Noise from engine on cold start - need help diagnosing

Joined
Jan 9, 2019
Messages
359
Location
Seattle, WA
I’m having a hard time tracking down a noise from the engine that only happens during cold starts. It sounds like someone playing a cabasa and gradually fades away after 2-3 minutes. I have a mechanics stethoscope and have listened to virtually everything I can think of under the hood. Checked, all accessory pulleys/bearings, water pump, SAIS valves and pump. Timing belt service was completed about 14k miles ago. Noise started within the last 500 miles. Truck is also running a little rough at idle, but not throwing any codes. I scanned today using techstream.

The noise is still present with the serpentine belt removed. I can only replicate the sound about once per day an the very first cold start so I don’t have a lot of time to listen. I had it at the shop that replaced the timing belt this past week and they could not trace the source and claimed it was difficult to replicate the noise reliably.

Looking for some suggestions on what parts to listen to when I start it up tomorrow.
 
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Joined
Jan 9, 2019
Messages
359
Location
Seattle, WA
FYI this is a cabasa …
66DD9DB4-544B-496D-82C6-2854189EDEA9.jpeg
 
Joined
Feb 21, 2019
Messages
30
Location
eugene
I've been chasing that noise for 3 years on my 2011 125,000 miles. I've replaced A/C compressor thought it did the trick. Came down to timing chain tensioner. Some one suggested an engine flush. After reading way too many u-tubes and forums I decided to try Sea Foam at about 140,000 miles. Noise from top of engine got better and mud came out of oil pan. waited too long to do it again, but over the last 3500 miles I've flushed it twice and switched to mobile one high mileage. I'm going to change oil and flush one more time after 2500 miles. I have not had any noises, the truck is getting a little better mileage and running much better. I bought the truck from my brother and I suspect that his mechanic was charging for mobile one, but not using it. I've worked on engines that have run mobile one and sludge was never an issue. The tolerances on the tensioner ore very close and sludge could be causing the issue. Plus check your PVC valve it's a $6.00 item.
 
Joined
Jan 9, 2019
Messages
359
Location
Seattle, WA
Have been running Castrol 0W40 without any issues for last 60K miles.

Timing bet tensioner and idler are two of the last items to check as far as rotating assemblies are concerned. Will check this weekend.

Will check PCV, too. Probably just replace as PM given I’m almost at 200k miles.
 

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