CarTalk.com Best of Deals Car Reviews Repair Shops Cars A-Z Radio Show

Synthetic Oil and Odd Sound

My 2003 Impala has 78,000 and this past weekend my husband changed the oil and used synthetic for the first time.The engine began sounding like a small engine plane.



He did overfill it slightly and since drained it to the proper level, however the sound is still there.



Any ideas why?

What was hubby’s reason for switching to synthetic in your Impala?

Did he switch to synthetic in his vehicle?

A slight oil overfill won’t do any damage, and should not make any unusual noises.

Please answer the questions above.

Just to clarify. Do we feel there might have been a problem with the car prompting him to make the decision to change oil type ?

Any specfic type of small engine plane? Give it another shot,describe the sound better (knock,tick,squeal,loud like a exhaust leak?).

I don’t think it has anything to do with the type of oil. I wonder if the air intake hose got knocked off. I once had a 1985 Ford Tempo that would sound like an airplane engine when the hose between the air cleaner and the engine would come off. I had to secure this hose with large clamps.

I had one more thought: Does the engine make the noise when the car is in neutral and you step on the accelerator, or does the noise occur when you are accelerating from a stop? If the latter is the case, the noise may not be in the engine at all but something in the drive train like a wheel bearing.

The type of oil (dino or synthetic) makes no difference. Chances are that he made some error such as knocking some part loose or, perhaps, accidently pouring oil all over the serpentine belt and pulleys.

He did recheck the level after lowering it I hope. I’d hate to find out that the plug was loose and the oil missing.

And I hope he didn’t drain the tranny. He would not be the first to make this mistake.

Are you guys talking about the sound the propeller makes or the engine? I can’t say airplane engines make any distinctive type noise.

It was on sale. Does 10W 30 synthetic compared to 5W30 regular make a difference?

Sounds like a fan running in the dashboard when you accelerate.

He rechecked everything today and everything is perfect. I do need brake pads - think it could be a wheel bearing?

It only makes the noise when accdelerating - sounds like a fan in dashboard that gets louder and faster as you accelerate. I do need brake pads - it could be a wheel bearing.

It might make a difference.

“On sale” is not a good enough reason to switch oil viscosity.

Your husband is crazy (you already know that), and he’s going to cost you money in car maintenance/repair if you allow him to keep doing “maintenance” on your car.

Take your car to an independent mechanic, and let him or her help you maintain your car in accordance with the factory maintenance schedule.

Tell Hubby to get over it.

I can tell a recip a mile away, even if it’s “feathered”, a turbine two miles. Well, okay, maybe I’m exaggerating on the distance a bit.

Of couse I did work as an avionics tech on the flightline for four years, I do work under the approach path of a small airport, and I do have numerous recips and turbines in various states of disassembly not 100 yards from me…so I’ve had lots of practice…

So is the OP talking about the noise the propeller makes or the noise the aircrafts engine makes? I have found propellers to be quite noisy sometimes covering up the noise of the engine (we are not talking about the Wrights on a Super Connie, what were they 3000hp each?),kinda hard to cover that up.

My guess is that she’s comparing it to a small boxer-style engine like would be found in a Piper Cub, while flying overhead during takeoff.

Hey everyone. Thanks for the responses. Sorry it took so long to post. It wasn’t the oil - turns out it was a wheel bearing. It just happened to go at the same time the oil was changed. Got it repaired and now my car has a vibration when driving it. At least it doesn’t sound like a plane anymore. Taking it back next week.

Hoping to hit the lottery and get a new one!!!

Thanks for letting us know what the fix was…we do appreciate it.

Thanks for answering the mystery.
Good diagnosis, Triedag!

Was he using Wal-Mart 10-30 full synthetic HIGH MILEAGE oil? (> 75,000 miles)
Is that not good for high mileage engines?

Thank you.

Robert