Toyota Tundra 4.6L vs 5.7L

[Zee09]

I don't see much difference in mpg or cost. That is a given.
So how does the engineering compare between the two??
The fact that the 5.7 puts up superior HP and torque is noted.

 

[dave123]

Have owned both engines can't go wrong with either but hands down no contest the 5.7 if given the option.

 

[CT8]

What is the cost of general maintenance and the ease of repair? Starters Cam chain or belt? Valve adjustment etc.

 

[dareo]

I like the fact that the 4.6 is a shorter stroke version of the 5.7. This is quite nice if your buying high mileage or putting a ton of mileage on and you don't need extra horsepower. In theory the 4.6 should last longer due to less piston movement and lower power per cylinder.

buuuut, i also like to have the absolute largest engine i can get my hands on so there's points for the 5.7.

 

[dblshock]

Check the cost of a 4.6 starter replacement and they do go.

 

[Zee09]

Seems the 4.6 runs 3.91 cogs and the 5.7 runs 4.30

 

[Zee09]

Your mechanic.com lists the starter replacement at $634. For the 4.6

 

[supton]

Originally Posted by dblshock
Check the cost of a 4.6 starter replacement and they do go.

Not sure why that matters--same engine family, so the starter should be in the same place for both of them.

Originally Posted by Zee09
Seems the 4.6 runs 3.91 cogs and the 5.7 runs 4.30

Yes, but... The 4.6 with the tow package came with 4.10's in the pumpkins. Which I strongly recommend. I took my truck out for a spin today, and with cruise set to 70mph it was kicking out of 6th on many hills on the relatively flat 101 highway in NH. I wasn't that impressed (nor when it was hunting!).

I would very much not recommend the crewmax with 4.6 and no tow package! Might as well leave the trans in 5th gear. Which is what I do if I know I'm not going past 55mph or so--it just can't handle any hills at that speed.

*

Been a while but IIRC the 4.6 is a lower deck height, and as such, bolt-ons like headers don't work. Just pointing that out, in case anyone wants to hot-rod one.

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Oh, and something else. The transmissions in at least the Tundra are slightly different. 1st, 2nd and I think 3rd are different--4 and up are the same gear ratios. Takeoff ratio winds up about the same between them, but technically the 4.6 gets a deeper 3.52:1 1st (as opposed to 3.33). I recall seeing the 2014 brochure and it looked like the 4.6 was getting the 5.7 trans--which means it would be more of a dog off the line. I don't know if that was a typo or not. But in 2014 my model truck went from like 7,900lb towing to 6,500lb. Makes me wonder if I really have 7,900 or not now--not that it matters, I wound up never towing with mine, but it's yet another consideration.

*

Just do the 5.7.

 

[supton]

Originally Posted by CT8
What is the cost of general maintenance and the ease of repair? Starters Cam chain or belt? Valve adjustment etc.

Should be the same between the two of them--same engine family.

Been a while since I read the manual but I don't recall any interval on those items. Just standard plugs and belt. "Sealed" trans should be checked at like 60k and only changed when one feels like it--it's a pain but not that bad to do (plenty of writeups).

One thing to watch out for is u-joints. Toyota wants them lubed like every 5k. The Tundra, at least my vintage, is a bit known for having a kick from the rear, from the driveshaft not sliding properly, which may or may not be related to inadequate u-joint greasing. Some day I plan to pull mine and grease, but it doesn't seem to be doing it all the time. I think there was a requirement to tighten the u-joint bolts also; hmm I should pull out the manual again.

Originally Posted by dareo
I like the fact that the 4.6 is a shorter stroke version of the 5.7. This is quite nice if your buying high mileage or putting a ton of mileage on and you don't need extra horsepower. In theory the 4.6 should last longer due to less piston movement and lower power per cylinder.

The 4.6 also has a taller final drive ratio, so it should make less turns per mile. At least until it kicks down to 5th.

*

These motors seem to have a problem with cam tower leaks--which I'm not sure what that is, but it likes to leak oil. I've never heard of it on the 4.6 but so few of those get sold. Big job by the looks of it to seal up. Water pumps have been a problem also.

 

[Snagglefoot]

4.6 327 lb ft @ 3400 rpm
5.7 401 lb ft @ 3600 rpm

Never play cards with a guy named Sam and always buy the largest engine. You're not buying a Yaris.

 

[dblshock]

4.6 reman Denso replacement is $1000 shop work w/part.

 

[cpayne5]

Are you thinking of the 4.7, dblshock? The starter on those is under the intake. On the 4.6 and 5.7, the starter is behind the right exhaust manifold.

 

[clinebarger]

Originally Posted by supton

These motors seem to have a problem with cam tower leaks--which I'm not sure what that is, but it likes to leak oil. I've never heard of it on the 4.6 but so few of those get sold. Big job by the looks of it to seal up.


The cylinder head is basically 2 pieces, The camshafts are held in their own carrier & is sealed to the lower part of the head with RTV (Seal Packing in Toyota speak). The factory RTV is Grey.......But the Service RTV is Three Bond 1207B which is black in color......You can look through the fender wells & see if it still has the original packing or not. I'm guessing the service RTV is more resilient to "Scrub" albeit more expensive.

 

[clinebarger]

Originally Posted by cpayne5
Are you thinking of the 4.7, dblshock? The starter on those is under the intake. On the 4.6 and 5.7, the starter is behind the right exhaust manifold.


The "UR" starters are actually more difficult & call for more labor hours than the "UZ" starter.

 

[cpayne5]

Originally Posted by clinebarger
Originally Posted by cpayne5
Are you thinking of the 4.7, dblshock? The starter on those is under the intake. On the 4.6 and 5.7, the starter is behind the right exhaust manifold.


The "UR" starters are actually more difficult & call for more labor hours than the "UZ" starter.


Thanks for the info. I've heard that the starters on the URs can be slipped out without much trouble, but I've never had the pleasure of actually doing one. We just bought a Sequoia, so maybe one day (hopefully not!).

 

[dblshock]

i do not own one, stand corrected, sorry 4.7

 

[FlyNavyP3]

Originally Posted by cpayne5
Originally Posted by clinebarger
Originally Posted by cpayne5
Are you thinking of the 4.7, dblshock? The starter on those is under the intake. On the 4.6 and 5.7, the starter is behind the right exhaust manifold.


The "UR" starters are actually more difficult & call for more labor hours than the "UZ" starter.


Thanks for the info. I've heard that the starters on the URs can be slipped out without much trouble, but I've never had the pleasure of actually doing one. We just bought a Sequoia, so maybe one day (hopefully not!).


The one I replaced on a 5.7 required removing heat shields, down pipe and manifold to extract. It sucked on a rusty northern vehicle.

 

[clinebarger]

Originally Posted by cpayne5
Originally Posted by clinebarger
Originally Posted by cpayne5
Are you thinking of the 4.7, dblshock? The starter on those is under the intake. On the 4.6 and 5.7, the starter is behind the right exhaust manifold.


The "UR" starters are actually more difficult & call for more labor hours than the "UZ" starter.


Thanks for the info. I've heard that the starters on the URs can be slipped out without much trouble, but I've never had the pleasure of actually doing one. We just bought a Sequoia, so maybe one day (hopefully not!).



There's no way to do the job correctly without dropping the Catalyst & manifold, I'm sure you could mangle some stuff, Lift the engine off the mounts, Leave a bolt out & get it done!