2002 Corolla - Vibrates And Turns Off In The Morning. - Toyota Corolla, Chevy Prizm (1998-2008)

DaRi_GJ

Hello,

I've seen many posts about vibrations, but I really wanted to post about this problem because my Corolla 2002 (automatic, CE, 101K miles) has an additional situation, besides vibrating when stopped.

When I turn it on in the morning, after about 6-7 second it starts vibrating a lot more than usual (extremely) and it even turns off sometimes.

I've had turned it on again, and the same occurs. I have noticed that if I step on the accelerator just a little bit and even for just 1 second, the vibration might continue, but the car doesn't turn off.

I mean after the engine is hot it has an annoying vibration many people have been posting about, but besides that I get an "earthquake" when I turn it on (when the engine is cold). Like I said if I accelerate it just once it doesn't turn off. And vibration is a lot worse when I turn on the A/C, when the engine is hot there's no problem turning on the A/C.

I changed the sparkplugs, cleaned the TPS, ran an injector cleaner with a full gas tank, changed all defective mounts, etc.

Any suggestions about this problem???

Check the MAF sensor (assuming this is a 1ZZ-FE engine with VVTi) - a dirty MAF sensor will not read the correct amount of air and would cause this stumbling idle issue. A clogged PCV valve or a vacuum leak somwhere will also cause this stumbling issue as well as a clogged/dirty thorttle body.

PCV is easy to check - remove it from the valvecover and shake it. If it rattles, is should be OK - you can further test it with a clean length of rubber hose - blow through both ends - should pass air one way and block it the other.

Vacuum leaks are harder to check - the biggest potential vacuum leak is a leaky airbox. Double check that the air filter is in good shape and the airbox closes tightly, no leaks. Check the length of rubber pipping leading to the throttle body - should be fre of cracks and tears - make sure it is securely atteched to the throttle body. Look for obvious vacuum leaks - missing, cracked, cut, or otherwise damaged rubber hoses under the hood. An old school way to check is with plain water in a squirt bottle (you can add a bit of detergent in it to help reduce surface tension effects, helps its spread over the coated part). Basically spary the rubber hoses, connection t's, around unions, around the intake and throttle body while the engine is running. The point where the idle improves, shows you where the vacuum leak is. Pin-point the leak and then take appropriate action.

If you havent cleaned the maf in 101k miles it definitely needs to be cleaned. Use maf cleaner, I use CRC brand. When was the last time you replaced the air filter? If you havent replaced it in the last 30k miles then you need to do that too.

DaRi_GJ

The air filter was replaced.

I'll check the MAF and the PCV, since that's a usual recommendation for these cases.

I'm concerned, about one thing if you could tell me.

If the problem persists, How do you know if the PCV valve or the MAF sensor need to be replaced?

The air filter was replaced.I'll check the MAF and the PCV, since that's a usual recommendation for these cases.

I'm concerned, about one thing if you could tell me.
If the problem persists, How do you know if the PCV valve or the MAF sensor need to be replaced?

You should just replace the PCV valve (since its cheap) so you can jump to the next problem.

MAF is alot more expensive, I will just clean it instead of replacing it.

In addition, make sure you clean the throttle body!! (if you haven't clean it yet)

Good luck

Toyota-Prizm

Thought I would chime in here, my wife has a 2001 Chevrolet Prizm, in the last year or so, the engine was not up to snuff off the line (take-off at stop or stepping on the gas while cruising), the engine seemed to bog down a bit and never really acelerated easily and fast like it use to, I cleaned the MAF sensor and the car runs like new, I had cleaned the MAF about two years ago and do not remember this much of a difference in performance, anyway, if your Prizm or Corolla appears to run like I described above, the MAF may need cleaning, also, the Haynes Manual does not mention that the MAF sensor could be the reason for a problem like this.

DaRi_GJ

I wanted to post an update on this.

My car used to vibrate when stopped, the solution was replacing 2 engine mounts for original ones, it solved that problem, now my car is really smooth when idle.

I still have the other problem, and it is the rumbling when the engine is cold. I feel the rpms go down after 6-7 seconds when I turn on the car (I don’t know if it’s normal) but that’s exactly when the rumbling starts. It might even turn off the car. If I try to run it like that, is a lot worse.

I cleaned the MAF sensor, cleaned the Throttle body, changed the air filter, replaced the fuel pump, changed the PCV valve, replaced the spark plugs, they supposedly cleaned the injectors, and supposedly there are no vacuum leaks.

