4G93 DOHC Problems

[drummydrew]

All. Does it gets louder when you drive or just when idling? Mine had that before. Just weird noise when idle due to the tensioner pulley bearing worn out.

yes the sound does get louder as i accelerate, ok i'll be sure to get all of the pulleys checked out when i visit the workshop this week.

every time i do something new for the car, it returns me with new noises, unpleasant ones

along with that just to share a quick one on my ANOTHER existing probem:

been having issue with the AC on both idling and driving, RPM tends to fall short by 300-400 whenever AC is on. troubleshooted with a new stepper motor but problem persists, mechanic confirmed that signals from ECU socket seem to be working fine so it is now either:

1. my previous mechanic (the same one who slit my throat) may have replaced my faulty AC compressor (15C) with a 17C one which is for higher displacement, causing it to run heavy.

2. Alternator. Will get the charge rating checked when i visit the AC guy on tuesday, hopefully that solves it once and for all

will be posting updates on both the AC/RPM and Modem-Dial-Up noise problem!

 

[sweelt]

Your ecu is working of course, giving signal to stepper motor to adjust idling.

Sometimes i confused. As read through googling.
Some say ecu wont know isc/stepper motor position. Fair enough.
But then the scantools can set isc to middle position. Dang....
At the end i use hand to set isc. :stupid:

 

[drummydrew]

Your ecu is working of course, giving signal to stepper motor to adjust idling.

Sometimes i confused. As read through googling.
Some say ecu wont know isc/stepper motor position. Fair enough.
But then the scantools can set isc to middle position. Dang....
At the end i use hand to set isc. :stupid:

that is one confusion stirred up right there :hmmmm:

i set the isc by a screwdriver too, told to do it only when the fan is running for better accuracy. any comment?

 

[sweelt]

that one you set by hand is BISS screw.
isc can only set by scantools.

http://www.3si.org/wiki/index.php?title=Idle_Problems&redirect=no
some idea about idling.

 

[parakey]

Oh! if all okay and battery goes dead after a few days, check for parasitic current draw also

Happened to me recently. If left for few days, battery gets drained. Finally tracked it down to the rear trunk lamp not getting switched off after trunk lid is closed.

yes the sound does get louder as i accelerate, ok i'll be sure to get all of the pulleys checked out when i visit the workshop this week.

If it's a bearing issue, the mechanic should have a stethoscope thingie to check the vibrations from bearing housing.

 

[drummydrew]

that one you set by hand is BISS screw.
isc can only set by scantools.

http://www.3si.org/wiki/index.php?title=Idle_Problems&redirect=no
some idea about idling.

thank you! i understand it better now. how i see it now, i can't see any wires leading from both the AC compressor and PS pump to the ECU socket at the firewall so the ECU is technically not processing anything to the stepper motor (aka ISC?) when the compressor and pump are on load. my fitted stepper motor and the old one seem to be fine as RPM raises then slowly falls back during start up.

how do you suggest i go from here? proceed by checking the alternator's and compressor spec, or scantool it?

 

[drummydrew]

Happened to me recently. If left for few days, battery gets drained. Finally tracked it down to the rear trunk lamp not getting switched off after trunk lid is closed.

If it's a bearing issue, the mechanic should have a stethoscope thingie to check the vibrations from bearing housing.

recently replaced a battery which didn't last a year, after i left my car unused for few days too! couldn't even jump start it :stupid: i NEED to resolve this issue before i waste another new battery! will begin by checking the alternator's charge as advised by bro vr2turbo, step by step i'm pacing very carefully this time. :secruity:

i really hope workshops are this canggih but sadly i haven't seen any mech who uses a stethoscope alike tool for diagnosis. of cos, this is only my world i'm referring to :wavey:

 

[parakey]

It's a simple but effective tool. Seen my mechanic use it

Just a stethoscope with a prod attached. Shouldnt be expensive

 

[vr2turbo]

every time i do something new for the car, it returns me with new noises, unpleasant ones

You change the weaker parts, then the next weaker one gives way.......lol

 

[drummydrew]

You change the weaker parts, then the next weaker one gives way.......lol

this shall be an automobile quote! i suppose noises are good for indicating problems, but meddling in it continuously can get sho frustrating..

 

[vr2turbo]

this shall be an automobile quote! i suppose noises are good for indicating problems, but meddling in it continuously can get sho frustrating..

Catching where the sound comes from can be very tedious. I had a fair share of it....

 

[parakey]

Catching where the sound comes from can be very tedious. I had a fair share of it....

Yup, must have sensitive ears and inquisitive mind. Doesn't help if the vehicle rattles a lot OR if you have loud exhaust OR power amps. LOL .. my mechanic's ears are quite deaf.

@drummydrew, you should buy Uncle VR a : .. and then get him to listen to it

 

[drummydrew]

Catching where the sound comes from can be very tedious. I had a fair share of it....

perhaps you can show me some pointers on tracing noises? hehe

Yup, must have sensitive ears and inquisitive mind. Doesn't help if the vehicle rattles a lot OR if you have loud exhaust OR power amps. LOL .. my mechanic's ears are quite deaf.

@drummydrew, you should buy Uncle VR a : .. and then get him to listen to it

precisely, my loud exhaust surely doesn't help when trying to listen out. yes i was wondering on that, yall sifus meet up for drinks for crazy car talks? i wanna join!

 

[sweelt]

thank you! i understand it better now. how i see it now, i can't see any wires leading from both the AC compressor and PS pump to the ECU socket at the firewall so the ECU is technically not processing anything to the stepper motor (aka ISC?) when the compressor and pump are on load. my fitted stepper motor and the old one seem to be fine as RPM raises then slowly falls back during start up.

how do you suggest i go from here? proceed by checking the alternator's and compressor spec, or scantool it?

About compressor, my 93t will give a (one second) "mouse" squeek sound when it kick in + i step on throttle.
Idle no squeek sound when it kick in. Any idea sifu ? Belting ?
Feel kind of heavy too.

 

[vr2turbo]

perhaps you can show me some pointers on tracing noises? hehe

Every noise/sound to trace are different. Need at least 2 if not 3 to trace, especially when need to drive to find the source. Like one of my problem, sound comes only when hot. Cold time no sound. Sound can be hear coming from driver side lower arm. Check for a long time, then one day ran until hot the sound came, straight drive to mechanic ask him check immediately. Jack up car using car lift still cannot find, then place on those 4 pole car lift where you need to drive on type. Raise up then violently try to shake car up and down. Hear the noise then trace, and finally found it coming from passenger side steering arm....:hmmmm: All the while from inside hear noise coming from driver side.....hhahahhaha
The steering arm dried up and squeak when hot, after change no more sound......lol