Knocking sound
 

This morning I started my FR-S, as the car was at cold start everything was fine, once the RPM dropped to idle there was a noticeable knocking sound from the engine while the car was still cold. Once the car had fully warmed up the knocking goes away.
Anyone else ever had that problem?

In cars with hypereutectic pistons (which this probably has - not sure), you will have noticeable "piston slap" until it warms up.

I have not noticed it. Did you have to get out of the car to hear it?

My BRZ does the exact same thing, and it goes away when it's warmed up. I'm glad I'm not alone!

No i can hear the noise from the inside of the car not the outside

I get it too.. Some say it's caused by the cat heating up. The engines knocks
and it feels like a backfire. Only a few stumbles and it smooths out. It's not piston slap..

The knocking lasting for about 20 minutes, is that normal?

Well, my FR-S doesn't do that ..... but it doesn't get real cold here.

I'd be a bit concerned if the "knocking" went on for 20 minutes.

Can you capture a video/audio and post it .. ??

....and, of course you have checked the oil level....http://www.runemasterstudios.com/gra...ages/smile.gif

My car sounds rough on a complete cold start.. Almost sounds like its knocking for the first few seconds after ignition, but it never lasts more than a few seconds.

If that knocking noise persists for 20 minutes, I'd be concerned.

No..

Was this thismorning? It's -40 with the wind chill up here so if your parked outside, my engine took over 20 m of driving to even move the temp quage.

My radio still hasn't turned on either

Hopefully my balls reappear soon

Edit: I see it was yesterday morning, still pretty cold. Go out thismorning and take a vid of start up and post it here.. Dress warm

I will try to get a video of it knocking, and i got an oil change two days before it starting knocking, and oil level is fine

I live in Florida, and on cold starts I get 2-3 loud knocks withing the first 30 seconds and then everything is fine once I put her in reverse. The knocks are so bad that the car almost shakes a little bit.

No codes, no drop in performance, etc. Seems to be normal on our cars when they get cold

It doesn't knock during cold start, but right after the RPM drops to normal idle, and the knocking is constant for about 20 minutes, and the car does shake a bit with every knock

Well, if I had to guess, I'd guess your car has a coil/plug or the wire leading up to one of them acting up.....:iono:

You sure they used the right oil?

they should of, but how would i check what type of oil they used?

You might check your work order or call whoever changed the oil.

No oil (except maybe 3in1 oil) would cause an engine to knock under light use.....;)

Is it the fuel injectors leaking air, then causing knock?

There is concern about the reliability of the seals and the design/quality of the system.

well i checked the oil level, called in about the type of oil they used and they claim that they used the right type

Well, I reckon it's time to post a movie .... ;)

I've noticed my engine doesn't sound quite right when cold either. I was going to chalk it up to a Subaru quirk but the more I think about it the more I'm worried. Would love to hear a video, I'll try to get one of my own if I can replicate.

Ive tried taking a video of the noise, but my phone wont capture the sound :bs:

tried taking a video but i cant capture the sound :sigh:
if you could take a video and post it, it would really help just to see if we both have the same problem

Not sure if I can get it either, it isn't consistent and it doesn't sound like the engine is falling apart, it just sounds kind of truck like and unrefined. Honestly wasn't going to post anything about it, chalk it up to normal noises cheap sports cars make.

I'm 95% sure that a dealership won't do anything without a CEL or ECU code. So that leaves us paranoid guys in a tight spot.
:bonk:

LOL ya your right, I'm heading to the dealership tomorrow to replace my tail lights because water is leaking inside. so I'm going to inform them about it. Hopefully the knocking starts when they see it

Is it like a rhythmic "marching" or "chugging" kind of sound?

its more of marching sound

I hear it too, ever since the car was new. I figured it was something to do with the fluids not being warmed to optimal temps yet. Will try to get a video of it when I cold start my car after work for reference

Holy crap, block heater help much?

I dont have a block heater

Ontarions think block heaters are for pussies

I have this noise also. It only happens when the motor is at idle 650 RPMs. It does not get any louder or I can't hear If I rev the motor. Driving around it seems fine, but if I stop and open the hood and I am at idle I can hear the noise.

I think I know what OP is talking about. Only happens when cold and after the initial warm up dance is over and the car has settled to idle. Engine temp is still low. A quick blip of the throttle makes the sounds happen but only under about 1,000 RPM. Anything above that and the noise is not there.

Yea, go figure, the sound isn't there when I want to record it. Oh well, I think it's a non-issue

It's only happened to me about 4 or 5 times.

i have had this too and it still does it sometimes

Ya thats exactly it, do you think its an issue?:iono:

I certainly hope not!

I wouldn't imagine that's it's the end of the world but it may be something to bring up with the service department. Though I'm sure all you'll get out of them is, "Well we can't replicate it so it's normal."

Cars do weird quirky little things all the time, especially this car. It just seems worse when it's your new vehicle and not a 10 year old hunk-o-junk. :eyebulge:

Well it seems like a lot of people seem to have heard there motor doing this so I am not going to worry about it. If an engine had a knock that was bad wouldn't it create a CEL light to come on?

ya your right, and it only has 6000 km on it