EGR Tube leak revisited

[91Merc5o]

Well I have the top end of the engine torn open since I fubared it pretty bad when making the merc a submarine last weekend. I've had the telltale exhaust tick of the leaky EGR tube, but what I found surprised me. You have the main tube that goes from the valve to the manifold, but after 174k, it is still structurally sound. Off this tube there are 2 smaller hoses, one a full hose, the other turns from rubber to metal, and back to rubber. These two hoses lead to the unit screwed into the back of the upper intake. Turns out, the middle metal section had a 1/2" hole in it, and one piece of rubber hose on that same line also was blown out. I cut off the bad section of tubing since it was very close to the end, and will just run a longer rubber section to compensate. It's 1/4" ID fuel line, so not hard to replace at all. Besides that, I've found the upper intake bolts weren't torqued at all, the vacuum tubes are already brittle, and my year old Edelbrock Performer IAS Shocks already have elongated bushings, but Edelbrock is sending new ones. Also, the upper intake plenum has a horrible casting imperfection. I had to really take away some material to port match it to the lower intake manifold. Curious to see how that'll affect the qualities of the 5-o. I'm really praying the new pushrods will kill the rap/knock I'm hearing. If not, 347/KB here I come!

 

[mhn3773]

so what did u do to ur truck?

sounds like it was a blessing in disguise u got a few problems corrected =)

 

[91Merc5o]

I was off road at night and dropped into a mudhole. As I was going through there was a deep pit that submerged the air intake opening. Truck died and I had it towed out, pulled about 2 quarts of water from the pan, pulled the plugs and spun the motor round a few times. Replaced the oil and added lucas. After that though I had a valvetrain rap so I figured I'd start easy with pushrods, and if it's still there I'll tear in deeper, if not replace the motor alltogether.

 

[mrboyle]

Just FYI, that hose is not rubber, its neoprene. Rubber can't take the high exhaust tempatures and will fail quickly.