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Timing Belt Replacement


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#1
ddq

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Hey guys, my girlfriend has a 01 626 v6. Im assuming the only v6 for the 626 was the 2.5? Anyway, about 2 or 3 days ago she complained of some bad noises coming from under the hood, like an animal was under the hood moving around. She also said it was performing poorly. At idle, it sounded like the noise was coming from the front valve cover or timing belt area. I wanted to take a quick look, so I removed the radiator hose and coolant reserve and pulled back the top corner of the timing belt cover. There were broken pieces of plastic leaning against the timing belt and a piece stuck between the timing belt and the tensioner pulley. I removed the stuck plastic and the other broken pieces of plastic and the noise was gone. Today however, she said its making a bad noise again perfroming poorly. Im guessing there is more broken plastic in the lower timing belt area. I know I need to change the timing belt, but I want to know what I need to remove to get it off? I just changed the timing belt in my 3.3L frontier but it looks like I will have less space since the timing belt of the 626 is on the side of the motor. Do I need to remove the passenger side motor mount? Do I need to remove all pulleys including the crank pulley? Will I need a crank pulley puller? Thanks for all the help! Also, where could the plastic pieces have come from? They are smooth and slightly curved, Im thinking maybe pieces from the inside of the timing belt cover? Thanks! BTW, the car has 106k miles and the valve cover gaskets have been leaking for a while, if that matters. <BR>And, if I buy a timing belt from mazda will it have timing marks to match up with marks on the cams? My frontier belt had marks and it made it&nbsp;real easy to make sure I put it on right.

#2
NickR

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Welcome to the board!

Here's a link to a word document that contains complete instructions, including pictures: http://home.comcast....atimingbelt.doc

It's for a Ford Probe, but it's identical to the 93-97 626 engine, which is very similar to the 98-02 6262 engine.

I don't know what the plastic parts would be.

#3
ddq

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Thanks! Do you know if it matters whether I get the belt from a dealer or napa? The belt for my frontier had marks on it because I got it from a dealer, but the belts from auto parts stores do not have marks. Also, I just called napa and they said they have 2 different tensioners, both are over $200! That cant be right, can it? Please tell me I'm not going to have to spend $200 to replace the timing belt tensioner!

EDIT: Advance auto has the belt for $47 and the tensioner for $73. This is the cheapest I have found. Is it important that I replace the drive belt idler pulley bearings as well?

BTW, here are the broken pieces of plastic, all these I retrieved from inside & the upper section of the timing belt cover, there is no telling what is in the bottom. You can see the piece stuck between the belt and tensioner pulley before I removed it.

Posted Image

Posted Image

#4
snailman153624

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That plastic is from the idler pulley, not the cover! Do NOT run that engine until you replace the belt, or you might trash something....

Get an eBay timing belt kit, they run around $130, come with a decent water pump, belt, idler pulleys/bearings, and some of the kits even come with a tensioner for a little bit more money.

They also generally may include new valve cover gaskets and cam & crank seals for a few extra bucks.

#5
ddq

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That plastic is from the idler pulley, not the cover! Do NOT run that engine until you replace the belt, or you might trash something....

Get an eBay timing belt kit, they run around $130, come with a decent water pump, belt, idler pulleys/bearings, and some of the kits even come with a tensioner for a little bit more money.

They also generally may include new valve cover gaskets and cam & crank seals for a few extra bucks.



I didnt think there was an idler pulley for the timing belt, just the tensioner pulley, the 2 cams and the crank "sprocket?"

#6
NickR

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There is also an idler pulley. It's black.. Sort of hard plastic. From looking at my old idler pulley, plus your photo, I think snailman's right. Plus, he usually is.

#7
ddq

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Let me guess, the idler pulley is behind the lower rear section of the timing belt cover?

How could the pulley have broken? She drove the car to work today, but as long as she makes it home it should be OK because I am going to start on it in the morning. Just to make sure I understand, I should not need a crank pulley puller, right?

And if you guys are 80% sure its the idler pulley, then I need to go ahead and get it tonight while Im in town. There is no way it could be the timing belt cover right? There isnt any sort of divider between the different cover sections?

#8
XeNoMoRpH

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It just wears out. The same thing happened to mine a while ago. The outer part of the pulley is made of plastic. It eventually fails and breaks apart, unless you change it every 60k. It's pretty easy to replace actually. I ended up going with an eBay set and I have no complaints.

#9
ddq

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It just wears out. The same thing happened to mine a while ago. The outer part of the pulley is made of plastic. It eventually fails and breaks apart, unless you change it every 60k. It's pretty easy to replace actually. I ended up going with an eBay set and I have no complaints.


Its 50 bucks from the local parts store. I need it by the morning so Im not going to be able to order it, Ive got to find it in stock. The stores keep asking if I want the upper or lower idler pulley. The upper pulley they are referring to is the tensioner pulley, right? So I need to get the "lower" idler pulley?

#10
snailman153624

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I can clearly see in your picture a damaged pulley, with half of the plastic casing broken off. It's the one between the two cam pulleys, immediately to the right of the oil dipstick. On top of that, the little plastic bits in your tray/lid are all curved, and have three grooves that match those in the pulley.

