Timing belt general
03-28-2011, 08:38 PM
#1
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Timing belt general
I did the timing belts yesterday. It took about 5 hours, with a big lunch. It really wasn't that bad of a job at all, not sure what all the hype is based on.
When I took the covers off I discovered the cam belt was pretty loose. Much looser than the motor sitting in the back of my garage and much much looser than the new belt.
Not sure how I feel about a 25 year old spring keeping my engine from certain doom, but I plan on checking often.
Also, it sure does whine a lot! And it doesn't go away much when it's warm, or maybe I haven't gotten it totally warmed up.
I didn't check the balance shaft orientation when I took it apart but it must have been off because the car is significantly smoother at idle than it was before
Anyway, no real point to this thread, just thought I'd share. If your thinking about doing your belts but your too nervous, don't sweat it!
When I took the covers off I discovered the cam belt was pretty loose. Much looser than the motor sitting in the back of my garage and much much looser than the new belt.
Not sure how I feel about a 25 year old spring keeping my engine from certain doom, but I plan on checking often.
Also, it sure does whine a lot! And it doesn't go away much when it's warm, or maybe I haven't gotten it totally warmed up.
I didn't check the balance shaft orientation when I took it apart but it must have been off because the car is significantly smoother at idle than it was before
Anyway, no real point to this thread, just thought I'd share. If your thinking about doing your belts but your too nervous, don't sweat it!
03-28-2011, 08:41 PM
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I did the timing belts yesterday. It took about 5 hours, with a big lunch. It really wasn't that bad of a job at all, not sure what all the hype is based on.
When I took the covers off I discovered the cam belt was pretty loose. Much looser than the motor sitting in the back of my garage and much much looser than the new belt.
Not sure how I feel about a 25 year old spring keeping my engine from certain doom, but I plan on checking often.
Also, it sure does whine a lot! And it doesn't go away much when it's warm, or maybe I haven't gotten it totally warmed up.
I didn't check the balance shaft orientation when I took it apart but it must have been off because the car is significantly smoother at idle than it was before
Anyway, no real point to this thread, just thought I'd share. If your thinking about doing your belts but your too nervous, don't sweat it!
When I took the covers off I discovered the cam belt was pretty loose. Much looser than the motor sitting in the back of my garage and much much looser than the new belt.
Not sure how I feel about a 25 year old spring keeping my engine from certain doom, but I plan on checking often.
Also, it sure does whine a lot! And it doesn't go away much when it's warm, or maybe I haven't gotten it totally warmed up.
I didn't check the balance shaft orientation when I took it apart but it must have been off because the car is significantly smoother at idle than it was before
Anyway, no real point to this thread, just thought I'd share. If your thinking about doing your belts but your too nervous, don't sweat it!
03-28-2011, 09:56 PM
#3
Proprietoristicly Refined
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The "whine" is usually the BB too tight. It will almost feel sloppy when tensioned correctly.
Here is a video on the BB sound-----bottom of page has another link.
http://arnnworx.com/tensioningbelts.htm
I retension new cam belt early. Usually at 300 miles. The new belt will seat in the gear cogs sooner and the new belt gets real loose very shortly.
GL
John
Here is a video on the BB sound-----bottom of page has another link.
http://arnnworx.com/tensioningbelts.htm
I retension new cam belt early. Usually at 300 miles. The new belt will seat in the gear cogs sooner and the new belt gets real loose very shortly.
GL
John
03-28-2011, 11:18 PM
#5
Three Wheelin'
So i started my engine to watch the belts spin after i put new ones in. everything seems fine, except the balance shaft belt seems to be slapping around a bit. it is bouncing off the idler and making it spin slightly. this is at about 1.5k rpm (unfortunately, that's where my car idles right now -- another story
). so is this normal? does the BSB really flop around that much? it's not terribly excessive, but it's enough to make me wonder. thoughts?
Last edited by bonus12; 03-29-2011 at 12:35 AM.
03-28-2011, 11:18 PM
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The "whine" is usually the BB too tight. It will almost feel sloppy when tensioned correctly.
Here is a video on the BB sound-----bottom of page has another link.
http://arnnworx.com/tensioningbelts.htm
I retension new cam belt early. Usually at 300 miles. The new belt will seat in the gear cogs sooner and the new belt gets real loose very shortly.
