piston slap in cold climat start.

[fr0st]

Yes i searched already,


I started the car this morning. Fresh oil change on 5W30 Amsoil.

Temp outside was -1 F. car not plugged in.

Once the car idled for 10 minutes or so, i drove off to work which is 2 minutes away..when i put the car in reverse to park it and at low RPM when slipping the clutch a little while parking it. i could here the typical piston slapping.. gets louder when under load.

Anybody has this? seems to have started when the cold weather came in.I assume it's because the oil is not fully warmed up?

The car has 40 000 miles, Stg 1 AP with a CBE and not beaten.

is this going to damage the engine more in the long run??


Once fully warmed up it's gone.

* Registered users of the site do not see these ads.

[bhinak]

Nope. It's normal. The pistons shrink in the cold weather. Expand when warm. Just let the car warm up before you romp on it.

[424wrx]

i get a little noise too in my 08. subarus have some weird noises in the cold. i hear a high pitched whistle coming from under the hood too at times. then it goes away.

[DerekB707]

-1, man that's cold. I was complaining about the 30's here. Out of curiosity, do you notice any higher oil consumption at the colder temps?

[fr0st]

Originally Posted by DerekB707

-1, man that's cold. I was complaining about the 30's here. Out of curiosity, do you notice any higher oil consumption at the colder temps?

i'm on 5W30 Amsoil. it start to move a little by the end of the 3000 miles where i do the oil change.. it gets dark and then burns a little.. reason i do it this early is because of that. my work place is 1 mile away and the car idles alot to get warm when its cold..While working 5 days a week i end up fueling the car every 2 weeks.. doesn't move much.

and it gets alot colder that -1 here.. i've seen -30 F...even -40 when i was a kid...but global warming took care of that

[XLR8T]

i wouldnt worry about it unless it continues when getting up to full temps...

my 04 ts made the noise at 209km when i got it.. our winters here are +5 to -30.
now the piston slap on cold mornings sounds almost like a rod bearing is beyond gone and it still goes back to normal as soon as its warm. its got 292k and is still going strong to this day......

[drewvdw]

Originally Posted by DerekB707

-1, man that's cold. I was complaining about the 30's here. Out of curiosity, do you notice any higher oil consumption at the colder temps?

-1 is cold? We often see 0-5* during the winter and will have days that get as cold as 15-20 below zero. The coldest I ever remember seeing was -32* 6-8 years ago...

I'm worried about piston slap on a built motor in those temps...

[fr0st]

Originally Posted by XLR8T

i wouldnt worry about it unless it continues when getting up to full temps...

my 04 ts made the noise at 209km when i got it.. our winters here are +5 to -30.
now the piston slap on cold mornings sounds almost like a rod bearing is beyond gone and it still goes back to normal as soon as its warm. its got 292k and is still going strong to this day......

Had an 02 TS a while back.. it was piston slapping and sounded like rod knock.

Had the dealer replace the pistons under warranty as the car had 15 000 miles on it. i took pictures of the pistons,it wasn't pretty..

[cynet2k]

Originally Posted by 424wrx

i get a little noise too in my 08. subarus have some weird noises in the cold. i hear a high pitched whistle coming from under the hood too at times. then it goes away.

The high whistle is not normal... You probably have a vac leak or torn tmic to throttle body cuppler... they rip all the time its a shat design

[424wrx]

Originally Posted by cynet2k

The high whistle is not normal... You probably have a vac leak or torn tmic to throttle body cuppler... they rip all the time its a shat design

its weird man. it only happens when the car is very cold for a few seconds and when i first take off when the car is cold. its like a humming whistle. then its goes away. ive read about air pump noises that are like mine. its been like this for almost 5 years.

[fr0st]

Originally Posted by 424wrx

its weird man. it only happens when the car is very cold for a few seconds and when i first take off when the car is cold. its like a humming whistle. then its goes away. ive read about air pump noises that are like mine. its been like this for almost 5 years.

Are you sure it's not the air pump??

It does make a humming whistling sound for like 7-10 seconds when started cold.. even in summer.

[424wrx]

Originally Posted by fr0st

Are you sure it's not the air pump??

It does make a humming whistling sound for like 7-10 seconds when started cold.. even in summer.

thats what ive read. i think it is. ive never had an issue with the car since it was new. i dont think its a boost leak or anything major. i see 21-22 psi on the accessport no problem with my current tune. its just a strange sound though. it will do it a little sometimes when i first accelerate to when cold.

[cynet2k]

Originally Posted by 424wrx

its weird man. it only happens when the car is very cold for a few seconds and when i first take off when the car is cold. its like a humming whistle. then its goes away. ive read about air pump noises that are like mine. its been like this for almost 5 years.

Ive never heard of this but I could be wrong but this is my thinking about it:

When your car is cold all your hoses and connections lossen that is why mechanics only do vac and boost tests when the car is cold. Now if your car only makes a hissing noise on cold I would assume that it is vac leak. Ive had a 2007 LGT stage 2 as a daily driver, Ive had a 2007 SpecB built to over 500whp+ on a mustang dyno and now I have a 2011 WRX pushing 375whp+ as my dialy and all with no hissing and they all had cyl air pumps and all have same engines. I have had 3 different Subarus and have never heard this noise when all the connections are tight and zip tied closed for extra protection.

If you have a small leak, your car will run and it could run pretty good but it doesnt mean its running right. It will not affect your car too much but it is hazardous and could cause problems overtime. I mean I could be wrong but I dont make excuses for noises unless I am 100% sure after doing the "proper" tests the "correct" way to rule out the obvious.

Dont get me wrong, I could be missing something here with what noise you are talking about but thats my thinking.

[meebs]

Originally Posted by 424wrx

thats what ive read. i think it is. ive never had an issue with the car since it was new. i dont think its a boost leak or anything major. i see 21-22 psi on the accessport no problem with my current tune. its just a strange sound though. it will do it a little sometimes when i first accelerate to when cold.

Throwout bearing whistle. Search for that over in trans forum...or YouTube.

[424wrx]

Originally Posted by meebs

Throwout bearing whistle. Search for that over in trans forum...or YouTube.

ill check this out. it did the noise quite a bit leaving work tonight. its a high pitched whistle. it comes and goes.i let it idle to warm up a few minutes and it made this noise about 5 times then went away.

[424wrx]

meebs, i think you nailed it! its the noise this 2010 makes at about 55-60 seconds into the video. so its pretty normal? im on stock clutch still at 51k on the car. thanks for the help.

2010 WRX throw out bearing issues? - YouTube

2010 WRX throw out bearing issues? - YouTube