WRXD

I am posting for my dad who owns an 03 w/ approx 70k on it. He had been getting some random check engine lights which read as misfires, replaced all plugs and still was getting the codes. He took the car to the dealership and they measured low compression in 3 cylinders and was told that he needs to bring the car back so they can pull the valve cover and check for bent valves. The plugs and coils were all tested and came out clean. The dealer tech also made an offhand comment saying 'you know you aren't supposed to downshift in these cars'. I am no expert, but that sounds ridiculous.

The tech said that if there are bent valves then there is probably cylinder damage which is going to cost thousands to repair.

Any common problems with symptoms like these? I can personally vouch that my dad, who is 59, drives this car like a granny so I know it wasn't abused. The car is bone stock except for an X-brace, H&R coilovers and AEM v2.

franky

You can check if you have a bent valve(s) by hookuping a vacuum gauge to the vacuum brake booster hose and look at the needle while its idling. If you have bent valve(s), the needle will fluctuate back and forward. Otherwise it should be steady. Or you can do a leakdown test on cylinder 3. If there is a bent exhaust valve, you can hear air from the tail pipe. If it's a bent intake valve, you can hear air in the throttle body.

INDYMAC

I think the tech meant to say "mis-shift" instead of downshift. A mis-shift is when you down shift when you actually meant to up-shift. A mis-shift can result in a mechanical over-rev on the engine if done at high enough RPMs.

vtec9

Down shifting is fine. Down shifting so that the RPMs exceed the redline, aka a purposeful 'mid-shift' can be very bad. Interested in the actual compression numbers.

INDYMAC

"I can personally vouch that my dad, who is 59, drives this car like a granny so I know it wasn't abused."

This means nothing! I'm 57 and drive like a granny when she is in the car...when by myself, it's a different story!!!

Nice try though.

Billman250

To add, if you have bent valves, the pistons and cylinders will be fine. this would be a simple head removal and valve job.

There MIGHT be some super light blems on the pistons that can be easily sanded down by hand with sandpaper in 3 minutes.

On about 5 head jobs I've done on the s2k with bent valves, none of them needed lower engine work.

If the engine broke a valve that would be different. But yours are surely not broken.