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Toothed Belt Sensor Functionality

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Old 09-16-2018, 02:14 PM
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jwbeck17
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Default Toothed Belt Sensor Functionality

I know he toothed belt sensor is a simple ground loop. If the belt is too loose, the ground loses connection at the tension adjuster and sends a warning. What if the belt is too tight? Does is send a warning as well?
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Old 09-16-2018, 02:37 PM
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no it cannot as the compression spring will always be held in compression.
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Old 09-16-2018, 02:53 PM
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That’s what I thought. Thanks, Stan. Just narrowing down my sensor issue.

Checked TB belt tension which was close to top of Kempf tool window. I adjusted the belt to be exact top of window. Belt quality and position looks good.

I thought I had ground tested the sensor wire circuit and thought the issue was somewhere in the wiring, but I don’t think my grounding wire was connected correctly, so I got a false error. I changed out the test ground wire with a solid connection and no warning, ruling out he wiring.

I had replaced the sensor plug connector which i used for the ground test, so that’s fine. I also had replaced the plug receiver in the cam cover that has the wire to the connecting tab.

Based on elimination, I’m now thinking that the warning is coming from somewhere in the central cam cover from the ground tab to the adjuster.

Knowing that getting to there can be a hefty job and that my tension is right, I suspect I’m ok to deal with it until the next TB change.
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Old 09-17-2018, 01:01 PM
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Just an FYI, when doing the belt Tension adjustment it needs to be done on a cold engine (room temp) and at TDC.
Belts like chains have a tight and a loose spot

Dave K
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Old 09-17-2018, 03:57 PM
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FredR
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To add to what Dave says, as I understand the tension has to be set with No1 cylinder at TDC on its firing stroke.
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Old 09-17-2018, 08:11 PM
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Originally Posted by davek9 View Post
Just an FYI, when doing the belt Tension adjustment it needs to be done on a cold engine (room temp) and at TDC.
Belts like chains have a tight and a loose spot

Dave K
Exactly, Dave. And I pity the genius who decides to do a timing belt check after a spirited drive. Forearms are overrated anyway...
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Old 09-18-2018, 01:42 PM
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Don't know what year your car is. Please put M/Y in your sig line.

From your initial question, I would recommend study of Dwayne's Garage write-up, or any other one (Kelly's manual) for picts, i.e., assembly of parts. PET pics are not so good. The system is simple except for the number of connections and individual parts. You could to a continuity test on each piece, put it together and it should? do it's job. If the connector between the tension arm (PET : "carrier for tension roller") and the wire to cam cover is a flat strip if metal, replace it with the braided wire connector. The "fault" (pun intended) here is that there are several parts and a misassembly or break in any one will result in a false warning, comes at 3 minutes after start.

BTY: the result of a too tight belt is just as bad as a loose or broken belt. The cam gear can break off the cam or wear excessively from the tension. Excessive wear shortens the life of the cam gear and may form an edge on the gear teeth that then wears on the belt, possibly causing belt teeth to disappear.
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