Oval Bore Syndrome - 1ZZ

[SteveJ]

Now, can somebody tell me if it is possible to drop a 1ZZ without using a ramp or pit?

Yep - raise the car on axle stands and drop the engine out underneath. Done it twice like that.

[Anonymous]

When the control rings get gummed up, the car will leave too much oil on the bores in places, or can scrape too much off the bores in others, so could well be a contributory factor. How about a combination of not enough oil feed (from the inadequate piston design) contributing to gunge staying in the control ring lands?

We know the Avensis (that has no precats) suffers the same issue of oil consumption, so I think we have established that the precats are not the primary cause.

Where did you dig that up from Les?

Chris

The picture etc, was a link from one of the posts, the paragraph was from something I already knew and a bit of research   s:wink: :wink: s:wink:

[Anonymous]

When I stripped that 1zz down, the oil bleed holes were totally clogged & all rings grooves were gummed up to the point where the rings could not retract.

The slow incremental accumulation of gum forces the rings out - thereby increasing ring loading and mashing up the bore wall.

[Anonymous]

I'm fairly sure I'll see something similar, Les.

Just out of curiosity, how much did your Crower / Wiseco setup cost? I used Crower cams exculsively in the US when drag racing during my mis-spent youth......  s:D s:D  

If I'm going to the trouble of dropping the engine, it would be a shame not to make a few mods.....

Stewart.

[Anonymous]

Ignore my last post! I've used the magic search facility!

[ChrisGB]

When I stripped that 1zz down, the oil bleed holes were totally clogged & all rings grooves were gummed up to the point where the rings could not retract.

The slow incremental accumulation of gum forces the rings out - thereby increasing ring loading and mashing up the bore wall.

This is one way it can screw the engine. I have also seen the gum build up above and below the rings, stopping them from moving correctly. They develop low spots and high spots as drag makes the edges roll partially, so both allow excessive oil use and rip the surface off the bores. A properly good synthetic should stop this from happening, but if the engine is used for short runs and never gets long periods with the oil up to temperature added to the design weakness, there could still be trouble.

Chris

[Anonymous]

Quick question - does anyone have contact details for someone in power at Mr. T  who can authorise the repairs? Or should I just contact the service dept at my local dealer?

[markiii]

you will have to go through your dealer in teh first instance, though if you have a choice in your area, one whos familiar with teh problem and already helped out someone in teh same situation may prove beneficial

[Anonymous]

Thanks.....

Which of course begs the question - does anyone know of a dealer in the North West (I live in Lancaster) who has been sympathetic? Locator says my closest one is Vantage Toyota in Preston, although I could go as far as Manchester.....

[Gleeman]

My engine has gone through pre-cat failure and I may talk to Bateman's in Lindale (S. Cumbria).  I'll let you know if they're helpful.

[Anonymous]

Oh No! Sorry to hear that.

Best of luck, let me know how it goes.

[Anonymous]

No joy at the dealer - it's out of the 7 year period.....And the workshop manager knew EXACTLY what I was talking about....


Grrrrrr.......

Looks like a post 2003 recon unit then, plenty on eBay.....

Does anyone have any recommendations as to a reputable supplier?

[Gleeman]

I spoke to the garage in Grange.  They said there was an extended seven year warranty on the bottom end of the MR2 engines and thought it may be worth writing to Toyota in case they are willing to pay some of the cost.