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tmcbob
Joined: 05 Jun 2002 Posts: 144 Location: Wheeling, Illinois
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Posted: Thu Jun 20, 2002 4:13 am Post subject: Timing Belt |
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Is this a job for a quality mechanic or can I tackle this one by myself. I have all the necessary tools and have read the procedure from the Bently manual at least a half a dozen times in my library (Midwestern term for bathroom). I'm pretty handy and have successfully repaired the items in previous posts, thanks to your excellent advice! Please enlighten me! |
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Ken Juul
Joined: 16 Jan 2002 Posts: 913 Location: Williamsburg, VA USA
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Posted: Thu Jun 20, 2002 5:51 am Post subject: Timing Belt |
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The timing belt is a straight forward job. The first one will take most of the afternoon to do. Plan on replacing the tensioner and water pump at the same time. Most agree the hardest part is getting the fan off. If you are leaking oil, it is also a good time to replace the seals around the crankshaft, camshaft and idler shaft they are all common leak points. Just follow the directions and make sure everything lines up and you should do fine. |
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Max
Joined: 17 Jun 2002 Posts: 15 Location: SoCal
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Posted: Thu Jun 20, 2002 1:44 pm Post subject: Timing Belt |
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From memory - did one for a friend at the weekend (my sixth one this year !!!).....
take the hood off - four bolts, plus you have to stop the washer fluid leaking away - small length of pipe (12") place the end in the washer bottle.
drain the radiator - or undo a couple of hoses, and let the coolant flow to the floor
undo the clip that hold the fan shroud on, and lift the shroud a little, and push it back over the fan.
remove the airbox - loosen the nuts, and the big clip, unplug the wiring harness.
undo the two (12mm ?) bolts that hold the radiator in place, ensure that the two hoses are undone on the thermostat housing.
Carefully lift the radiator, and wiggle the hose out from the bracket by the alternator.
remove the fan shroud
Using a thin adjustable wrench undo the fan/waterpump conection - this is a backward thread !!!!
loosen the bolts that hold the pulley wheel to the waterpump, and loosen the alternator, PS pump and AC pump.
remove the dstributor cap, and then the rotor arm and the plastic shield.
rotate the engine until the timing marks all line up - there is one on cam drive, and one on the pulley on the end of the crank. get them lined up now !
stick the car in gear and pull the brake on.
undo the bolts holding the pullywheel onto the crank - either six or eight of these.
Slide the pully off - its keyed so putting it back is easy, this will also remove the belts.
take the cover off the front of the engine - several bolts including a but on the bracket that holds the alternator in place.
You can now see your timing belt.
As you have got this far, its a good idea to check the water-pump - if there is any movement on the shaft, or any signs of seepage, replace it. No, I take that back, replace it anyway, and the bypass hose - as this is horrible to get to later.
Also check the seals on the front of the motor for oil seepage too.
ensure that the timing marks are still aligned - you will find a couple of marks - one on the crank, one on the cam drive.
Carefully, undo the timing belt tensioner, and push it against its spring, then re-tighten it - for the moment at least.
This gives you just enough space to ease the old belt off - or in the case of the one I did this weekend, allows you to get all three strands of the belt off.
make sure the timing marks are still aligned.
remove the old tensioner.
remove the waterpump - you are going to replace it !
remove the old gasket - carefully.
check that the timing marks are still alinged.
Install new waterpump and new gasket.
place NEW tensioner in place - DO NOT RE-USE THE OLD ONE.
push tensioner all the way in, and tighten it down.
the new belt is "fun" you have to get the bottom half in place, then the cam part - be really careful here, its really easy to underestimate the tension belt is under on the "straight runs".
Once it is in place, check the timing marks again !
loosen the adjuster, and it will spring into place and put the belt under tension, I check the marks again at this point.
turn the engine two complete revolutions by hand - a BIG socket in the end of the crank will work - remember to take it out of gear first though.
