Surprise "fix" to the EGR tube/manifold leak

[Doc]

So I've driven my 97 F-150 (4.6 L) around for several months now listening to that wretched left side exhaust leak caused by the nut on the EGR tube rotting off the nipple on the manifold. I tried plugging it, taping it with that exhaust "bandage" tape, etc. Nothing obviously ever lasted. And I sure didn't want to try replacing the manifold and then dealing with the potential broken studs, etc. Then I finally got around to getting the gas tank straps replaced with that recall. So I took it to the dealership this past Friday. I mentioned the EGR tube leak kind of in passing. The service manager said they could fix it for about 80 bucks. He said they had successfully removed quite a few of those nipples without replacing the manifold. I kind of thought to myself "yeah right" (considering I live in the rust belt with all the road salt, etc.) and told them to go for it. Not surprisingly, they called me back later in the day and said they couldn't get it out, and he quoted me an $800 price to replace the manifold, etc. I just told him to plug it instead. When I picked up the truck, I learned the mechanic decided to WELD it instead of plugging it. I was pretty surprised that he tackled it, and he actually did a pretty decent job in sealing it except for one small pin hole on the back side between the welds. I mixed up some JB Weld and filled the pinhole. The welds may fail or the JB Weld blows out tomorrow, but, in the meantime, I don't have to listen to that wretched exhaust leak constantly. At least I'll have a few days peace if not longer.

[Lennyg]

I have a 2001 F150 XL 4.2L that had the same disintegrated compression nut of the EGR tube at the nipple on the exhaust manifold. I finally did get the nipple removed but it took a lot of work. I took the plastic wheel well off and removed the tranny dip stick tube and O2 sensor to get at the problem better. I sprayed with penetrating fluid, hammered, heated, applied pressure in both directions with a wrench, vice grip and helper bar over and over for about an hour and it finally loosened.
Then I paid the outrageous Ford parts prices (over $30 for the nipple and over $60 for the new EGR tube) and spent $30 for a tap to clean the threads. But I didn't have to pull the exhaust manifold!

[Lime1GT]

Originally Posted by Doc

When I picked up the truck, I learned the mechanic decided to WELD it instead of plugging it. I was pretty surprised that he tackled it, and he actually did a pretty decent job in sealing it except for one small pin hole on the back side between the welds

If he had plugged it you may have experienced engine ping at part throttle conditions.

[ryoken31]

I had the EGR tube welded on my pickup in the fall. Lasted a month or two then the weld fell apart. I ended up buying a new tube from ford with the fitting for 100 bucks and a set of headers for 300 bucks. Did the trick just nicely.

[Doc]

Good information. Well it's almost been a month and so far so good on the tube (but I wouldn't be surprised if it blew off any day). Unfortunately, the famous EGR insufficient flow code has come back regularly. So my next task is to probably clean the EGR ports. I'm no expert at all on this, but it would seem logical that the ports on my truck would stand even a higher chance of being clogged considering I haven't had sufficient flow through them in some time?

[7700Rob]

I recently had the manifold side nut disintegrate. I cut off the lower flange, had a short (1 1/2" long) 1/2" copper pipe that just happens to fit nice and snug in the nipple. I did up some JB Weld and mated the egr tube to the copper tube and let it sit. I did use use silver solder around the manifold nipple where the copper piece is. It's been two weeks, I haven't pampered it, and it's holding up.

[Spotty]

My nut was gone also....rust belt victim. I wire brushed it and wrapped the whole thing in aluminum tape.....like HVAC guys use in ductwork. Then put two small clamps on it top and bottom ( on the tape). Works great.,...not a peep, about 4 months now....smells kinda' funny for about a week. I had about 4 pinholes that were leaking on the manifolds. I bought a small tube of that fireplace -boiler repair stuff...like $3.00 bucks. wire brushed it first, then took some waded up pieces of steel wool covered them in that stuff and stuck them to the manifold. some are over a year old....it works slick. I've had the manifolds off before for broken studs, some day I will tear all this stuff off and do manifolds and EGR tube.

[Dave G.]

That flare nut nipple is just a plain steel part, exactly the same thing you can pick up at any box store or hardware, for $3.00 or so. 3/8" NPT on one end and 3/8" flare nut on the other, I think. ( possibly could be 1/2"). I always have a bunch laying around, so I just use the one that fits the tube nut.

Dave

[Spotty]

Yeah....I had some around also that would fit, but no way were those old threads coming out of that manifold. Just one huge rusty mess with no threads of any kind left...Minnesota salt. Took me 4 hours to do one tie rod end today....rust is slowly winning....

[Doc]

Just to give an update. It's been almost 4 months now and that welded EGR tube to the manifold is still holding strong. I also removed the throttle body and cleaned the EGR ports--no more "EGR insufficient flow" code.