A bit of a story so I will try keep it short. Ive been noticing a ticking lately which sounded like an exhaust leak but thought nothing of it(02 Tacoma 3.4) so last week Im driving down the highway and the truck studders a little bit, get off the highway and the CEL come on and instantly the motor starts running like its missing, I scan it and it says a coil is bad, I change it out truck runs good again but the Ticking is much louder now, it sounds like its coming from the drivers side top of the motor. I chance it and get the truck home, as it warms up the noise goes away, I get it home and th e noise is gone so I let it sit over night and start in the morning and sure enough its back but this time it sounds like something is loose inside banging around so I shut it off rightaway. I am only assuming its something to do with the valves but cant say for sure. Anyone have a simmilar experience, what should i do now.

 

How many miles? Have the valves ever been adjusted? How is the oil level? Condition of the oil?
Pull the valve cover and look for anything out of place.

 

Oil is good as well as the coolant, there is 300,000kms on it and the valves have never been done as far as I know.

 

At that km/mileage, it would be good to check them out.

 

Looks like the plennum has to come off to get at the drivers side, go figure.