Hey there,
I just wanted to share this experience with everyone, just in case it can help others diagnose what turned out to be a simple fix.
I had my timing belt changed this past fall (approximately 8 months ago), and after that I started getting a random chirp on cold startup (not every time). During warm startups it wouldn't happen. After some time had passed, it seemed to not be as prominent. I (foolishly) wrote it off as the drive belt settling in. Korean winter's are relatively dry, so I barely used the defroster (A/C compressor) during that time.
3 weeks ago in the midst of Spring, I had my valve cover gaskets and HLAs replaced along with a complete upgrade of my intake system and an ECU reflash. This involved removing and reinstalling the the drive belt and timing belt again. Click here for the details of this process: http://www.newtiburon.com/forums/showthread.php?t=207421&page=2
Afterwards, the problem continued to happen on cold starts and now sometimes on starts after a period of an hour's rest or more (not hot but just cooled down after shopping or something similar). However, the chirp turned into a full blown squeal/scream when the A/C or defroster was turned on just following startup AND the steering wheel was turned. But once the front wheels were straight the sound stopped.
At the shop, we could see that the drive belt was moving sideways on the tensioner, and the squeal was occurring when it rubbed against the lower timing belt cover. We replaced the drive belt, tensioner, and adjacent drive belt pulley. However, the sound continued to occur when the steering wheel was turned with the A/C on. The next thing we did was replace the power steering pump assembly (including the pulley). The idea was that the old assembly was most likely worn and causing the shaft and pulley to wiggle oh so slightly under load. The new assembly seemed to help (but it was most likely just the reinstallation of the drive belt) and I left the shop.
Over the following week, the squeal/scream became more prominent at every startup (cold and hot). Additionally, during the week I had to use my defroster in slightly foggy weather conditions and found out that when the A/C compressor engaged there was a chirp (not a full on squeal). This was significant because my steering wheel was straight this time. However, when at full operating temperature in hot weather there would be no chirp when I tried to recreate the scenario. I was lamenting the idea of replacing the A/C compressor assembly (under the same presumption used for the power steering pump assembly).
At the shop this past weekend, we pulled out the stethoscope and found that the chirp was actually coming from the crankshaft pulley (which is much cheaper to replace than the A/C compressor assembly). Here is what we had after removing it:
Notice the scoring on the rubber surface that coats the inside of the outer portion.
This final picture is how I remember seeing it on the engine after using the stethoscope and really taking a good look at it. Note that the inner portion is not flush with the outer portion. After inspecting our new crankshaft pulley, in hindsight the fact that the two pieces were not flush should've been a dead giveaway:
Now the scary thing was that even though you see a hammer in these pictures, only one tap was needed to push the inner portion out of the outer portion when it was warm (not hot). When the crankshaft pulley was cold I could slip the inner portion inside the outer portion with a light push of my palm. I could just as easily push the inner portion out with my thumbs (and pulling the outer portion in an opposite direction with my other fingers) with hardly any resistance at all. After doing this it was quite clear to me what had been happening over the past 8 months or so.
I hope that documenting this process might help others if they experience these symptoms, or if they want to avoid these symptoms altogether. Replacing the crankshaft pulley is actually not a difficult process when one has the proper tools for the job.
Thanks for your time.
I just wanted to share this experience with everyone, just in case it can help others diagnose what turned out to be a simple fix.
I had my timing belt changed this past fall (approximately 8 months ago), and after that I started getting a random chirp on cold startup (not every time). During warm startups it wouldn't happen. After some time had passed, it seemed to not be as prominent. I (foolishly) wrote it off as the drive belt settling in. Korean winter's are relatively dry, so I barely used the defroster (A/C compressor) during that time.
3 weeks ago in the midst of Spring, I had my valve cover gaskets and HLAs replaced along with a complete upgrade of my intake system and an ECU reflash. This involved removing and reinstalling the the drive belt and timing belt again. Click here for the details of this process: http://www.newtiburon.com/forums/showthread.php?t=207421&page=2
Afterwards, the problem continued to happen on cold starts and now sometimes on starts after a period of an hour's rest or more (not hot but just cooled down after shopping or something similar). However, the chirp turned into a full blown squeal/scream when the A/C or defroster was turned on just following startup AND the steering wheel was turned. But once the front wheels were straight the sound stopped.
At the shop, we could see that the drive belt was moving sideways on the tensioner, and the squeal was occurring when it rubbed against the lower timing belt cover. We replaced the drive belt, tensioner, and adjacent drive belt pulley. However, the sound continued to occur when the steering wheel was turned with the A/C on. The next thing we did was replace the power steering pump assembly (including the pulley). The idea was that the old assembly was most likely worn and causing the shaft and pulley to wiggle oh so slightly under load. The new assembly seemed to help (but it was most likely just the reinstallation of the drive belt) and I left the shop.
Over the following week, the squeal/scream became more prominent at every startup (cold and hot). Additionally, during the week I had to use my defroster in slightly foggy weather conditions and found out that when the A/C compressor engaged there was a chirp (not a full on squeal). This was significant because my steering wheel was straight this time. However, when at full operating temperature in hot weather there would be no chirp when I tried to recreate the scenario. I was lamenting the idea of replacing the A/C compressor assembly (under the same presumption used for the power steering pump assembly).
At the shop this past weekend, we pulled out the stethoscope and found that the chirp was actually coming from the crankshaft pulley (which is much cheaper to replace than the A/C compressor assembly). Here is what we had after removing it:
Notice the scoring on the rubber surface that coats the inside of the outer portion.
This final picture is how I remember seeing it on the engine after using the stethoscope and really taking a good look at it. Note that the inner portion is not flush with the outer portion. After inspecting our new crankshaft pulley, in hindsight the fact that the two pieces were not flush should've been a dead giveaway:
Now the scary thing was that even though you see a hammer in these pictures, only one tap was needed to push the inner portion out of the outer portion when it was warm (not hot). When the crankshaft pulley was cold I could slip the inner portion inside the outer portion with a light push of my palm. I could just as easily push the inner portion out with my thumbs (and pulling the outer portion in an opposite direction with my other fingers) with hardly any resistance at all. After doing this it was quite clear to me what had been happening over the past 8 months or so.
I hope that documenting this process might help others if they experience these symptoms, or if they want to avoid these symptoms altogether. Replacing the crankshaft pulley is actually not a difficult process when one has the proper tools for the job.
Thanks for your time.
