to make the car operational again was simply replace the timing belt.
By the way, the head was replaced prior to the timing belt breaking because the car needed a valve job (no compression). I bought a rebuilt head from Ebay for $90 and a head gasket set for $60 and put the car together. First time for me and my only error was the bearing caps. It made me feel good about my abilities getting the car back on the road again.
Steve

unbe · #9 02-07-2006, 05:02 AM

Quote:

Originally Posted by frets14

Unbe,
Replacing the head and having the bearing caps too tight was not the issue. All I was saying is that after the timing belt broke while it was running, all I had to do to make the car operational again was simply replace the timing belt.
By the way, the head was replaced prior to the timing belt breaking because the car needed a valve job (no compression). I bought a rebuilt head from Ebay for $90 and a head gasket set for $60 and put the car together. First time for me and my only error was the bearing caps. It made me feel good about my abilities getting the car back on the road again.
Steve

Steve
Thanks for clarifing,I was thinking you meant something else,BTW,how many miles did you have on your 95 when it broke.Ive got 170k on my 96 with the original belt on it.
Unbe

jdmetro · #10 02-07-2006, 06:48 AM

Steve, that's good news. my 95 metro has 208,000 and was running great up until the timing belt snapped. jd

BeoWolfe · #11 02-07-2006, 08:57 AM

Greetings JD,

http://www.theautoshop.com/timing.html#GEO Shows the 1.0 as a non-interference engine. If your engine was an interference type and the piston hit a valve you would of heard an ungodly amount of noise as your valve got smashed into kindom come

. As far as the water pump replacement - the mechanic has to remove the water pump pully inorder to replace the timing belt, if the water pump extremely old and has signs of wear (squeaky bearing, excessive weepage) then it might not be a terrible idea to replace it. If it looks in good shape then why waste the money.

frets14 · #12 02-07-2006, 05:13 PM

Quote:

Originally Posted by unbe

Steve
Thanks for clarifing,I was thinking you meant something else,BTW,how many miles did you have on your 95 when it broke.Ive got 170k on my 96 with the original belt on it.
Unbe

My Metro had just under 100,000 miles on it. However, the belt didn't break due to its age. It broke because, as an amateur mechanic, I didn't use a torque wrench on the cam caps. The camshaft seized up when I first started up the engine but the crank kept trying to turn and broke the belt. I was lucky the it didn't cause any harm to the cam. Anyhow, I tell you this so others can learn from my mistake.

As far as the 95 Metro is concerned, I picked it up in non-running condition for $100 (plus it had $15 worth of change laying in it). My sole purpose was to learn how to fix it. I figured out that it had no compression and the most common cause of that is burnt valves. When I replaced the head, I solved the problem. I have since donated the car to our minister and his family. They love it!

jdmetro · #13 02-07-2006, 07:29 PM

Hello Beowolfe, I saw the link and sure enough it doesn't indicate an "interference" type engine for the 1 Li. Geo engine. My mechanic however stated that the computer at the shop showed it having an interference type.
In either case, he replaced the T-belt and said the old water pump was okay. He said visual inspection of the valves showed no damage. Although he did state that one can never tell when it comes to this kind of repair and that we'll just have to wait and see. Not much comfort there, huh? My final question now is: HOW LONG WILL I HAVE TO WAIT WHILE USING THE CAR TO SAFELY INDICATE--NO DAMAGE;A OKAY ? 1 WEEK? 1 MONTH? OR 1,000 MILES? OR NEVER??

carpenter_jai · #14 02-08-2006, 03:12 AM

HOW LONG WILL I HAVE TO WAIT WHILE USING THE CAR TO SAFELY INDICATE--NO DAMAGE;A OKAY ? 1 WEEK? 1 MONTH? OR 1,000 MILES? OR NEVER??

You would know the second you turn over the engine. Bad noise. I've seen the engine listed as non-interference in maybe a dozen places, but every once in a while, somebody get's it wrong. You're timing belt is supposed to be replaced every 55, 000 miles, which you had doubled. These things do stretch ever so little, and that will be enough to effect timing.

Jai

jdmetro · #15 02-09-2006, 06:51 AM

JAI, The Metro seems to be running fine. Sounds as good as it did before the break. I hope the mechanic checked it for the correct timing when he installed the new Timing Belt. If not, are you saying that I will be able to tell instantly if the timing is off? Thanks for the input everyone.

Now I'm looking at a 96 Lumina with 92,000 mi. Seller claims that intake gasket was changed along with head gasket. This is after I mentioned that the 95-96 Lumina is notorious for having leaky intake gaskets. How can I tell if he's telling the truth? Just check for a leak on the ground? Anything else I should look for with this car? I heard they go through brakes like nobody's business..

JD

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