So i just got my oil changed on saturday and after i left i started hear some weird sound from under the hood. It sounds like a hard vibration coming from the left side of the engine. I can reproduce the sound by popping the hood and manually pulling the throttle. It happens as the rev is coming back down. It also happens when i have it in drive in first and second gear.

Took it back to the oil change place and told them it started after they changed the oil. Their mechanic(previously had a TLS) listened to it and said it could be coming from the timing belt. He said it could be that the case is loose and touching, or it could be time to replace it. But im not convinced this is it. Wouldnt you still hear the sound regardless of how high the rev is, because the timing belt is still running? He also said it could be something to do with vtec but i have no check engine lights on.

It doesnt seem to happen as much when the car has warmed up. Definitely need help. Any suggestions will help, even if you just think it could be something loose.

 

pray its the ac belt tensioner located on top behind alternator
very common wearout, mine went at 80

listen with mechanics stethascope or long screwdriver

if the timing belt is tearing apart and flapping,,,its going to toast the engine!!
a loose cover/ what kind of mechanic is this guy? dont let him work on your car!!

ck your engine oil level since a shop did it !

 

what rpm are we talking here? 5000? or 2000 and let off

 

if its a grinding sounding kind of noise thats the noise my tl made too I replaced it with a Gate auto tension-er and belt

 

When i am driving, the sounds starts at around 2500 in first and the same with second gear. When it is in park and rev, it starts around 2000. Any ideas on why it would lessen when the car warms up? Thank you both for your quick responses. I did check the oil and its at a good level.

 

Check for a loose air filter box since they usually check them in the oil change places.

 

my thought exactly--
often the top is not placed back on correctly
or worse they break a corner off the cover!!
its supposed to be a well sealed box

take a look there

 

Yup the 4 screws get rusty and break make sure to wiggle it around to make sure

 

Check the air filter box and that's not it. Its coming from the side of the engine where you check the oil level. I opened the rubber plug over the timing belt case and it got a little more louder. I also opened the other rubber plug more towards the left of the other plug (after the belt in the left of the picture)and it was a little more louder as well. I have attached a picture of the plug i am talking about. Any more ideas? It is hard to pin point because it also sounds like its coming from the top back of the engine.

 

Best to take that cover off and inspect the timing belt to be on the safe side. I'm not sure if yours has the same sound as mine but mines sounds like somethings rubbing in there also gets abit louder when you take off the rubber part but its not extremely loud, I changed the timing belt and water pump and tensioners and still there i`m at 225k and its been like that for a year now. My guess is the plastic covers warp over time although im not 100% on that .

 

Thank you. That seems like what I'm gonna have to do. I'm kind of tight on money right now(trying to pay for school) and i would have been really frustrated if i spent the money on the timing belt, water pump, etc. and the noise still be there.

 

It's easy to remove the front sprocket cover in a couple of minutes.....4 or 5 bolts. Run the engine and see what's going on there.

 

Hey QueenCityTLS,
I had a similar issue a few oil changes ago, but im not sure if the "hard vibrations" you're referring to are the same sounds I encountered.

The vibes I faced was more of a rattling sound than a vibration, and I caused it by mixing oil grades. Long story short, I tried to get a head start on my oil change before my brother dropped off my oil one day, and when he arrived I realized that he ordered the wrong case of amsoil.

Having already drained my oil, I decided to mix the 2x 0W-20 I had left from my previous case with 3x 10W-30 from the case my brother brought.

Although everything felt great and powerful, i noticed a rattling sound when accelerating... I guessed that it was the valves not being properly protected or something, so I changed my oil again a week later (with just 0W-20) and the rattling noise stopped.

Figured I'd share this with you. If you didn't see what your/the mechanic put in your engine, consider another oil change if your "hard vibrations" could also be described as a rattling sound (valves opening and closing, metal to metal contact kind of sound?)

Good Luck!

 

You shouldnt have had any issue with the 10w30 in there, especially not being mid winter on a cold startup Its not normal that you had what you described from 3q of it in there so you might want to have your valves checked

 

^^agree^^
How many miles ? Ever had any previous issues ?

 

I have 250K now, and had maybe 235K at the time. Never had any issues prior to this, and changing my oil got rid of the sound.

I thought to myself that it was weird, but I have a CAI, headers, high flow cat, and a catback exhaust, so i didn't want to risk any damage. The sound appeared right after the oil change so i knew it had to be the cause.

I recently got my timing belt and pullies changed as part of a major service, everything is running beautifully now.

Difference in compression?

 

Update:
Finally got fed up with the sound and took it to a shop. Turned out that my tensioner had gone bad, making my timing belt rub up against it. So, did the whole timing belt thing(belt, tensioner, water pump) as well as 3 oil rings(because apparently they were leaking). Got my car back today and everything feels great, as well as sounds great. Thank you all who replied back with suggestions. I thought i would post this to help anyone else who might have this problem.

 

Yay for actually updating the problem with the fix!