StorminMatt

I have a cracked head on a 3RZ that will need to be replaced. And I have been looking at new replacement heads. They are quite reasonably priced compared a refurbished OEM head. But naturally, you have to wonder about their quality. Also, LC Engineering says that no aftermarket head is of the quality of OEM Toyota, so they only sell OEM heads. BUT, with everyone and their dog getting cracked heads, it is pretty clear that, quality-wise, the OEM head leaves something to be desired. Could an aftermarket head REALLY be THAT much worse than the already flawed OEM head?

83

I'm no engineer or market expert, so take this for what it's worth.

Yes.

I don't have experience with the 3RZ so I can't know whether cracked heads are really that common, or it just seems like it to you. I know that over the years, Toyota engines have had "problems". The head gaskets and timing chains on the "R" series engines, and especially the 3.0 when they first introduced the V6 in pickups. But even those problems were only problems by Toyota standards. Compared to most manufacturers, those engines with problems were still far better than average. Most of these problems happened at well over 100,000 miles, when a lot of other trucks had been retired to the junkyard. It's only that Toyotas are on the road so long that you see some of these problems.

So...what's the design flaw causing cracked heads? Is it something to do with the actual quality of the head, or is it related to the overall function of the engine? Because if you take a slightly flawed engine design that can cause a cracked head, then add a inferior quality head (Chinese) to that engine, it's just going to cause more problems.

I'll be the first to give a weak defense of Chinese products...they aren't 'by definition' bad. Many crappy Chinese products are actually US-based companies setting up factories in China to keep costs rock-bottom (and profits sky-high), and don't care about quality.

All that might be beside the point, though. In the end, very few aftermarket products come close to the quality of Toyota. So take a flawed OEM part and swap it out for a product from a place known for crappy quality, and what do you get? Likely an even worse product.

So...how many miles before your head cracked? I know OEM CV joints are far higher quality than anything else on the market. But when mine started clicking at ~270,000 miles, I figured I didn't need the new one to last another 270,000. But I was not willing to buy crap. Like the Autozone CVs people buy because they have a lifetime warranty, but are crap, and they don't mind replacing CVs every couple years through warranty. That's not for me. But I was willing to go with a part not as good as OEM, but still high quality. I got a NAPA part because they were pretty much the only aftermarket with decent reviews. OEM was something like $400, NAPA was something like $130.

But I'll never put crap parts on my truck. Especially when it comes to something like a head. Are Chinese heads crap? I don't know.

I definitely understand that you can only do what's in your budget, and sometimes you can't go OEM. So you need to figure out what line to walk. Are Chinese heads good enough to get you down the road 100,000 miles? If so, depending on your current mileage, that may be more than enough to last the life of the truck, and worth saving money. But if it cracks on you 20,000 miles later, now you're going to be in the hole farther than if you just went with OEM the first time.

Old83@pincher

Hmmm....this sounds like all those other problems that these trucks/engines are "supposed" to have...completely blown out of proportion by the internet/social media! A quick "Google" of 3RZ problems lists some stuff that in my experience is pure nonsense. Apparently you are suppose to adjust the valves every 30000KM (20000 miles), replace the timing chain every 160000KM (100000 miles), water pump, balance shafts, etc. Well if that is the case my truck is about 24 valve adjustments and 4 or 5 timing chains short! These R series engines, be they the 20/22R or these 3RZ's are the small block Chevy V8 of Toyota...they've made millions of them, there is bound to be a few problems with some of them, but over all, indestructible. I have put this in the same place as all the other urban myths perpetuated by internet mechanics!

Yes...there is some head cracking, mostly between the exhaust valves, as well as between the intake valves and the spark plug hole. Is this caused by an engineering issue, poor metallurgy, bad maintenance procedures, who knows? I doubt its a common problem, only commonly reported! Further to this are these cracks, unknown to the owner, causing any problems in an other-wisely perfectly running engine?

So to the OP's point...having worked in maintenance in industry for the better part of 40-45 years I've seen a lot of equipment/parts/etc. from China. Some of it worries me, by the fact these guys really know what they're doing and are a real threat to the economies of the west and their allies (remember the term "Jap scrap" from the 70's and 80's?). They also make some stuff that is pure garbage, and a lot of stuff that sits in between. Generally the stuff made in China for someone else is of reasonable quality, for the price. You have to ask yourself if you trust the metallurgy, heat treating and machining of an off-brand Chinese cylinder head while supporting their economy?

StorminMatt

The function of the engine probably has LOTS to do with it. 2RZ heads seem to have MUCH less of a problem with cracking than 3RZ heads. But they are the same heads! However, there are HUGE differences in the way that a 3RZ is used vs a 2RZ. The 2RZ is used in small, lightweight 2wd trucks that are mostly used as daily drivers. They might haul an occasional load of firewood or bring a washer and dryer home from the Home Depot. But by and large, these engines are subjected to use similar to a car engine.

The 3RZ is different. With the exception of a few Pre Runners, it was never used in 2wd Tacomas. Only 4Runners, T100’s and 4wd Tacomas used them. These are not only substantially larger and heavier vehicles than 2wd Tacomas. But they are likely
to be used in much more adverse conditions. Remember that even a basic 4Runner weighs around 4000lb. This is ALOT for a four cylinder engine. 4wd Tacomas are pretty heavy as well, as are T100’s. And all of these vehicles are FAR more likely to be used for towing or hauling heavy loads of cargo and (in the case of the 4Runner) people vs a 2wd Tacoma. Off roading imposes other challenges, as the engine is often run at fairly high power at low speed. All of these things add up to one hard-working engine that is going to be (on the average) hotter than your average 2RZ. Add to this the way that most people neglect cooling systems, and there is little margin for error.

So is the head a bad design? Not necessarily. However, maybe it was not the best design for an engine that is used in the way a 3RZ is. But perhaps a bigger question is whether the 3RZ was truly a good choice in these vehicles, particularly the 4Runner and T100. Notice that Toyota did not elect to use four cylinder engines in later models of the 4Runner and Tundra.

83

That makes sense. I was a die-hard 4 cylinder fan, and had at least 5 20/22R/E Toyotas through the 90's and early 00's. When I was looking for a new truck in '15, I was looking specifically for a 4 cylinder Tacoma. But I found a deal I couldn't turn down on a V6. Turns out I love the V6. My Tacoma weighs ~4,400lbs, with a topper and the typical stuff I carry in the back.

StorminMatt

Looks like you made a good choice. Honestly, a four banger gets CREAMED in this sort of vehicle. I mean, how often do you hear about people burning valves and cracking heads in Camrys?