High pressure in COLD radiator. Cracked head? Just blown gasket? '05 Taco 4X4 4.0LV6

mjbtnus

New member
The radiator on my son's '05 Tacoma 4x4 with 4.0LV6 recently failed after adding coolant because it was low and running hot. He had driven it another 20 miles, but says the temperature gauge was remaining normal and it appeared to be running fine. When it first got hot, he stopped before it got into the Red. When, later, the radiator ruptured, he turned the engine off immediately. I had it towed home, and, not suspecting anything other than the ruptured radiator, so I went ahead and changed out the failed radiator myself, no problem.

But it was when I was first cranking up the engine after the initial coolant refill that I realized I had a bigger problem on my hands. FWIW, I always bleed coolant refills/top-offs on cold engines with the cap off. And, it usually burbs and gurgles as trapped air makes its way up. But if you take a moment to look at the 19 second video I've attached, you will see that it's blasting out way more than trapped air.

I know at the least, a head gasket is blown, but with that much force, could my woes include warped or cracked heads? I've read many mixed feelings about how long you can drive above normal engine temp before these 1GR-FE engines suffer permanent damage. And, because i really don't think the engine was run for more than a few moments when the temperature really climbed out normal range, I'm just not sure it's more than the gasket. The truck has 205,000 miles. Can't be sure if the previous owners ever had issues, but at least up til now, it has not been a problem for us.

At the end of the day, I'm going to have to have it towed to a shop. But I'm so leary about paying to have it broken down just to tell me I have a cracked head as well. And, at the same time, my gut feeling is that if it was in fact something really bad like that, that it would be far better to replace the engine than pay $4K+ for a complete rebuild. On the other hand, it may just be the gasket having failed from age, and nothing worse. But would a failed head gasket alone push that much compression & gas into the cooling system to result in what you see in the video?

Thanks for any thoughts you guys can share!

[video]https://youtu.be/auMbRoKCt44[/video]
 

JLee

Adventurer
A blown head gasket can cause symptoms like that. Do the 4.0's generally have problems with heads cracking? I would find that unlikely, but I'm not familiar with that engine.
 

mjbtnus

New member
Depending on what you read, not so much cracking, but apparently warped heads from overheating a much more common problem with this engine. I'm half tempted to try and open it up myself and take a look as I've also read that this engine doesn't like rebuilds, but if it were just a failed gasket and didn't require machining, then it's not so drastic a repair. It's that unknown factor that's got me not wanting to rush it into a shop (as I'm of the impression that most want to rebuild them for the labor $$$ they can glean off of it). That's probably being a little unfair sight unseen, but I really don't have a local shop that I 100% trust! :)
 

Trophycummins

Adventurer
I send the head out to be machined/checked at a machine shop any time I have to replace a gasket. Only cost $15 to have it checked.
 

mjbtnus

New member
Unfortunately for me, because it's a 4x4, looks like you can't get the oil pan loose to uncouple the front panel without lifting or removing the engine. the suspension frame is reinforced there (to say the least). I don't have a hoist. So, looks like I've no choice but to take it to a shop.

Some else on another forum said that rebuilding 1GR-FE was problematic. If the gasket job for an '05 Taco 4x4 really is $3-$4K, should I just seek to replace the engine? It is a 200K+ miler.
 

JLee

Adventurer
Unfortunately for me, because it's a 4x4, looks like you can't get the oil pan loose to uncouple the front panel without lifting or removing the engine. the suspension frame is reinforced there (to say the least). I don't have a hoist. So, looks like I've no choice but to take it to a shop.

Some else on another forum said that rebuilding 1GR-FE was problematic. If the gasket job for an '05 Taco 4x4 really is $3-$4K, should I just seek to replace the engine? It is a 200K+ miler.

Why do you have to pull the oil pan for head gaskets?
 

Buddha.

Finally in expo white.
You might as well pop the heads off first and see if it's come to a full replacment or not. If the engine is already junk you cant make it worse.
 

mjbtnus

New member
Why do you have to pull the oil pan for head gaskets?

That was just something I read. Had to do with being able to remove the timing case cover. Best I understand, they are interlocked somehow. I think all this is also outlined in the FSM, though I haven't yet looked at this specific procedure. But if it is in fact a requirement, I've already looked and there's no way to get at the oil pan bolts without at least lifting the block up off the suspension frame. Because this is a 4x4 off road model suspension, it has reinforced steel plating underneath the transmission and differentials. Some say you can lift it without having to disconnect the transmission, but already, that is getting way beyond my tooling here at home.
 

mjbtnus

New member
You might as well pop the heads off first and see if it's come to a full replacment or not. If the engine is already junk you cant make it worse.

That was my initial intent. But if it's going to require lifting the block up or pulling the engine out altogether (as I've read elsewhere), then that's getting into more than I'm setup for here at home. I'm certainly game to try it otherwise.
 

Marinetaco

New member
Mjbtnus,
First off, you don't need to worry about lifting the engine out or even up. There are 4 - 12mm head bolts that go through the upper oil pan into the time cover. 2 short 2 long. Take the plenum off, valve covers off, ps pump, alternator, and ac compressor of . Don't have to discharge the ac lines. Just unbolt the 4 compressor bolts and set it softly down. There is a 10 mm head bold near the middle of the timing cover that holds that ac line in place. Take that off. Obviously, take out the radiator and crank pulley. You are now on your way to getting the head of . Chances are your head gasket blew. Either between 3-5 or 4-6. Send the head off to be checked but DO NOT machine it. Toyota doesn't recommend it because of the tight tolerance of the valves. Good luck
 

djtc

Adventurer
When my head gasket started to leak there was no overheating or evidence of oil mixed with coolant. My only system was overpressurizing of the cooling system (not as bad as yours). I had replaced all the possible cheaper items but in the end it was a gasket leak between both cylinders .
 

Forum statistics

Threads
185,840
Messages
2,878,749
Members
225,393
Latest member
jgrillz94
Top