Loud Knocking from left side of engine when warms up.
Thread Starter
Newbie
Joined: Mar 2015
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Gl450
Loud Knocking from left side of engine when warms up.
Yesterday, my GL450 started a loud knocking. At first, I thought, OH NO! its a rod! But I don't think so. When the car is cold, the sound is not there. after about 20 or 30 seconds it comes in sporadic and then when the motor warms about 1 or 2 mins, it increases, it also increase in frequency with RPM increase but doesn't seem to be tied directly. Engine performance is fine. Runs fine, just this loud, embarrassing knocking. I notice it more on the left. Could it be tensioner or water pump? Oil? Maybe CAM? Not sure. The sound is almost like "Morse Code", but increases in TAPS as engine warms. Any ideas?
Last edited by Blmbryan; Mar 28, 2015 at 11:22 AM. Reason: Add link to video.
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Joined: Dec 2004
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Yesterday, my GL450 started a loud knocking. At first, I thought, OH NO! its a rod! But I don't think so. When the car is cold, the sound is not there. after about 20 or 30 seconds it comes in sporadic and then when the motor warms about 1 or 2 mins, it increases, it also increase in frequency with RPM increase but doesn't seem to be tied directly. Engine performance is fine. Runs fine, just this loud, embarrassing knocking. I notice it more on the left. Could it be tensioner or water pump? Oil? Maybe CAM? Not sure. The sound is almost like "Morse Code", but increases in TAPS as engine warms. Any ideas?
Thread Starter
Newbie
Joined: Mar 2015
Posts: 2
Likes: 0
Gl450
Thank you for replyingl
I agree. Picking one up today. Using the "Screwdriver to the ear" method, it sounds like timing chain box, but hard to tell exactly. I was thinking timing chain tensioner. Maybe?
