Rep Power: 0

Hi, I have an '02 Ex, 5-speed with 160k. This car was just purchased a few months ago, and I don't know the maintenance history, but I assume it was not very good.

The car recently started to miss badly and throw a p0304, occasionally the light blinks also. Coil and plugs were good. Did a dry compression test. Got 180 on 1-3, and 125 on 4.

My guess would be burnt valve, any other things this could be? Could bad valve adjustment cause this? I've never adjusted them.

My dilemma is this. If it is a burnt valve, I need to purchase valves, head gasket, also would do timing belt at this time. The car also has other oil leaks. I'm getting a lot of oil running down on the right side of the motor (intake gasket?). I'm thinking instead of putting all that money I may be better of getting a used lower mile engine on ebay for $7-800 and swapping.

Have any of you ever bought one of these? Most of the engines are labeled as JDM. Is there anything I may be missing, or is it a pretty direct swap?

Also, I need a new clutch, if swapping, I will do this also. Is it easier to pull the engine and tranny together, or separately? Any tutorials posted on the site for engine pulls? Thank you!

 
Rep Power: 211

Code P0304: http://www.obd-codes.com/p0304

Best to slow down and not rush to the worst case scenario at this point. Try to inspect and test as much as possible before replacing parts. The beauty of owning an older Honda is there's several forums such as this one to help solve issues. Also, several DIY repairs on just about every type of issue since it's a 14 year old car. Start with:

1) Resetting the ECU: disconnect negative (battery) terminal, turn on bright head lights and press brake pedal a few times to drain residual charge, reconnect battery terminal, inpsect for CEL and check code if it CEL appears.
2) Pull the spark plugs and inspect for: http://www.hondaatvforums.net/forums...spark-plug.jpg
3) Inspect and adjust timing belt if loose
4) Coil pack test: 5) A wet compression test: 6) Fuel injector test: 7) Code P0304 diagnosis: 8) Valve lash adjustment.. routine maintenence:

 
Rep Power: 519

Adjust valve clearances FIRST then recheck compression to see if it improved.

 
Rep Power: 157

I would do a leak down test and see if you can determine where you're loosing compression. A wet compression test would also help determine if if anything is getting past the piston rings.



The valves get tighter and tighter the longer it goes without adjustment, it'd be a good place to start without having to remove the head. My car had a similar issue and I took the head off and had to clean all the carbon deposits out of it as the misfiring cylinder was especially bad.


The timing belt is due to be replaced every 100K so if you don't know the service history it probably wouldn't be a bad idea to replace the timing belt. The head gasket and all would still be less than a new engine. Just depends on if you plan on doing the work or not. The labor costs would most likely greatly out way the costs of parts.

Leaking oil could be from the valve cover gasket. Can you clean it and see where it leaks back out from?



Haven't messed with it personally but from what I've read you have to drop it out from under the car. It won't come out through the top.

 
Rep Power: 0

I'm going to do a valve adjustment tonight and see what I find there. Also, looks like my oil leak is from the cam cap behind the EGR valve. Going to install a new one of those tonight also. Thanks for advice so far. I'll update after I check the valve clearance