Tighten the tensioner, and put it all back together
I've found that this whole task can be completed in about three hours, and that its a really good move to replace all of the belts ($4-5 each) and the hoses ($20 total) whilst you are there - the water pump is such an easy, and inexpensive job whilst you are there that its pretty much a no-brainer.
Good luck. |
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tmcbob
Joined: 05 Jun 2002 Posts: 144 Location: Wheeling, Illinois
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Posted: Fri Jun 21, 2002 4:42 am Post subject: Timing Belt |
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OK...Picking up the belt, tensioner, waterpump and various hoses this afternoon. If I have to call my wife tomorrow to pick me up from the shop here, I'm 'gonna personally hunt you guys down and force you to buy me a beer!!
Have a great weekend and you'll hear from me on Monday with the results! |
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Ken Juul
Joined: 16 Jan 2002 Posts: 913 Location: Williamsburg, VA USA
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Posted: Fri Jun 21, 2002 6:28 am Post subject: Timing Belt |
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nice write up Max. As this topic comes up about once every 3 months, may want to save it somewhere for easy access for the next time. Saves the retyping. My only comment is I think I did mine without removing the radiator, but it's been a couple of years so I may just be forgetful. ![](images/smiles/icon_smile.gif) |
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Max
Joined: 17 Jun 2002 Posts: 15 Location: SoCal
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Posted: Fri Jun 21, 2002 11:28 am Post subject: Timing Belt |
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Thanks
Removing the radiator is a ten second job - it is probably possible, but dammed difficult due to access "issues", to do it without it, but it gives you the ability to flush it too......
oh - Thanks - I'm getting good at this job.... |
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Hamfisted
Joined: 21 Jun 2002 Posts: 4 Location: Ft Lauderdale
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Posted: Fri Jun 21, 2002 2:31 pm Post subject: Timing Belt |
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Nice write up. One thing I always do is add some sealant, either hightemp silicone RTV or Teflon tape to the waterpump mounting bolt's threads. In the past I've seen leaks develope from water in the block's waterjacket seeping on the waterpump mounting bolts since the threaded holes go straight through the block's face and into the waterjacket area in front of the number one cylinder. This will completly seal the coolant system. Also check the two O-rings on the resevoir cap and replace them if they are more than ten years old. Good luck ....... Ham ![](images/smiles/icon_biggrin.gif) |
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tmcbob
Joined: 05 Jun 2002 Posts: 144 Location: Wheeling, Illinois
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Posted: Tue Jun 25, 2002 3:59 am Post subject: Timing Belt |
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Did'nt get around to changing the belt this weekend. Its amazing how many "freinds" you have when you're in the refrigeration business and the first heat wave hits the midwest!
Anyways....
On the coolant side of things would anyone reccomend the new high mileage anti-freezes that are available or just stick with the good 'ole 50/50 Prestone mix. |
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moapys
Joined: 18 Nov 2008 Posts: 4
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Posted: Mon Oct 27, 2014 8:44 am Post subject: Valve/Piston intercourse; how much damage is "too much& |
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Hi - I just suffered an "interference situation"; not a belt breakage - but an idler shaft shearing...same effect - valve/piston collision.
My question: Beyond the usual bent valves (all intake <?>) and broken rockers (all six intakes <!>), I have one badly nicked piston top. I'd say that the depth is as much as a 1/16" in a few locations.
If I grind/polish out the high spots, is there much of a chance of "burning through" the injured piston?
Thanks for your opinions.
Paul |
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85-325e
Joined: 30 Jun 2002 Posts: 4712 Location: Southampton, NY
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Posted: Mon Oct 27, 2014 9:49 am Post subject: |
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Paul...
I don't have an answer, but it would help if you posted a photo of what the top of the piston looks like. I guess it all depends upon the damage. The tops aren't paper thin, but they're not super thick either... _________________ Cosmo - 1985 BMW 325e, Single Owner, 265,000+ ORIGINAL miles and still going strong! But now on the East Coast and the salt air corrosion is eating my beautiful car alive...
![](http://www.vailsoft.com/bmw/ubb.jpg) |
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