Identifying 4.6 SOHC engine
03-15-2012, 01:26 PM
#1
2nd Gear Member
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Location: Texas
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Identifying 4.6 SOHC engine
I'm about to start buying some basic rebuild parts for my 2002 Mustang GT, but I thought it would be a good idea to make sure my car still has the original engine since it has 140K miles on it. The engine should be the X vin Romeo engine. Not being a Ford expert, what's the best way for me to identify this actual engine? is there a serial number to match to the vin? If that doesn't match is there an easy way to see if this is the correct type of engine? thanks for your patience with a Ford newbie guys!!!
03-16-2012, 08:19 AM
#2
TECH SAVANT
Join Date: Dec 2006
Location: Saint Augustine, FL
Posts: 10,938
The X in the VIN just means that it's a 4.6L SOHC used in the new-edge Mustangs, contrary to a common claim it does not ID the engine source. As far as I have been able to determine code W in position 8 of a Mustang GT VIN code indicates the '96 through '98 non-PI engine--however I have no solid confirmation of this.
This is from Ford's 2000 VIN decoder (1999 & 2000 GTs had Windsor engines):
Note the W in the engine description, but the VIN code is an X.
This is from the 2002 decoder (2001 through 2004 GTs had Romeo engines:
The easiest way to tell which you have is to count the cam cover bolts, Romeo engines have 11, Windsor engines 13 or 14...
---------------------------------------------
You can download the VIN guides from Ford, click here.
This is from Ford's 2000 VIN decoder (1999 & 2000 GTs had Windsor engines):
Note the W in the engine description, but the VIN code is an X.
This is from the 2002 decoder (2001 through 2004 GTs had Romeo engines:
The easiest way to tell which you have is to count the cam cover bolts, Romeo engines have 11, Windsor engines 13 or 14...
---------------------------------------------
You can download the VIN guides from Ford, click here.
03-16-2012, 12:54 PM
#3
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Join Date: Jan 2011
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but even if I do verify that it's a Romeo engine, that won't necessarily mean it's the original engine, or whether it's even a PI Romeo engine?
As it happens though, the passenger valve cover still has the white label. That label gives a date of 3/27/02, and the door tag gives a build date of 04/02, so it seems likely that this is the original engine.
PS - do you have a decoder for the 2002 door tag??
As it happens though, the passenger valve cover still has the white label. That label gives a date of 3/27/02, and the door tag gives a build date of 04/02, so it seems likely that this is the original engine.
PS - do you have a decoder for the 2002 door tag??
03-16-2012, 01:32 PM
#5
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it actually does run pretty well, but my installation of 4.10 gears has made it obvious just how little steam this engine has above 3500-4000 rpm, so I was thinking a mild performance rebuild would restore it to a little better than it was when new. After some research though, it seems to be the opinion that rebuilding a normally aspirated 4.6 sohc for extra performance is not only expensive, but the benefits are not that great compared to the cash outlay. On top of that, I was looking at what it takes to install headers and all of the sudden the stock engine was sounding better all the time (although replacing the K-member with a lighter racing piece seemed interesting). So, the new plan is to save for a Paxton or Vortec supercharger and use it with minimum boost on the stock engine until I really need to rebuild it. Well, I guess I better get to saving, more news in a couple of years.
03-16-2012, 03:03 PM
#7
TECH SAVANT
Join Date: Dec 2006
Location: Saint Augustine, FL
Posts: 10,938
but even if I do verify that it's a Romeo engine, that won't necessarily mean it's the original engine, or whether it's even a PI Romeo engine?
As it happens though, the passenger valve cover still has the white label. That label gives a date of 3/27/02, and the door tag gives a build date of 04/02, so it seems likely that this is the original engine.
PS - do you have a decoder for the 2002 door tag??
As it happens though, the passenger valve cover still has the white label. That label gives a date of 3/27/02, and the door tag gives a build date of 04/02, so it seems likely that this is the original engine.
PS - do you have a decoder for the 2002 door tag??
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