Gen 1 V6 Engine Question

[PXLpainter]

Got a question from another board that I have no clue about - hopefully someone here can help...

Need to know if the 3.0 V6 on a 2K Solara is interference type or not - and how critical is it to change the timing belt at 100K mi?

Thanks guys!

[anttarz]

replacing timing belt afte 90k is pretty important. Visual inspection at that point more acurately determines the immediate need.

[crispone]

I think he wants to know if the valves will contact the piston head if the belt breaks and his valves and pistons are out of time... hence, "interference".


Don't know on those, PXL. Historically, Toyotas are NOT interference... whereas Hondas ARE... (as a "general" rule...)


Anybody know for the 3mz while we're at it?


-crisp

[CASTRO]

i remember from an old discussion that it will not hit when the belt breaks loose. so in short, the 1mz is not interference.

[Jon11582]

5SFE and 1MZ are non-interference. A failed belt will only require a belt change and will not destroy the valves or cylinder heads.

2AZ and 3MZ are interference. Although the 2AZ is an interference engine, it has a timing chain though that does not require maintenance and will not break due to lack of maintenance. 3MZ IS interference and uses a timing belt though, so you Gen2 V6 guys need to make sure you change your belt when its time to, because a snapped belt will most likely destroy some of your valves.

[Astro]

I actually had my timing belt snap while I was driving and I didn't have any problems.

[**PoshPepper**]

5SFE and 1MZ are non-interference. A failed belt will only require a belt change and will not destroy the valves or cylinder heads.

2AZ and 3MZ are interference. Although the 2AZ is an interference engine, it has a timing chain though that does not require maintenance and will not break due to lack of maintenance. 3MZ IS interference and uses a timing belt though, so you Gen2 V6 guys need to make sure you change your belt when its time to, because a snapped belt will most likely destroy some of your valves.

Strange that they would change the engine "interference" from the 1mz to the 3mz... all along I thought those engines were pretty much identical except that the 3mz had been bored out a little...

I actually had my timing belt snap while I was driving and I didn't have any problems.

I wouldnt say any problems... LOL... (this was the time we were all going to the beach for that photo shoot right? )

[Jon11582]

5SFE and 1MZ are non-interference. A failed belt will only require a belt change and will not destroy the valves or cylinder heads.

2AZ and 3MZ are interference. Although the 2AZ is an interference engine, it has a timing chain though that does not require maintenance and will not break due to lack of maintenance. 3MZ IS interference and uses a timing belt though, so you Gen2 V6 guys need to make sure you change your belt when its time to, because a snapped belt will most likely destroy some of your valves.

I'm not so sure about the 3MZ anymore. I was pretty sure I read somewhere before that the 3MZ was interference. However, I thought it was interference since they increased displacement by increasing the stroke, and with the cylinder head going further, would invade the space where the valves would be. It turns out that the 10% increase in displacement is all from increased bore, not stroke, so I'm not exactly sure how it became interference, unless the actual geometry of the valves changed for VVT-i, or if the valve lift was increased as well as increasing bore. VVT-i itself shouldnt affect the interference of an engine.

[**PoshPepper**]

so I'm not exactly sure how it became interference, unless the actual geometry of the valves changed for VVT-i, or if the valve lift was increased as well as increasing bore. VVT-i itself shouldnt affect the interference of an engine.

And VVT-i was implemented on the 1mz (Avalon (?), ES300...)

[Jon11582]

so I'm not exactly sure how it became interference, unless the actual geometry of the valves changed for VVT-i, or if the valve lift was increased as well as increasing bore. VVT-i itself shouldnt affect the interference of an engine.

And VVT-i was implemented on the 1mz (Avalon (?), ES300...)

http://www.clublexus.com/forums/showthread.php?t=133378

Heres a thread I found that discusses just this. Its dated back to 2004, and has our old ex-Solaraguy friend Flipside in it. It seems that at the end of it, they settle on the fact that the non-VVTi MZ's are non-interference, and the VVTi MZ's are interference.

So it looks like the valve heads probably have higher valve lift on the VVTi valvetrain and invade the piston space, so if you have an MZ with VVT-i and the timing belt snaps, your going to have a small party inside any cylinder where you have a valve up.

[**PoshPepper**]

so I'm not exactly sure how it became interference, unless the actual geometry of the valves changed for VVT-i, or if the valve lift was increased as well as increasing bore. VVT-i itself shouldnt affect the interference of an engine.

And VVT-i was implemented on the 1mz (Avalon (?), ES300...)

http://www.clublexus.com/forums/showthread.php?t=133378

Heres a thread I found that discusses just this. Its dated back to 2004, and has our old ex-Solaraguy friend Flipside in it. It seems that at the end of it, they settle on the fact that the non-VVTi MZ's are non-interference, and the VVTi MZ's are interference.

So it looks like the valve heads probably have higher valve lift on the VVTi valvetrain and invade the piston space, so if you have an MZ with VVT-i and the timing belt snaps, your going to have a small party inside any cylinder where you have a valve up.

Good to know, and nice find

[SPF 0]

I'd personally get the belt change done, interference or not.

[SolaraGuy22]

Good to know considering I just hit 97k

[blaK]

[crispone]

I'd personally get the belt change done, interference or not.

I'm more concerned about my limitations on MILLING the 3mz for compression bump, now. Hmmmmm.... this was a concern from before, ever since Brian cautioned on milling.

Logically, I can see it in that the 1mz is set up for INDUCTION, which usually wants a lower compression anyway... less "squish".

Now I really need to understand this engine a little more...

Let's see... where did I put that complete 5 volume 2004 Toyota Solara Manual set...


-crisp