I have a 2wd 1990 toyota tacoma 3.0L v6 with the automatic transmission. The number 3 sparkplug has shot out on several occasions. When re-installing it I torqued it to spec and it still came out. Also it recently started stalling/knocking when hot, could this be related? I checked the coolant and it looked brownish and had metal in it. Is this the end of my trusty taco, or can I still drive it for a little longer.
Ok, sounds like you have a few issues.
1. #3 Cylinder, it has been cross threaded, the threads on the head are stripped out. You have two options. Drill it out and install something called a heli coil. This is basically a threaded insert. Or find a head from a used engine with lower miles, have it cleaned up at a machine shop and install it.
2. The brownish metal flaked stuff in your radiator. Sounds like either your radiator is disintegrating or you have oil mixed in with your coolant.
So what to do? Check your oil, see if it seems higher level than it should, or looks same color as what is in your radiator. Stop driving it. Order a head gasket test kit. (About 22 bucks on Amazon or HarborFreight) don’t forget the test fluid. If you head gasket is blown I would recommend just getting a used head and go that route. If the test comes back clean and your head gasket is ok, then just do the heli coil and radiator.
I would say stalling and knocking you likely have water in your oil as well from a blown head gasket. You should also drain your oil, put some type of cheese cloth on top your oil drain pan and look for metal shavings. You should also take off your filter, cut it open after you strain the oil from it same way, examine that oil and the inside of the filter for metal particulates. If you have any in the oil at all then it’s time to consider a used engine, rebuild, or another vehicle.
I agree with @Thumpy.
Another thing worth doing is sending an oil sample to analyze in the lab so they can tel you what’s inside, then you can figure out what exactly is going on.
