Engine Idles Rough - Corolland: the Toyota Corolla Forums

Hello.

I just got my new car last night and I was wondering if something was normal...

I got it with 166 miles on it, the dealership drove it from a different lot to my location.

I drove it about 20 miles home.

With it sitting in my driveway idling, it seemed to idle rough...like a slight pattern, repeated.

I wound it out on the road afterwards, to about 5000 RPM after that two or three times, and the engine runs great and runs very smooth...seems like its much smoother above about 2k RPM.

So, I was wondering if it is normal for this new engine to idle slightly odd...is it the engine design or the fact that its still new?

My wifes Stratus with 80k on it idles much smoother, my old Dakota with 152k idled smoother.

Of course, this is the first four cylinder vehicle I have ever driven, so perhaps I am not used to the buzzy-ness.

Thanks for any feedback,

Garrett 'nervous new car owner' Socling

The engine really didn't get broken in yet - so it probably get better as the miles rolls on. Could also be an issue with the dealer driving it from one lot to another. If it was relatively close - under 20-30 miles - maybe it would be OK. If they had to transfer it from outside the state - they should have flatbedded it in or sat it on a car carrier.

Four bangers are generally buzzier than your 6 or 8 cylinder engines. That is just the way it is. As long as the engine doesn't surge at idle (+/- 500RPMs from idle) - you should be OK. I never owned a four cylinder that was butter smooth (compared to a V-6 or inline 6) - they always run a bit rougher at lower RPMs. But they straighten out at higher RPMs.

The engine really didn't get broken in yet - so it probably get better as the miles rolls on. Could also be an issue with the dealer driving it from one lot to another. If it was relatively close - under 20-30 miles - maybe it would be OK. If they had to transfer it from outside the state - they should have flatbedded it in or sat it on a car carrier.
Four bangers are generally buzzier than your 6 or 8 cylinder engines. That is just the way it is. As long as the engine doesn't surge at idle (+/- 500RPMs from idle) - you should be OK. I never owned a four cylinder that was butter smooth (compared to a V-6 or inline 6) - they always run a bit rougher at lower RPMs. But they straighten out at higher RPMs.

Thanks for setting my mind at ease. She doesn't surge at all, its just not a quiet, smooth idle that I would expect.

I'll post back after a 1k or so and update for future reference.

PS I wanted to have them flatbed it in, but they moaned about how much it would cost. I calculated that they are making about $1k after holdback and whatnot, I don't see what their problem was...

Don't worry. New corollas are ticky (valve noise) ) and sometimes they idle a little rough at first. Perfectly normal.

My advice is, after you get thru the breakin period - 1500 miles, go to the dealership and have them start a few corollas to compare.

If an adjustment is needed, they can do it. But I doubt an adjustment will be needed.

Sounds good.

I took a couple Corollas for test drives before I bought this one, and this one seems the roughest...but it sounds like this is a normal part of the break-in process.

I just got back from a nice 50 mile or so drive in the country, a mostly 55mph two lane, Route 287 from Route 220 to English Center and back, a wonderful drive.

I haven't had the car past 5000PRM, been trying not to break 3000RPM for the most part, a couple times to 5000RPM when pAssing someone (oh my does she fly when I drop it into third and give it gas...whew! default_biggrin ).

When I got home, I let it idle for a minute (I did the DRL disable via switch and checked to see if my ground was still tight). The engine was idling worse than ever, sounded lopsided and bad. It ran so smooth on the road, it amazed me at how rough it runs when parked. I popped the hood and the engine was shaking...sigh.

I'm still only around 300 miles, so I'll just try not to let it bother me... default_wink

I just got a 2005 Corolla S and it doesn't seem to idle roughly at all... it's very smooth and quiet when I first start up and also after having driven it a short while (which is not much since it only has 150 miles). There definitely doesn't seem to be any shaking.

So, this is only one data point, but based on my experience maybe there is a problem with the spark plugs or the idle setting or something like that... Does anyone know if the warranty covers this?

You mention it only has 300 miles... did you even refuel it yet? It could be as simple as a poor tank of fuel. The engine is a bit picky sometimes.

Also, 5k RPM is a bit fast for the break-in period default_wink

No refuel yet.

Only to 5000 RPM a couple times. Figured I should stretch things out a bit. For the most part I drive very sedately.

I've read so much about breaking in an engine that I don't know what to believe anymore.

I decided to just drive moderately most of the time with occasional 3/4 throttle revs to 4000 and a handful of full throttle to 5000. Throw in some downhill engine breaking...

I dunno...

I'm trying to drive it as much as possible, I'll report back on any changes.

Thanks all,

You should take it in for a look if after refueling you haven't noticed an improvement. I mean, if you are experiencing a very rough idling sensation in the cabin, that is not normal.

I wish you the best.

Mike

Well I'm over 2000 miles now and I figured I should report back in.

The engine idles without the slightly out of synch lope it used to have. It now sounds like everything is firing in synch and the same rate.

However, it still vibrates enough to feel it inside when the car is idling after being driven.

If I pop the hood while idling, it still shimmies and shakes. Its a regular shake, but it is one heck of a lot of vibration.

I also notice vibration above 4000 RPM while accelerating and a fair bit of vibration at cruising speed on the highway: around 3000 rpm, the engine noise is primarily a slight vibration, audible and present in the wheel. Think 'mmmmmmmmmmm', and it isn't present at lower RPM's (push in the clutch and everythings as quiet as can be).

Other than that the engine runs great, has lots of power and gets great milage.

I think I will stop by the dealership to take a few other cars out and about, and see what they say.

What would be adjusted? Is there a possibility that the dealership will just make it worse or create a new problem?

I can't see how the vibration isn't going to eventually loosen everything to the point where I'll have a squeaky, rattle-filled POS after 100,000 miles... default_blink

I wouldn't worry too much. Probably depends on the dealership, bnut they could try the easy fix of raising the idle. Basically thye will end up messing it up.

Chances are - the vibration is a function of being a four cylinder. I've never had one that I could call "perfectly smooth or vibration free". The 1ZZ-FE, IIRC, does not employ balance shafts in the engine. These generally will help with vibration at idle and some resonant RPM range later - but tends to sap some efficiency out of the motor.