[rediranch]

Hi all,

I've read some threads on here about rebuild vs used (JDM's), and they provide some good info. I have a couple of questions that weren't covered in what I read, and of course everyone's experience is at different levels and I wanted honest answers based on my level.

Situation - I have a 1998 & 1999 SR5, both with the 3.4.

The 99 has the Toyota Supercharger on it and is a 5 speed manual. It has 194K miles on it, and when I used the Autozone OEM compression tester, 5 cylinders showed 120psi, and one was 100. It does run very strong still, though.

The 98 does not have the Supercharger and is an automatic with 172K miles. The compression tester showed 5 @ 120psi and one at 140 (that one throws engine check lights now and then and runs rough now and then but not constantly).

My thoughts were to get a long block from a junk yard or someone parting out a wrecked 3.4 and have the machine work done, buy a kit, and start building it up. Once built up, swap it into the 1998.

Then tear down the old one from the 98 and rebuild it for the 99 (the one with the supercharger).

Before I get into my questions, I'll let you know my wrenching level. I have been able to fix almost everything just by using a Haynes manual, and have ended up with good results. I have never, however, torn down and swapped an engine - on my own. My brother is a big diesel mechanic and has rebuilt many large diesel engines along with big block Fords. I've even helped him do 2 swaps on a Ford 460 and he's walked me through doing bearings and rings (years ago). I have him on speed dial, but he's across the country.

OK, questions -

1. I assume that when I pull the 3.4 out of the 98, I should be able to take that bell housing off and put it on the 3.4 short block I just rebuilt. Is that correct? Same for the 99 manual transmission?

2. Since this isn't a turbo but a supercharger, I assume that having a supercharger on one and not the other should NOT pose a problem doing what I outlined above?

3. I've read a few threads about rebuilding these 3.4's and some seem to mention that there are some tricky parts to it that seem to be specific to Toyota 3.4's. Are there parts of this rebuild that will fail due to secrets known only to those who have trained for these engines? Know what I mean?

4. 3rd generations are 1995 - 2002. When looking for a long block to get myself started, can I get any 3.4 from this range?

For now that's all I got.

I've looked at JDM's, and there's even one avail now for $1050, but I really don't want to be doing this again due to putting in a used one.

Then there's the Yota shop offering a short block for $1450 and a long block for $2900. I figure that the long block priced there will be about $1500 more than me doing the work, and the cost of the 2 rebuilds.

I guess worst case I can always fly my brother out to help do the rebuild (done it before), but he's never worked on Toyota engines.

Thoughts?

Thanks

[GrassFed]

Best of luck, I am in a similar situation with some suspected bad valves causing misfires on #2 and #6. If by some miracle it was sludge causing the valves to stick I would jump for joy.

I wish I could be of more help to you, but in regards to the compression readings I have seen reports that the autozone compression testers are not real reliable, definitely hit or miss.

Best of luck to you, I'll be watching this thread like a hawk.

Matt

[lkhunter]

In a similar boat as well, my 3.4 has leaky valve stem seals and was poorly maintained by the PO. I'm thinking of going with a jdm for the sake of being a cheap ass. Rebuilds worry me unless they are done by a reputable machinist.

[GrassFed]

There is a gentleman by the tag of " worsethanchiggers " on youtube who has an incredibly good video series on his experience rebuilding his 5VZ-FE.

lkhunter - I hear there is a good amount of swap over from a US 5VZFE and a JDM engine if you're going to tear into it yourself.

[amalik]

It could just be this forum (But.. keep in mind this is probably the largest T4R forum alongside YotaTech) -- but I've never seen a 5VZ-FE rebuild on here. Simply too many junkyard or JDM motors available to swap in and people take that risk instead.

The rare rare exception is someone gets a Jasper 5VZ-FE which by the way has a warranty on it and are 're manufactured' and NOT 'rebuilt'. Their website has a lot more information. Speaking of, curious if any members reading the thread here have actually used a Jasper 5VZ? They have been around since 1942 and seem legit according to the website.

But again, never have I seen a 3rd gen section 5VZ-FE DIY/Machine shop rebuild. People with oldschool pickups are often rebuilding the 22R series left and right.

[T4R2014]

I've only heard bad things from mechanics about Jasper engines. They are "remanufactured" with cheap parts.

[jstim]

Man you have me really interested and I want to do something very similar to what you're doing. I just hope that if you start a rebuild that you document it, and share with us.

