45below

Hey there, new to the forums.
I have a 1994 Toyota pickup, 4x4, with the 3.0 V6 in it. This truck has had a rough life... it's a backwoods Alaskan rig, rebuilt title, and is pretty beat up, bought it 6 months ago from a guy in Wrangell.

I'm having some problems with my engine, and I would like an opinion if you please.

The truck runs very smoothly. It takes a lot of cranking to get it started in the morning (along with holding the accelerator to the floor), but once it's running it runs nice.
The problem is, the acceleration is very poor, and it's getting terrible gas mileage. (10 mpg, if that)
I replaced the spark plugs and wires, and checked the cap and rotor. Then, I did a compression test. Three of the cylinders are good, in the 150 psi range. Another cylinder is around 100 psi, and the last two are at 30 psi and 50 psi. (I don't remember which cylinders were good and which were not) I also did a wet compression test, and there was little change, perhaps a 15 psi jump in each.

What does this mean? It seems weird to me that the engine would run as smooth as it does with having three cylinders at low compression. In any case, could burnt valves be a problem? Would this be something I could fix by rebuilding the heads and replacing the head gaskets?

Thanks in advance. I appreciate it.

rustyf99

iTrader: (1)

My guess is you are looking at a head gasket job, or at least valve adjustment which means you may as well pull the insurance card and do the head gaskets while the engine is all torn down. It's not a pleasurable job but worthwhile if you take your time and follow many write-ups on here.

Check your cold start injector too.

Then, learn how to use the "search" function on here, before we paddle your behind!! Nearly every issue I've had with my Runner was already written up on here - TONS of good info at your fingertips!

supertech

Okay im a technician at a dealership and every time I have had bad compression it has never been the head gasket. typically it is from the pistons hitting the valves and bending them, or the piston rings are all lined up and you are getting very bad blow by. blow by is when the explosion blows past the piston into the oil pan. if it is the piston rings I would recommend just putting in new pistons but if its the valves get a new or remaned head and also replace the gasket.