Head gasket question

Ok, I did a search, a couple, and I cant find the exact symptoms my truck is having.

2002 Tacoma 3.4 4x4 supercharged

The cooling system is always pressurized even when its cool/cold, except when i relieve the pressure. About 10-15 seconds after starting the motor with the radiator cap off the coolant starts to overflow. I have not seen any bubbles in the cooling system and it does not over heat. The temps run about 175-182 with a 170 thermostat. I do get a smell of coolant when I start the truck and found the radiator to have a couple pin holes at the bottom. It will be replaced later this week along with the thermostat just for good measure. The rad cap is new and in working order. I have a cooling system/rad cap tester.

One of the searches suggested the head gaskets might be in question. I did a compression test today, below are the results. The truck runs fine and pulls well.

1 - 165
2 - 125
3 - 135
4 - 150
5 - 145
6 - 125

I'm not sure if the low compression is due to the rings or the head gasket being shot, or both.

Please help!

 

How many miles? Do you know how long it has had the SC on? The head gasket is a far more common issue with the 3.4 than the piston rings from what I can tell. How long has it been since the water pump and timing belt have been changed?

 

My Ford interior started smelling like radiator fluid when my heater core went out. Then my head gaskets started going out after that. I drove around for a long time with the heater not working.

I'm not sure if this helps out with Toyotas or not.

 

145,00 miles, the supercharger was installed about a year ago at 130,000 miles. The water pump and timing belt where changed last April at 135,000 miles.

 

Ok. My money would be on the head gasket. I'm sure a new radiator and thermostat wouldn't hurt anything either as you already plan to do both. Have you checked the oil out as well to see if it has water in it?

 

Keep an eye out for white smoke from the tail pipe and ANY missing radiator fluid.
If you see either of these issues then the head gasket is the problem, the compression does show a problem,
My head gasket went out at 489,000, white smoke, just a little radiator fluid loss.
Supercharged the whole time,
Maybe you will find some info on my posting when it happened to me below

https://www.tacomaworld.com/threads...epair-or-replace-engine.397363/#post-11004749

 

I don't get any white smoke/steam out of the tail pipe. A fellow toyota guy at work recommended running it to TDC and hooking up an air compressor to help figure out what is leaking. I'll be doing this when I get home.