GS3.0

iTrader: (1)

We had a pretty bad snow storm last week and my car got stuck outside my house b/c they hadn't shovelled the laneway to my garage. I finally got the car out and into my garage, but i got this engine knocking sound now. Im not sure if its from over-revving the car but everytime i start the car there is this knocking sound coming from the engine. However, the car drives fine and there are no CEL on the dash.

Can you guys chime in on this before i bring it to my mechanic?

Debonair

Have you check to make sure it has oil?

Mr Jokster

iTrader: (8)

does it change speeds as it revs higher?

link13

It's only on startup and it goes away? My 1GS had similar symptoms, but it was more of a rough startup than a knocking sound. It turned out to be the crankshaft pulley in my case. How many miles on your car?

GS3.0

iTrader: (1)

I just got an oil change last month, but i'll check again. I doubt i burned that much oil in such a short period of time.

im not sure what you mean. but it drives fine and shifts fine and no CEL.

the knocking sound is always evident, but more on startup and slowly dies down as i start to drive the car. but even after driving for a while and the car is idling, you can hear the knocking sound. i'll make sure to make note of the crankshaft pulley when i get my mechanic to check it out.

Debonair

He means is the speed/type/loudness of the Knock affected by the RPM's of the engine?

GS3.0

iTrader: (1)

well the knocking somehow becomes less obvious as i drive, but if you listen really carefully you can tell the speed/rpm increases the knocking (ie the knocking gets faster as the the speed/rpm increases).

GS4_Fiend

iTrader: (22)

Sounds like your pistons/rings are getting loose from those over-revving. The best bet is just use thicker oil. 20w 50. GL!

GS4_Fiend

iTrader: (22)

But of course.... DO check the oil level before jumping into conclusions.

GS3.0

iTrader: (1)

is it probably that during my last oil change, my mechanic used some kinda "engine flush" before changing my oil? He also used Castrol "high mileage" engine oil 10W30. Also, Im almost hitting 200K miles on my car.

Debonair

Time for a new mechanic. I would never run a Engine Flush on a high millage vehicle. It does more damage then good. Pretty much any "flush" on a high millage vehicle is not a good idea.

Previous Post on the subject:Could This Damage Your Car? Engine Flush

GS4_Fiend

iTrader: (22)

200k ?! Maybe that's why. IMO, try using 15w50 or 20w 50 see if the noise goes away. The noise could be from the valve lifters (maybe it's time to adjust it) or the rings on the pistons are getting loose. But if they are loose, you would be burning oil. And if it is burning oil with 10w 30, then try using 15w 50 or 20w 50. GL!

Mr Jokster

iTrader: (8)

"Debonair" stated correctly. I mention this because I had a similar problem with my other car (no CEL either) sounded like something was banging the top of the inside of my intake manifold (metal to metal) though a valve was hitting or someing.. So after taking a ghetto stethoscope (rubber hose to ear ) all over the engine bay trying to find the source of the sound, I accidentally found this:

well couldnt find the pic sorry LoL.. but I found that a chunk of the rubber in the harmonic balancer was gone! Yes, it too went away at high rev untill it tossed another chunk out then it was constant. So it could either be the same thing or maybe something with one of the pulleys. I dont know if all harmonic balancers are the same, but I'd check for cracks in the rubber. As it turns, it may be stretching it and throwing it off balance. (this is all a stretch/guess on my part) but thats what happened to me

djspawn00

I had a similar problem after letting my car sit in the cold for four days... loud scary knocking that went away after a few minutes (reduced to ticking) then never came back.

DASHOCKER

iTrader: (2)

Is this a brief knocking sound that lasts under 10 seconds during cold start up? If so, it is normal..