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Old 1st August 2024, 06:24 PM
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steamship steamship is offline
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Default My Weird Engine Squeak is Back

Before the annual meet in June I had noticed a repetitive squeak coming from the engine. Others noticed at the time as well. After getting back, I investigated the alternator as a possible source, and replaced it as the rear bearing on it was shot. At the time, my squeak disappeared, so assumed that was the culprit.

Well, it's back again. So I took off the timing belt covers to check everything out, and noticed two things. The first is that the timing belt was rubbing on the lower cover. The highlighted section of the photo shows where it has been worn down slightly.

The second is possibly more worrying. With the covers off, I was watching closely and listening for the squeak. There wasn't any squeak, but that may have been because the covers were removed or because the engine had warmed up. I'll start the car tomorrow with the covers off and see if the squeal is still there or not.

However, the visual check resulted in the following short video. As you'll see, the belt is moving in and out on that particular pulley, and also showing the same slight movement on all the pulleys. When I did the front end of the car last April (2023), all the components were replaced and every single nut and bolt was torqued to spec, and the squeak only appeared this year. For those parts of the belt I can reach, it all seems tight. Can't really check the pulleys as they're all under tension from the timing belt.

https://youtu.be/_XDH7pnG8tM
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2001 A8 D2 FL 3.7 Q - LPG Conversion, Engine: AKC, Gearbox:FBB, Colour:LY5X Aqua Blue pearl effect, Interior:WJ light beige/dark beige valcona leather with burr walnut inserts

My DIY jobs - Replaced alarm horn, Replaced Coolant Temp sensor, Updated RNS-D firmware, Installed Reversing Camera and Digital TV, Dashcam Installation, Retrofitted Rear Blinds, Auto-Dimming Rear View Mirror, Chrome Boot Struts

Sold! 2008 S8 D3 5.2 V10 - Engine: BSM, Gearbox:KLW, Colour:LY7F Suzuka Grey Pearl Effect, Interior:Black/Black with Silver/Black valcona leather with carbon atlas inserts, Bang & Olufsen, Heated windscreen, Soft-close doors, TV, DAB, AMI, Quad Zone, Auto Boot, Auto dim Mirrors, Keyless entry, PDC with rearview camera, AFS II Headlights

My DIY jobs - Fan Jet Windscreen Washers, Retrofitted Electric Side Blinds
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  #2  
Old 1st August 2024, 09:38 PM
strummagnet strummagnet is offline
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Quote:
Originally Posted by steamship View Post
Before the annual meet in June I had noticed a repetitive squeak coming from the engine. Others noticed at the time as well. After getting back, I investigated the alternator as a possible source, and replaced it as the rear bearing on it was shot. At the time, my squeak disappeared, so assumed that was the culprit.

Well, it's back again. So I took off the timing belt covers to check everything out, and noticed two things. The first is that the timing belt was rubbing on the lower cover. The highlighted section of the photo shows where it has been worn down slightly.

The second is possibly more worrying. With the covers off, I was watching closely and listening for the squeak. There wasn't any squeak, but that may have been because the covers were removed or because the engine had warmed up. I'll start the car tomorrow with the covers off and see if the squeal is still there or not.

However, the visual check resulted in the following short video. As you'll see, the belt is moving in and out on that particular pulley, and also showing the same slight movement on all the pulleys. When I did the front end of the car last April (2023), all the components were replaced and every single nut and bolt was torqued to spec, and the squeak only appeared this year. For those parts of the belt I can reach, it all seems tight. Can't really check the pulleys as they're all under tension from the timing belt.
I had something similar on my old 2.8QS. Found it to be the bearing on the tensioner that was wearing and creating slight play. Didn't notice it until I released the tension on the belt.
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  #3  
Old 2nd August 2024, 09:37 AM
Saff Saff is offline
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Hi Sean,
As Paul mentions and after watching your video something is either out of alignment or is allowing the belt to run a bit wonky. To ask the bloomin' obvious the belt, rollers and tensioner were all of the highest quality? Sorry to ask as I'm aware of your attention to detail. Obviously something is wonky and all I can think is that one of the components has failed. I wish you good luck.
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Old 2nd August 2024, 10:34 AM
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Quote:
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To ask the bloomin' obvious the belt, rollers and tensioner were all of the highest quality? Sorry to ask as I'm aware of your attention to detail.
No need to apologise, but highest quality is something I literally can't afford. No idea which part was which brand, but the components were either INA, Meyle, Febi or ContiTech.

