Differences between auto and manual engine

[Opie]

Originally Posted by finch1750

I know you guys have done a lot of swaps but are you 100% the harnesses are the same? I was missing at least one connector on the MT harness for the AT it looked like, unless the one I got was hacked. Plus the MT to AT transmission DIY claimed they were different.

Yes, 2013 - 2015 MT & AT cars use the same engine harness. The bulkhead harness is different, but the actual engine harness is the same.

[mdavis]

On this same topic I just had to put in a junkyard engine into my manual FRS. There is one open coolant inlet/outlet on the back top of the block which I'm pretty sure wasn't on my old motor. Discovered it when adding coolant and water started pouring out. Is this a water line for the automatic transmission cooler?

The weird thing is that the car runs fine and there is a block off plate on the passenger side cylinder head. Maybe someone already did this swap?

Can I just cap off this inlet/outlet if it is indeed for the automatic transmission?

[mdavis]

Should've read this thread more carefully as it is explained in post #26. Looks like someone put an auto coolant crossover pipe on this engine for some reason. I'm just going to cap it off for now.

[I_amhassan]

Hey,

So did you use the same engine harness? PnP? Are the engine harnesses same for both MT & AT throughout the years?

I need to replace my engine harness for 2013 AT GT86

[finch1750]

Originally Posted by I_amhassan

Hey,

So did you use the same engine harness? PnP? Are the engine harnesses same for both MT & AT throughout the years?

I need to replace my engine harness for 2013 AT GT86

Yes, engine harness is the same

[fancymalard]

Anyone have any idea how to remove the dowel pins off the vacuum pump location?

[Opie]

Originally Posted by fancymalard

Anyone have any idea how to remove the dowel pins off the vacuum pump location?

Vice Grips

[fancymalard]

Originally Posted by Opie

Vice Grips

Indeed vice grips and wd40 worked pretty good.

[EndlessAzure]

Just went through this recently with my own swap. Although everything was described in words, it would have been much more helpful to have a visual comparison to identify all the parts. So I took some time to record it all in pictures.

Also few things I did differently compared to methods folks have mentioned/tried previously:

1. AT Vacuum Pump Dowel Pins: Knocked them from the front, out the back
   
   • I didn't have a lot of luck with vice grips on the dowel pins. I mangled the top one trying to get it going. Eventually had to knock the top one out from the back, which wasn't perfect because I was lazy to remove parts for hammer clearance. There is probably enough clearance to knock the pin clear out the back. This is what I did for the bottom one. Much more consistent and clean.
   • 
2. AT Coolant Crossover Pipe: Used MT Cover with Coolant RTV
   • The metal coolant crossover pipe is physically different between the MT and AT. The MT has a machined o-ring groove and flat cover plate. The AT is just flat (with no groove) and seals against the AT thermostat. I didn't want to go through the trouble of swapping the entire pipe and didn't like the idea of capping and bleeding a thermostat.
   • I ended up using some Coolant RTV (Threebond 1282B) to seal the MT cover plate against the AT coolant pipe. The shadow of the o-ring/coolant against the MT cover plate made a perfect template to lay the bead, and I verified that the sealing location and surface matched using the AT plate. Used the short bolts from the MT configuration. Finally, used a magnet to help guide the plate on and align properly. (See below picture)
   • 
   • 
   • 
3. AT Vacuum Pump Oil Line Cap: Bought a new plug and gasket
   • I didn't transfer the MT oil galley plug and gasket near the DI ECU. I elected to just buy a new one from Toyota ($3 total: SU003-02193 & SU003-02155)
   • You only need one plug for the actual galley on the top of the engine. The port on the back is just left open to the elements in the MT. I just wanted to plug mine to keep it clean

The rest of the below images are the side-by-side of the parts you should expect to interact with during the configuration change:

• Coolant tubes/hoses: Heater Core Line (MT) vs Heater Core Line & AT Cooler Line (AT)
• Coolant Cross-over Pipe Connection: Pipe Block-off Plate & O-Ring (MT) vs Thermostat, Thermostat Housing, & AT Cooler Line (AT)
• Brake Booster Vacuum Supply: Cam Cover Plate & Intake Manifold Hose (MT) vs Vacuum Pump, Vacuum Pump Hose, & Intake Manifold Plug (AT)
• Vacuum Pump/Oil Galley Supporting Parts: Plug (MT) vs Banjo Bolts & Oil Supply Tube (AT)

[Ultramaroon]

Oooo.... you sprang for the GOOD stuff.

[EndlessAzure]

Originally Posted by Ultramaroon

Oooo.... you sprang for the GOOD stuff.

If you gonna go shmoo, use the good goo.


ThreeBond 1207B also technically works (the RTV specified for Toyota oil pans), as Threebond says it's coolant compatible. I believe TB1207B is what Aisin calls for for their water pump installations. However from what I read, cured TB1207B is much harder to scrape-up/clean-off from parts if something goes wrong.


It's worth nothing: absolutely do not use ThreeBond 1217G/H (the RTV specified for Subaru engine block and oil pans), as it is not compatible with coolant.