ok two problems with my car... first off ever since i got my car from my friend who i trust whole-heartedly, its made this crazy sound. listen to it when it revs down... it almost sounds like a mini backfire

http://66.75.118.29/badsound.wav

problem number 2

some my car will randomly shake violently when i first start the car and it kinda sounds like a diesel engine. the sound is just... ugh. it sounds like the timing is off or something.. maybe? i dont know much about timings.. or anything at all. after about 1 or 2 minutes and a few revs to about 4000 the violent shaking will go away, the sound of the engine changes to a higher pitch, cleaner pitch, and smooth. it then sounds like a normal car should sound..

anyway... help me out here. i dont knwo when the timing belt was last checked or chagned... i know it had a tuneup about 4-5 months ago (right before i bought it). spark plugs and wires were changed.

*shrug* i need help, thanks

 

^bump^

anybody?

 

Have you had the headgasket recall done/checked?

Have you performed any engine mods?

You bought it from a friend...

How many miles on it?

Are you the original owner?

More info please...

 

I don't really have any idea, but could it be a bad cold start injector that is causing your 2nd problem? I don't really know much about engines and stuff, but thought I'd mention that anyways.

Kind of off topic, but your sig says that you have a 3.0lt. Is that a turbo? If so, is it aftermarket or stock? Kinda curious.

Have fun.
DH6twinotter

 

Ive heard that type of noise on vehicles with a completely rusted out muffler (baffles on the inside gone). Perhaps it has to do with less backpressure.

As for your second concern, Is the engine "missing" (not running on all cylinders)? Sounds like it.

 

Now that I think of it...

This is the exact symptom of a broken exhaust manifold stud. Once the engine warms up, the seal expands and blocks the pre-02 sensor leak (the reason your engine shakes only when cold).

Another thing that comes to mind is bad MAFS. Sheesh, it could be a lot of things.

 

I called a local stealership, he said that my VIN didnt apply for the recall. it was one of the few that didnt apply.

Only mod is a flowmaster exhaust. It made the popping/backfire sound before the flowmaster, but the rough idling just started recently.

Bought it from a very trusted friend.

94000 miles on it

I'm the 4th owner. it was first leased for 3 years. then auctioned off. then sold to my friend, then i bought it.

DOnt know what else to add... when i left my school today (car had rested for about 4 hours) it shook some... once i got up to about 25-30 it decreased, then you could actually feel it kick in and it would run perfectly.

 

I would check the following area's first:

Exhaust manifold studs

Injector operation

MAFS operation

The last 2 can be tested with an ohm meter.

 

no.. not a turbo. whats so hard to understand about a 3 liter engine?

The muffler is brand new...

my friend randomly blurted out my catelitic converter is bad for the popping sound... he thinks he knows a lot, but i dont believe him about this kinda stuff.

how id you derive the idea of my engine not running on all cylinders? my gas milage sure says it is

I'm not very concerned about the popping but am very concerned about the rough shaking when i start the car...

somebody said "well the gaskets are expanding" i dont think they have enough time to expand if i can get it to go away after about 1 minute, but hey, what do i know? thats why i'm here asking.

thanks for any help

 

info on checking all 3?

thanks

 

Exhaust studs: You can manually check these by torquing on each one LIGHTLY. If one spins, or the nut is missing, then you found your problem. Dont just tighten it, you have much bigger problems now.

MAFS and Injectors: You will need a multimeter and a FSM to measure the resistance. If you have no idea what I just said, you will need someone to do it for you.

You may want to check out your 02 sensor just for kicks while you are at it.

As far as your cat being the problem, its possible, but not probable with that type of mileage.

 

is it possible to visually check the O2 sensor?

 

Yes and no. Generally speaking, a bad O2 sensor will have visual defects too. But not always.

Besides, you should know what a "good" O2 sensor looks like at that mileage, so you have something to compare it to.

 

I should?

 

Let me rephrase:

If you are willing to take it out to see if its bad, then you should know what you are looking for.

 

Concerning the shaking problem...

I'm getting bad gas milage around town... but pretty average on the highway. My friend noticed im putting out white smoke.. which means its running rich, right?

could my O2 sensor be dead?

 

White smoke is coolant in the cumbustion chamber.

Sounds like a headgasket problem now.

 

I'd second on the lazy 02 sensor...Have you had that checked? Maybe when you first start, the sensor is late to readdoesn't send the correct info to the ecu) and so you have a horrible idle until it finally reads and then sends the correct info to the ecu and it then finally smooths out. Let us know what you find out.

Salue

 

No.. if you have white smoke at the tail pipe (that is not steam) you head gasket is shot.. Just because it is not cvovered by the SSC, does not mean it can not go bad.. the motor still has the root of the problem in in.. (IHMO the stock exhaust manifoilds...)

When you get "white smoke" does it smell funny??

With your mileage, don't bother trying to check an O2 sensor.. it is over due to have a new one.. just replace it...

 

I just called toyota and he said exactly what you guys have said, its the head gasget. unfortunatly my car isnt applicable for the head gasget recall... according to two different dealerships.

the guy said that it would probably be somewhere upwards of 1600 just to replace the head gasgets... and thats assuming that fixes the problem. if theres more of a problem... then well... :pat: :cry: