Tensioner makes 'snap' noise
Thread Starter
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Joined: Mar 2004
Posts: 230
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From: Grapevine, Texas
2004 Capri Blue C32
Tensioner makes 'snap' noise
I haven't posted in a long time, but I've been reading. I searched but couldn't find anything related to my problem.
When I start the car, I hear a fairly loud metal 'snap' noise, but only when I start it. It runs smooth with no strange noises or lack or power or anything. I just replaced the belt and put my ASP pulleys on (new crank pulley), replaced the plugs and put my Magnecor wires back on. I also took the tensioner off to check it out, and replaced the pulley with the one I removed when installing the ASP ones. It's been driving me crazy, so tonight I had my wife start the car while I looked for the sound. When it happens, I can see the tensioner sort of jump just as the car turns over. Once running, the tensioner appears to be fine.
I'm not driving it anymore until I get a new one, but I was wondering if anyone else has had this problem. Could I be overlooking something, other than, or in addition to, the tensioner?
Thanks.
When I start the car, I hear a fairly loud metal 'snap' noise, but only when I start it. It runs smooth with no strange noises or lack or power or anything. I just replaced the belt and put my ASP pulleys on (new crank pulley), replaced the plugs and put my Magnecor wires back on. I also took the tensioner off to check it out, and replaced the pulley with the one I removed when installing the ASP ones. It's been driving me crazy, so tonight I had my wife start the car while I looked for the sound. When it happens, I can see the tensioner sort of jump just as the car turns over. Once running, the tensioner appears to be fine.
I'm not driving it anymore until I get a new one, but I was wondering if anyone else has had this problem. Could I be overlooking something, other than, or in addition to, the tensioner?
Thanks.
Thread Starter
Member
Joined: Mar 2004
Posts: 230
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From: Grapevine, Texas
2004 Capri Blue C32
Nobody?
Does anyone know where I can buy a new tensioner, besides at the dealer? All of the websites I searched say that the Dayco 89354 fits, but I bought one and it doesn't fit.
Does anyone know where I can buy a new tensioner, besides at the dealer? All of the websites I searched say that the Dayco 89354 fits, but I bought one and it doesn't fit.
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Joined: Jul 2006
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From: Maine
Not an AMG :(
....When I start the car, I hear a fairly loud metal 'snap' noise, but only when I start it. It runs smooth with no strange noises or lack or power or anything. I just replaced the belt and put my ASP pulleys on (new crank pulley), replaced the plugs and put my Magnecor wires back on. I also took the tensioner off to check it out, and replaced the pulley with the one I removed when installing the ASP ones. It's been driving me crazy, so tonight I had my wife start the car while I looked for the sound. When it happens, I can see the tensioner sort of jump just as the car turns over. Once running, the tensioner appears to be fine....
Some play is to be expected in the tensioner, especially upon startup, so I wouldn't automatically think the tensioner is dysfunctional.
You stated that you recently installed an ASP crank pulley and installed a new belt.
Did you also install other pulleys to prevent overdriving of accessories?
This may seem like a dumb question, but did you inspect the new belt to make sure it is in the right orientation and running true such that it doesn't jump on any of the pulleys?
When you torque the belt tensioner down so that you can remove the belt, how does the tensioner behave? Does it 'stick' in position or does it rotate back to its natural position?
Thread Starter
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Joined: Mar 2004
Posts: 230
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From: Grapevine, Texas
2004 Capri Blue C32
Thanks for the reply.
Yes, I installed the water pump and idler pulleys that came with the ASP setup. And I have checked the belt to make sure that it's not coming off any pulleys or drifting while the car is running. It runs very smooth once started. One reason I suspect the tensioner is because before I installed the pulleys and belt, there was a lot of squeaking when I started it up. Then last night I looked at it while starting and its movement seemed a little unusual, and timed perfectly with the strange sound.
The tensioner doesn't feel sticky or loose when removing the belt. I just did that again last night to check.
I plan to retrace all my steps tomorrow to make sure that everything is installed and seated correctly. I'll work backwards to see if I can isolate something else - put the old belt back on, the old pulleys, etc.
Yes, I installed the water pump and idler pulleys that came with the ASP setup. And I have checked the belt to make sure that it's not coming off any pulleys or drifting while the car is running. It runs very smooth once started. One reason I suspect the tensioner is because before I installed the pulleys and belt, there was a lot of squeaking when I started it up. Then last night I looked at it while starting and its movement seemed a little unusual, and timed perfectly with the strange sound.
The tensioner doesn't feel sticky or loose when removing the belt. I just did that again last night to check.
I plan to retrace all my steps tomorrow to make sure that everything is installed and seated correctly. I'll work backwards to see if I can isolate something else - put the old belt back on, the old pulleys, etc.
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Joined: Nov 2001
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From: OC
C32
One possibility is the belt may be slightly too long and the tensioner is bottoming out. Usually if this is the case you will hear a ticking noise while idling. I suppose it might just bottom out on start up if it is close. If this is the case you can install one slightly larger pulley on one of the accessories.
Thread Starter
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Joined: Mar 2004
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From: Grapevine, Texas
2004 Capri Blue C32
Could a noise be the result of some kind of timing problem? I also replaced the plugs, but this sounds mechanical and outside of the engine so I haven't been looking in that direction.
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Thread Starter
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Joined: Mar 2004
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From: Grapevine, Texas
2004 Capri Blue C32
Well.....no luck isolating this sound. I took the belt out, removed the tensioner and pulley - seems OK. Checked the torque on the crank pulley - OK. Put everything back and on the first start, no noise! The second start - noise back. So I tried installing the original idler pulley to see if the belt would fit (the water pump pulley ends up too close to the ASP crank). With the OEM idler, the belt is too small. So, I continued retracing my steps, and removed all the plugs and wires to make sure that they're all gapped the same (.035), and the wires are OK. There was some crud already built up on the plugs, but otherwise no problems. Put everything back together, and again, the first start had no unusual sound, but the second did.
I tried taking a video and audio of startup, but the rest of the engine drowns out the sound when recording. I do still hear a faint squealing sound, and it appears to be louder when listening from the passenger side.
I just had my front bumper replaced last weekend. Could there be something in that replacement process that may not have been tightened, that could cause a strange sound on startup? Or could replacing the crank pulley somehow have misadjusted the timing? My power steering fluid is at the minimum level for 25 degrees (after the car sits for a while). Not sure if that could be a contributing factor, but I'm looking at everything I can think of at this point.
I tried taking a video and audio of startup, but the rest of the engine drowns out the sound when recording. I do still hear a faint squealing sound, and it appears to be louder when listening from the passenger side.
I just had my front bumper replaced last weekend. Could there be something in that replacement process that may not have been tightened, that could cause a strange sound on startup? Or could replacing the crank pulley somehow have misadjusted the timing? My power steering fluid is at the minimum level for 25 degrees (after the car sits for a while). Not sure if that could be a contributing factor, but I'm looking at everything I can think of at this point.
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