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Matt, Mechanical Engineer
Category: Toyota
Satisfied Customers: 21860
Experience:  BEng, Repaired my own cars and others for 20 years, worked in Formula 1 for 10 years
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I have a loud engine knock and I wanted to know your

Customer Question

hey I have a loud engine knock and I wanted to know your thoughts on possible causes. it is an 2001 Toyota corolla with 140000 miles. it is coming from the left side of the valve cover near the timing chain.
Submitted: 2 years ago.
Category: Toyota
Expert:  Matt replied 2 years ago.


This sounds like the timing chain tensioner may have failed or is sticking in its bore

depending on the engine type it may be possible to replace this without removing the timing cover

but on most engines this cover has to come off to access the chain