5sfe / 3sfe ????

[MR-Deuce]

I have a 91 mr2 with a 5sfe. My 5sfe has started making alot of engine noise. Sounds like a rod to me. A local salvage yard has a 3sfe for $400. My question is, what are the differences between the 5sfe and the 3sfe? Since I have had no luck locating a 5sfe I need to find out what I have to change in order to swap it with the 3sfe??? any help will be appriciated! Thanks

[MR2Jedi]

You sure you just don't need a knock sensor? I don't know the differences between the 2. I think that engine came in the Camry, making them a front wheel drive set up.
I think I would determine the cause of the noise in the 5sfe before taking on a project/expense like that. I can tell you with certainty that there is way more to the swap than just changing engines. Transmissions, wiring, coolant hoses,speedo cable, trans linkages, etc.
I have never heard of anyone swaping a 3sfe into an MR2. But it doesn't mean it hasn't been done.
Hopefully someone with more knowledge of the 3sfe will chime in. Maybe ask the Camry guys about this.

[MR-Deuce]

my thought is that the mr2, while it is a RWD, It is similar to a FWD since it is a mid-engine car. I would prefer the 5sfe just as it has now. I'm just having trouble finding one. If anyone has one sitting around left over from a 3sgte swap or somthing let me know if it's for sale. Thanks

[Ghostyman]

Yes, you can swap the 3SFE right in and reuse almost all of your existing 5SFE components. The only thing that I'm aware of being different are the intake manifolds. The exhaust will bolt right up so you won't have to worry about that. The throttle cable might need some adjusting since the intake manifolds are different and the throttle cable is coming from a different direction. If you get a 3SFE transmission, the linkage will be on the wrong side but you can just reuse your 5SFE tranny.

You really don't want a 3SFE in your MR2 though. It suffers a lot compared to the 5SFE. As was put by someone else:

Originally Posted by Zalera on mr2oc

3SFE(compared to anything):
Pros: none
Cons: 2.0L, narrow powerband, no power.

5SFE (comapred to 3SFE)
Pros: 2.2L, wider powerband, more power, better intake manifold.
Cons: none

[MR2Jedi]

So the 3sfe and 5sfe share the same block and head?

[Ghostyman]

Originally Posted by MR2BAD

So the 3sfe and 5sfe share the same block and head?

The block is different. The 3SFE uses the 3S block which is 2.0L so it's .2L smaller than the 5S block.

The heads are interchangeable between blocks from what I've heard. You could put a 3SFE head on a 5S block and vice versa. They might even be the exact same heads.

[MR2Jedi]

Hmm? Do you know if the 3sgte head mates to the 3sfe block? Just curious

[MR-Deuce]

so I should be able to put my intake manifold and transmission on it and it'll go right in?

[Ghostyman]

Originally Posted by MR2BAD

Hmm? Do you know if the 3sgte head mates to the 3sfe block? Just curious

I'm not 100% positive but they both use the 3S block so they should. You'd want to double check to make sure the coolant passages line up. Worst case you'd have to drill them out a little bit.

The only differences that I'm aware of from the blocks for the 3SFE and 5SFE versus the block for the 3SGTE are the lack of piston oil squirters in the FE blocks and the GTE block is tapped for an oil return line.

5S block + 3SGTE head = 5SGTE
3S block + 3SGTE head = 3SGTE (possibly w/o squirters and oil return)
5S block + 3SFE head = 5SFE
3S block + 5SFE head = 3SFE

[Ghostyman]

Originally Posted by MR-Deuce

so I should be able to put my intake manifold and transmission on it and it'll go right in?

Depends. 3SFE and 5SFE have different intake manifolds that I don't believe are interchangeable. Use the intake manifold that matches whichever head you use.

If you get a full 3SFE engine, swap it in and just reuse any missing sensors, etc. You should be able to run it on the 5SFE ECU although there might be slightly weird A/F ratios.

Transmissions are probably the exact same minus the linkage mounting. Most of these trannies are machined to mount the linkage on either side but you might have to drill and tape a few new holes to mount it.

Oh, also I don't think the MR2 blocks have the block machined to to accept the FWD power steering pump. MR2s use electric PS pumps in the front of the car.

Hope this helps.

[MR-Deuce]

my mr2 doesn't have power steering should that should help. My intensions are to use the 3sfe and to either rebuild my 5sfe or locate a 3sgte this winter when I have more time and money. My transmission is in excellent shape so I just want to swap the engine for now. I think the 5sfe has just became extinct in Indiana lol!!!!

[Ghostyman]

That sounds good. You'll notice a fair loss of power with the 3SFE but it will get you around town. If you happen into a 3SGTE, jump on it wit' da quickness (as the kids say).