sinneDBTB

If anyone recalls I have been asking a lot of questions about the 5vzfe over the last several months and I thank everyone who helped me out again.

to recap...

-I swapped a 99 taco 3.4 into my 90 4runner
-at the start up phase i discovered my crank was bent
-rebuilt my parts motor 97 4runner 3.4
-new everything but oil pump and main bearings (cost)
-my dad honed out the block while i was away and set up the pistons
-machined the heads
-put everything back together
-start up no prob

Now 5-6000 km later, I have been using oil at a steady rate of 1-2 liters a week. without a trace of a leak on the engine.
98% sure the rings haven't set properly. My dad is convinced they will just seat eventually. This is the first rebuild for me so I kinda have to take his word for things when I cant find the answers on here.

I used top line rings from lordco as they are considerably cheaper than oem.

So, if the rings aren't seated properly was it the:
-seating method (work the motor without lugging or rat-bagging)?
-wrong idea to go cheap on rings?
-honing my dad did?

I know a bunch of guys on here have rebuilt this engine too.
I followed the fsm directions step by step on the entire job.

WHAT DID I DO WRONG?
HOW DO I TELL WHAT I DID WRONG?
WHAT SHOULD I DO TO REMEDY THIS?

sinneDBTB

i think the worst case scenario would be taking the engine out again and having a machine shop re-do my bottom end; hone/bore cylinders, machine the crank, new bearings, new rings.

some one please tell me there is a best case scenario

Kiroshu

Um... So the motor in your truck now is the original block correct?

-Burning 1-2 liters a week is a considerable leak.

-Did your dad check the cylinder bores before and after honing?

-To be burning that much its more than likely the honing process was faulty....

-assuming the cylinders were not already worn out and needed to be bored...

-Piston rings installed incorrectly? (Improper piston to cylinder wall clearance)

-Valves seals possible but its more than likely pistons to be leaking that much.

-Did you do a compression test?

Looks like you might be pulling that motor again.... >_<

tirogers

I sorry to hear that man, what a bummer! Hang in there, dont give up!

sinneDBTB

The motor in my truck is a 5vzfe from a 97 4runner.

My dad claims to have checked the bores before and after but... he is getting older.. hahaha i wasn't there when he set up my bottom end. So i dont know for sure.

I had the heads re&re'd at the machine shop so highly doubt theres a problem there.

I haven't done a compression test, good idea. Blanked on that one. I guess that should confirm what seems pretty obvious.

I would just like to know from anyone else who has rebuilt on of these engines if they have had the same or similar problems?

Thanks for the input.

Kiroshu

Did you look into the intake?

Is there wet oil?

Pcv valve installed?

sinneDBTB

My intake is spotless, pcv valve is brand new.
I did however have to put a piece of plywood against the wall in my garage where my exhaust will sometimes barf out wet black "soot" to keep the wall from getting too nasty. Its pretty gnarly, pretty sure thats some sort of by product from all the oil being used....

As of right now i am considering having a machinist set up the bottom end of the 99 taco engine i have with a bent crank. Just so that my daily driver isnt down for too long.

murphyz

if that is true your cat is going to need to be replaced before long now...

keep up the good work. your close

sinneDBTB

yeah i pretty much figure that i'll be re-doing my exhaust after this episode

i wonder if i can just re-hone the cylinders and get oversized rings?
is there such a part? i remember when i was shopping for rings that they didnt offer oversized. and after all the difficulties with the difference between bearing sizes in each journal maybe piston rings are just as complicated...?

murphyz

do it right, that way it will not be out of the truck for a third time...

cadman

Ok, lets stop here.

First, grab a Toyota FSM. Dimensions and tolerances for the cylinders and pistons will be here, as well as info on what pistons originally came with the block.

Next, once you pull the engine, get a bore mic and measure the cylinders per the FSM. Do not use inside micrometers. Keep in mind, you are checking the cylinders for size, roundness, and taper.

Now you'll be armed with the info you need to determine what shape the cylinders are in. As far as OEM Toyota parts, there are three standard piston sizes and one oversize. Rings are one standard and one oversize. The oversize piston is .50MM (.0196 in) larger than standard, so no you cannot use oversize rings on the standard piston.


In your case, at a minimum you most likely need rehoning, new rings and a proper break-in.

Worst case:

Rehoning will make the cylinders out of spec, will need boring.

The cylinders are worn and need to be bored.

Like the saying goes in my line of work, measure twice, cut once.

Good luck.

DeathCougar

iTrader: (23)

Pretty much answered your own question

See this thread also: https://www.yotatech.com/forums/f116...ealing-215113/

Although its a different engine, its the same basic idea

sinneDBTB

Thanks Deathcougar a lot of valuable info in that thread

Thanks Cadman, I have read your build thread, a lot of good info there too.
I was hoping to hear there was an easy fix, or that patience would probably have them seat in time...
I just got a company truck so I will be pulling the engine soon now that my truck can become more of a project and less of a daily driver.
Maybe a proper rebuild technique thread is in order?