[Seltzinator]

Earlier today, I had a "pending" CEL pop up for P0300, P0301, P0302, P0303 all at once. Pending in that it hasn't actually made the light come on, but its going to soon (I pull codes with Torque every day). I have not noticed any performance issue and didn't feel the car misfire, which is what those codes indicate. The car did have a bit of a rough idle when it was warming up, so I guess that could have been it?

I drove the car around quite a bit today with the code up and it never moved from pending to the light actually coming on. So this evening I turned on the knock detector and did a couple hard accelerations to ~60mph. The knock detector indicated there were no detonations. However, the car then threw another "pending" code for P3500, which a search of google tells me I'm the first person ever to get this code.

As a bit of background, I recently had to get the timing chain replaced on the car as it was loose and rattling around. They also replaced the actuators and sprockets while they were in there, along with the water pump.

Thoughts? Could this all be the result of a mis-timed engine, or did I wind up with a lemon? I just put $2400 into this car in repairs and really hoped that would be the end of it for this year at least.

 

[Seltzinator]

The only other thing I can think of is my battery cable is a bit corroded and I can hear the alternator really droning while the car is on. If my battery is going bad, could it cause these symptoms?

 

[TX08manualGXP]

did you change out the plugs when you did your 100k mile tune up? did you use stock plugs and stock gap? How many miles have you put on it since you had the work done? I'd put my volt meter on the battery and check it with the engine off and then check it at 1800rpm and see if it's putting out at least 14v. I'd also check connections as they might have forgot to tighten something and now it's loose. check the cam sensor connectors for moisture as well as anything else they they could have unplugged.

 

[The_Ghost]

What do you mean by you “turned on the knock detector”? I’m unfamiliar with this. I know that we have knock sensors that keep the engine from “knocking”. I also know that if you tune the car yourself and you disable the knock sensor, and the engine does “knock” under load that the motor won’t last very long. I also don’t know what you mean by “pending” code. Our ECMs store ALL codes that have ever been the reason for a CEL. They are not eraseable out of memory. I only know this because my GM engineer friend told me that I have had 7 O2 CELs in my car’s lifetime as well as one for a misfire. Please elaborate on this “pending” state as well….

 

[Seltzinator]

Knock detector in the torque app for smartphone.

Pending code is common parlance. It means a problem was detected but it hasn't made the CEL come on yet.

Sent from AutoGuide.com Free App

 

[The_Ghost]

I know you said you're tuned....do you have the ability to put the original OEM tune back in the ECM? Or are you like, you have no clue who tuned your car....

 

[Seltzinator]

I know you said you're tuned....do you have the ability to put the original OEM tune back in the ECM? Or are you like, you have no clue who tuned your car....

I'm not tuned. Only mods to car are werks HF cat and magnaflow catback.

did you change out the plugs when you did your 100k mile tune up? did you use stock plugs and stock gap? How many miles have you put on it since you had the work done? I'd put my volt meter on the battery and check it with the engine off and then check it at 1800rpm and see if it's putting out at least 14v. I'd also check connections as they might have forgot to tighten something and now it's loose. check the cam sensor connectors for moisture as well as anything else they they could have unplugged.

The battery is original as far as I can tell, so I need to change that anyway. There's visible corrosion on the terminals.

Can you give me more info on what connectors I might want to check? I don't know where that stuff is.

 

[TX08manualGXP]

well, I'd check my battery with a volt meter first and then the alternator output. I assume to pull the front of the motor that they have to remove the alternator and the wires that go to it could be suspect. then just look around the front and I'd check every plug I could get my hands on. especially having that many miles, just be careful as they could be brittle at this point.

 

[Seltzinator]

well, I'd check my battery with a volt meter first and then the alternator output. I assume to pull the front of the motor that they have to remove the alternator and the wires that go to it could be suspect. then just look around the front and I'd check every plug I could get my hands on. especially having that many miles, just be careful as they could be brittle at this point.

Thanks, I'll check the connections. Could a problem with the battery or alternator cause the engine to misfire? And does anyone know what the mystery P3500 code could be? It went away on its own between starts, then came back again, then went away again between starts and hasn't returned yet.