P303 trouble code

Hi all, my 2002 taco sr5 w/2.7 just started throwing a p0303 code cyl 3 misfire. The engine runs well when I first start it up in the morning, but when it gets up to operating temp, and I shut it off, on the restart it throws the code and is missing on one cylinder. Reading the fsm indicates a number of possible issues. My diagnostic time is limited (I'm selling my house), but I swapped coil packs and put in new plugs. I tried the dealer, but rather than using the diagnostic tool they have, they tell me it's "probably" a head gasket or bad valve.

So, does anyone have a similar experience? And, of course, a fix? Thanks in advance, Jim

 

Do a compression check. That will verify (or not) the dealer's diagnosis. Burnt exhaust valves are fairly common, many times due to valves out of adjustment.

 

Going through the same problem. Did the coil pack and plugs, then got compression checked. Compression was only 50psi in cylinder 3, and a leakdown test revealed a faulty exhaust valve. Now I'm trying to decide if I want to pay the shop $1800 to fix it, replace the engine, or attempt replacing/rebuilding the head myself.

 

If the testing was both wet and dry and included leakdown, proving the valve issue, and no ring issues, I'd go for the head. Assuming the mileage and rest of engine health is worth it.

http://www.cylinder-heads.com might be a good source for you. (No affiliation, just a satisfied customer)

 

The thing that gets me is that it only fails after the engine reaches operating temp and is shut off and restarted. Each time I start the engine, it runs without missing.

On the plus side the dealer is replacing my frame under warranty, and as a loaner, I am driving a 2015 Tacoma rental free of charge until it's done.