Jbthompson

Hi everyone. Upon getting off work tonight at 1am my car started to stutter and not accelerate smoothly. Check engine light and then check VSC came on. Drove it home and here are the codes:
P0300
P0301
P0308

Looks like a misfire of some sorts. Any ideas where to start? Car is an 01 with 109k miles.

Tom57

Misfire on cylinders 1 & 8. Has the timing belt been replaced? If not, I'd think twice about trying to re-start the engine.

Jbthompson

Yes timing belt has been changed.

Arcturus

The 0300 is a general random misfire. 0301 and 0308 are misfires on cylinders 1 and 8. Check for vacuum leaks and then the spark plugs and ignition components on cylinders 1 and 8. Could be a number of things including the coil packs, but start with those first.

Tom57

Have you replaced the spark plugs or are they original? You could swap the ignition coils on cylinders 1 & 2, and 7 & 8, then clear the codes and start the engine to try and isolate if the ignition coils are faulty. If you then get codes 302 and 307, then it's likely those two coils.

Jbthompson

Ok checked on the engine. The vaccum box and has a crack in one of the hoses (I've known that and have the hose connected with tape). After reattaching that hose, I started the car
up and I am still getting a misfire in cylinder 8. Would the next step be to replace the spark plug? They are original to the car as far as I know.

Can the whole vaccum box be replaced?

Lavrishevo

iTrader: (1)

Seriously doubt it's the plug itself with your mileage.

volson

As mentioned before next step is to SWAP COILS AROUND. Good luck

Arcturus

I would have a look at the number 8 plug to check the condition. If there's any damage to the electrode, insulator or terminal replace it. You could replace it anyway to be sure.

If it's okay swap the coil pack with one from another cylinder as stated previously to see if the misfire moves to the cylinder with the suspected faulty coil.

Double check again that there are no vacuum leaks before proceeding. These often make a hissing sound.

Boomer01

This^^^

I had a similar problem a month ago and pinpointed the coil pack by switching them around. The check engine code should change also.

Jbthompson

Looks like a coil pack issue after some more testing. So questions now:
1. Is it okay to just replace one coil pack or will it cause problems for the other ones?
2. I'd like to replace all of them and the spark plugs but at 85-100 bucks a coil it's not cheap. Is there a reliable aftermarket alternative for the coil packs?

PersianOne

It's fine to just replace the faulty coil pack, but some would recommend to just change em all at once if you're willing to drop the $$$. Amazon has Denso coil packs for $60 a piece. Cheaper than the dealership. Can also buy it from ebay, another member gave me a link in one of my threads regarding my coil packs.

Boomer01

I just replaced one.

Jbthompson

Ok I changed the coil pack on the number 8 cylinder and the spark plug on cylinder 8 and 6. Cylinder was my problem child, and there was oil in the spark plug tube. Is that a big problem?

The car runs amazing now, no lights except the check VSC popped on but the car is running great.

Also I was having a horrible time accessing cylinder 2 and 4 to change the plugs. I will do all of the plugs eventually but I ran out of time tonight.

Arcturus

Glad you fixed it. There are spark plug tube seals that can wear out over time. This may be the source of the oil. They often come with a replacement valve cover gasket kit and will be changed out at the same time. Valve cover gaskets are a known issue on this car at higher mileage. You may want to check them out and see if they are leaking. Some on this site say the valve cover gaskets are easy to change out, others say it is a more involved task. I haven't done it myself but may do it some day soon as I can see a slight seepage.