Little shaking at idle and little hesitation

MMamdouh · Post by **MMamdouh** » Sat Dec 17, 2005 11:59 pm

what could cause little shaking at idle and little hesitationin the begining of second gear?

the engine shakes just a little bit on idle but you can spot that if you are looking at the engine or if you are in the car by feeling a little "bump" in the regular engine running cycle and you can notice that at the exhaust as it will feel as if the exhaust gets disturbed at its usual path out of the engine every some 2-3 seconds.

i also feel the car lost a little of its torque so yuo have to be at a bit high rpm to ovecome that... we are talking 500RPM over the regular drive that anyone else does.

i got no CEL whatsoever and the car readout was good on the OBD scanner... we are talking 1.5 SOHC lanos with:

Air filter 6,865 Km
Fuel filter 8,275 Km
Fuel pump 56,000 Km
Ignition coil pack 69,195 Km
Injectors 7,580 Km
Spark plugs 6,675 Km
Spark plugs cables 6,865 Km
Timing belt 28,075 Km
Timing belt tensioner 7,580 Km

last time IAC was cleaned and injector cleaner was applies was some 4,000 Km ago.

current mods are:

removed intake resonator.
removed CAT.
BOSCH super 4 spark plugs.

i know i should be the one answering that but i am all out of ideas and i need some help... i recon it is something electrical but i can't tell if that correct and if so what can it be??

any ideas?

MMamdouh

Audacity Racing · Post by **Audacity Racing** » Sun Dec 18, 2005 3:09 am

after heavily consulting the manual... i have a few things for you to try and such.

1. inspect sparkplugs for ecessive wear, cracking, heavy deposits, etc... replace if they look bad (look for a golden brown color on the plugs to ensure proper fuel burning)

2. inspect leads for the same thing...
~ spray a fine mist of water on the leads while the car is running at night to look for any arcing of electricity to determine if there is a voltage leak

3. check O2 sensors for excessive wear/deposits... also check for faulty RTV sealant (on the threads).

4. moter mount mis-hap. the manual talks about a motormount that is out of alignment or broken. this might also cause the tranny whinning sound. seeing as how you just replaced the mounts and then had these problems, it seems to point to them

. i recommend getting the bolts retorqued and making sure the mounts are setup right.

let us know what your findings are

MMamdouh · Post by **MMamdouh** » Sun Dec 18, 2005 7:36 am

thanks for the advice man... did the manual sepacify which motor mount that can cause the whining sound?

MMamdouh

Audacity Racing · Post by **Audacity Racing** » Sun Dec 18, 2005 7:37 am

check the trans mounts

MMamdouh · Post by **MMamdouh** » Sun Dec 18, 2005 7:42 am

their was one particular mount that gave hard time to the mechanic... it was the one on the tranny facing the radiator, it could be that one out of alignment or so.

got ot give it a good inspection and maybe my tranny problems will go away.

also i was having the shaking problem before the engine mount replacment and i think it got a little better after i replaced them given that 2 out of 3 were totally broken.

also my oil change is due after 800 kms and that is always associated with a major engine checkup including spark plugs and all... will give you feedback on what i find.

MMamdouh

Audacity Racing · Post by **Audacity Racing** » Sun Dec 18, 2005 7:45 am

i'd tell you to consult the manual i posted... but it's missing the engine trouble shooting for some reason

i do have my paper copies though and that's where i got my info from to begin with

MMamdouh · Post by **MMamdouh** » Sun Dec 18, 2005 7:53 am

thanks for the help man... i really appreciate it.

MMamdouh

koh · Post by **koh** » Tue Dec 20, 2005 2:45 pm

My two cents worth contribution.

How about engine mounting failed ? It might be the case.

MMamdouh · Post by **MMamdouh** » Tue Dec 20, 2005 3:49 pm

that problem was their prior to replacing the mounts, spark plugs, spark plug wires and injectors... thats why it has to be something tricky.

i also reseted my ECU a thousadnd times as well as TB and intake cleanups... nothing got better.

MMamdouh

KIMO · Post by **KIMO** » Sun Jan 01, 2006 11:16 am

dear mamdouh

did you notice any varyation in the sound of the fuel pump disturbance with the engine dumb.

because i noticed that and change the pump with no change

MMamdouh · Post by **MMamdouh** » Sun Jan 01, 2006 12:42 pm

no... the fuel pump sounds the same at all times.

MMamdouh

karim · Post by **karim** » Tue Jan 03, 2006 10:28 am

Check the spark plug wires, and the ignition coil. I was going to say the engine, trans mount but you said that you changed it, was it a geniue part, or aftermarket one.

MMamdouh · Post by **MMamdouh** » Tue Jan 03, 2006 11:54 am

engine mounts are genuine GM products... spark plugs been replaced and the same shaking was their for the past 2 sets of spark plug wires... nothing left but hte coil pack.

MMamdouh