P0300 Code with Coolant Loss

All,

I recently had to replace my radiator on a 2002 V6 Pre-Runner (177,500 miles). That is when the P0300 started to appear. I changed the plugs, wires & boots. Cleaned the Mass AirFlow Sensor and since had a mechanic tell me that most of the misfires are in #4.

Since the radiator change, the coolant reservoir has been loosing volume every few days.

The motor rough idles at start up and seems to stop at 2,000 rpm's and when it is at running temp. (my OBDII reader says 200°). I thought running temp should be 180°?

Any thoughts and thank you in advance for your replies.

Regards,

ToyTaco02

 

I'd put the old wire back on #4 just to see if the miss goes away.

As for the coolant loss. It can only be a faulty /loose hose clamp. As it wasn't there before.

 

Cruisedon66,

Many thanks for the reply. I am also thinking about switching the coil pack(s) around to see if the miss moves with the coil.

As for the coolant, there is no visible leakage under the hood or on the ground.

The shop manager/mechanic, who told me where most of the misfires were coming from, stated that because the loss was coming after the new radiator was installed, maybe there is a head gasket issue?

Regards,

ToyTaco02

 

I'd check the rubber seal & fit of your Radiator cap. Antifreeze may be evaporating.

Go for the easy stuff first.