Good afternoon. Because searching this forum has been so helpful to me in the past, thought I'd share my experience with a recent problem, and the solution. I'm a mobile mechanic and my work truck is a 1992 F-450, 5.13 rear, manual shift. I bought it last December with 116,000 miles on it, and aside from the expected "maintenance" items, it's been pretty good to me. Runs smooth & strong, and gets about 10 or 11 MPG on the highway, loaded to 10,950 GVW most of the time (slow as hell, but whatever).

Starting in May, I noticed a very sharp but faint tick that comes and goes at all speeds and all operating conditions. Seemed to be coming from the center of the RH valve cover. IR thermometer showed a perfectly even temperature on all exhaust runners, ruling out an injector problem or a serious valve problem. Stethescope couldn't pinpoint the problem, indicating to me that it was somewhere under the valve cover. Since the noise started (or I started noticing it), it never got any worse. In my experience, sometimes a noise is just a noise, and this seemed to be one of these cases, but I wanted to fix it in case it was something that could cause damage down the road, and so my customers wouldn't see me show up with a truck that had an obvious engine problem.

When I had some downtime a few Sundays ago, I opened the valve cover, and saw this:



On the No. 3 exhaust valve spring, note that the end is poking out from under the retainer just a little bit, as if it's severely out of square or the stem is bent. Jiggling all the valve stems by hand, all had SOME clearance, indicating no valves were binding, and none had very much clearance, so no indication of severe guide wear or anything of that nature. At this point, a good customer called with an emergency, so I buttoned it back up and took off. As it turned out, it would be another 4 weeks before I got into it again.

In the meantime, I had an oil test done by Blackstone, which showed absolutely no out-of-spec metals contamination in the oil (shout out to Blackstone and Fumoto, both of which made this a very easy, fast process). Doing a search here on my downtime, I found that the springs for this engine have dampers- which I didn't know previously- and that sometimes they break. I reasoned that my damper had broken and overlapped itself, pushing the spring to the side as seen in the picture. Yesterday I stopped at NAPA (another great outfit to deal with, make sure you bring your NAPA guys beer sometimes because they deserve it!), and picked up a new spring assembly. Got some downtime today, and replaced the spring:



All in all, replacing the spring took about 1.5 hours, tops. I'm blown away by how stone simple (and CHEAP) these engines are to work on. Remove alternator bracket (I have serpentine drive) and fuel filter bracket, remove dipstick bracket, remove valve cover, and you're in.

Rotated the engine to TDC on No. 1, and confirmed by using a lever-style spring compressor (like this: https://www.napaonline.com/en/p/BK_7769094 ) to make sure the valves hit the piston. Rotated engine backwards 90 degrees to get No. 3 on TDC (I'm too lazy efficient to turn it forwards 270 degrees), and used the compressor to confirm BOTH No. 3 valves were hitting the piston on the way down. This is why I like using the cheap lever-style compressors, you get great tactile feedback on what the valve is doing. Once I had double-checked this, pushed the spring all the way down, removed the keepers with a magnet, switched the springs, and put the keepers back in. They're pretty tight on this engine, and the valves aren't slanted downwards, so I didn't need any grease to put them back. Checked the rotators and oil shield at the time, they're good. Installed a new valve cover gasket for the hell of it.

After buttoning it back up, the tick noise was completely gone. I washed the spring off in the kitchen sink, and you can clearly see that, as predicted, the damper slipped away from its intended position, and is overlapping itself. These springs are fairly light, and I could even reproduce the clicking noise by compressing it between my hands. I have no doubt I could've run this spring for another 100,000 miles, but I'm happier knowing it's fixed and not having to hear the noise. In the photo below, note the abnormal wear on the top coil of the damper spring. It's not obvious from the photo, but every time the spring compresses, the "tail" of the damper spring slides over the "tail" of the main spring, and randomly either makes a "click", or binds up on itself, causing wear but little noise.



Thanks to you all for your help on this and many other issues, and let's keep these old beasts going!

 

Thats what required the 7.3 in our 92 to get overhauled back in 97. Exhaust spring broke and it dropped the valve. Good that you caught it.

 

Good job!

 

good deal, IF 2 are failed then the Rest are too or not far from it IMHO

 

You're probably right. So far I've been putting about 5,000 miles a month on her, so I should be good until next winter. If they need to be replaced in the meantime though, it takes all of a 0.5 hour to get the RH valve cover off, and probably 5 minutes for the driver side. I think the spring cost me all of $5 on the company account. This engine still blows over 500PSI on all 8, so it's in pretty good shape otherwise.

Again, the biggest benefit of an IDI, as I see it, is how stupid cheap / simple they are to work on. I don't have a shop, and my landlord frowns on auto repair at home, so I've been able to do everything from glow plugs to a water pump in random parking lots in a few minutes. Not tryna start a 15-page argument, but I may or may not dump most of my drain oil (about 50 gallons a month) straight into the fuel tank, so that's nice too. I can say from experience that would be a $5,000, 5-day repair on a T444E or later engine.

Next up is new leak-off lines. They don't leak under vacuum yet, but they **** fuel everywhere.

 

How many miles when that happened, what kind of truck?

I've seen these motors go to 650,000 without major work, but only in pickup trucks. Not sure mine will make it that far because of the lower final drive. 3100RPM on the highway!

 

These v8's love to sing, rpms aren't really an issue like with an inline motor. I've heard talk that without a turbo after 2200 rpms these motors lose there efficiency but mine loves to sing up high.

 

That`s just getting broken in, check out this thread. The guy has 1,006,000M miles and is po`d because
his Cruise Control cable broke...LOL

https://www.ford-trucks.com/forums/1...r-a-cable.html

Charlie