How good of a mechanic are you?

Hi, I am a computer science undergrad and I do not know anything about cars, but I do need your help. I was hoping somebody could share some knowledge with me. Here is my story:

We have three cars a VW 96 GTi, a WV Jetta GLS 97 and a Honda Civic DX 98, and all three of them have the Check Engine Light on.

The codes on the GTi are:

P1582 - Idle Adaptation at Limit
P0140 - O2 Sensor Circ.,Bank1-Sensor2 No Activity Detected

The car drives fine, no problems at at except the engine hesitates from time to time. When idle the gauge is not perfectly stable; it jumps +/- 100 rpm's. I have not done anything to this car, except than regular mantainance, replacing the Radiator Fan and the timing belt. Also, the A/C broke down last a couple of days ago; I week after replacing the timing belt. :frown:

The Jetta is throwing 3 codes:

P0303 - Cyl.3 Misfire Detected
P1583 - Transmission mount valves Short to B+
P0510 - Closed Throttle Pos.Switch Malfunction

The engine hesitates a lot. When driving, the cars loses power for half a second and then recovers. This is very annoying. This happens all the time, but more often when the engine is cold. The timing belt on this car was replaced a month ago and the A/C compressor broke down right after this was replaced. :confused:

The honda is only thowing a P0135- O2 Sensor Heater Circ.,Bank1-Sensor1 Malfunction. We just bought the car and I don't know what the previous owner did with this car.


If you have any insight, suggestion or comment, I would more than glad to hear. Please guys (and girls), I really need your help.

THanks.

RC

Is the A/C problem related with the replacement of the timing belt? I just thought it was really weird that on both cars it broke down after replacing this item.

Also, how can I check if the A/C compressor is in working condition?

Thanks.

Hope that somebody replies.

Go to car-torque.net/forum, they give you all the codes.!! good luck.

It sounds like the GTI needs an O2 sensor, bank 1 sensor 2 is the one behind the catalytic converter. Hopefully this will also cure the 1582 code. If not you may be in for a throttle body or cleaning, but that code can be terrible to pin down. On the Jetta I'd look at the closed throttle switch located on the throttle body as it appears not to be functioning. Check you #3 plug & wire, but coils commonly go bad on that year. I'll have to look into that 1583 as I don't know that one off the top of my head. It sounds like the O2 on the Honda is bad also, it's the one before the cat. As for the A/C compressors you should check to see if the clutch engages & spins when you turn it on. If not you can check to see if it is getting power, but more than likely it is low on refrigerant or an electrical problem.

It sounds like the GTI needs an O2 sensor, bank 1 sensor 2 is the one behind the catalytic converter. Hopefully this will also cure the 1582 code. If not you may be in for a throttle body or cleaning, but that code can be terrible to pin down. On the Jetta I'd look at the closed throttle switch located on the throttle body as it appears not to be functioning. Check you #3 plug & wire, but coils commonly go bad on that year. I'll have to look into that 1583 as I don't know that one off the top of my head. It sounds like the O2 on the Honda is bad also, it's the one before the cat. As for the A/C compressors you should check to see if the clutch engages & spins when you turn it on. If not you can check to see if it is getting power, but more than likely it is low on refrigerant or an electrical problem.

On the GTI sensor 2 is simply to detect catalyst efficiency and should have nothing to do with the Idle code. Idle adaptation sounds like it has something to do with Idle air control, I'd start there. As far as the O2 sensor, I would doubt strongly that the sensor is bad do to no activity detected, a bad sensor will usually still produce voltage. As far as the honda is concerned you are having problems with the heater inside the O2 sensor, these heaters are used to bring the O2 sensor up to operating temp. quickly, if you are getting power into the heater and have a good ground for the heater element it would be very likely that the heater inside the O2 sensor has failed. You may also have high resistance in the power feed or ground for this heater. You should do a voltage drop test across the O2 sensor heater, the heater should consume source voltage. as far is the jetta is concerned p0510 is refering to the throttle pos. sensor, you should have 5v going to the sensor, a ground and a signal, the signal should very when the throttle is actuated from approximately .5v to 4.5v any value below or above these figures is generally a bad sensor. Use only a digital multimeter or o-scope on these circuits or you will damage the modules on these vehicles. TPS sensors are very simple they are nothing more than a potentiometer they require nothing more than 5v input and a ground to produce a proper signal. on the jetta dont rule out cylinder 3 as a fuel problem. and a bad coil will most likely affect all cylinders on a distributor ignition system. SOUNDS TO ME LIKE BOSCHMANN SPENDS A LOT OF MONEY ON PARTS AND NOT VERY MUCH TIME GAINING KNOWLEGE. GOOD LUCK thanks for reading.

sounds like riffy spends too much money buying parts and not very much time gaining knowledge. i dont think mk3's have a distribution ignition system (when did vw go to coilpacks?).

but yeah, some points that Riffy and boschman brought up are plausible. i guess im not much of a mechanic, the jetta sounds pretty bad tho. the throttle plate sensor is located right next to the throttle plate (obviously) connected to the manifold. unplug it (if it isn't already) clean it then plug it back in, make sure its in good. i had the same problem when i made my grounding kit... and forgot to plug the thing back in when i finished

sounds like riffy spends too much money buying parts and not very much time gaining knowledge. i dont think mk3's have a distribution ignition system (when did vw go to coilpacks?).

but yeah, some points that Riffy and boschman brought up are plausible. i guess im not much of a mechanic, the jetta sounds pretty bad tho. the throttle plate sensor is located right next to the throttle plate (obviously) connected to the manifold. unplug it (if it isn't already) clean it then plug it back in, make sure its in good. i had the same problem when i made my grounding kit... and forgot to plug the thing back in when i finished


Hey genius, I never stated that the 97 jetta had coil packs what I said was don't rule out number three cylinder as a fuel problem, and if you had read the owner's complaint properly you would know that he had a misfire on cylinder 3, only cylinder 3. boschmann stated that a bad coil could cause this problem, this is very unlikely on a ignition system that uses a distributor due to the fact that the single coil provides current to all cylinders, you would most likely see a misfire on all cylinders or a code stating misfire detected (without a cylinder #). Please in the future do not question my knowledge unless you are absolutely certain you are correct. You may want to check with a qualified service technician next time and not your local CHECKER AUTO PARTS. DONT bother replying to this because I dont want to hear anything you have to say. Thanks for reading, and BETTER LUCK NEXT TIME.

wow...bad day?