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Originally Posted by strummagnet View Post
Found it to be the bearing on the tensioner that was wearing and creating slight play. Didn't notice it until I released the tension on the belt.
I had another look at it last night and was wondering how I could check the pulleys and tensioner without having to pull it all apart again. That's if I can even access them.

Would this possibly work? Turn the engine by hand to get it into the service position. Place the bar across the top and lock the crank. If I can get access to the tensioner, release the tension on it (I'm assuming it works the same as the one on the serpentine belt). I think the answer is no looking at the timing belt before it was tensioned, because it's only the tensioner that I could check. The pulley to the right of it and the water pump above still have tension on them.
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2001 A8 D2 FL 3.7 Q - LPG Conversion, Engine: AKC, Gearbox:FBB, Colour:LY5X Aqua Blue pearl effect, Interior:WJ light beige/dark beige valcona leather with burr walnut inserts

My DIY jobs - Replaced alarm horn, Replaced Coolant Temp sensor, Updated RNS-D firmware, Installed Reversing Camera and Digital TV, Dashcam Installation, Retrofitted Rear Blinds, Auto-Dimming Rear View Mirror, Chrome Boot Struts

Sold! 2008 S8 D3 5.2 V10 - Engine: BSM, Gearbox:KLW, Colour:LY7F Suzuka Grey Pearl Effect, Interior:Black/Black with Silver/Black valcona leather with carbon atlas inserts, Bang & Olufsen, Heated windscreen, Soft-close doors, TV, DAB, AMI, Quad Zone, Auto Boot, Auto dim Mirrors, Keyless entry, PDC with rearview camera, AFS II Headlights

My DIY jobs - Fan Jet Windscreen Washers, Retrofitted Electric Side Blinds
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  #5  
Old 2nd August 2024, 04:39 PM
Saff Saff is offline
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Your choice of parts seems to be excellent.

Wouldn't you need to time up the engine and lock the crank AND the cam pulleys before releasing any belt tension? Sorry again to state the bleedin' obvious.
Just thinking aloud, I'm sure the cam and crank sprockets would be true so any wobble would have to be in the renewable parts or perhaps even the belt itself?
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Old 2nd August 2024, 07:20 PM
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steamship steamship is offline
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Quote:
Originally Posted by Saff View Post
Wouldn't you need to time up the engine and lock the crank AND the cam pulleys before releasing any belt tension? Sorry again to state the bleedin' obvious.
I'm sure that's what I suggested, or at least meant.

Quote:
Originally Posted by Saff View Post
Just thinking aloud, I'm sure the cam and crank sprockets would be true so any wobble would have to be in the renewable parts or perhaps even the belt itself?
That's my thinking as well. One of those three in the middle, which whatever way you look at means the front end off and another strip down.

Never thought about the belt being a possible culprit, but either way, I'm hoping that when I can get around to it, the culprit is easy to spot.

Just what I need at this time of year when I'm just about to fork out another 41% extra for the car insurance!