[St Runner]

One of the reasons we love our 3rd generations so much is that they are so durable and that is mostly because at the time they were built Toyotas quality control was excellent. This is not a insult to anyones mechanical ability, but it is very difficult to rebuild it better than it came from the factory. Your best bet ( and cheapest) is to find a lower milage engine that was well maintained and has good compression. JDM, Tacoma, T 100 and our 4runners all ran the same engine.

[lkhunter]

Originally Posted by St Runner

One of the reasons we love our 3rd generations so much is that they are so durable and that is mostly because at the time they were built Toyotas quality control was excellent. This is not a insult to anyones mechanical ability, but it is very difficult to rebuild it better than it came from the factory. Your best bet ( and cheapest) is to find a lower milage engine that was well maintained and has good compression. JDM, Tacoma, T 100 and our 4runners all ran the same engine.

Agreed. The only reason I have issues with mine at nearly 200k miles is because of lack of proper and timely maintenance by the PO. If you keep these maintained they will run forever, albeit they are gutless wonders.

[superdavebigD]

Originally Posted by St Runner

One of the reasons we love our 3rd generations so much is that they are so durable and that is mostly because at the time they were built Toyotas quality control was excellent. This is not a insult to anyones mechanical ability, but it is very difficult to rebuild it better than it came from the factory. Your best bet ( and cheapest) is to find a lower milage engine that was well maintained and has good compression. JDM, Tacoma, T 100 and our 4runners all ran the same engine.

I am leaning toward what ST RUNNER stated here.

I am in a similar position as the OP and really cannot make up my mind on this! Mine is different in that My 3.4 5vz-fe T4R is overheating, but still runs amazing, starts right up. 99% sure it's head-gasket/cracked head.

Is it worth rebuilding these motors??? Or best to just replace used/jdm and hope for the best??? Can people with experience please chime in!

[rediranch]

Couple of things to add -

I really didn't trust the Autozone compression readings either, since they put 5 of the cylinders from my strong running supercharged 3.4 the same as 5 of the cylinders on the poor running 3.4, so I took some time and finally won an auction on Ebay for a set of SnapOn MT308L gauges, and they just arrived, so I plan on trying to do another compression test soon with them. Will let you know the difference (but then again, these are used, could still be inaccurate).

Don't hold your breath for my rebuilds - I'm doing research and this thread was part of it to try to guide me one way or the other. If I do end up doing a rebuild, I don't think I'll need to do one immediately, and would start looking for a block this summer for the first rebuild.

I will, however, do my best to document it if I do the rebuild. I'm sure I'll be able to supply you all with a long list of things NOT to do.

If you guys come across something in your quest, please throw it in here for consideration.

And of course those who have actually done this build - please provide your wisdom.

[rediranch]

In case you didn't see this thread

5vzfe rebuild process/reccommendations

[Guyver192]

I Just purchased a 3rd gen with a Jasper rebuild and it only went 91k the wrist pin believe is causing issues. Would never use Jasper engines. Have seen every one of them come back for oil problems spun bearings or just generally component failure. I am in the process of going to reseal a junk yard Toyota motor. To go into my newly acquired 3rd gen

[jgue467]

Up to now my 3.4 is humming along getting 19+ mpgs on highway while going 80 but all good things must come to an end, right? I'm not sure what I'd do when the time comes.

I have a very trusted mechanic I've used since the early 80s and a couple years ago i noticed a Jasper sign in his front window. I see they offer a 3 yr warranty: Remanufactured Gas Engines | The Jasper Process

Or perhaps my mechanic would like a stab at rebuilding it himself. Or just maybe neither can recreate the 'magic' the factory 3.4s have?

[amalik]

Originally Posted by jgue467

Up to now my 3.4 is humming along getting 19+ mpgs on highway while going 80 but all good things must come to an end, right? I'm not sure what I'd do when the time comes.

I have a very trusted mechanic I've used since the early 80s and a couple years ago i noticed a Jasper sign in his front window. I see they offer a 3 yr warranty: Remanufactured Gas Engines | The Jasper Process

Or perhaps my mechanic would like a stab at rebuilding it himself. Or just maybe neither can recreate the 'magic' the factory 3.4s have?

Like everything online, you will see people having mixed reviews of the JDM engines and Jasper engines.

Unless you know the person posting is a mechanic with direct experience with that type of engine, I wouldn't take it to heart.

I wouldn't worry about it until that time comes... there are 5VZ-FE that roll to 500k without needing a headgasket/rebuild/valve job/etc.

And in your specific scenario, really nothing to worry about since you work so long with the same mechanic