I brought my car to the track (Thunderhill) yesterday. After having two very fun sessions, when I started up my car for the 3rd session, the check engine light came on.

I had two problems at the end of my last track run, 1) my catch can had overfilled and I had engine oil spill into the intake, 2) I had misshifted once, but I don't think I lifted the clutch all the way up.

The engine still feels quite powerful at the end of my last track run.

Using a borrowed OBD II reader, the error codes were P0304 and P1399 which were Cylinder #4 misfire and temporary cylinder misfire respectively.

I looked at the spark plug for cylinder #4 and it looks a little fouled, so I replaced it with a working used one from a very kind fellow S2000er on the track. Peering into the cylinder with a torchlight, it looks "dirty" but since this is the first time I have done that, I don't know how it is supposed to look like in the first place (30,000 miles on the car). After resetting the ECU, I started the car for a few minutes and the MIL light pops up again, this time with code P1399 only. I am able to rev very smoothly but the car idles just a little less smoothly than usual.

My urgent question is whether it is safe to drive the car to a dealership near my house(about 100+ miles away) or do I have to tow it (very expensive!)

Any help or suggestions? Thanks very much.


- lawrence

 

I wouldn't reccomend driving it, not knowing the engine was over-reved. If the valves made contact with the pistons, they are bent. You may be able to drive it back, but the bent valves can fail at anytime, causing even more damage.

It has happenedon other cars where a mild over-rev occured, only to run fine for a while until the head of the valve broke inside the engine.

A cylinder leakdown test will tell you if the valves are bent. It's cheaper to replace the damaged components in the cylinder head than an entire engine.