Community Forums

mappleg8 · 09-11-2016, 08:24 PM

I've read several of the posts on here re the Ford 460, exhaust manifolds, and exhaust leaks. Now I'd like to seek advice from those with knowledge and experience on this problem (it certainly isn't me!!)

I've got a 1995 Holiday Rambler Endeavor LE on the F53 chassis with the 460 engine. 75,xxx miles now, 8,000 of which are mine since April 2015.

Coming back from a short trip (300ish miles) in mid-July, we got a horrible exhaust smell in the rig. Opened all of the front windows to vent it, and it was driveable, so we made it home. I immediately took it to a local repair shop which service semi trucks and RVs (there are no good dealers or independent shops I've found here in central Missouri). I've been satisfied with the other work they've done for me, mostly minor.

So, exhaust leak. I took it in to them and was told there was at least one bolt that was completely missing. Without manifold removal he couldn't tell if it was broken or missing. He also found some loose bolts and studs. They did work on it; removed both exhaust manifolds and said there were no cracks, but several loose bolts, and only the one missing (gone, not broken).

They replaced manifold gaskets and reused bolts as possible, replacing a few as needed. They said the engine was running nice and quiet, and they detected no exhaust leaks.

This past weekend, 10 days or so after the repair, we tried to take another short trip. After 25 or 30 miles of driving, we noticed the exhaust leak again. We tried to go a bit further, but gave up and turned around to return home. I took the MH back to the shop today, and they're supposed to start looking at it tomorrow.

I did notice that the gasket/weatherstrip/seal around the doghouse cover was pretty well shot, so I'm going to replace that. While I had the cover off, I notice a valve at the back of the engine, which I took to be the EGR valve. It had (not has, but had) a 3/4" or 1" rubber tube running to some kind of connection on the right side valve cover. The rubber tube was cut just above the nipple on the EGR(?) valve and had been plugged with a bolt which was clamped in place. But, the remainder of the tube into the valve was left open, and I could see into the valve.

So now I wonder if this valve is related to the exhaust problem. Or am I in a position where the manifolds cannot be securely reattached. My repair was $501.98, which was $450 labor and $50 for manifold gaskets and a stud kit.

If this is going to be an ongoing curse, as it kind of seems it might turn out to be, am I going to better off with headers? That seems to be a common repair/upgrade to alleviate this problem.

DW really likes the floor plan of the MH, and we do intend to keep it for several years, but she is starting to get concerned with the value of the repairs we have put into the MH in the last 17 months.

Any advice or ideas will be greatly appreciated!!

02rld · 09-11-2016, 09:39 PM

Had a 1995 with Ford 460. Heard about exhaust manifold problems and at approx 20K I installed the complete banks manifold and exhaust system as well as the transmission shift module (your rig also has potential transmission troubles). Best money I ever spent, significant increase in usable power to climb hills etc. After that I changed trans oil (full flush not just a pan drop) regularly (approx. every 20K-the oil gets burned and that is the beginning of trans trouble). I sold the rig to a relative at 100K who put another 20K on it before he sold it. We never had any exhaust or tranny problems and could run with the sports cars over the mountains. Not kidding!

subford · 09-12-2016, 06:32 AM

Quote:

Originally Posted by mappleg8

They replaced manifold gaskets and reused bolts as possible, replacing a few as needed. They said the engine was running nice and quiet, and they detected no exhaust leaks.

This one of the problems, you do not use exhaust manifold gaskets on a 460.
Maybe some high temp RTV but not gaskets or they will leak. Also the bolts need to be re-torque after the engine in warmed up and cooled down.

Not sure what valve you are talking about.

The location of the EGR valve:

House Husband · 09-13-2016, 01:26 PM

To add to what subford said. There is a good chance one or both of the manifolds are warped and won't seal correctly. They may need to be resurfaced. At least that was my experience with my right manifold.
Again, NO gaskets.

Richard

mappleg8 · 09-13-2016, 05:05 PM

The latest word from the mechanic is that there is no manifold problem this time.

They found a hole in the exhaust pipe which they are repairing, and as soon as I pick it up I'm going to go out on the highway for a "sniff test".

Thank you all for your input!