Toyota engines destroyed by loosened head bolts

Messages
712
Location
St. Louis, Missouri
I just learned about a possible defect in Toyota's popular 2AZ-FE engine in which the head bolts work loose over time, destroying the threads, and killing the engine. The "repair" can be a new engine costing $4,000 to $6,000 in parts and labor. One poster has said 2002 to 2006 Camrys are affected. A different poster has said 2001 to 2004 Camrys are affected. It would be nice to know which vehicles can get clobbered. Lexus cars don't seem immune--not sure about Highlanders with the 2AZ-FE. The engines usually have been failing between 50,000 and 100,000 miles, often out of warranty. Considering I have an '06 Camry with the 2AZ-FE engine, I'm not happy to hear about this. You can read more about it here: http://www.camryforums.com/forum/showthread.php?t=1301 Does anyone know if the problem was fixed after the '04 model year Camry? Or are '06's affected too?
 
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Messages
1,714
Location
CA.
Wow, I'd have them replace the head bolts and install heli-coils in the block so the threads won't fail. Those heli-coils are a life saver! AD
 
Messages
1,565
Location
Elkridge, MD
Not sure I'd use a Heli-coil in every head bolt, or worry about it at all. The 2AZ-FE is not exactly an exciting engine and I'm sure if yours dies from this weird cause there will be another one sitting in a J/Y somewhere waiting for you.
 
Messages
6,987
Location
Michigan
This is a little distrubing as I have a 2003 Toyota Camry with the 2.4 in it. So far so good at over 100,00 miles. Maybe it was a defect from a certain engine plant.
 
Messages
22,188
Location
Colorado Springs
 Originally Posted By: mstrjon32
there will be another one sitting in a J/Y somewhere waiting for you.
If you read all the "threads" (no pun intended) about this problem, people who get replacement motors from the junk yard or other sources - motors without the redesigned block, all most all of them have loose head bolts! So it looks like a potentially huge problem. Geeze, the 2.2L and 2.4L Toyota 4 bangers are real pieces of [censored], between this problem, and the sludge problem.
 
Messages
1,347
Location
wytheville, va
Heli-coils are stronger than factory original tapped threads... Here's an interesting article: http://cjsupra.kendra.com/Helicoil.html But of course going to the trouble to put the heli-coils in would be a pain and an expense. The article referenced said that Heli-coils are often used in aluminum heads for the exhaust manifolds of turbo and racing engines, for added strength. I had always thought Heli-coiling was a compromise of sorts... I did not realize that the Heli-coiled threads were actually stronger than stock, but it makes sense when you understand how they work. Dan
 
Messages
4,622
Location
Western Washington
Nice article about heli-coils. We've been using them in our shop for over 50 years, they are life savers and definitely not a compromise. They were designed for aircraft use back in the late '30s. In fact, we've kept the kits in the original boxes that say "Spencer Aircraft" on them.
 
Messages
1,714
Location
CA.
Heli-coils have saved many a day. If I had a Toyota with that engine, I would rather be safe than sorry, and do some PM before I had a problem. AD
 
Messages
3,756
Location
CA
I used to install heli coils in the exhaust bolt holes in my aluminum heads for the GN. Now I automatically do every bolt hole. It might be overkill to do them all but it sure beats doing it with them on the car later on.
 
Messages
5,570
Location
New Zealand
Haven't seen that in the 2AZ engine as we don't see many here.But I've seen loose head bolts in other engines,for Toyota it was the Y series.It was caused by the head losing hardness,going soft.The tension comes off the head bolts,and they loosen.I've seen head bolts fretted down inside their seats.If you see one of these engines,get a hardness test done on the cyl head.On head gasket jobs,a hardness test is sometimes the first thing done if they are known to have problems.
 
Messages
6,987
Location
Michigan
It sure would seem that with all the 2.4 motors Toyota has produced that could have this problem that they would have a larger outcry then this. Especially since it costs possibly a new motor. **But then again maybe alot were fixed under warranty. Maybe a news agency needs to do an investigation.
 
Messages
25,046
Location
ON, Canada eh?
 Originally Posted By: ZZman
It sure would seem that with all the 2.4 motors Toyota has produced that could have this problem that they would have a larger outcry then this. Especially since it costs possibly a new motor. **But then again maybe alot were fixed under warranty. Maybe a news agency needs to do an investigation.
Just let Mori know about it... He has a big mouth and I'm sure will spread it for you. (J/K - Mori)
 
Messages
2,097
Location
kansastan
If I had an affected engine, I would be awful tempted to pull the valve cover and re-torque the head bolts (this was standard procedure for John Deere engines for decades. Still is for Yanmars): Might save quite a bit of time/trouble. But not knowing ANYTHING about a Yota engine... be aware that I AM talking out my a$$ here. Before disassembly, one would want to investigate whether or not the bolts are accessible by simply removing the valve cover (some engines require that the cam be removed). Other pertinent questions would be along the lines of: What is the bolt torque? Is this a torque-turn application? Are these head bolts reuseable or torque-to-yield? Etc.? Some general comments about heli-coils: I've installed them more times than I can count in both cast iron and aluminum, and have NEVER had a problem with a heli-coiled bolt hole, so long as the insert was properly installed. I personally wouldn't think twice about putting a heli-coil in every single head bolt hole if it proved necessary; might not be a good strategery for the faint-of-heart or the inexperienced... but IMO, MUCH easier and cheaper than an engine replacement.
 
Messages
22,727
Location
CA
I don't think the problem is that common. I've heard about it on another Toyota site, and it seems to only be affecting some of the early 2AZ-FE engines.
 
Messages
2,248
Location
Chicago IL
 Originally Posted By: Built_Well
One poster has said 2002 to 2006 Camrys are affected. A different poster has said 2001 to 2004 Camrys are affected. Does anyone know if the problem was fixed after the '04 model year Camry? Or are '06's affected too?
Good question and one that I'm trying to answer as well. Does anyone know if and when Toyota "addressed" this issue? Specifically, which model years are affected?
 
Messages
1,563
Location
North Carolina, USA
 Originally Posted By: The Critic
I don't think the problem is that common. I've heard about it on another Toyota site, and it seems to only be affecting some of the early 2AZ-FE engines.
A very small number of units ever saw the problem. Not one poster here can say it's happened to them or at least they have not posted as such. It was early units that saw the problem and few of them I may add.
 
Messages
4,998
Location
Milwaukee, WI
Oh my god. Four people on an internet forum having a problem! Run like [censored]. I wouldn't buy a Camry from that vintage, or any, after hearing about this. Then again, is there any car on the entire planet that a four second internet search wouldn't yield similar problems with? Put this in context. Toyota sells sold over 250,000 2az-fe's alone, every year from 2001 until 2009. If this affected even 1 tenth of 1 percent of those, the post on that forum would be two hundred pages long. But it's not. It's three years old and there are four pages with three engines affected, and one is off a 1992/93. I'm not saying these cars are perfect, but you're never going to buy a car if something like this will scare you away.
 
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