Timing belt

[Jerseybuilt]

I'm installing a new timing belt, on my son's 2003 MP5. When I removed the valve cover, I found that the belt stripped itself of most of it's rubber cogs and slid off the rear camshaft pulley. With the crank shaft at TDC, the cam shaft I and E no longer line up. Should I be able to spin with a 14mm wrench or socket, to align??? Any help would be great!! Thank you

 

[pcb]

I was wondering that same thing when I did my timing belt.
At the rock auto web site they list this car as an interference engine, but allot of people here said that it wasn't.
With that in mind, I would take out the plugs (if you didn't do that already) and then slowly turn the cam shaft if a valve hits the piston I would assume you would feel it.
I was going to spin my crank shaft on purpose without the belt just to see if anything hit, but I forgot to do it.

I'll send you another post with further details later. This should get you started.

 

[Brains]

when i was doing my timing belt, i somehow managed to spin the crank independently of the gear that's on the shaft. I had taken out the little metal bar that's responsible for keeping the timing belt's gear on the crank shaft, the actual crank shaft, and the crank pulley from spinning independently so when i stuck a socket on the shaft it spun and i assumed the crank wasn't really spinning because the gear wasn't spinning.
At least, i think that's what i assumed. You should never assume, especially if it's assuming an assumption. You know, the more i think about it, i can't remember why i was spinning the crankshaft in the first place. Maybe i was trying to get it to TDC. Who cares.

Point is, i turned the crank a full 360 with no problems, so you should be fine. The engine is listed as an interference engine, but i don't believe it is. I think, when the valves are fully protruding into the cylinder, they're going into a grove in the piston, so they never really contact the piston.
Don't tell anyone i said that cause it's some BS speculation on my part... but i thought you should hear it anyways.

You should be fine (2thumbs) make sure you don't damage your tensioner spring, or the plastic timing belt cover.

 

[Jerseybuilt]

I read that you can turn the crank, slowly to the right and rotate the camshaft slowly to the left. As long as you don't feel any resistance. I tried it and the rear camshaft wouldn't move. I don't want to force it, until I know for sure, if I can.

 

[pcb]

You should consider a water pump when you're in there, as well as valve cover gasket, cam and crank seals (I didn't bother, they looked good and they can be pita to replace. You can use a small flat head to do them but you have to be really careful.)
I also changed my Idler and tensioner These parts are relatively cheap especially when you consider the cost at a garage (I was quoted $1600)
Here's a link with every thing you you will need.

http://www.rockauto.com/catalog/raframecatalog.php?a=G-mazda

I would throw in a few extra items to help justify the shipping cost. (oil filters (I use the one for the 02 626, it's bigger and cheaper)air filters, head lights, plugs etc) Get the other belts too, about $20 AC and alternator.

Make sure your kit comes with a tensioner spring. If you're not sure just order one,..$2

The tensioner spring is important because the the tensioner pulley is "active". It pivots freely even when you lock down the tensioner.

I had a hard time with the cams. They wouldn't stay still when I wrenched them into place. They would spring back a tooth or so when I let go of the wrench. One guy mentioned to use two combination wrenches tied together to hold them still but I couldn't figure out what he meant. I hope you have someone to help you. 4 arms certainly make it easier.

I also left the spring off till the belt was on but it was too hard to attach it after it was on so I tied piece of wire to the end of the spring so I could pull it up and hook it on the pin. The end at the tensioner has to be attached before you install it.

I also realized that the timing marks are also on the other side of the cams and it's way easier to see them when you look at them from the driver's side.

Make absolutely sure all three marks line up. Rotate everything a bunch of times till you're certain.

I had my belt on and off 8 times before I was satisfied. I had to use my elbows to hold everything while I put the belt on. That part took me 4 or 5 hours, but I finally got it.

Make sure you use the right timing mark for the crank shaft it's the one underneath the crank pulley, a little notch.

 

[pcb]

when i was doing my timing belt, i somehow managed to spin the crank independently of the gear that's on the shaft. I had taken out the little metal bar that's responsible for keeping the timing belt's gear on the crank shaft, the actual crank shaft, and the crank pulley from spinning independently so when i stuck a socket on the shaft it spun and i assumed the crank wasn't really spinning because the gear wasn't spinning.
At least, i think that's what i assumed. You should never assume, especially if it's assuming an assumption. You know, the more i think about it, i can't remember why i was spinning the crankshaft in the first place. Maybe i was trying to get it to TDC. Who cares.

Point is, i turned the crank a full 360 with no problems, so you should be fine. The engine is listed as an interference engine, but i don't believe it is. I think, when the valves are fully protruding into the cylinder, they're going into a grove in the piston, so they never really contact the piston.
Don't tell anyone i said that cause it's some BS speculation on my part... but i thought you should hear it anyways.

You should be fine (2thumbs) make sure you don't damage your tensioner spring, or the plastic timing belt cover.

Awesome, I'd rather get my car towed home instead of straight to the junk yard.

