Engine Swap - AWD vs RWD - HELP

A

A4SixtyNinerRR

Member
Location
Columbus, OH
Hi guys, so I need to find out what the difference is between the '03 awd engine and the '03 rwd engine for an FX35? My '03 FX awd had the water pump die a few weeks ago and I overheated along the highway. I had the pump replaced for $700 and was back on the road for five days when I started getting a knocking noise and a loss of power. I had it towed to the dealer again and they dropped the bomb that I need a new engine. Their theory is that the overheat caused a head or gasket to warp which allowed coolant into the crankcase. The lack of lubrication has now shredded my lower end and I need to swap motors. I did confirm there is infact coolant as well as some metal shavings in my oil. I've been told there is a difference between the awd and the rwd engines, but no one really knows for sure what that is. A guy on infinitFX.org said he was confident that it is only the upper and lower oil pans so I could swap my pans to convert a rwd engine to awd. I need to know this for sure b/c I have only been able to locate one "awd" engine for $3000 vs 10-15 "rwd" engines for $1200-$1800. Both motors are the VQ and are both VIN A so I'm assuming the differences would be minor?? Any info/advice someone could give would be great. Thanks!!
 
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call the dealership and ask, should be the same. I cant see them making a different engine for a RWD. The only thing would be how the trans mounts, but you have your old engine so you could use that adapter if they use one. best to call or go to the dealer and see if engine vins are the same....
 
vanfx said:
call the dealership and ask, should be the same. I cant see them making a different engine for a RWD. The only thing would be how the trans mounts, but you have your old engine so you could use that adapter if they use one. best to call or go to the dealer and see if engine vins are the same....
Click to expand...

I've actually talked to three dealers in my area and none could give me a straight answer. They said the engines had different part numbers, but that was for the complete motor. I have a feeling the guy from infinitiFX.org is right, but I'm just trying to confirm.
 
The biggest giveaway is the location of the oil filters. On AWD engines the filter is mounted on the front of the engine, towards the bumper. On the RWD, the oil filter is located on the sides, not sure which side.
 
hey man, welcome to the scene... I'm the one who answered you at the org too :) the problem is, everyone treats the engine as an assembly when they try to answer this, but the lower part of the engine is the upper & lower pans, this is the difference fwd-awd, even the oil filter location is changed, yes, to make room for the dif, but, this too is a result of the lower pan & not the actual engine block...

I'm pretty sure that the block itself is interchangeable, just would have to swap awd upper & lower pans to the rwd motor & it becomes an awd motor... but, as I haven't actually done it with my own hands I can't really say 100% sure to the point of guaranteeing it... without having actually done it first hand it's hard to be 100% sure there aren't any things that I'm not fully realizing...

heres a picture of the break down sections:

1



I still say check with a performance shop who builds engines, they probably know for sure...
 
turbocad6 said:
hey man, welcome to the scene... I'm the one who answered you at the org too :) the problem is, everyone treats the engine as an assembly when they try to answer this, but the lower part of the engine is the upper & lower pans, this is the difference fwd-awd, even the oil filter location is changed, yes, to make room for the dif, but, this too is a result of the lower pan & not the actual engine block...

I'm pretty sure that the block itself is interchangeable, just would have to swap awd upper & lower pans to the rwd motor & it becomes an awd motor... but, as I haven't actually done it with my own hands I can't really say 100% sure to the point of guaranteeing it... without having actually done it first hand it's hard to be 100% sure there aren't any things that I'm not fully realizing...

heres a picture of the break down sections:

XXXXXXXXXXXXXXX


I still say check with a performance shop who builds engines, they probably know for sure...
Click to expand...


Heyy, I wondered if you were on here too. Thanks for the pic, it really helps to give a visual. I definitely think you are correct that the block should be the same and its just a matter of bolt on's being swapped out. I talked to my mechanic who is going to do the work and he agreed that it sounded correct, but no one seems to know 100% for certain. Any suggestions on a good engine builder to contact? We used to have one or two performace speed shops here in Cbus, but they have gone out of business. I'm calling the dealer tomorrow to see if the block numbers match and that should give me a pretty good indication as to my answer. I've thought about just trying to sell my FX as is and let someone else deal with it, but I think the smartest thing is to make the swap and then decide on its fate. Anyway, thanks again for all the info... you've by far been the most helpful. Btw, your FX is sweeeeeeeeeet!
 
A4SixtyNinerRR said:
...I definitely think you are correct that the block should be the same and its just a matter of bolt on's being swapped out. I talked to my mechanic who is going to do the work and he agreed that it sounded correct, but no one seems to know 100% for certain. ...
Click to expand...

According to our preferred OEM parts source (infinitipartsusa), the following engine components are NOT interchangeable between the AWD and RWD iterations:

1) All engine/transmission mounting components
2) Upper and Lower oil pans
3) Overhaul gasket set (probably due to the oil pans)

**After looking through every engine component to compile the above information I noticed that they list the Y-pipe as interchangeable as well, and if memory serves it isn't. That said, I'm not sure how reliable this info is in reality... :laugh:
 
tchuck said:
According to our preferred OEM parts source (infinitipartsusa), the following engine components are NOT interchangeable between the AWD and RWD iterations:

1) All engine/transmission mounting components
2) Upper and Lower oil pans
3) Overhaul gasket set (probably due to the oil pans)
Click to expand...


Ok so the mounting components are different, but it makes me wonder if the mounting positions on the block are the same? Hopefully I could just swap out my mounting hardware and make it work.
 
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