The next step the wanted to take was changing the MAF sensor, but they’re not sure that will help. Since, this is not a cheap part, and I haven’t found the way to test it from another car, I wanted to know:

Is there a practical way to know if the MAF sensor is wrong, I don’t have a CEL error, and I’m running out of options to explore in the search of this problem, any other ideas that might help???

There are two parameters that you can check on the MAF sensor:

One is its change of resistance for a given temperature. Measured between terminals ET and THA - the first two pins on the left, MAF opening pointing downward, you are looking straight at the bare pins [MAF disconnected from the car]

- at (-4) degrees F - 13.6.2k ohm to 18.4k ohm

- at 68 degrees F - 2.2k ohm to 2.7k ohm

- at 140 degrees F - 500 ohm to 700 ohm

The other is voltage variation with air movement past the sensor. Measued with the MAF connected to the car, ignition turned on, and you have a voltmeter backprobed to the third and forth pins from the left - same orientation as above.

- voltage should fluctuate (hot-wire setup)

But the problems you are seeing may not be a MAF issue. Still sounds like a vacuum leak somewhere.

This only happens with a cold start? What happens once the engine gets up to operating temperature - and you shutdown the motor, let it sit for a couple of minutes - then restart. Do you still get the funny idle?

DaRi_GJ

This only happens with a cold start? What happens once the engine gets up to operating temperature - and you shutdown the motor, let it sit for a couple of minutes - then restart. Do you still get the funny idle?

Yes, it happens only when cold. After it gets up to the operating temperature there's no problem, I had a vibration before, but as I said it was solved by replacing two engine mounts.

It happens in the morning. Sometimes I get it during the day when the motor is shutdown for many hours, but with less intensity.

Another point I want to make is that if I try to run the car forward or reverse it when still cold, the rumbling gets tougher. Then if I step on the pedal to the bottom I feel the car 'struggles' a little bit to go forward, seldom i hear a minor backfire, but if i keep it steady for a while all the symptoms go away.

My routine in the morning is to turn on the car, after a couple of seconds watch for the rumbling since it has variable intensity, then if its at it worst I step on the gas pedal (still parking) until i feel there's no risk of the car shutting down by itself.

Now, with this information, does it still sound like a vacuum leak, or are there any more options?

Thanks for the valuable input.

From that information - sounds like you have either an ignition issue or fuel delivery problem.

Since you change the plugs and fuel pump - I would suspect it could be an injector issue. A clogged or dirty throttle body could cause that hesitation - but it does sounds like your vibration is more a misfire issue. If the car sounds like it is going to backfire - then I'd lean more to a misfire problem.

Could also be heavy carbon buildup inside the combustion chambers. When you replaced the plugs - how did they look? Lots of carbon on them? Did they look wet? Did you verify plug gap (0.044")?

Having to stand on the accelerator pedal to smooth out the idle means there is something definitely wrong.

- Make sure the coil packs are working (verify spark, when you ground them to the chassis - make sure to diconnect the injectors so you don't load the cylinders with gas).

- Make sure the injectors are working (audible test with an automotive stethoscope or NOID light will help). They could need to be ultrasonically cleaned if they are really dirty, or are clogged inside - fuel injector cleaner may help, depends on how clogged they are.

DaRi_GJ

From that information - sounds like you have either an ignition issue or fuel delivery problem.

Since you change the plugs and fuel pump - I would suspect it could be an injector issue.
Could also be heavy carbon buildup inside the combustion chambers. When you replaced the plugs - how did they look? Lots of carbon on them? Did they look wet? Did you verify plug gap (0.044")?

I wanted to post an update on this topic.

Since I solved the problem.

It's was indeed an apparently a problem with the injectors, since i cleaned them.

There was also a leak in the fuel system, near the fuel pump. Both problems were solved, and the symptoms disappeared.

Thanks for the valuable input!!!

Good to hear that you got it resolved. Glad we were able to help out.

How do you clean the injectors?

How do you clean the injectors?

Fuel injector cleaner added to the tank will clean lightly gummed up injectors. For injectors that are heavily gummed up - you can have them cleaned with a special solvent run through the fuel rail while on the car (usually have to have a garage do this) - or remove the injectors and send them in to be cleaned professionally (ultrasonically cleaned, flow-balanced and fully tested - basically like new at a fraction of the cost of replacing them).