Leaking coolant from the head?

[scnvsleep]

Hi all...not new to AF, but new to the Toyota forum. I've been through all the FAQs (which are much more thorough than the Blazer/Jimmy FAQs I'm used to )

I recently purchased a 93 4Runner, AT/4WD, 3VZE motor that now has 155K. The previous owner did the radiator, water pump and timing belt shortly before I bought it (approximately 8-10K miles ago).

Everything has been fine (except for the starter contact issue that this forum was a godsend for) until Friday. Got to work (6.5 mile drive, medium traffic) and heard a gurgling and had steam from under the hood. Checked quickly before I had to clock in and saw the resevoir was empty. No sign of leaking underneath, no sign of head gasket failure (oil clean on dipstick). Waited until after work and poured in a gallon of coolant, plus half a gallon of water and drove home. At home, the resevoir is full, but the radiator is empty. No pressure in the system (upper hose soft). Open the cap and the rad is dry. White staining around the neck of the rad.

Hmmm....Resevoir is full, but rad is dry. Maybe a bad cap and the coolant is blowing out of the cap as opposed to the resevoir? Pressure test the cap and sure enough its bad. Unfortunately, I couldn't test the system because the kit I borrowed from AutoZone didn't have the small fill neck adapter. But I figured cap is bad, hypothesis proven.

Got a new cap, filled rad and bled air from the system. Took it for a test drive (7 miles). Got home and coolant is pouring out...from the back area of the motor. Kill the engine, pop the hood and see coolant streaming from the top of the motor. Looked like from the number 4 injector. Couldn't be that, right? So I investigate further. I pull the valve cover and find a puddle of coolant (duh) along with what appears to be carbon chunks. I say "appears to be" because this stuff looks more like burnt wood...? In addition I found what I would LOVE to be the source of my leak; wires going into the head between the 4 and 6 injector. I would LOVE for this to be my source because my other option is a cracked head. But I shy away from the head because there's NO coolant in the oil.

Questions:

1. What do those wires between the 4 and 6 cylinder go to?
2. Could I have a bizarre head leak that leaks up as opposed to down into the oil galleys?

I am not a professional mechanic, but have been working on cars for fun and money since I was 12. I know my way around a car for basic stuff (and some complex things), but this one has me stumped. I figured I would come to a group of experts before just starting to tear $h!t apart.

Thank you in advance for any help you can offer.

[OzzyO]

The 4Runners V6 are notorious for the head gasket going and there is a recall on them so your local Toyota Dealer should replace it free. Check to see if you get the work done else where if Toyota will still cover the costs.
I had the head gasket go in my 94 4Runner a few years back and I know for sure thats it is a recall that Toyota has made and is covering.
I hope this helps, I'm no mechanic either but just wanted to let you know about that yoda V6 head gasket recall.
They also have a recall on the front steering linkage of your 4Runner, I know mine was covered but I'm not sure exactly what year of 4runners are covered or if all of them are covered.

OzzyO

[scnvsleep]

UPDATE -

It's not the head. Its the fuel rail. Managed a makeshift pressure test (Mmmmm...ethylene glycol...) and noted that the coolant is leaking from the fuel rail?!?!?

Its got a pinhole in a small cap in the fuel rail.

If anyone can tell me why I should tear apart the fuel rail and replace the tiny, little cap, as opposed to sealing it off with JB Weld has two days to convince me....

[scnvsleep]

OK...so I thought better of sealing off the hole with epoxy, thinking maybe that hole was there for a reason. I discovered that the previous owner had installed the thermostat incorrectly, so I replaced it and installed correctly (jiggle valve @ 12 o'clock).

It still blows coolant through this pinhole as soon as the stat opens...

My question now is, WHY is there coolant in my fuel rail? I initially thought it was to "warm" the fuel on cold days, but that makes no sense because the truck runs 10 minutes before the coolant gets to the rail.
Is this a precursor to a catastophic failure that I can address now before the motor blows up? If not, Iis there a way to bypass the flow of coolant through the rail? Is it inherently important to the operation of the motor?

I am lost here, truly.

[OzzyO]

Have you tried looking at The Service Manuals on This Site. It's the 4th Post/ Thread down on every 4Runner page. They have alof of advice and Trouble shooting and it may be there that you will get an answer? I honestly don't know myself.
Check it out The Service Manuals Have A Wealth Of Information.

OzzyO