Hello All,

Sorry for the vague description and not checking the forum for similar posts, but kind of desperate.
Got 2001 GS 300, was running great till now. The check engine light is on and also blinks but also makes and feels the puttering. Though it runs but decided not to keep driving. Moved San Francisco recently and know have been putting wear and tear on it. But any idea what the issue could be. Calling a mobile mechanic soon but kind of want to have an idea. Has oil and all, but can feel the engine puttering. Thanks in advance.

 

get codes read; otherwise it's like asking what's in your pocket.

 

Get an obd reader and the torque app if you have an android phone and read the fault codes yourself!

Without the codes no one can help you...or you have to take it to a shop.

 

What he said ^^^

You can use our app, Carista OBD2, to check and reset your codes for free (once you have the $10-ish Bluetooth dongle). See this link for examples on what Bluetooth OBD dongle to get.

Also, it is unwise to keep driving the car in this condition. You might be causing additional damage to the engine by doing that. The most likely cause is something silly like a bad sensor, but that can lead to an incorrect air/fuel mixture, which can then lead to pre-detonation inside the cylinders, which causes all sorts of bad stuff to happen (in extreme cases, blown head gaskets, piston rings, etc.). So definitely check what the problem is before putting too much more "wear and tear" on it.

 

+1 on getting the codes read. You can take it to Auto Zone and they can read your codes for free. Hopefully its something small like the mass airflow sensor. When mine went, the car ran like crap. $60 fix that took 5 minutes to throw together.

 

Thank you all for the replies, definitely helps. I got the codes and there are four.
P0300 Random/Multiple Misfire Detected
P0301 Misfire Detected (Cylinder 1)
P0303 Misfire Detected (Cylinder 3)
P0305 Misfire Detected (Cylinder 5)

The guy who did the tested mentioned I may have to replace the coil or something along the line
Also my VSC light is on as well and wont turn off. VSC and VSC OFF are both on. Not sure if that has anything to do with it.

Again Thank you for helping

 

Since the problem is happening on multiple cylinders, the problem is probably NOT the coils. These cars have a separate coil for each cylinder, and it's unlikely that they all went bad at the same time. It's also unlikely that 3 spark plugs went bad at the same time, unless something specific fouled them. So it's either an electrical problem with the ECU, or it's a fuel or air/fuel mixture problem. Could be clogged fuel injectors... do you remember putting in crappy gas? Or running the tank to the bottom, where the pump may have sucked in sediment from the bottom of the fuel tank?

And the other option is a problem with a sensor related to the air intake, such as a MAF (mass air flow sensor) or intake air temperature sensor. Those could cause an incorrect air/fuel mixture, but it would have to be a far-off incorrect mixture to actually cause misfires. One thing you could try is unplugging the MAF and IAT sensors and seeing how the sound of the engine changes. If it gets worse, it wasn't those sensors. If it gets better, then one of those sensors is probably to blame. The engine ECU has a "fallback" mode that can run without those sensors.

 

I user premium fuel always. But have been recently filling up to driving it with a quarter tank of gas, not full or half. Also Im sure driving up and down these San Francisco hills can put a strain on the car. I'll try unplugging the two sensors and see how the car sounds. Thanks for reply and help. Much appreciated.

Thanks,

Darshan

 

So I unplugged the MAF/IAT sensor and started the car. Seemed to run the same. no better no worse, still feel sputtering.


Hope it was the right thing I unplugged.

 

Without further mechanical skills; you can look around for any disconnected vacuum hoses or leaks. Long shot, maybe unlikely this would throw the codes you put up but a quick and easy check.

See if there are actual hoses that are puttering and not just the engine itself. Be sure to look all around, there's some hoses behind the engine (near pcv and the throttle cable) as well as some on the sides.

 

Hmm, yeah, so the MAF & IAT test was inconclusive. By the way, that test may have set off new engine codes, so next time you read them, you can safely ignore those.

Then I'd go with what the previous poster said - check for visible cracks, disconnections, etc. on the hoses.

Another test I can think of is to disconnect the plugs for each ignition coil one at a time. This will show you whether the puttering is caused by 1 specific cylinder not firing, or whether it's caused by some failure that affects all of them. However, based on the error codes, it's most likely that it's NOT just 1 cylinder that's causing the trouble, so I don't really know if this test is worth doing. I guess do it if the plugs are easily accessible. Note that those plugs (wiring harnesses) do not carry high voltage, so it's not dangerous to unplug them while the engine is running. Still, wear gloves just in case, and make sure the pins of the harnesses don't touch anything metal when they're unplugged.

And then another relatively cheap thing you can do is replace the spark plugs, especially if they're kind of due for replacement anyway. It's easy to do by yourself, you just need a spark plug holder, which is available at any parts store for under $10. But again, the only scenario under which the spark plugs are the issue is if something happened that fouled all of them at the same time.

 

this was also happening on my gs,
someone told me that my oil filter was clogged...
so i changed the oil & filter, added some engine restore
.......problem fixed

 

When was the last time the plugs and wires were changed. Could be either of these. Also, if your valve cover gaskets are leaking, the oil can collect in the plug valley and cause the plugs to miss. I'd start with these items before replacing the coils.

 

Wait, I may have given you incorrect advice in my last post. Do these cars have individual ignition coils on each cylinder, one on top of each spark plug? I was assuming that that was the case... but people keep talking about "wires"... a setup like that doesn't have your typical spark plug "wires" that lead from the coil (or rather, the mechanical distributor cap) to the spark plug because there's no distributor and there's a separate coil sitting directly on top of each spark plug. The wires are merely small wires that give an electronic signal to the coils to fire, controlled by the ECU. Not big fat high-voltage wires that relay current from the coil to the spark plug.

So, was I mistaken?

 

Yes you are mistaken. If you're not familiar with the engine perhaps stop typing before foot goes further into your mouth. J/k. Wasted spark; 3 coils, 3 wires. Its neither of the options in the paragraph you typed up.