 

[ccrunner2011]

If it's lined up at E it's at top dead center of the exhaust stroke... If it's lined up at I it's in the intake stroke.. There's actually two 'dots' that were on my cam gears to line up timing. They were really notches if i remember correctly, but they only come around every 4 turns of the crank.


If the timing is way off, valves can and probably will hit a piston...

 

[pcb]

He' is worried that he can't even turn the camshaft at all without damaging something.
Now that I'm 98% sure that it is a non-interference engine, he is free to spin any cam or crank without doing any damage so he can go ahead and line up his marks.
The timing marks on the cams are little nicks that are on the edge of the cam they are not lined up with any exact tooth on the cam but they must line up so that they point directly at each other. Left cam at 3 o'clock and right one at 9 o'clock.
If you try to look from the passenger side it's hard to see if the lines are "EXACTLY" lined up.
if you look from the drivers side, you can see the lines better by leaning down till the marks line up with the straight and flat mating surface of the valve cover.

If this was an interference engine it would probably be shot any way and the fact that brains spun his crank right around I'm pretty sure he could do the same with either cam as well.
With the cams not moving I'm almost positive that at least one or them would be open for the piston to hit when the crank is spun.

Now I really wish I had remembered to spin all of them when I did mine.

My cams were really hard to turn as well. I only had to turn it a tooth or two but then I had to hold it because it would spring back a tooth notch when ever I let go.
There is allot of force needed to push down a valve spring, but the crank should spin much easier with plugs out.

 

[pcb]

Holy s***, I just read the original post again.
The I and E aren't supposed to line up. You've gotta line up the marks on the cams.

 

[pcb]

I just checked the manual and the I and E are right there beside the timing marks.
I thought I remembered that they were each at the 12 o-clock position when the timing marks were aligned.
I just knew to ignore the letters and look for the marks.
Same for the crank, ignore the pulley and look for the mark underneath it.

 

[pcb]

I'm installing a new timing belt, on my son's 2003 MP5. When I removed the valve cover, I found that the belt stripped itself of most of it's rubber cogs and slid off the rear camshaft pulley. With the crank shaft at TDC, the cam shaft I and E no longer line up. Should I be able to spin with a 14mm wrench or socket, to align??? Any help would be great!! Thank you

How many teeth or degrees are you out?? I know I had moved mine at least 2 or 3 teeth while playing, so I know that much is safe.
Was there any kind of clunk that a piston hitting a valve would make??

My guess is that the cams would be left behind and the crank would move ahead. Being that your crank is at TDC you should be able to move your cam gears up to 90 degrees in the forward clockwise position and be safe.

Maybe their is a "sweet spot" that things could land in to not end up with damage. I guess luck is involved.

 

[pcb]

OK I think I got it !!!

If your crank is at TDC then No. 1 cylinder as well as one of the others is also at TDC. The other two are at BDC. That means, if you rotate your crank shaft 90 degrees, all cylinders would be at MDC (middle) there fore no valve can hit a piston.

So move your crank shaft to the three o-clock position. Set up your cams then move the crank, counter clock wise, back to TDC

 

[pcb]

If in your slow and careful turning, you hit something try going to 9 o-clock instead then back to TDC.

 

[Jerseybuilt]

I have spun the crank, freely by hand, and don't feel anything hitting it. The plugs are out, the timing belt is off ( it was off when we removed the valve cover). I can rotate the front cam, back and forth. The rear cam won't move, ( using the same amount of pressure, as I did with the front cam). I put the crank in all three positions and went 360, and did it again. I have followed the steps to change the belt, but when I got to the step to align the timing marks. This is my question, do I need to apply alittle more pressure to the cam shaft?

 

[pcb]

I have spun the crank, freely by hand, and don't feel anything hitting it. The plugs are out, the timing belt is off ( it was off when we removed the valve cover). I can rotate the front cam, back and forth. The rear cam won't move, ( using the same amount of pressure, as I did with the front cam). I put the crank in all three positions and went 360, and did it again. I have followed the steps to change the belt, but when I got to the step to align the timing marks. This is my question, do I need to apply alittle more pressure to the cam shaft?

I think you've got a separate and different issue.

Seized cam bearing ??

If it were me, (and it's not and I'm guessing again), I'd remove that cam and look for a seized bearing (or bushing).

I'd probably reef the hell out of it last time before giving in to the extra labor. (that's just me though)

 

[pcb]

I checked the manual and it looks like you're next step is to remove the cam shaft. (other than removing the exhaust, but you're not removing the whole head).

Your either going to unscrew the cam gear bolt or the cam will start turning. (or you strip the bolt or your knuckles)

 

[tweety2300]

Pretty sure we don't actually have cam bearings

 

[Jerseybuilt]

I removed the intake cam and discovered a gulled up journal, by number3. Thanks for the help, I'm in the process of removing the head, to get machined.

 

[pcb]

Great !!!

 

[P-Funk!]

Good! I was gonna' say don't install the new belt until you figure out why the old one failed like that!