Egr nut size question

[Ripco]

Ok, title sounds stupid but I have a 2004 LS 3.9L and last week the CEL came on with a P0402 code. Something to do with the EGR valve so since I had a 97 Mark and needed to replace that one towards the end, I figured just to order one and keep fingers crossed the valve is bad.

Unlike the Mark, where the nut that attaches to the tube going to the cat converter was out in the open, this one seems like a pita to access and loosen.

The thing is, the biggest cresent wrench I have is 15/16th and it's definetly too small. Until I have everything I need and remove that fuel pressure sensor, I can't even get my 6" calipers in there to measure it.

Does anyone know what size cresent I'll need? 1" or 1 1/8, is it metric like a 24 or 25?

Also that fuel pressure sensor, I'm assuming as long as the engine isn't running there will be some gasoline leaking until the rail depressurizes? It's not like you have to disconnect the fuel lines or empty the tank? Is there a gasket under there, I don't see one for that online, just asking.

Sorry to ask the stupid but we're getting into the 20/30's here with snow already predicted to for the weekend. Would like to get this done in one shot.

Thanks,
-bruce

 

[joegr]

I think it's 27mm, but I'm not 100% on that. I've done it 3 or 4 times now (two LSes), but my memory is not perfect. I use a wrench out of this set: www.harborfreight.com/15-piece-metric-service-wrench-set-93668.html

As for the fuel rail, very little gasoline comes out. Throw an old washcloth or such over the sensor as you pull it off. That way, if any does spray it won't get in your eyes or anywhere else that you wouldn't want gasoline. Note that the sensor won't just pop off when you remove the two bolts. You have to pull on it pretty hard to get it off.

Note that it has been reported that aftermarket EGR valves don't seem to work well on this car.

 

[GreyWisent]

I used an adjustable pipe/parrot wrench for the EGR valve nut. Not sure of the size. Mine wasn't seized and the adjustable wrench was the most accessible tool, so I decided to try it and it budged with surprising ease. I'm thankful to the previous person who touched it for not getting macho with it. You will know from experience that the adjustable wrench will "torque out" much more easily than a crescent wrench, so be careful not to round corners. There are no torque specs for this connection.
Remember that you're trying to disconnect the nut from the EGR module, and not the nut from the tube. To loosen, the top of the nut should move from the passenger side to the driver's side. There isn't much room, so you get about 45 degrees of swing.

Also that fuel pressure sensor, I'm assuming as long as the engine isn't running there will be some gasoline leaking until the rail depressurizes? It's not like you have to disconnect the fuel lines or empty the tank? Is there a gasket under there, I don't see one for that online, just asking.

The fuel rail is under some pressure even when the car/fuel pump is off. You have to depressurise the system first:
2006 Lincoln LS Workshop Manual
Once that's done, you can use the fuel schrader valve to remove the last bit of "squirt". This way you minimize spillage at the fuel sensor, to just a couple of drops.
There IS an o-ring where the fuel pressure sensor connects to the fuel rail. The manual doesn't require mandatory replacement, but obviously recommends inspection: 2006 Lincoln LS Workshop Manual (step 5)

(There is however a metal gasket between the EGR module and the throttle body - you were asking about the fuel pressure sensor gasket though.)

 

[GreyWisent]

Joe's memory is impressive. I just measured it with calipers:
27mm
My 1 1/16" (26.9875mm) open ended wrench also fit perfectly.

Good luck.

 

[rgorke]

Joe's memory is impressive. I just measured it with calipers:
27mm
My 1 1/16" (26.9875mm) open ended wrench also fit perfectly.

Good luck.

I've been eyeballing a 1 1/16" crows foot for a 3/8" ratchet for this purpose. Of course, I had to use the crescent wrench this time...again!!! I was considering shaving down the sides of a wrench to get a little more room. As you said, it shouldn't be on there really tight.

 

[Ripco]

Hi all,

Just wanted to say thanks for all the input, got the new EGR valve on this past saturday, everything seems ok so far.

Couple of points to make, 1) yes it is a 27mm nut and those wrenches from Harbor Freight worked well. Be aware the handles are quite short but are narrow enough to slide a pipe or tube on the handle for needed torque without being too long so you don't have swing.

2) Please please please, anyone reading this in the future, do remove that fuel pressure sensor next to the valve before working on the valve itself. Without knowing that, I am sure I would of broke off the tit from the side of it, thats around a $100 part. Unless mine was dressed different with the tubing and sleeves, that thing is totally in the way of both the cat nut (the 27mm one) and the rear bolt holding the egr to the block.

So again, thanks everyone, really appreciate it.

-bruce