Valve Cover Off (Toyota 2AZFE)

[ttvr4]

Originally Posted By: LeakySeals
Also, get a new Toyota OE PCV valve. Don't use aftermarket, they are noisy and for whatever reason suck more oil.

And..

Your aware of the headbolt issue right? Change the coolant early and often. No substitute coolants. Maybe the pink, but its more expensive than the red.


Thanks for all the good info. I will give M1 HM a shot to see if oil consumption reduces. I replaced the PCV valve 15k miles ago. I am not aware of the head bolt issue on this vehicle but I am looking to replace the coolant and water pump soon. Can you elaborate on the head bolt problem?

-ttvr4

 

[LeakySeals]

Are you sitting down? google "stripped head bolts Toyota". It ties into the consumption in a way, heat related. They shaved too much aluminum off the block to lighten it. The result was poor heat dissipation. Add design.. insulating foam between the plastic intake and the block.. the foam traps heat on an already hot block at 3 headbolts behind the intake. Under the right conditions like a hot day with old tired coolant... Pop, pop, pop go the threads in the block. The head separates from the block. The head gasket no longer functions. Rapid coolant oil mix. Sudden catastrophic failure. The 02-04 2AZ-FE is known as a ticking time bomb for this reason. You never know where or when its going to happen. Hasn't happened to me, but I'm a neurotic coolant changer because I know the truth about the 02-04 builds. Pop pop pop!

Truth in pictures. The block shaved down to skeletal form. Note the 3 bolts with coolant channels on one side, hot pistons on the other. There's just not enough metal to dissipate heat. Add the foam insulating the plastic intake, its just too hot for whatever aluminum they chose. The coolant being so close, its the best source to dissipate heat away from those threads. why I think its critical to have that 50/50 mix just right, drain and fill every other year/40k.

All is not lost provided you pull over and shut down. The fix is timeserts. Re-drill and tap the holes larger, insert a metal sleeve, new bolts. Back on your way fixed forever. Expensive if you can't DIY. Its the labor. Can get it done for under 1k.

 

[Quest]

If memory serves: 04 2AZ-FE already has that stripped cyl head bolts issue resolved, so OP's engine should be good.

Wifey's 04 2AZ-FE has been good all these years (bought 2nd hand @ 54k, now has over 163k), no headbolts issue, no water pump leaks, etc. Just the usual servicing stuff.

*in fact: 1 mnth ago: I replaced the valve cover gasket and spark plugs on it...*

drain-n-fill of factory Toy LLC pink upcoming this summer.

Q.

 

[LeakySeals]

Nope. 02-04 build, red coolant. 05-06 has a switch to pink super long life coolant. 07+ has a modified HG design. The modded HG design gives more play between the head and block during expansion and contraction, lessening stress on the bolt threads. Added HG metal gives "some" added heat dissipation. Whats interesting is the problem seems to rear its ugly head around 100k, the specified interval for red. By then the coolant has evaporated some. Use of the pink, longer interval, it makes sense. Stay on top of the red, no problems. Switch to the pink, longer intervals. Either way stay on top of it.

 

[ttvr4]

Originally Posted By: LeakySeals
Nope. 02-04 build, red coolant. 05-06 has a switch to pink super long life coolant. 07+ has a modified HG design. The modded HG design gives more play between the head and block during expansion and contraction, lessening stress on the bolt threads. Added HG metal gives "some" added heat dissipation. Whats interesting is the problem seems to rear its ugly head around 100k, the specified interval for red. By then the coolant has evaporated some. Use of the pink, longer interval, it makes sense. Stay on top of the red, no problems. Switch to the pink, longer intervals. Either way stay on top of it.


Out of the factory, the car came with Toyota Super Long Life Coolant (pink stuff). Does this mean the stripped head bolt is not an issue on this vehicle?

-ttvr4

 

[LeakySeals]

The full use of Pink on the 2AZ-FE was 05+. In the 04 year you could have either Red or Pink depending on how close it was to 05. You have pink so the intervals are longer. So sticking to a suspicion, if it were to happen because of old tired coolant it would be at higher mileage. But its potentially the same issue, there are no physical mods other than coolant till 07. For red its 100k for the first, 50k thereafter. If you look at the book for what does it say for Pink change interval?

 

[ttvr4]

Originally Posted By: LeakySeals
The full use of Pink on the 2AZ-FE was 05+. In the 04 year you could have either Red or Pink depending on how close it was to 05. You have pink so the intervals are longer. So sticking to a suspicion, if it were to happen because of old tired coolant it would be at higher mileage. But its potentially the same issue, there are no physical mods other than coolant till 07. For red its 100k for the first, 50k thereafter. If you look at the book for what does it say for Pink change interval?


