Cold start up popping noise
 

Hey guys,

So a fair bit of owners on an Australian forum seem to be disheartened due to a "champagne cork" like popping in the engine bay during first start up and only during cold starts.

One claims the engine rev's drop before popping also noise seems to be apparent on both transmission types.

This to me, sounds like the initial stages of the infamous DI seal problem folks seem to be having. I don't know if I am being paranoid but better safe than sorry.

So my question is, would this be something they (and I, who do not have such issues) should be worrying about?

Thanks!

I had it once in the winter when I first got the car ( too early for DI failure) and once this summer, but never when driving. My understanding is if its DI seal failure it should happen during driving when the engine is under load. Can anyone confirm this??

I, too, have experienced the popping sounds at startup during the cold winter months.

[ame="http://www.youtube.com/watch?v=Ky_vDK4ePHI"]FR-S cold start - YouTube[/ame]

Several people have experienced this on a brand new car so unless they did a faulty install from factory I assume it can't be a DI seal problem?

I've this quit consistently in the winter during start-up as well.
is it normal?

It's normal. It's nothing to do with seal failures.

I would have to agree, DI failure problems from popping to misfires/etc escalates relatively fast and some people have experienced this start up pop for a long, long time.

I've been getting these pop/knocks on start up as well. Not sure if you can call it a "cold" start up, as the morning temperature here in socal is currently around 65 F. I'm currrently at the dealership and I reported this pop/knock start up issue just so they can have it on file, and the "Master Technician" insisted he wanted to try and duplicate to inspect it. So we'll see what happens, will keep posted.

**Update
Tech couldn't reproduce it, should be no biggie.

I think it should be normal, I get it sometimes during a cold start esp in colder weather, but I mostly hear it through my exhaust (Perrin nonres)

Cold as in a cold engine, not that it's freezing out ;)

The popping happens during the cat light-up portion of warm-up, not normal cold idle.

Got it
 

I've wondered about this because I have it too. I noticed it first during this last cold, winter Dec-Jan, etc. but it still does it occasionally during the summer when I'm starting it for the first time that day, etc.

Bump. So what exactly causes this? I'm noticing it more frequently on my car - maybe due to the cooler weather.

do not have these issues...9400 miles in.

I got it alittle yesterday and then this morning it was reallly loud pop sound idk wtf it is but i know its normal. My cars gonna be at toyota overnight tonight so they can duplicate the sound, we'll see wht happens

Keep us posted

-22 thismorning and this was worse than ever... Hope it's normal cause it does it a lot.

At least it started for you... That's crazy cold..
It was 23 degrees here this morning.. So it's probably 55 in the garage
And it will pop and stumble some when I go to start it.. My car is spoiled down here in the Carolina's... Stay warm!

Mine is not as nearly pronounced as the video above, but only during the first 20 seconds or so on start up there's a very very faint pop sound, then once the revs drop down it goes away, and doesn't happen at any other point in time. Sounds like it's just running very rich on startup.

mine went on for a good minute thismorning, very loud and the first time ive seen it actually change the rpms.

weather is just starting to stay cold here now, im goign to get a video in the morning and bring it in to subaru. it does look like this is common... hopefully this car doesnt explode in the cold. to broke for a beater.

I posted a thread about this exact issue earlier and your video is what I experienced this morning. I hope this isn't a common occurance with this factory cold start tune.

I heard that noise all last winter during cold starts, warm weather came back and made it through the entire summer and never heard it again.

It has yet to be cold enough here for me to hear it again so far this season...so it sounds like normal crazy cold start sound this car makes in the cold. The exhaust is crazy loud during the startup, the cam phasing / spark timing must be acting up to warm up that cat fast and makes wierd ass noise in the process.

I can confirm that the revs drop under 1k before any popping occurs

Imo this is normal on cold starts

My popping/missing/stutter sound as in the video only occurs during the first 15-30 seconds of startup. Once the revs drop to 1k and lower it goes away completely. It only started doing it once the temps dropped below 40F.

If I start the car and immediately change gear out of park (auto trans), the revs immediately drop to ~1k and there is no weird popping. I assume it's the crappy cat warm-up procedure with negative timing. Maybe the engineers in Japan didn't spend much time testing in freezing cold environments?

I don't know if this matters or not but my car is manual so maybe that goes into account ?

As soon as a drive the car for 15 mins, the noise would disappear

After 15min of driving, the car should be fully warmed up.

Have you noticed if the pop/stutter goes away once you get rolling? I can bump to neutral in my auto and it goes away completely as the revs drop immediately as it passes through reverse. If you give a light blip of throttle does that make a difference?

