The ever so popular Under Valve Cover Harness Plug problem with the 7.3L Powerstroke Diesel has cost many people alot of money and frustration. It can however be a rather cheap and easy fix. Read more to find out how to fix the problem for $.25.

7.3 Powerstroke Running Rough

The way the problem started on my 2002 F-250, was with slightly rough running motor. The first time it happened it only lasted about a minute or so, and then went away. I blew it off to some bad fuel or something. Them a few days latter I got in my truck and it would barely start, and ran rough. Once it started I shut it off to see if it would start and run normal the next time, I assumed it wouldn’t, and I was right. I drove it to work and and back, it was running terribly rough, and had a big loss of power. On the way home it got really bad and would barely run (I had to go about 25mph).

I did a lot of research and narrowed it down to most likely being this plug under the valve cover. So I pulled the driver side first (its easier and it seems like it is on this side more than it is the passenger side).

So first I pulled the intake, intercooler tube, ect. When unbolting the valve cover, the bolts in the back are kind of hard to get to, but they are not to bad, nothing a swivel socket and a couple of extensions cant get. After you have it off you will be able to see if the plug is unplugged. Mine was obviously partially unplugged. So I plugged it back in, and started it with the valve cover off, which is ok to do (oil will not squirt out). It ran fine, i was thrilled.

But what if it comes unplugged again? There are a few different preventative measures you can take. There are updated clips you can buy, which will fix this. But if you are in a crunch for time to get back on the road, like myself, there is a

 trick that will only cost you 25 cents. What you will need to do is put a quarter in the plug to hold it clipped on. A quarter is the perfect thickness and fits perfectly, only you will need to grind down one side of it a little bit as shown. After I trimmed my quarter, I placed it in there, and put everything all back together, and drove it around the block, it ran great. I did this about four months ago, and my truck has been running great since.

This entry was posted on Sunday, April 5th, 2009 at 9:21 pm and is filed under 7.3L Powerstroke. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.