I have a 96 with the 3.4 motor, 5 speed and 230K miles. The first thing I noticed was a water sound from inside my dash behind the steering wheel, was told I may have air in the coolant system and to bleed the system, I then noticed it runs rough when first started then clears up, have also noticed I'm loosing coolant. I'm guessing I either have a head gasket issue or cracked head. I can get a 3.4 motor from Japan with less than 40K miles for under $2k or is there a different motor that would fit right in that would be better? (I looked at the 4.7 V8 but I don't think I have the skill for that conversion) I have heard of a head gasket pour in repair stuff that I'm guessing would be like putting a band aid on a severed leg, but would that buy me some time? and If I'm replacing the motor anyway, what would be the negative of giving this a try? Or should I just rebuild the motor I have? I have loved the runner (its name is Zombie Slayer) and plan on keeping it for a while. The runner is for playing in the hills and where I live we don't have emissions to worry about so I can get a little creative with motors.
So what do the experts out there in the world recommend?
Thanks,

I did the JDM thing and no complaints. $1350 for the motor.

Keep in mind, the JDM engines are almost always out of 2WD minivans and NOT 4Runners. This means you will need to move your oil pan, your oil cooler and open up the 2nd tap for the oil filter on the JDM engine.

Also - all your accessory mounts etc will have to come from the original 4Runner engine, even the crank pulley is different.

Oh and the throttle body will probably be different if you get a JDM 2004 motor.

look at post #7.

Heater Core ? for you guys

I'd remove the two hoses going into the firewall and put a water hose on one and flush it out.

I had planned on doing the heater core flush when it warmed up a bit but now I'm seeing other problems such as running rough and loosing coolant and figure the flush would be a waste of time, am I wrong? Please tell me I'm wrong and that all I need to do is flush the heater core. Please please please.

You say you hear water behind the dash? Is your carpet wet in the front?

No, the carpets not wet, and I can't find any leaks anywhere. I think what I'm hearing is air in the system so it makes a bubbling noise. The oil looks fine but I do get a little white cream looking gunk on the bottom of the oil cap (is that normal). I think I have a little white smoke out of the exhaust (hard to say because it's still cold here. If ya'll think that bleeding the heater core might help, I can do that tomorrow.

If you can do that then just go with the $2k option. It will probably be under $1000 to put the engine in.

Water in oil makes a milky mix. Have any on the dipstick? Isn't sounding good.

As far as your question about those pour in type sealers....what could it hurt at this point? I would start looking at getting that 3.4 from Japan

I know water in the oil is bad news but the dip stick is clean, and always has been, the question is if a little white goo on the oil cap is normal or if that is a sign of bad things to come?

Just for the heck I call my mechanic and asked what it would cost to have the head gaskets repaired and he said it would be $700 plus the cost of parts. Or would I dare take this job on myself? I'm so so with a wrench. So now what is the vote? Everything else is good, it doesn't burn oil but again it has 230K miles. Anyone out there have a crystal ball?
Also this runner is for playing in the hills so not a lot of miles will be put on it.
Thanks

If you aren't getting water in the oil, then it's probably not a headgasket. I would look closer at the heater coil or the lines going to it. I wouldn't spend $2k on a motor if I didn't need to! My .02

OP,

What you need to do is check the compression on all CYL and post the numbers.

Any decent mechanic should be able to do this for < $100.

Those numbers will tell you a lot.

Normally a head failure causes a CEL, sometimes misfiring, sometimes coolant loss. If you are losing coolant then it is going somewhere but hopefully it is just a leaky hose.

Is this site great or what. Thanks for the great advice. I will take the runner into my mechanic Monday and see for sure whats up instead of guessing.

Draayer, how close are you to my location? Maybe we could have a look, Ive been into the 3.4 that deep before. Feel free to PM