1Zz-Fe Rebuild Question

[Son of MGmike]

Hi,

You might want to change the pistons while you are in there as they changed design around 03 for improved oil control.

I'd be real interested to get a photo record of the strip down and rebuild.

Most interested in what state you find the crankshaft and how clear (or not) the oil holes in the piston skirts are. Also interested in the bore condition and any difficulties or tips you find as you go long.

Best of luck with it

[dawesy]

ive rebuilt one in my dads avensis,

they are no harder than any other engine to rebuild,

worth noting that the rod and main bearing bolts need to be replaced (about £65 from MrT for the set)

as said worth replacing the pistons as its most certainly these that have caused high oil consumption and starvation causing the bearing failure.

these are the pistons from my dads engine, it had covered 91,000 miles and had full dealer service history!!

and the new pistons for comparison ( note the four oil return holes each side as opposed to the 2 on the old design)

[Son of MGmike]

Dawesy, those old ones look right 'orrible! It's hard to tell from the pic's, were the drain holes blocked?

Question for all 1ZZ Guru's... Is there a definitive list of design changes to the engine in the face lift model?

Or a list of recognized mod's to do when rebuilding an early lump?

[ormi]

if its suffered high oil consumption fitting modded pistons wont help......as the boars will be oval..hence why when toyota changed these under warranty they changed the block and pistons....as changing the pistons had no effect..

[Son of MGmike]

Ormi,

I agree that changing the pistons should only be done AFTER checking the condition of the bore. As you say no point putting good pistons in to a bad bore!

However, I not yet convinced that Mr'T reasons for changing the short block are as a result of bore problems. Hence my question to all for information on the design changes.

The more I think about this the more I'm inclined to think the use of a short block was a commercial decision. My thinking is it would be much cheaper to build extra blocks in the factory and ship to the dealer network than it would be to ship the seperate parts and pay dealer labour rates to diagnose which bits need changing and then fit them.

If you (or any other Guru's) have any info on the design changes I'd be very grateful.

regards