*** V6 Head Gasket Action Request ***

Scott,

Thanks for the hopefully encouraging news. It has not overheated during our ownership. Did you do both headgaskets at the same time? I've been doing some research but I haven't found any definitive reason why the gaskets fail in the first place. If it's the design of the cylinder block and/or head itself, it's likely harder to completely eliminate the condition. If there's an upgraded gasket that helps solve the problem there's perhaps more reason for hope.

Ultimately it comes down to "do I prophylactically replace the headgasket on the other head while I'm replacing the one on the failed side or do I hope for the best?" That's never an easy decision to make.

-tj

I don't have the V6..BUT I would highly recommend doing both sides, I don't think you can buy just one head gasket, in all my years of doing mechanic work they always came in a set for all V type engines, you will also have to buy the intake gaskets, valve cover gasket as well, and yes Toyota did as mention redesigned the head gaskets in late 2005 and they are thicker now, the original gaskets were too thin which is why the early V6s had this issue.

I have not read of anyone having any other issues after replacing with the redesigned gaskets, so the engine should be good for many, many more 1000s of miles.

We did both on mine. Once you're in there, it just makes sense to do both. They did re-design the gaskets.
 
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2005 V6 4Runner Limited
135K miles

We've owned it since 2010 and maintained her appropriately.
Yesterday she through the CEL (and trac control) lights. OBDII terminal read P0306 error condition. Made In Japan completed a block check and determined "exhaust gas in coolant."

They recommended an engine replacement which is ludicrous. I'm not knowledgeable about 4Runners but I have built and engine or two in my day.

Based on the previous 800+ responses it's most likely a failed head gasket. The question of course is "did the head warp?"

I'm going to ask for a second look and talk to some other shops but I'm hoping that it's a simple matter of replacing the head gasket, and that the head itself is not warped or cracked.

Regards,
TJ

When we did mine I took the heads to a machine shop to get checked. They required slight machining to true them up. As mentioned if it didn't overheat. Sounds like you have experience. It's not hard but a lot of work. Make sure to get the top for the head bolts ahead of time.
 
2004 toyota 4runner v6 headgaskets replaced at 187,000 miles

Yup, I have no idea how they havent done a recall. I believe toyota is fully aware of the problem. Since headgaskets are one of the most expensive things to fix... Toyota is ignoring the problem and pretending like they are not at fault. Toyota is 100% at fault for this headgasket problem, as it is a manufacturing defect. Also since its not a "Safety" issue, Toyota doesnt really want to shell out millions in repairs for something that probly wont end up in a lawsuit. Would i like to get my money back for a problem that is toyotas? yes. I shelled out close to $4000 at Toyota dealership to fix a headgasket problem that was Toyotas to begin with. What can i do about it? nothing. and Toyota knows this.
 
When we did mine I took the heads to a machine shop to get checked. They required slight machining to true them up. As mentioned if it didn't overheat. Sounds like you have experience. It's not hard but a lot of work. Make sure to get the top for the head bolts ahead of time.

Mine was .001" out of tolerance also, which required milling. I've seen several others with the same experience.

I have to believe that the heads were not machined properly and that this is the root cause.
 
Mine is in the shop currently getting both head gaskets replaced. I wouldn't call it an epidemic either by any means, but I also would not ignore the fact that it is happening to people. Google search "P0306 Toyota 4.0" and read through a few. If are researching prior to a purchase, I would advise making sure you start the vehicle from a cold start in the morning and confirm that it runs smooth immediately. Toyota quotes this job at $2500-3200 and that is a very heavy expense for some.

What would one consider as "runs smoothly"? Just purchased an 03 v6 with 140k yesterday and it seems to be running fine. It doesn't run SUPER quiet, but it also doesn't seem to shutter, or come close to dying. No codes, all fluids are clean, no visible exhaust fumes and no exhaust smell from the radiator.

I am a little concerned that there was that Khameleon coolant put into it in 2015. Don't know if its been changed since then. Khameleon is orange which is close to toyota red, so its hard to tell. I plan on doing a flush asap with toyota red. Granted, they didn't drive it much since 2015, as they had a company vehicle to use.
 
What would one consider as "runs smoothly"? Just purchased an 03 v6 with 140k yesterday and it seems to be running fine. It doesn't run SUPER quiet, but it also doesn't seem to shutter, or come close to dying. No codes, all fluids are clean, no visible exhaust fumes and no exhaust smell from the radiator.

I am a little concerned that there was that Khameleon coolant put into it in 2015. Don't know if its been changed since then. Khameleon is orange which is close to toyota red, so its hard to tell. I plan on doing a flush asap with toyota red. Granted, they didn't drive it much since 2015, as they had a company vehicle to use.

The V6 isn't a quiet running engine, so don't worry about that. If the head gasket it leaking, what you will experience at cold startup is a misfire. As it gets progressively worse, the CEL will illuminate and you'll get the codes listed elsewhere in this thread.

The misfire at cold startup is the most obvious symptom. If you haven't experienced it, and like the 4R, then keep driving it and don't worry about. it. :thumb:
 
The V6 isn't a quiet running engine, so don't worry about that. If the head gasket it leaking, what you will experience at cold startup is a misfire. As it gets progressively worse, the CEL will illuminate and you'll get the codes listed elsewhere in this thread.