Factory manual says initial replacement for Super Long Life @ 100,000 miles. 50k thereafter.

-ttvr4

 

[Quest]

@ Leaky,

I've serviced a few 2AZ-FE so far (incl. my colleague's Highlander, etc.) and none of them have any headbolt issues (fortunate us), and all are on original Toy LLC.

While I'm sorry that your 2AZ-FE failed in the past, me thinks it's a manufacturing quality-control issue of the engine itself, less so on the coolant or stuff.

Q.

 

[LeakySeals]

If your thinking I had the problem, your not reading what I wrote. Thats fine, think what you want. Just trying to help the guy.

 

[LeakySeals]

Originally Posted By: ttvr4
Originally Posted By: LeakySeals
The full use of Pink on the 2AZ-FE was 05+. In the 04 year you could have either Red or Pink depending on how close it was to 05. You have pink so the intervals are longer. So sticking to a suspicion, if it were to happen because of old tired coolant it would be at higher mileage. But its potentially the same issue, there are no physical mods other than coolant till 07. For red its 100k for the first, 50k thereafter. If you look at the book for what does it say for Pink change interval?


Factory manual says initial replacement for Super Long Life @ 100,000 miles. 50k thereafter.

-ttvr4

Interesting, the same interval as the Red, but Pink is supposed to have a longer life. That would lean towards tired Red coolant as a cause. I would stay shorter than 100k even with Pink. Use the thereafter from the beginning to be on the safe side. Maybe 60-70k max. You've googled by now, the problem is real. With no mods till 07 other than coolant, no answer from Toyota why it happens, better to err on the side of caution.

 

[LeakySeals]

Q. Your not giving yourself enough credit. Its not happening to you because your taking good care of your vehicles. Same here. I have an 02 running Red @ 270k, no issues. Neurotic coolant drainer. I suspect that has a lot to do with why it happens to some, not others. Look at the block and what I said about the design. Its obvious whats wrong.

 

[ttvr4]

Leakyseals, you are correct. Better to be safe than sorry. I am going to replace the coolant tonight and while I'm at it, I'm going to replace the thermostat and thermostat gasket. My sisters '06 Camry is coming up on 100k so I'll flush out the coolant this weekend. Her 2azfe on her camry is not burning any oil which is good.

-ttvr4

 

[LeakySeals]

Yeah, good idea. I considered lowering the temp of the thermostat as more prevention. But idle, fuel air mix, vvt-i valve advance/retard/overlap and several more are relying on engine coolant temp sensor readings. Too low, not sure what happens in each case. So I went with the OE, same opening temp.

 

[crinkles]

Has anyone checked their valve clearances using feeler gauges while the cover is off? My Haynes manual shows you slot them under the cab lobes to check.

 

[supercity]

Originally Posted By: crinkles
Has anyone checked their valve clearances using feeler gauges while the cover is off? My Haynes manual shows you slot them under the cab lobes to check.


Not on this engine. That is how you do it though, with the lobe pointing away from the shim. Are they not hydraulic?

 

[Hokiefyd]

Originally Posted By: supercity
Not on this engine. That is how you do it though, with the lobe pointing away from the shim. Are they not hydraulic?


I believe they use a bucket/shim type lifter, which means you can't adjust the valve clearance without replacing parts. I'm all for adjustable solid valvetrains (I don't care for hydraulic valvetrains), but this is not the way to do it in my humble opinion.

 

[LeakySeals]

Its vvt-i, so you remove the lifter and measure its thickness with a micrometer. Use the proper shim to maintain correct thickness, replace the lifter. Either way.

 

[LeakySeals]

My guess is he doesn't like the valve noise.. loops back to the discussion. The sound of a thin skinned aluminum Toyota I4 with vvt-i running on 15w-40.

 

[supercity]

I have a 1AZ-FE and its pretty noisy too on MS 5w30 when cold.

 

[supercity]

Originally Posted By: Hokiefyd


I believe they use a bucket/shim type lifter, which means you can't adjust the valve clearance without replacing parts. I'm all for adjustable solid valvetrains (I don't care for hydraulic valvetrains), but this is not the way to do it in my humble opinion.


You don't like the design or the method for adjusting it? I've always liked the simplicity. Very common on old DOHC engines and I don't mind adjusting them. Once you have a stack of shims from doing a few it's easy.