Louder engine during acceleration aft oil change

[chrisu91]

I've finally switched to synthetic oil in preparation for the winter. Vehicle has about 66,000 miles. 5w30 was in the vehicle before, and replaced with the same grade but with synthetic this time. When accelerating the engine is noticeably louder than it was prior to the oil change. The oil level is good. When I'm at highway speeds and when the vehicle is idling, the engine sounds normal. In addition, when the car is in neutral and I step on the gas I do not hear the loud noise; it only occurs when the vehicle is in drive. Is this the nature of the thinner synthetic oil? Thanks.

[Scanman]

I've never heard of an oil change causing an engine to get louder. Can you tell if it's an exhaust noise, a whine, maybe a tapping sound?

[chrisu91]

Not a tapping sound nor a whine. My engine sounds like a pickup truck at around 2800+rpm but only in drive.

[Scanman]

IMHO, It kinda sounds like an intermittent exhaust leak. One that only leaks when the engine is under a load (acceleration). I'm not sure it's related to the oil change, but I'd check the exhaust manifold bolts & the bolts in the flange between the manifold & the exhaust piping. Those are stress points when the engine is moving around. Maybe the motor mounts are loose. Just my best guess. I hope it helps.

[serega12]

I've finally switched to synthetic oil in preparation for the winter. Vehicle has about 66,000 miles. 5w30 was in the vehicle before, and replaced with the same grade but with synthetic this time. When accelerating the engine is noticeably louder than it was prior to the oil change. The oil level is good. When I'm at highway speeds and when the vehicle is idling, the engine sounds normal. In addition, when the car is in neutral and I step on the gas I do not hear the loud noise; it only occurs when the vehicle is in drive. Is this the nature of the thinner synthetic oil? Thanks.

Could be thinner oil. I'd be more worried about timing belt snapping at your mileage.

[petrified.rabbit]

synthetic is not "thinner" as far as viscosity, the difference is its molecularly the same... meaning in synthetic oil all the "beads" are the same size where as in dino oil there are still different sizes..

this almost means the flow through the engine better and can potentially clean out sludge from a older dino oil engine.. I would say the noise might be the cleaning process at work, fresh oil getting to clogged places etc. i would say if the noise does not get worse, and does not go away after an oil change, that you might have an actual issue. But until then it might just be sludge movement..

[chrisu91]

I had my timing belt replaced in August

I also believe I've tracked down the issue. The shop that did my oil change I guess "checked" everything else, and by doing so, they lost one bolt and broke another on my air filter box. So, I'm going back tomorrow to get that sorted out and hopefully the issue should be resolved. I got the vehicle back at night so I didn't have a chance to look in the daylight until today.

[chrisu91]

Air filter box is now sealed properly and the engine sounds normal under load. Woot.

[Scanman]

Glad I was WRONG!!!! Glad it's fixed!

[Brian10002]

Thanks Chrisu91. I had a similar problem on my camry where the guys left the air filter bolts loose. I googled and found this page and after fixing the bolts, the issue was gone.