2UZ Head gaskets vs 3UR-FE (200 series)

[Asanka]

This guy is raising concerns over head gasket failures on 200 series engines for quite a few times. His guesstimate is coolant gets acidic and eates the plastic/rubber coating of the gasket and leaks.

Question for the 100 series experts, any first hand experiences on 2UZ? what year and mileage if there any. Btw, the guy praises 2UZ at the end of the video. I thought it's worth to ask the question and get recommendations on coolant maint interval and importance here.

 

[Trunk Monkey]

Not really an issue with the 2UZ. Very, very few reported here but it's been related to something else - like the heater T blowing. I'd just follow regular maintenance interval for coolant swap and then keep an eye on the radiator as it ages and miles, look for pink crusties along the tank edges top and bottom.

 

[ClassyJalopy]

Agreed, non-issue for 2UZs. Also, not 100% sold that it is a common issue with the 5.7 3UR-Fe. Plenty of Tundra, Sequoia and LC/LX with high mileage and no headgasket issues.

 

[Asanka]

May be an issue of Japanese made engines?

Agreed, non-issue for 2UZs. Also, not 100% sold that it is a common issue with the 5.7 3UR-Fe. Plenty of Tundra, Sequoia and LC/LX with high mileage and no headgasket issues.

 

[excessive]

I think that the 1UR is aluminum block, or it's sleeved or something that makes it quite different than the 2UZ. Either way, stay on top of your coolant flushes

 

[ClassyJalopy]

2uz requires a timing belt every 90k miles, which more or less forces a coolant flush.
3ur on the other hand have "maintenance free" timing chains that last "forever " so no one flushes coolants or changes water pumps until it's s too late

 

[Rhetoric]

Agreed, non-issue for 2UZs. Also, not 100% sold that it is a common issue with the 5.7 3UR-Fe. Plenty of Tundra, Sequoia and LC/LX with high mileage and no headgasket issues.

My counter point here is: Sure, lots of trucks without issue. But maybe they followed the coolant replacement interval? The data is still thin here.

I appreciate that he goes into detail and actually makes a case for it instead of just shrugging and throwing parts at it like many techs do.

I liken this to the fuel boiling issue on later 100 series trucks. Sure, not all have the issue. But they keep popping up more with age.

Its all good data and a reminder to follow maintenance recommendations.

 

[2001LC]

The 5.7L 3UR in 200 series video above post. Is and eye opener with respect to their head gasket.

There were reports, of 4.7L 2UZ-fe: "no apparent reason head gasket failures". Many years ago. Search mud, you'll find them. But when we look close at them. They were, hearsay coming from some dealership service manager.

IMHO:

4.7L head gasket failure. Are always due: To improper service. Number one being; PM of the coolant system. Not some assemble, manufacture defect or design issues. Except one could say, a design related issue because:

• Difficult in bleeding air from coolant system. (This was corrected in the 200 series)
• Placement of water temperature sensor. Which is, high in the engine. If coolant low, below sensor level. We'll get a false, low engine coolant temp (ECT).
• Heater tees, are high point of system. Which even the smallest amount of air in system, will end up in Tees after cool down. Result in, premature failure. (The Tees placement was corrected in the 200 series).

But these coolant issues are so easily overcome. With proper PM. Which starts with radiators (3) fins:
Radiator fins need cleaning! Alert Alert Alert - https://forum.ih8mud.com/threads/radiator-fins-need-cleaning-alert-alert-alert.1151006/

As mile rack up. It's seems more and more the 200 series 5.7L w/3UR. Head gasket, is doomed to fail. Even when properly maintained.
I'm seeing, 200 series drop in value as 100 series are increasing. Which isn't supply, driven valuation. I seems the 5.7L 3UR is a 1/4 million miles engine. Whereas the 4.7L is more than a 1 million mile engine. How much more we don't know.

 

[rexington14]

IMO, more concerning than the (largely unknown) failure rate is the potential costs should you blow the 5.7L motor completely.

There's been instances reported in this forum where a 5.7L used engine replacement in a 200 series costs in the range of $16k-$20k. With many months downtime often required to locate a "good" candidate used engine out of a junkyard.

Imagine what happens when the 200s get even older and depreciate even more and they unfortunate enough to lose an engine for whatever reason? Not going to be pretty for those owners.

 

[Asanka]

Same guy examined a 100 series head gasket failures too

 

[2001LC]

Same guy examined a 100 series head gasket failures too

Certainly, we need to be on the watch, as 4.7L ages.

But in the above video, of the 4.7L w/coolant loss:

• No compression test.
• No sign of coolant leakage, into any cylinder. With a borescope or once heads off.
• No mention of BK2 head, flatness inspect.
• No sign of coolant leak on head gasket, head or block surfaces.
• Coolant leak not idenfield.
• No concern, with how engine was running.
• I don't recall a statement of any smoke from tailpipe.
• Conjecture, that never overheated.
• No records provided of coolant flushes or with which coolant.
• No mention, if head gasket R&R corrected mysterious coolant loss or the singular oil report.

The rubber like coating on head gasket, delamination/flaking. Is concerning! But should it be expected, when heads pulled off. Would it result in head gasket failure?

 

[baltistyle]

Did you ask your questions on his comment section? Since we don’t see many of the things that he does and of course it is edited so not every step is listed, the big question is did this head gasket repair fix the coolant loss. He did speak about coolant in the Pistons if the head gasket failed in that manner, and this makes me understand that he checked this and was just explaining it to the audience. Also, that he stated it was a mystery and he couldn’t find the issue anywhere likely means he did that compression test as well. It’s been a few days since I watched it so I can’t remember if he said he did the other bank off camera.

For the super detail oriented audience, we can always find issues with the videos that online car mechanics post, but have to remember that it’s a story and involves lots of editing often not done by the mechanic themselves. Car care nut is someone to watch for the greater story versus the finer details of the repair. I find his videos to be good for the general Toyota enthusiast that just wants general information.. the hard-core DIY guy or professional Toyota mechanic already knows the story and the sequence and might tell it a different way.

My other car brand is Mercedes and I find myself sometimes knowing more than is portrayed in the videos by master mechanics, but then I realize I’m not a master mechanic and I only know what they’ve told me, not what they know. This is why it’s always important to cross reference any sources of information whether written or oral.

 

[dbfw]

Isn't the 3UR an open deck design vs. closed deck on the UZ series? That may be a big contributing factor.

 

[Asanka]

Did you ask your questions on his comment section?

Don't think we will get an answer given how popular that guy and he works on customers cars not his own one.

 

[OEMGUY0720]

What I’m curious to know is how “acidic” has the coolant chemically changed to even consider that as the culprit of pitted surfaces that eventually would be the culprit of internal coolant leak/head gasket failure. It’s easy to say that yes over time and countless heat + cold cycles it makes the coolant acidic but has someone really ran a laboratory test to classify it as “too acidic” and what are the parameters.