GL
John
Here is a video on the BB sound-----bottom of page has another link.
http://arnnworx.com/tensioningbelts.htm
I retension new cam belt early. Usually at 300 miles. The new belt will seat in the gear cogs sooner and the new belt gets real loose very shortly.
GL
John
03-29-2011, 01:34 AM
#7
Rennlist Member
i second this! and congrats to the OP!
So i started my engine to watch the belts spin after i put new ones in. everything seems fine, except the balance shaft belt seems to be slapping around a bit. it is bouncing off the idler and making it spin slightly. this is at about 1.5k rpm (unfortunately, that's where my car idles right now -- another story). so is this normal? does the BSB really flop around that much? it's not terribly excessive, but it's enough to make me wonder. thoughts?
So i started my engine to watch the belts spin after i put new ones in. everything seems fine, except the balance shaft belt seems to be slapping around a bit. it is bouncing off the idler and making it spin slightly. this is at about 1.5k rpm (unfortunately, that's where my car idles right now -- another story
). so is this normal? does the BSB really flop around that much? it's not terribly excessive, but it's enough to make me wonder. thoughts?Trending Topics
03-29-2011, 01:48 AM
#8
Three Wheelin'
just for reference, is the BSB too loose if it slaps around within a one-inch space and spins the idler at low engine rpm? i measured .1 mm (a piece of paper) between the idler and the belt.
03-29-2011, 01:53 AM
#9
Rainman
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balance belt you should tighten until you can twist it 180* with your thumb and finger without too much effort. the roller should barely barely contact the belt. the belt should not slap around that much.
it should whine, but not obnoxiously.
it should whine, but not obnoxiously.
03-29-2011, 04:45 AM
#10
Drifting
replacing the belts is not difficult. but you can't screw up as you risk wrecking your engine.
also biggest problem is tensioning the belts. without the factory tool there isn't really a reliable way to tension the belts unless you are experienced with tensioning belts and know how a proper belt should feel like.
I don't think the kricket/ twist method are that reliable.
other than that it's pretty easy I also took 5 hours last night including cleaning up and jacking up the car etc.
also biggest problem is tensioning the belts. without the factory tool there isn't really a reliable way to tension the belts unless you are experienced with tensioning belts and know how a proper belt should feel like.
I don't think the kricket/ twist method are that reliable.
other than that it's pretty easy I also took 5 hours last night including cleaning up and jacking up the car etc.
03-29-2011, 11:33 AM
#11
Rainman
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twist method has proven 100% reliable on my car and many other rennlisters who i have done the work for for the last 5 years.
i dont recall who posted it, but the twist method is what is used by many independent shops and the porsche dealers before the special tool was made available.
i dont recall who posted it, but the twist method is what is used by many independent shops and the porsche dealers before the special tool was made available.
03-29-2011, 11:38 AM
#12
Nordschleife Master
twist method has proven 100% reliable on my car and many other rennlisters who i have done the work for for the last 5 years.
i dont recall who posted it, but the twist method is what is used by many independent shops and the porsche dealers before the special tool was made available.
i dont recall who posted it, but the twist method is what is used by many independent shops and the porsche dealers before the special tool was made available.
Knocking viggorously on wood desk right now
YMMV!
Congrats to the OP.. good job!
03-29-2011, 11:29 PM
#13
Drifting
when I was thinking of buying a 944 like 5 years ago when I bought it I kept on hearing so many horror stories about the belts and how they have to be tensioned with the special porsche tool etc.
i'm pretty sure any experienced mechanic can set a timing belt tension by feel. I doubt the belts are designed to tensioned with high precision.
i'm pretty sure porsche just made the tool so people take their cars to the dealer to have the timing belt done.
for people like me though that don't have enough experience with timing belts the twist method makes me a bit nervous. like how hard are you suppose to twist, how easily should the belt twist to the 90 degrees.
i'm pretty sure any experienced mechanic can set a timing belt tension by feel. I doubt the belts are designed to tensioned with high precision.
i'm pretty sure porsche just made the tool so people take their cars to the dealer to have the timing belt done.
for people like me though that don't have enough experience with timing belts the twist method makes me a bit nervous. like how hard are you suppose to twist, how easily should the belt twist to the 90 degrees.
