[lamikela1]

I've searched the forum to see if anyone is having similar issues but can't find anything. Here's my problem.

A few weeks back I got an engine code of P0306 which is a cylinder #6 misfire. I changed the plugs since it was due and the code cleared but a couple weeks later I noticed that my engine coolant was low.

After some additional troubleshooting I have determined that the left bank head gasket is bad and needs to be replaced. What's happening is that when the engine is running it is over-pressurizing the cooling system and causing the coolant to be pushed out of the system via the radiator cap. I also see bubbles rising from the coolant recovery tank from the increased pressure in the system.

The reason that I got the P0306 code is that coolant is leaking into the #6 cylinder and causing the misfire. Also, when the engine is running, combustion gases are bleeding through to the cooling system.

I will say that this is all based on my findings so far but I will be bringing my Taco to the dealer this Saturday to have it checked out.

I would ask that anyone who has had this problem respond to this thread as by searching the Internet I have found several more complaints of this on Tacomas, FJ's and 4-Runners and more of us may have this problem as our trucks rack up more miles.

Mine has just over 94K on it now and is extremely well maintained so this is very premature for a Toyota.

I'll keep you informed of my progress as I do believe that Toyota should take care of this even though my truck is out of warranty. Needless to say I am very bummed out.

 

[RTFM]

Off the top of my head, I think you are the first blown head gasket I've seen posted here.

I don't know why you think Toyota should take care of it. You are many years and many miles out of warranty. If you were a few days, or a few miles, I might consider asking, but:

Most blown head gaskets I've seen have been a result of operator error, running with low water or low oil, due to not replacing hoses or something that developed a slow leak. I am sure your drive train warranty would not kick in, since it says something like:

Any repair or replacement to engine, ......l that becomes necessary due to a defect in materials or workmanship is warrantable with the exception of the items listed under "What Is Not Covered

And

Items subject to normal wear and tear, noise, vibration, or deterioration are not warranted.
Parts associated with vehicle maintenance services are not warranted beyond 12 months or 12,500 miles


They will probably pressure check it, find a bad hose, and say "Sorry, your fault". Hate to be a wet blanket, but people with reasonable claims are having to fight all the way to small claims court.

 

[lamikela1]

I appreciate your reply but you are wrong on all counts as this truck has been properly maintained throughout it's lifetime using high quality products. Also the dealer has performed all recalls.

Having said this I would agree that if the truck were abused or not serviced properly then Toyota would not be liable for this.

When I investigated this what I found is that there are many owners of the 4.0 liter engine who are having this problem with only cylinder #6 failing. If this were a random cylinder failure then your statement may have some creedence but it is not. Also I did not mention that Toyota also decided to supercede the original head gasket somewhere between 2006 and 2007 presumably because of problems discovered from user failures or their own testing. In one case the question was asked of a user who experienced the failure and the Toyota zone office totally ignored his request for information about the gasket change.

You are welcome to do your own research as I have done mine. I do hope that you do not have this problem as it costs a bundle to get it corrected.

 

[RTFM]

I appreciate your reply but you are wrong on all counts

Good Luck

 

[Splicer]

For your sake, I hope you can document a pile of similar failures caused by a common defect. IMO, that may be the only way to convince Toyota to pick up the tab. As RTFM correctly pointed out, regardless of how well the truck has been maintained, its warranty has long since expired. Good luck.

 

[lamikela1]

I am prepared to go to small claims court if needed.

 

[silversport]

I don't doubt that this failure was due to a defect and not operator error but after 7 years and 94k miles... I doubt Toyota will do anything for you.

I feel for you. Major repair bills are a downer. Find an independent shop to fix it. If it really is just the gasket, pretty straightforward repair.

 

[green91]

Unless you've had the vehicle serviced regularly at a dealership and have a good relationship built with them, good luck on getting it covered. Even then its a big (ok a HUGE) stretch that they will cover it since your 34k! miles out of the powertrain warranty.

 

[integlikewhoa]

It's good to know I'm still under Warranty....... So how does this work I just go any time and tell them I think they should cover it anyways or I'm going to take them to court?

Good luck man, you have a written and signed paperwork showing what your warranty period is and you have went a little...... Wait alot past it and your going to fight it.... LOL

This is the kind of customers I don't want in my repair shop, you give them something (written warr. period) and it's not good enough they still will threaten to sue if you don't give them everything they want.

How many times have you had the truck in under warranty?

 

[05Moose]

Unless you've had the vehicle serviced regularly at a dealership and have a good relationship built with them, good luck on getting it covered. Even then its a big (ok a HUGE) stretch that they will cover it since your 34k! miles out of the powertrain warranty.

Not as huge as you think. I was at 93k miles (no extended warranty) when I got the front diff vibe after putting on the 5100s. One call to Toyota Corporate was all it took. They covered it 50/50. Now I had a really good relationship with my service adviser and a long history of buying Toyotas...