EDIT: Question. Opinions on Gates and SKF as parts option.
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2001 A8 D2 FL 3.7 Q - LPG Conversion, Engine: AKC, Gearbox:FBB, Colour:LY5X Aqua Blue pearl effect, Interior:WJ light beige/dark beige valcona leather with burr walnut inserts

My DIY jobs - Replaced alarm horn, Replaced Coolant Temp sensor, Updated RNS-D firmware, Installed Reversing Camera and Digital TV, Dashcam Installation, Retrofitted Rear Blinds, Auto-Dimming Rear View Mirror, Chrome Boot Struts

Sold! 2008 S8 D3 5.2 V10 - Engine: BSM, Gearbox:KLW, Colour:LY7F Suzuka Grey Pearl Effect, Interior:Black/Black with Silver/Black valcona leather with carbon atlas inserts, Bang & Olufsen, Heated windscreen, Soft-close doors, TV, DAB, AMI, Quad Zone, Auto Boot, Auto dim Mirrors, Keyless entry, PDC with rearview camera, AFS II Headlights

My DIY jobs - Fan Jet Windscreen Washers, Retrofitted Electric Side Blinds

Last edited by steamship; 2nd August 2024 at 08:03 PM. Reason: Question about Parts Manufacturers
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Old 13th August 2024, 02:24 PM
donp38 donp38 is offline
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I simply don’t know.
However, it cannot be ignored.
Sorry, but I think only a full strip down will get to the problem.
Maybe see if you can talk to a vag specialist and send them the clip?
Best of luck
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Old 13th August 2024, 04:47 PM
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Just an update on this. After much searching, I ordered the Gates timing belt kit and the INA water pump, as those were the only 'quality' ones available.

Got the box today and lo and behold, a picture is worth a thousand words:

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2001 A8 D2 FL 3.7 Q - LPG Conversion, Engine: AKC, Gearbox:FBB, Colour:LY5X Aqua Blue pearl effect, Interior:WJ light beige/dark beige valcona leather with burr walnut inserts

My DIY jobs - Replaced alarm horn, Replaced Coolant Temp sensor, Updated RNS-D firmware, Installed Reversing Camera and Digital TV, Dashcam Installation, Retrofitted Rear Blinds, Auto-Dimming Rear View Mirror, Chrome Boot Struts

Sold! 2008 S8 D3 5.2 V10 - Engine: BSM, Gearbox:KLW, Colour:LY7F Suzuka Grey Pearl Effect, Interior:Black/Black with Silver/Black valcona leather with carbon atlas inserts, Bang & Olufsen, Heated windscreen, Soft-close doors, TV, DAB, AMI, Quad Zone, Auto Boot, Auto dim Mirrors, Keyless entry, PDC with rearview camera, AFS II Headlights

My DIY jobs - Fan Jet Windscreen Washers, Retrofitted Electric Side Blinds
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Old 14th August 2024, 07:33 AM
Saff Saff is offline
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Wow! This is what I'm finding with new car parts. A lot of 'branded' stuff now originates from China. I'm sure the parts will be fine. Very best of luck Sean.
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  #10  
Old 14th August 2024, 10:19 AM
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steamship steamship is offline
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Quote:
Originally Posted by Saff View Post
I'm sure the parts will be fine. Very best of luck Sean.
Let's hope so, as it was an INA timing kit I fitted last year!
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2001 A8 D2 FL 3.7 Q - LPG Conversion, Engine: AKC, Gearbox:FBB, Colour:LY5X Aqua Blue pearl effect, Interior:WJ light beige/dark beige valcona leather with burr walnut inserts

My DIY jobs - Replaced alarm horn, Replaced Coolant Temp sensor, Updated RNS-D firmware, Installed Reversing Camera and Digital TV, Dashcam Installation, Retrofitted Rear Blinds, Auto-Dimming Rear View Mirror, Chrome Boot Struts

Sold! 2008 S8 D3 5.2 V10 - Engine: BSM, Gearbox:KLW, Colour:LY7F Suzuka Grey Pearl Effect, Interior:Black/Black with Silver/Black valcona leather with carbon atlas inserts, Bang & Olufsen, Heated windscreen, Soft-close doors, TV, DAB, AMI, Quad Zone, Auto Boot, Auto dim Mirrors, Keyless entry, PDC with rearview camera, AFS II Headlights

My DIY jobs - Fan Jet Windscreen Washers, Retrofitted Electric Side Blinds
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