Odd problem, 2.2 only revs to 5, odd exhaust note Options

[Spart]

I have a 95 Celica GT liftback, 5 spd. The car is normally rev limited at 6.2k, and you can tell when it hits the limiter because it "bounces" off.

So today after driving away from work to go to lunch, I did a U turn because I forgot my wallet, as I sometimes do. And as I sometimes do, I decided to floor it, being out in the middle of nowhere. And then a strange sensation, the car just sort of stopped revving at 5k. And I noticed that the exhaust note was "funny." A little metallic sounding, whereas normally it's just grumbly. There doesn't seem to be any loss of power until you get it up to around 5k.

Quick look under the hood, nothing seems off. CEL isn't on.

I'm at a loss.

[Spart]

You'd think that I'd notice other symptoms if the head gasket was bad?

I tested the mileage on a trip to KC last time I went down there, still 28, very consistent with what I've always gotten.

The car sounds and runs exactly the same below 4k. After 4k the exhaust note starts to sound different, sort of like I've got some sort of resonator.

Seems more like a cam, fuel, or electrical issue.

I can go ahead and do the compression test anyway, what sort of PSI should I be looking for? Should the cylinder be at TDC for the leak down test or at some other point?

ETA: I just changed the oil and it looked perfect. Haven't looked at the coolant, but last I checked it was fine.

This post has been edited by Spart: Apr 28, 2009 - 3:51 PM