Alright, I know a lot of people have had problems with this, but I'm just making sure. Just bought an '02 Z24, 2.4L engine, automatic, MagnaFlow exhaust, and all like that. My problem is with the way it idles. Everyone seems to disagree on this. When the car starts up, it revs up to about 1500 then settles down to 1000, which is fine, but then settles even further to about 600-700 rpm. I don't mind a rough ride, I like to feel what I'm doing, but the dash shakes like nothing else. Is this normal? I ran Sea Foam through it, which was fun more than anything, replaced the air filter, replaced the spark plugs, and cleaned the throttle body. What else can I try, or should I even bother? Thanks for any info you could give me...

when u first start it and it revs up then settles and once warm settles to the 600-700rpm range that is normal...

as for the dash rattling do u have motor mounts? they would cause alot of the vibs in the dash... and dash rattle seems to be common in j-bodies, not mine tho my dash doesnt rattle...


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ayo 8 Iz Enuff

Since your is an automatic, it should idle around 600-700. If yours was a manual it would idle around 900. My auto ecotec idles at like 550 or 600 when its fully warmed up. It does start at like 1500 and work its way down. Your car is operating properly.

id blame the egr but as you say it settles down and stays at normal if it couldnt choose an idle speed and shook real bad it would be tho

Check motor mounts... too bad that model has no way to get at the injector plugs. You could pull each one and listen for a change... possibly finda clogged injector

Check the motor mounts. There really is not much else that would make the rattle like that. If I a getting the right mental picture. I am new to J bodies as well. I am going here from my first car a '69 Olds with the 350 Rocket. That car shook like you would not believe until I had the motor mounts reworked. After the motor mounts were reworked the car only had the normal vibs for the power.

Postal Bunny wrote:Check motor mounts... too bad that model has no way to get at the injector plugs. You could pull each one and listen for a change... possibly finda clogged injector

What.....? He'd know if an injector was not working at all, and if one was just not working well... it would still change the idle when he pulled it.

Sounds like a regular auto with a lower motor mount dogbone. Look under the car on the passenger side. If the dogbone holding the engine to the subframe looks a bronzish color and has pollyurethane inserts, it is aftermarket and is why it shakes. The stock mount looks very, very stock.



Cardomain|Myspace

M I N I O N - Sinbird wrote:

Postal Bunny wrote:Check motor mounts... too bad that model has no way to get at the injector plugs. You could pull each one and listen for a change... possibly finda clogged injector

What.....? He'd know if an injector was not working at all, and if one was just not working well... it would still change the idle when he pulled it.

Sounds like a regular auto with a lower motor mount dogbone. Look under the car on the passenger side. If the dogbone holding the engine to the subframe looks a bronzish color and has pollyurethane inserts, it is aftermarket and is why it shakes. The stock mount looks very, very stock.

SHE...SHE'D know if an injectorwas not working.

anyway, that's what we were thinking....it has to be the lower mounts...hard to get at 'em though

thanks guys for all your suggestions!

Hard to get at them? You can look right at it from outside the car but laying on the ground..... There is absolutely nothing covering it.
BTW... my names Josh, I'm a scorpio.. I enjoy long walks on the beach and romance movies.



Cardomain|Myspace

My car is too low to the ground to be classified as "easy to get to". That's what I meant.

And I'm not a big fan of romance movies.

I'm going with the motor mounts. My car takes awhile to warm up ('99 Sunfire GT 2.4 auto) but once it does it shakes and rattles at the lower RPMs (thank you Karo). You get used to it (just worried something's going to rattle off) but your passengers'll probably chose a different car to ride in next time they go out.


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* Student of the University of Oklahoma. Go Sooners!
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James Larsen wrote:(just worried something's going to rattle off)

yeah, i'm terrified my car's going to vibrate apart...I already have a crack in my dash.

and as for passengers, who needs 'em? they just add extra weight

Dash Crack is a Cavalier issue, unrelated to the vibes, they just do. Like others said, lower motor mount, if its performance, live with it, as you have an auto. My manual doesnt vibe anymore after all 4 mounts were added, but in your case, being an auto, it idles at lower RPM. Everything is normal.

Quote:


And I'm not a big fan of romance movies.

I meant funny movies... yah.....


Slide a mirror under it... seriously.... it is RIGHT THERE.... my old cavfire was dropped 4" and I could see it.



Cardomain|Myspace

M I N I O N - Sinbird wrote:my old cavfire was dropped 4"

wow, I already slow down to about -5 mph when I go over train tracks...can't imagine dropping it further

i'll tell you EXACTLY whats wrong.....your injectors are partially clogged so run some fuel injector cleaner (its like $3) through and it will run like a champ.

^^^^^^^^^

You're joking right?
The compputer balances out the idle via the idle air controller. If the idle was low due to incomplete combustion it would open up further and increase the idle speed until it was right.... the idle is right where it should be.

