Hi everyone! My 99 3rd gen just turned 250k miles. Same week, she starts drinking coolant (more than likely head gasket) . I do not want to tear into the top end just to find out the head is cracked too and all that time was wasted. So I'm going the seemingly easier route and just dropping another engine in. Does anyone have experience with any machine/engine shops and the 5VZ they would vouch for? Ive found plenty of JDM 5VZ options online that will ship to my door. They show compression checks and odo confirmations etc. Yota1 is 8 months out on their engines as they were my first choice (Timmy!). I appreciate any feedback and recommendations from folks with experience in this matter. Thanks!

What makes you think that another similar mileage engine won't develop the same problem in a short amount of time?

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It's actually 5VZ not 5VG.

Yeah, it sucks that Yota1 has such a long wait. 8 months is a long time, but they do really nice rebuilds. I visited the gang at Yota1 recently. They helped me with a EGR issue that was causing me to fail smog on my 85 4runner.

I think all other options are a serious crapshoot that you get a good engine. That's the huge issue going used whether it's domestic or JDM. You're taking their word for how many miles the engine has on it.

If you're doing the work yourself, and you don't mind the risk that you're doing a bunch of labor you might have to repeat sooner than you'd like, I'd say go for a used engine and cross your fingers you get a good one. If you're going to pay someone to do the swap, that's a ton of money to risk on a used engine. If it doesn't go well, you're paying a large labor bill again.

You could tear the engine down and see what you see. Even if the head is cracked and you have to replace it, a replacement head is a more affordable than buying a used engine. Again, this is advice provided you are willing to do the work yourself.

This guy did a great job documenting the process of replacing a head.






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What makes you think it Would? Not like these engines are known for issues and there are lots of folks in the 300k clue with original/untouched engines, and a few more in the 400k club.

I'm cheap, I'd just buy something local (car-part.com). Not a big deal to do a compression test on a bench engine either, and Usually the shops on car-part will only pull the engine as it's requested so you can get an ODO on the vehicle.

I assume you are referring to a JDM swap. They typically have 40-50k miles on them. There is more work on swapping parts over. But, that gives me 200k+ miles until it could or could not happen again.

Capable in the garage, I am. Patient, I am not. This is a busy time of year for me with work and the kids. So, my extra time is almost non-existent. I appreciate the link and info Tim.

If time is an obstacle I would not do an engine swap. After doing a few engine pulls I can do it in a few days, less if I'm not putting a new one back in. But putting another engine in is a whole other story. When I swapped my engine over the holidays in 2018 it took me a long time to get it back on the road. Between Christmas shopping, activities with the kids and long work days it took me about 8 weeks to do a JDM swap. It's a lot of work. Replacing one head would have been less than half the time as it's only removing the exhaust (which you have to do as well with an engine pull), top end and then all those hoses and wires (which you have to do more of with an engine swap).

Have I convinced you yet that an engine swap won't save any time but instead take longer?

First do a compression test and get a direction.

But why not just pull the heads and see what's up?

Minimally, it's new gaskets.
Medially, you're having your heads mag'd and milled flat (thicker gasket to make up for material removed)
Maximally you're replacing head(s)

Either way you get to do valve lash/adjustment and valve cover gaskets and RnR the top end.

Much less work and cost than swapping an engine.

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i trust my engine guy over a JDM anyday. Its your call. All shortcutts have their draw backs.

If you have a repor with someone does engine work.....


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My engine was rebuilt at 200K-ish due to a blown head gasket/head issue I believe. It has CP Carrillo forged internals according to the previous owner's build invoice that I have; now at 310K miles and no issues. I'd check for scoring along the cylinder walls with some sort of borescope while doing a compression test. You can't "really" go wrong with either but if were up to me, I'd take the heads off and see if it's A: blown head gasket or B: Cracked/warped head and go off of it from there.

This is the ticket. You can get a rebuilt cylinder head from International Cylinder Head in Grand Prairie TX for under 500 dollars. My buddy is running one of their rebuilt heads on his 3.4l Swapped 2nd Gen 4Runner. In total, you can do a head job on 1 side for under 1k if you do DIY.

I'm thinking about replacing head gaskets at 250k as a preventative measure. I know they can go longer, but I wheel hard, and spend a lot of time above 3000 RPM.

I'm leaning this way, too. PM the HG and do valve adj and gaskets at the same time.

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Toyota went through 3 or 4 (5?) HG revisions over the life of the 3rd gen. Starting off with a mostly conventional one, adding larger steel surfaces, larger, and finally a completely steel "MLS' style gasket.

The problem, shared with many engines from many makes, is an aluminum head bolted to an iron block. When the engine warms up, the metal heat and expand at different rates. Causing them to rub slightly relative to each other. And the HG caught between them takes the brunt of this rubbing, and over time, it simply physically wears out. More of a matter of the number of heat cycles more than the overall mileage. So if they (somewhat) mythical JDM engine with 50K miles was used for lots and lots and lots of short trips, they could be closer to failing than one with 200K miles that did lots of long highway trips.

And of course, failure to maintain the cooling system with old coolant, the wrong coolant, or overheating it, can cause more serious damage.

My wife's '96 needed HG's when it was a bit over 300K miles. She just sort of rolled it in with a (more or less) due TB/WP replacement, since the front end of the motor needs to come off anyhow. That's half the work of getting the heads off.

With the heads off, the bores looked GREAT still, crosshatching still on maybe 95% of the bore. Just a couple of smooth triangles at the top of the bore. She used the latest revision HG's, just buy them for an 01/02 4Runner, they're all steel, and are best suited for the job of surviving between a block and head scooting against each other.

I did mine about a month ago, the engine was throwing code P0300 random misfire. Sure enough I found out the hard-way that it was due to hairline crack cylinder head! A lot of work when it comes down to changing cylinder head gasket!
If you have the skill of working on engine, then its a plus! if not, option would be to get it done professionally or buy a JDM engine!

Good luck!

Boom. Great post John

The TB on my 4WD is due at 300k according to the sticker on the radiator support. I will make a full weekend out of it and do the HGs and VCGs at that point - basically 51K miles from now

How about bolts/studs : reuse, factory new, ARP?