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Howdee.....Newbie/Troll here with a question about the compatibility between AWD and FWD 3MZFE (3.3) engines. I read in another thread here on SC that there are differences between the two....namely, the way the mounts attach to the two blocks?

The one I'm working on is a 2005 AWD "Limited" Sienna and I've already dropped the front subframe with the engine and AWD tranny (plus, the a-arms, half shafts, knuckles, steering, cat conv's, etc.) and it's resting on axle stands underneath the "raised" van. The motor was severely-o/heated by one of my customers and - after removing the heads - I've found that it's damaged beyond repair (one "chunked" piston, several scored cyl walls, warped heads and several seized exh valves).

I don't have a FWD version here with which to compare, but it would seem that the only differences MIGHT be at the back of the block, where one of the mounts attaches to a bracket bolted to the right (engine front) side of the "power takeoff" that powers the driveshaft for the rear diff. That "takeoff unit" bolts to the right-axle output of the transaxle, directly behind the engine block. Confusing?? :).

Anyway........what say y'all? Different blocks? The reason I care is because there seem to be quite a few more used FWD/2WD motors in my neck-of-the-woods that AWD versions.......for less money.

C'ya - RAY
 

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Three months and not a single reply, means that no one here knows?
No shit, Sherlock! You'd think one of the braniacs on a SIENNA site would know the answer to such a basic question! But, no matter, I found the answer elsewhere and bought a used $750 motor locally that's quiet and smooth - very pleased. BTW.....if anyone else needs the answer as to whether or not the blocks are interchangeable, he/she can go pound sand, lol. :p

TTFN ~ Ray
 

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Discussion Starter #6
The two blocks are different!

I don't know about using an AWD-compatible engine with a FWD transaxle......it might work ~ but I DO know that the AWD transaxle requires special mounting points on the block and, therefore, will not bolt up properly to the FWD-only block. Rather, it requires the use of an AWD-compatible block that has those mounting bosses.
 

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The two blocks are different!

I don't know about using an AWD-compatible engine with a FWD transaxle......it might work ~ but I DO know that the AWD transaxle requires special mounting points on the block and, therefore, will not bolt up properly to the FWD-only block. Rather, it requires the use of an AWD-compatible block that has those mounting bosses.
That's a bummer, that it sounds like you had to go through quite a bit of hassle in determining that you couldn't use the FWD engine, but hopefully your Limited is back up and running now, for many years to come.
 
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