Engine Rattle During Acceleration
Administrator
Joined: 10-13-2011
Posts: 40,083
From: Welland,Ont Canada
Sometimes the camshaft phasers can loosen up and have a rattle, I’d look at the serpentine belt and tensioner, pop the valve cover and check the front guide! Did you install the replacement bolt ? The OEM bolts can vibrate loose and shatter the black plastic guide.
Thread Starter
Senior Member
Joined: 01-16-2017
Posts: 384
From: Ohio
Thread Starter
Senior Member
Joined: 01-16-2017
Posts: 384
From: Ohio
Senior Member
Joined: 12-05-2014
Posts: 3,368
From: Northern Ohio
First and foremost, do not assume the front guide is intact just because it’s newish. While plastic does fatigue, it can shatter anytime if it’s bad plastic or subjected to high rpms. Roller chains suck for high speed and rattle like crazy. The latest Ecotec has an inverted-tooth timing chain.
Supply chain issues have turned fuel quality to crap. Suppliers are excusing themselves and regulators have played along. Even “Top-teir” seems to be accepting excuses. Poor detergency in fuel leads to carbon deposits in the chamber, leads to carbon hotspots, leads to knock.
Try some Shell 93 or other top-shelf asap, maybe detergent fuel additive, still takes awhile to work, use a light foot and lowish rpm in the meantime.
Check for codes, but maybe a knock sensor, anyway.
Even with de-coking, tricky to get valves clean near the guides. Sticking valves.
Bad lifter(s). Or rocker(s). Or something loose. Or broken. Hard look under the valve cover?
Supply chain issues have turned fuel quality to crap. Suppliers are excusing themselves and regulators have played along. Even “Top-teir” seems to be accepting excuses. Poor detergency in fuel leads to carbon deposits in the chamber, leads to carbon hotspots, leads to knock.
Try some Shell 93 or other top-shelf asap, maybe detergent fuel additive, still takes awhile to work, use a light foot and lowish rpm in the meantime.
Check for codes, but maybe a knock sensor, anyway.
Even with de-coking, tricky to get valves clean near the guides. Sticking valves.
Bad lifter(s). Or rocker(s). Or something loose. Or broken. Hard look under the valve cover?
Last edited by PulpFriction; Jul 29, 2022 at 08:24 AM.
Senior Member
Joined: 12-05-2014
Posts: 3,368
From: Northern Ohio
Gonna hit all my cars with some detergent fuel additive.
Forgot to mention the possiblity of piston slap or rod knock from plain ‘ole engine wear.
Last edited by PulpFriction; Jul 28, 2022 at 07:03 PM.
Administrator
Joined: 10-13-2011
Posts: 40,083
From: Welland,Ont Canada
My niece insisted that her oil change guy said Dino oil was the. Best 10w30 never let him down, her 2009 Sierra , just threw a rod out the block only 238,000 kilometres on the odometer, I just changed the transmission cooler lines! Time for a new crate engine!
