I think my timing belt broke, but it didn't break while I was driving...it broke when I was trying to crank my car this morning.

Does this mean my valvetrain is screwed? Is cranking a motor with a broken timing belt as bad as breaking it while driving??

Any help would be appreciated!


Modified by chet90si at 10:58 PM 3/2/2008


Modified by chet90si at 10:58 PM 3/2/2008

 

Its not as bad as breaking it while driving. But theres still the chance that it has bent something.

Its easy to see if your belt is broken or not, go and check if your unsure.

 

Yea I know its easy to go check, but I'm already back up at school...and the car is back home.

I didn't get a chance to check before I left...

 

**** sucks happen to me when i was driving in my ls ((bent valve)) dont try cranking it. it'll make the situation worse trust me

 

And the verdict is?

 

Well since I'm back up at school, I can't really take a look at the car myself.

However, I got my friend to go mess with it, and when he took off the valve cover, he found atleast 7 bent valves...but the timing belt was still intact!!!

I really have no clue what happened. This is a brand new swap (that I bought from Hmotorsonline). I literally drove it only once, and the next morning the car just wouldn't start.

Any idea what could have happened, or where I should go from here? I was really easy on the motor on the 1 drive that I did take. No redlining, no WOT, no hard downshifting, etc...

 

how does he know the valves are bent without taking the head off or at least the valve springs? Are they that bent?

Your belt could not have been tensioned properly and jumped a tooth or four...

my timing belt broke while I was reversing into my parking spot. I cranked it for a second before I remembered what that fast no compression cranking sound was. My valves were all fine. I just threw a new belt on her and away I went.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by chet90si &raquo;</TD></TR><TR><TD CLASS="quote">Well since I'm back up at school, I can't really take a look at the car myself.

However, I got my friend to go mess with it, and when he took off the valve cover, he found atleast 7 bent valves...but the timing belt was still intact!!!

I really have no clue what happened. This is a brand new swap (that I bought from Hmotorsonline). I literally drove it only once, and the next morning the car just wouldn't start.

Any idea what could have happened, or where I should go from here? I was really easy on the motor on the 1 drive that I did take. No redlining, no WOT, no hard downshifting, etc...</TD></TR></TABLE>

I doubt you've managed to jump enough teeth to have bent valves. I think your friend is lying.

 

Thanks for the replies everyone!

Ok, so lets assume that my friend is wrong, and my valves AREN'T bent. He confirmed that the timing belt was still intact...so what else could be causing the "no-compression" cranking?

 

Check the timing belt, if it came on the motor (its old) it could be missing teeth and just sitting there not turning.

 

Explain to me why you think your timing belt broke, why you were so sure at first, and now have no idea. I would like to know exactly what you did to the car prior to posting this. It seems you are not giving us all in the information, which makes diagnosis harder, not to mention more expensive.

 

then check it

 

Ok, I'm going to try to give all the info that I can think of...

I got the engine installed by an extremely reputable shop here in NC (RLZengineering). On Saturday, I went and picked up the car, and drove it home. On the drive home I was EXTREMELY easy on it... only revved up to 6k once just to make sure VTEC engaged, butter-shifted the whole way, etc. When I parked the car it was running exactly like it should.

On Sunday I had to go back up to school in Greensboro (in my other car). I wanted to fire up the CRX and take her for a quick spin before I left...I did just get a brand new motor swap after all, I was excited! The noise I heard was an extremely fast cranking sound...what I've always associated with "no-compression" cranking. I didn't have time to diagnose it since I was literally on my way out of town, but since it was a fast crank I just naturally assumed it was the timing belt.

Yesterday, my friend went over there to mess around with it. He's mostly a hardcore D-series guy (as was I before my swap) but he said that when he pulled the valve cover to check the belt, he found atleast 7 bent valves... and that the belt was still fine.

Now what I'm getting from this thread is that you can't tell whether the valves are bent by JUST taking off the valve cover...correct? If thats the case, what could my friend have been seeing that made him say bent valves? Are B-series and D-series valves that different to where he though he was seeing something that he wasn't?

I can't wait to get home and take a look at it myself, and take pictures to show you guys whats up. Thanks for all the help!

 

well i know that all the valves are under the cams on the b series motors and im pretty sure there is no chance in hell that you can see the valves by removing the valve cover only, for i have removed my b series valve cover and i cannot see my valves, and like stated above your timing belt would have to jump a great deal of teeth to bend your valves, many people run on the wrong timing everyday with no bent valves for example... I think you should have took it back to the shop that dropped the engine in... I hope you guys taking apart didnt void any warrenty you had with the shop..

 

You can be pretty certain that your timing belt is fine. If you had been out driving it, parked it, then it wouldn't start. the forces of driving would have broken it if it were on its way out, not just cranking the engine over.

How long did you crank it over for? I would imagine if you thought it was a broken timing belt you would have stopped pretty quick?

Maybe it just needed more time to crank before starting.

 

I tried cranking it about 4 times, for about 3-4 seconds each time. It definitely didn't sound like it was gonna start.

 

so did you find out if your valves are acutally bent?

 

call up the shop you got the swap from and tell them what happened. this should fall under the Lemon Law. yes its a real law lol.

 

Well I talked to my friend again, and he said that when he tried to move the rockers a little to get the valves to move, the "bent" ones weren't moving. He came to the conclusion that the shaft of the valves were bent, and thats why they were stuck.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by chet90si &raquo;</TD></TR><TR><TD CLASS="quote">
Yesterday, my friend went over there to mess around with it. He's mostly a hardcore D-series guy (as was I before my swap) but he said that when he pulled the valve cover to check the belt, he found atleast 7 bent valves... and that the belt was still fine.

Now what I'm getting from this thread is that you can't tell whether the valves are bent by JUST taking off the valve cover...correct? If thats the case, what could my friend have been seeing that made him say bent valves? Are B-series and D-series valves that different to where he though he was seeing something that he wasn't?

I can't wait to get home and take a look at it myself, and take pictures to show you guys whats up. Thanks for all the help!</TD></TR></TABLE>

I don't know about the rest of you but when I check a timing belt I don't usually take the valve cover off.
Sometimes you can't tell if a valve is bent until you take it out of the head.
I would take the timing cover off and inspect the belt, make sure your cams and crank are aligned right. After you are 100% sure that the timing is right start checking out the valves.
If you check out the valve cover you might be able to tell if a valve is stuck down by checking out the height the springs are at. Keep in mind you have to have all your cylinders in mid-stroke so all the valves will be closed.
If you have a compression tester get that out, if a valve is bent it should have really low or no compression. It should be obvious which cylinders have bent valves.
And finally the only real way to know if you have bent valves is to disassemble the head remove the valves and check each one individually. It might just be something weird going on. I wouldn't think that you'd have enough damage to have to replace pistons, I'd say worst case you have a bent valve or two.

I'm just an amateur/hobby mechanic so that's just what I'd do and such, it might not be factory procedure or anything. I'm sure someone with more knowledge will chime in.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by civicjoe &raquo;</TD></TR><TR><TD CLASS="quote">

I don't know about the rest of you but when I check a timing belt I don't usually take the valve cover off.</TD></TR></TABLE>

I was thinking that too, but B series have their timing belts covered by the valve cover and not just a separate cover like the D series.