Now.... the bad part... NONE of those "add it to the tank" injector cleaners work... period. All they are good for is prevention. Since there is no real density to the formula it would be virtually impossible for an "injector cleaner" to unclog the injectors... especially as deluded as they are in the tank.
There is one thing that works though but it is rather expensive... if you have ever gone in for a tune-up and seen "fuel injection service" advertised, this is it. They use a special formual that is strong as hell and actually run the car off of it. There is a gravity fed line that you plug into your fuel system and hang a canister from the popped open hood. Disconnect the fuel pump fuse... turn on the car... You pretty much let the car run off of this canister until it is empty.. the car will die on its own. The smoke that comes from your tailpipe is THICK white and smells very sweet like a blown headgasket. The system works but it is expensive. Those little bottles you can buy at parts stores..... they aren't worth their weight in gasoline.



Cardomain|Myspace

M I N I O N - Sinbird wrote:^^^^^^^^^

You're joking right?
The compputer balances out the idle via the idle air controller. If the idle was low due to incomplete combustion it would open up further and increase the idle speed until it was right.... the idle is right where it should be.

Now.... the bad part... NONE of those "add it to the tank" injector cleaners work... period. All they are good for is prevention. Since there is no real density to the formula it would be virtually impossible for an "injector cleaner" to unclog the injectors... especially as deluded as they are in the tank.
There is one thing that works though but it is rather expensive... if you have ever gone in for a tune-up and seen "fuel injection service" advertised, this is it. They use a special formual that is strong as hell and actually run the car off of it. There is a gravity fed line that you plug into your fuel system and hang a canister from the popped open hood. Disconnect the fuel pump fuse... turn on the car... You pretty much let the car run off of this canister until it is empty.. the car will die on its own. The smoke that comes from your tailpipe is THICK white and smells very sweet like a blown headgasket. The system works but it is expensive. Those little bottles you can buy at parts stores..... they aren't worth their weight in gasoline.

actually it aint that expensive 3m makes a kit that you can buy for next to nothing (40-50 bucks at a parts store) all you do is find where your pressure test valve is on the rail and plug it in, disable the fuel so it only runs off the cleaner and when the car dies its done and cleaned (its the same formula the dealerships use just made for uh... u know average joe use)

05cavalier07 wrote:i'll tell you EXACTLY whats wrong.....your injectors are partially clogged so run some fuel injector cleaner (its like $3) through and it will run like a champ.

Seafoam Thinking of actually having them cleaned ($50 at mech). Those bottle cleaners usually don't work that well, they might need to be flushed /w chemicals.

That's why I refered to unpluging the injectors or plugs b4, when you unplug a working injector you get a miss... when you unplug a clogged one it sounds almost the same. Guess that post was "modderated".

The computer will never be able to compensate one injector for being clogged... mabey if she gets FAST. The computer will calc the a/f ratio well, but not be able to make one injector that is clogged push more fuel than the rest to smooth out the rough idle. I would pay $ for that ECU What he was refering to was if only 1 or 2 of the injectors is a little clogged it won't affect higher RPM as much as it would 600rpm idle.

If that's the case it'll get worse as she tries to fix the problem... eventually leading to a complete miss. My $ is on the mounts like you said b4.

Ben Wick wrote:
actually it aint that expensive 3m makes a kit that you can buy for next to nothing (40-50 bucks at a parts store) all you do is find where your pressure test valve is on the rail and plug it in, disable the fuel so it only runs off the cleaner and when the car dies its done and cleaned (its the same formula the dealerships use just made for uh... u know average joe use)

Do you have the name or any info on that kit? I got a mech that will do injector cleaning for $69... but if I could buy parts for that and do my cars all together and save $ that'd be great. Just about ever car over here is over 75k and is due for either cleaning or new injectors.

http://products3.3m.com/catalog/us/en001/auto_marine_aero/automotive_aftermarket/node_GSRTBL245Qgs/root_GST1T4S9TCgv/vroot_GSLPLPKL4Xge/bgel_QF2T43N7Q7bl/gvel_GSJX1THS8Hgl/theme_us_aad _3_0/command_AbcPageHandler/output_html




well thats the regulator i have no idea how much that costs but i know that all auto parts stores sell the cleaner bottles in a kit comes with throttle plate cleaner and injector cleaner for around 50 bucks if the regulator is expensive its worth it one size fits all domestics (adapters are reasonably cheap also otc tools makes a damn good kit too that you hook up to shop air and dump some fuel and cleaner additive into a can and run the car on it

http://www.otctools.com/newcatalog/detail.php3?id=11

both systems i have used they both involve screwing the line into that little schrader valve that you use for testing fuel pressure

Nice, thanks for the links.

Also, had a chance to look at her mounts under more light and the center of the upper mount is red poly.. the lower dogbone is brass colored metal /w red poly bushings. definately aftermarket. Hopefully the only cause of the vibrations.

Found some mounts on rockauto.com and @ autozone but they look to be the wrong stuff... have to check out GM to see what part #'s etc to find. I can only seem to find a "oil filled hydrolic mount" for "front right" which I assume to be the dogbone.

Look for racing mounts in the classifieds next month