 

[integlikewhoa]

Now I had a really good relationship with my service adviser

This doesn't happen buy having one problem with your truck and then telling them your going to take them to court if they don't pay for it outside of warr. Actually it makes enemies.

 

[landphil]

Not as huge as you think. I was at 93k miles (no extended warranty) when I got the front diff vibe after putting on the 5100s. One call to Toyota Corporate was all it took. They covered it 50/50. Now I had a really good relationship with my service adviser and a long history of buying Toyotas...

It can happen to get goodwill coverage (also known as policy) as you experienced, but it almost never covers the entire bill as you experienced. Most of the time it only happens for common issues like you experienced with the diff vibe, rather than rare occurances like a 1GR head gasket failure, which I will add, has not been confirmed at this point. Removal of the head, inspecting the gasket, and pressure testing the head is the only sure way to confirm.

 

[Splicer]

Removal of the head, inspecting the gasket, and pressure testing the head is the only sure way to confirm.

Can't they do a leakdown test -- injecting air into each sparkplug hole?

 

[green91]

rare occurances like a 1GR head gasket failure, which I will add, has not been confirmed at this point. Removal of the head, inspecting the gasket, and pressure testing the head is the only sure way to confirm.

This is not how a headgasket is diagnosed at all. In fact most id say 75% of headgaskets i've looked at after being removed (that were confirmed bad by a block test) you couldn't tell if it was good or not because they generally come apart. Pressure testing the head also would not tell you anything about the headgasket.

The best way to test for a blown head gasket is to use a block tester, which tests for combustion gasses within the cooling system. There are also rare occasions where they will leak coolant into the oil and that is usually visible by draining the oil, but generally these don't cause misfires.

 

[green91]

Can't they do a leakdown test -- injecting air into each sparkplug hole?

A leakdown test is useless with a blown headgasket that is causing occasional misfires because it doesnt replicate true cylinder pressures and also because most of the time they only do it when hot or cold and the gasket expands/contracts. A block test is how most headgaskets are diagnosed.

 

[landphil]

Can't they do a leakdown test -- injecting air into each sparkplug hole?

This is not how a headgasket is diagnosed at all. In fact most id say 75% of headgaskets i've looked at after being removed (that were confirmed bad by a block test) you couldn't tell if it was good or not because they generally come apart. Pressure testing the head also would not tell you anything about the headgasket.

The best way to test for a blown head gasket is to use a block tester, which tests for combustion gasses within the cooling system. There are also rare occasions where they will leak coolant into the oil and that is usually visible by draining the oil, but generally these don't cause misfires.

While all of the above can confirm there is an issue, none can pinpoint the exact location of the combustion leak into the cooling system. A cracked head can behave exactly the same way, even a cracked block in rare cases. A failed head gasket almost always leaves evidence of leakage to the trained eye.

 

[lamikela1]

Thanks to all of you for your responses. One thing that I want to make clear though is that I am not threatening the dealership with anything at this time. Going to court is my absolute last option.

I have owned 9 Toyota products in the last 35+ years (I currently own the '05 Taco and a '08 Lexus) and I am hoping that my long relationship with Toyota will count for something. Also, of all those vehicles I have never had a problem such as this. Some were driven well over 200,000 miles with no major failures.

As far as the troubleshooting needed, the leakdown test would show head gasket problems if the problem exists at low pressures but as green91 stated if the problem is apparent only at combustion pressures it may be hard to detect that way.

In my case it may not work as it appears the leak is very slight, no water in the oil, and a slight scent of combustion gasses when you open the radiator cap. I do think that a bore scope may detect it if you let it sit overnight as the engine does collect some water in #6. It's not enough to cause the cylinder to hydraulic but it does run rough on first start.

I am waiting for the dealer to call me back as they are checking it today... BTW before I went to the dealer the P0306 code came up again so I know that #6 is affected.

 

[green91]

A block test is done while the engine is running and is highly effective at detecting combustion gasses in the coolant system. The dealer is more than likely using this method.

 

[lamikela1]

OK, it's official that the head gasket is blown. The dealer offered me a 10% discount off the cost of replacing both head gaskets but the bottom line is that it will run about $3200. I just found out that the heads are not warped and within tolerances so it should be a bit less as their price included resurfacing the heads.

I spoke to the Toyota Customer Experience Center but got the scripted blurb about not having any recalls for this problem. My next step is to escalate to the Toyota Field Representative for this area.

I asked about the spiral cable recall for my truck but curiously mine is not on the recall list.

Stay tuned...

 

[05Moose]

Have you gone into Toyota's website and input your VIN to confirm yourself that it's not on the spiral cable recall list? I thought they all were (mine is).