The misfire at cold startup is the most obvious symptom. If you haven't experienced it, and like the 4R, then keep driving it and don't worry about. it. :thumb:

Loss of coolant is another symptom. If your coolant level keeps going low, then it is getting into the cylinder.
 
Loss of coolant is another symptom. If your coolant level keeps going low, then it is getting into the cylinder.

Or a leaking radiator. Both my friend and I have had leaks develop around 185k miles. Pinhole leaks.

I replaced my radiator when we did the head gaskets.
 
Or a leaking radiator. Both my friend and I have had leaks develop around 185k miles. Pinhole leaks.

I replaced my radiator when we did the head gaskets.

I meant that when you have a head gasket issue, that the coolant level will change and you have to add coolant every few weeks. Of course, leaking coolant is a symptom of a radiator leak. But coolant, running rough, and a check engine light indicates that you may have a head gasket problem.
 
Mine is in the shop currently getting both head gaskets replaced. I wouldn't call it an epidemic either by any means, but I also would not ignore the fact that it is happening to people. Google search "P0306 Toyota 4.0" and read through a few. If are researching prior to a purchase, I would advise making sure you start the vehicle from a cold start in the morning and confirm that it runs smooth immediately. Toyota quotes this job at $2500-3200 and that is a very heavy expense for some.

New owner of an 03 v6. No codes. A little white smoke coming out of the exhaust at start up that goes away after a few seconds. Coolant is below low line in the reservoir, but I don't know when it was last topped off or changed. Previous owner did not put Toyota coolant in. Khameleon was put in after a flush at some shop. I'm really hoping there isn't an issue.

Has anyone tried the chemical tester kits? If so, which one is preferable, and have you had success? Also, would a compression/leakdown test cause/worsen the problem?
 
Does anyone have positive confirmation that the early 4th gens use Toyota Red LLC, instead of premixed pink? Mine is an 03, and I just read in another forum that red is supposed to be used in the 03.
 
New owner of an 03 v6. No codes. A little white smoke coming out of the exhaust at start up that goes away after a few seconds. Coolant is below low line in the reservoir, but I don't know when it was last topped off or changed. Previous owner did not put Toyota coolant in. Khameleon was put in after a flush at some shop. I'm really hoping there isn't an issue.

Has anyone tried the chemical tester kits? If so, which one is preferable, and have you had success? Also, would a compression/leakdown test cause/worsen the problem?

We used a radiator exhaust gas tester on mine and it came up negative. We used a borescope with an iPhone and saw coolant in #6 after sitting.
 
Headgaskets can fail in several ways...which will need different methods of detection.

A blue juice test at the radiator will only detect if combustion gasses are leaking out of the cylinder into the cooling system, but won't detect if coolant is leaking into the cylinders. Just because one condition exists does not mean that both exist.
 
Got a master seal kit from Toyota to day. What are the bolts the are required to be replaced for a head gasket? I have the head bolts orderd.
 
I think the instructions call for new exhaust manifold nuts or studs or something but why o that really? Mine haven't fallen off yet.
 
Hello every. I recently traveled a good ways from home to buy a 2003 4runner with 130k that has kept up decently. It is a Limited and only problems I can really find are it needs struts(non xreas system), has very minor leak on a seal on left side front diff output shaft, ans brakes work but feel kind of soft. Not sure if thats just how they are but everything else I drive the brakes kick in way earlier in the pedal. Anyway after getting it home and doing some reading I came across all these threads about the head gasket issue with 2003-2005 and I felt like I could taste my a**hole after reading this stuff. Mine doesnt appear to be bad but now I feel like reselling even at loss and getting Tahoe or other pushrod engine. I've always been a Chevy guy bur heard how great Toyotas were so I thought I would give one try and now I have some buyers remorse.
 
Hello every. I recently traveled a good ways from home to buy a 2003 4runner with 130k that has kept up decently. It is a Limited and only problems I can really find are it needs struts(non xreas system), has very minor leak on a seal on left side front diff output shaft, ans brakes work but feel kind of soft. Not sure if thats just how they are but everything else I drive the brakes kick in way earlier in the pedal. Anyway after getting it home and doing some reading I came across all these threads about the head gasket issue with 2003-2005 and I felt like I could taste my a**hole after reading this stuff. Mine doesnt appear to be bad but now I feel like reselling even at loss and getting Tahoe or other pushrod engine. I've always been a Chevy guy bur heard how great Toyotas were so I thought I would give one try and now I have some buyers remorse.

Why? It's not leaking so worry about it? That's like worrying about getting struck by lightning. Sure, it could happen but it's not likely. You're buying worries that you don't need.
 
I see your point but I see to be a guy that has bad luck so I assumed I would get it. I didnt read wvery page but it like 04 and 05 were worse for some reason than 03? Maybe i will get lucky with my 03. Do you know if I buy a motor from a wrecked 06+ would it be direct swap? Sometimes that stuff is on Copart for crazy cheap and I could have a spare motor if the 06+ fits everything the same.
 

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