It'd be nice to know what exactly is causing the pop. Seems almost like a misfire/cutout or split second power loss like cylinders not firing intermittently. The fact that it goes away as soon as the revs drop and the car warms up makes me think it's a startup fueling issue that Subaru or Toyota should sort out.

Mine does this when left outside and 25 F or lower. It's a backfire in the intake system. Cold fuel in the intake not atomizing and probably pooling. Cold start enrichment (the choke for old carburated guys). This fuel is then ignited in the intake system and you hear the muffled pop.

I'm getting the same popping noise on cold starts as well...was kinda alarming at first, but after the car settles down all is well.

yesterday was -7 degrees celsius (approx 19 F) car starts at 2k idle...then 1.5...then 1. About 4 minutes later, the car is ready :)

Same noise here. Cold start, it "pops" once or twice then stops, never does it during driving...Normal(i hope)

I had this on Monday morning it was in the teens and I heard a few thump sounds from the engine and that was it after 30 secs or so.

I've had this issue as well since the cold mornings started. I'm 99% sure it's coming from the exhaust. It also shakes the car just a tiny bit when it happens. Once everything is at operating temperature, it goes away though.

FWIW, I have the dealer-installed Borla Exhaust installed on the car.

Seems like no one else really emphasized the fact their car shakes when this happens but mine does. Hopefully that is what others experience too.

Occurs very infrequently when it is warm out, but not uncommon when it is cold. It is a bit disconcerting.

My car has the same symptoms. Cold weather Cold engine starts 1-3 pop/thunk within the first 10 sec. I can feel it in the chassis and I also noticed the rpm drops a couple hundred and the immediately goes back up.

It's been worrying me a lot but I took it to the dealer. They said it's not abnormal and it has to do with emissions. He said they had many people coming describing the same issues.

Ditto, though tonight it happened 3 or 4 times -- 1 initially, then 2 or 3, closer together -- more than the 1 or 2 I'd gotten used to it, so it worried me. Agreed that it happens when the weather is colder -- less than 40's. Always after the idle dip also.

Some people had noted this happened in other cars, esp MT, but this was brand new for me.

Does it for my car as well. Within 30 seconds of a cold engine start up, it makes a 'popping' noise and shakes the car a bit. It's happened a few times within the past 2 weeks (weather's been below 40F lately)

This happens before the normal RPM drop after the car warms up a bit ~ 30 secs

Funny thing, I was referred to this thread after I contact conacco 76 about a gas station I was using. At first I was wondering why my car was doing this because it didn't after my initial week after I bought the car which they put in shell gas. Then ever since after the first tank, I noticed it has been doing this and I realized that I have only used 76 gas and only at 1 location for the 6 fill ups. So I contacted them to check it out because after I thought about it and went across the street to Arco instead, my problem stopped. So far this tank I had no knocking using Arco gas. As soon as this tank is done, gonna switch back to 76 gas at that same location to see if I get knocking at start up again.


Below is a response from our fuel distributor for this station.

Hope this helps,

Cheryl Marquardt
Consumer Services
Phillips 66 Company
1-800-527-5476 (Office)
1-918-977-8034 (Fax)

______________________________________

Sent: Wednesday, December 11, 2013 11:41 AM
Subject: RE: Phillips 66 Company

Good Morning. We have had no fuel complaints regarding this station. If it's a brand new car, they might want to take it back to the dealer and have it checked out. It should not be knocking at the initial start up. I have attached a link below where it seems they're not the only ones having this knocking problem. Please let me know if you have any questions.

Thank you,
Bryan Holmes

http://www.ft86club.com/forums/showthread.php?t=43408


Bryan Holmes
SALES
R.M. PARKS, INC.
PO BOX 469
PORTERVILLE CA 93258

OFFICE: 877.784.2384
FAX: 559.784.1098
WEB: www.rmparksinc.com

have same issue. started doing it this winter when it was -30C outside. Occasionally get this now.
Will try to replicate with dealer this week, as the temps will be dropping to -15 or so. Just want this on file.

if anyone figures out wtf this is (since it started 20k km in for me) please post here.

Imo it's normal like some other members say

It only Does it in below freezing weather and once the car warms up the noise is gone

Keep us posted on your findings

Sent from my SM-N900W8 using Tapatalk

The cause has been posted several times in this thread:
Cold start warm up sequence.

It's more pronounced when the temperature is actually cold, rather than just the engine being cold started (Engine cold start = Engine started and not at operating temperature). The engine cold start program uses different fuel and ignition timing to light the cats and bring the engine to operating temp faster. This sequence takes longer if:
A) The ambient temps are cold
and/or
B) You sit and idle until the engine is up to operating temps instead of driving right away.