Ford / International 7.3L diesel vulnerability

[Mike S]

I had an experience last week with my low mileage (90K) Ford SD 7.3L. The engine stuttered and began to run very poorly, producing very little power. Drove to an International dealer/repair shop and they diagnosed the problem...

There is a wire harness for the glow plugs inside each valve cover and one of them was toast. I was running on 4 cylinders.

Good news is that they replaced it in about and hour and the total cost was $190. No damage to the engine, and it is now running like new - again.

I vaguely recall hearing about this vulnerability and now I have first hand experience.

 

[truck mechanic]

oh yeah I see it all the time, if I go under the valve cover and find factory harnesses I replace them just because.
Paul

 

[shortbus4x4]

The 7.3 is an awesome engine, especially compared to some of the later Ford diesel engines but under valve cover harnesses melting down is one of their few weaknesses. And I mean few weaknesses. I have repaired quite a few of them for this problem. They have the glow plugs and injector wiring all running through that one or two plugs, depending on year, in the valve cover gasket assembly. The glow plugs drawing a lot of amps seem to cause the melt down and then the injectors stop working too. Its pretty standard to replace the UVC harnesses if you pull the valve covers at all. Its quite often cheaper and you get HD truck quality parts by getting your engine parts from International rather than Ford.

 

[Rot Box]

Hmm... i wasn't able to find any wires under the valve covers on my 7.3?

I've seen it a time or two. Also not a bad idea to replace higher mileage glowplugs while its down.

 

[IdaSHO]

The valve cover harnesses on the 7.3 Powerstroke are a common problem. Injector wiring and glow plug wiring for all 8 cylinders, in 4 fairly light duty plugs.

There is a special tool that you can buy to replace the connectors, and contacts within the connectors. Though once the valve cover gasket connections are burned up, you must replace the valve cover gasket. A bit of the harness is built i right into the gasket.