ZOMGXB

I've seen mention of this before, but now that I'm pushing 70K on this thing I'd like confirmation.

After it's been warmed up for awhile, at stoplights (and in drive-thrus) my box goes "chugga-chugga-chugga-chugga-chugga." Like, noticeable vibration. It's fairly frequent once the car has been warmed up for awhile.

If I put the car in neutral, it goes away, but if I sit in DRIVE with the brakes on, it kind of...chugs. Like an old washing machine.

It has been doing this for the last 40,000 miles, and not gotten better or worse.

a) WHAT is this
b) is there something I should be doing about it
c) should I call Car Talk? I've kind of always wanted to.

I'll post video if necessary....

rickbreitenfeldt

Welcome to owning a 4cyl automatic car. They all do it. Toyota, Honda, Hyundai, Chevy etc.

The engine is torquing and the counter rotating shaft is good but a harmonic vibration carries through the motor mounts at idle with the transmission engaged. If you take your foot off of the brake while in D and the car moves away at idle you will also notice it disappears like when you go to N.

MadMike550

when was the last time you changed the spark plugs?

sounds like you might need a tune up

prophetx2

as mentioned before this is due to your car being a 4 cylinder car (more specifically it's the nature of an inline engine). You have nothing to worry about.

bB2NER

Try new plugs and a can of Seafoam every oil change. Mine did this and since the Seafoam treatments is all good. 1 oz. per gallon every 3K miles or so.

Zman

Isn't it something with the variable valve timing that makes it vibrate?

I just try to eliminate all the possible rattles with small pieces of rubber attached inside the glove box or wherever makes an annoying sound.

ShawnBenton

my xb does the same thing, and its pretty noticable outside the car up front, i have an open grill and the perrin intake, so when it starts chugging at a stop you can hear the intake pretty loud. its kind of annoying, but ive heard its completely normal.

Sciond

Shawn do what Jeff recommended and go with iridium plugs

dgenem

Agreed, I changed my plugs around 30k miles with iridium plugs. It's nice and smooth still and close to 80k miles. And yes, I do regular Seafoam treatments. It will make it smoke, but I believe that is carbon deposits being burned away.

There is a slight rough feeling while stopped at a light, but it has not changed since the first day. Just typical feel of a four cylinder with an automatic in gear with brakes applied.

Unrelated note, we need a sign to mention "Seafoam Engine Cleaning In Progress" so people will know there is nothing wrong when it smokes like that from the Seafoam.

bB2NER

Mine doesn't smoke when being treated with Seafoam. Maybe you are using more than 1 ounce per gallon of fuel?

ShawnBenton

so i went and got some ngk iridium IX plugs the other day, and put them in last night, i cant believe the difference, the box runs better than ever. it idles so smooth.

frogbox

Your only adding it to the gas ? Read the container , there are other ways to use it in your car.

bB2NER

The only method I've needed so far was to clean the injectors and combustion chambers. It also works in the crankcase for engines that haven't seen regular oil changes and intake manifold to clean dirty valves.

Sciond

I used a vacuum line

frogbox

Bet she really smoked , did anyone call the FD ? Guy that used to live down the street did when the shop down the street did it that way.

bB2NER

I wonder what effect this method has on the O2 sensors and cat? It should clean all the top end carbon out tho.

mrfuzzy4

do spark plugs really make that big of a difference? or is it just good for older boxes?

frogbox

Cleans them as well.

ShawnBenton

it made a big difference on mine because the plugs that were in it were shot to hell, they looked horrific.

but since the new plugs, it idles so smooth, and when accelerating, it feels a lot better. not faster or anything, just better.

NC_Pinz

Approx. 30k for stock plugs is a good mileage limit.