The one on my car is all metal. Yours is metal too, it just has a plastic shell. I think the plastic shell is there to reduce vibration/wear, and perhaps make the belt a little quieter, but I really don't know. Again, on my car they are all metal...on the '99 626 and '98 Millenia V6 we used to have, they were both plastic coated like yours.

#11
ddq

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If that is the broken pulley then I just bought the wrong part. I bought the lower idler pulley which is metal with a plastic shell as well. I guess I will have to try to exchange it for the upper idler pulley early tomorrow morning. Also, the hydraulic tensioner arm I bought does not look like the one in the picture from the link to the ford probe timing belt write up. The arm I have is a cylinder, but has bolt holes on opposite ends. I really hope its the right part.

#12
XeNoMoRpH

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You don't necessarily need a new tensioner. As long as there are no visible leaks and it's functional, it should be good to go. If I recall, my factory service manual did show two different tensioners. I believe they are interchangeable, but I'm not too sure as I reused mine.

Here is a link with a good walk through.

http://www.mx6.com/f...on-updated.html

And to quote snailman

Honestly, the timing belt is a very easy job. I did mine in perhaps 4 hours; I spent maybe 9 hours TOTAL doing that, removing the cams, replacing the valve springs, retainers, and oil seals, and reinstalling everything.


You don't have to remove the engine or lower it as many people think. You can just remove the side mount (I didn't even have to support my engine, it hardly moved...), take water pump pulley off, take the power steering pump pulley off (if you can get the nut loose, otherwise you can work around it), take the two belts off, remove the timing cover, and you're in.

If you insist on doing the cam and crank seals (I wouldn't unless they look bad, or are leaking...I did mine this time because I had the cams out anyway), you'll also have to take the intake manifold and valve covers off to get the cam pulleys off.

Anyway, from here it's a breeze. The timing covers come off very easily, just a few bolts. With these off, you have easy access to the timing belt and tensioner. The tensioner is held in by two bolts, and the tensioner arm by a single allen bolt. The other idler pulleys are held in by one bolt each.

Lining up the belt is cake too, I didn't bother with the instructions in the Hayne's Manual or the factory service manual, they have a way of overcomplicating things.

To line up the belt, position the crank so the little notch on the outer ring of the timing belt sprocket lines up with the "V" above the crankshaft. If you have the car on jackstands, you can do this easily by putting it in 5th gear (most leverage), wedging something under one of the wheels, and turning the other by hand. This forces the engine to rotate.

With that lined up, put the belt on the sprocket. Pull all of the slack out, and using a ratchet with a 17mm wrench, line up the front cam pulley (the one closest to the front of the car) timing mark (it's the painted dot, with the letter "L" or "R" pointing directly at it) with the ridge on the head (see the manual for an illustration). Slide the belt over the pulley, making sure there is no slack. You can then use the ratchet to apply some additional tension to ensure you're not off by a tooth.

Once you have the front bank aligned, do the same for the rear. Line up the cam, and using the ratchet you can rotate the cam to just before the alignment mark, slip on the belt, and apply tension with the ratchet. With some moderate force, all of the timing marks should be lined up, and you should have no slack in the belt.

Now all you need to do is install the tensioner. I used a jack and a spot underneath my car to compress it, and slid a cotter pin into the hold to keep it compressed. Then, just bolt it up, pull the pin, and spin the engine over (you can use the wheels again) a few times then re-verify the timing alignment.


FYI, I reused my old tensioner, it was fine. If it's not leaking oil, and has no visible wear, it's a waste of money buying a new one. The aftermarket ones are probably more failure prone than the original part. The factory service manual recommends measuring the rod length to ensure the tensioner hasn't lost pressure, and re-using it if it's ok.

I did replace my idler pulleys, as they were making a little bit of noise, even though they felt smooth and probably would have been ok too. But hey, I had an almost-new set on the other blown motor, so I took the parts off of it.

The factory service manual calls for a timing belt INSPECTION at 60,000 miles, and recommends replacement at 100,000. My engine has maybe 50,000 miles, and my belt still looks brand new.



#13
ddq

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Thanks! I picked up the upper idler pulley this morning. The parts I will be replacing are the timing belt, upper idler pulley, lower idler pulley and tensioner arm. The total cost of these parts were around $205. 41 bucks for the belt from advance auto, 73 for the tensioner arm from advance auto, and 40 bucks each for the idler pulleys. Im gona grab a bite to eat and start on it in about 30 minutes. Ill post up if I run into any problems.

#14
ddq

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I have all the drive belt pulleys off and the front timing belt cover, but the rear timing belt cover wont come off and I cant get to the engine mount bolts. All the bolts are out of the cover, but it gets stuck when I try to pull it up or pull it through the bottom. Im going to mess with it some more. Ive been at it 3 hrs and havent even gotten half way.

#15
ddq

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I got the cover off and am trying to lign up the cams before I takeoff the belt. I have turned the cams 5 complete rotations by hand and the mark on the crank has not even been close to aligning with the mark on the block. Should I lign up the crank and then just take the belt off, then rotate the cams to lign up with the marks? The 2 cams lign up with the marks, but when they are ligned up, the crank is WAY off.
EDIT- Ive gone 9 full rotations and the mark on the crank has not been visible when I stopped, any of the times.




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