This weekend I went camping with a friend of mine. I drive a new to me 2005 F350, he has a 2001 F350. While we were talking he said he didn't think his pickup had the power it should have. He pulls a 5th wheel camper that weighs around 8000 pounds fully loaded. He said it takes a couple of miles to get to 55 mph, and it is hard to hold the speed. It doesn't have the power it did when he first got it last year. He was told that a diesel is slow getting started. He rode with me in mine, when I dropped it about half throttle to pass a slow car he said he could tell mine had way more power.
His check engine light is not on, it starts good both when hot and when cold. It runs smooth, no miss as far as I can tell listening to it.
I would like to be able to help him out. What are some common issues that could cause this? He did just change the oil and fuel filters, not sure about the air filter. He said the power loss came before he serviced the engine, and did not improve after the fuel filter change.
Any ideas on where to start? He was also told to check the filter inside of his fuel tank, so he is getting ready to drop his tank.

 

Generally:

-Tired/Clogged Injectors (and or orings/cups)
-Air in Fuel
-Boost Leaks
-Bad or Degraded Sensors
-Exhaust Leaks
-EBP Sensor
-And the list goes on, best to get it hooked up to AE and start the diagnosis.

 

If he is going to do that, he should to the Hutch mod. Search the site.

 

Too many things to start guessing. Everything listed above are possibilities. A scan tool can help out in this area a lot. Exhaust leaks are usually easy to identify though. Get a good flashlight and look around the exhaust manifolds where they bolt to the block, the up pipes coming off the manifolds going to the turbo, the pipes where they go into the turbo, (those are the common places to leak), the "babies butt" where it bolts to the turbo. Look for black soot at those connections. If you find soot, you have a leak.

 

Going for a very common one: If there is no black contrail out the back when he floors it, the ICP sensor pops high on the suspect list. He can pull the ICP sensor connector off (the engine light will go nuts here), to inspect it for oil in the connector and go for a test drive. It is perfectly safe to do this - it's one of the procedures straight out of the service manual. It's also a "get home" procedure if that very important sensor were to fail.




There are other time-consuming tests he can conduct that sometimes involve building or acquiring tools he may not have... or... he can acquire a scan tool/gauge. Torque Pro, Auto Enginuity with Ford bundle, FORScan, DashCommand, and a few others are available, depending on the technology your friend already has - PC, Android, or Apple.

 

Thanks for all of the ideas.
It seems to run fine, no check engine light, it is not blowing black smoke, easy starting hot or cold. In all appearances it is running fine, just does not have the power it should.
I was a mechanic for years and do most of his mechanical repairs for him, but I am not a diesel mechanic! I think this this would be a good one to defer to an expert!

 

Help us, help you, (and him). Try what Tugly said first. Where are you guys located? we may have someone near by with AE and we could do some data logging and go from there. Low power could be so many relatively easy and cheap fixes that someone with your wrenching skills could help him save a bunch of time and money. A 7.3 liter, even stock, should have little issues getting to and maintaining 55mph with an 8K pound load.

 

I am in south central Nebraska, he lives about 45 miles from me.
I talked to him tonight, he said that on the trip home from our campout he had no power issues. He said the pickup got up to speed and held the speed without a struggle. He also said it doesn't have the same power my 6.0 has, but it was running a lot better than it did a couple of days before.
I do not think his truck "fixed itself", but whatever the problem is it is intermittent.
I think your probably right, before I give up on him I need to plan a trip to go try some of the suggestions here. I have been out of the mechanics field for about 20 years, but have kept up with the latest technology, but this diesel is just a little intimidating!

 

In tank mods may be the answer. How much fuel was in it when you noticed a drop in power?

 

I don't know when he first noticed the power loss. He has owned the pickup for a little less than a year. This is the first diesel vehicle he has driven, but his wife owned a diesel before they were married. He told me that she said it runs normal for a diesel? She told him that a diesel takes a mile or two to get up to speed, so he thought it was normal until he rode with me with my 6.0. I cracked mine to about half throttle to pass a car, he said his at wide open doesn't have the acceleration that mine does at half throttle.
Whenever I get time I am going to help him drop the tank. We will flush the tank our and check the filters to make sure that is not the problem to begin with. I am also going to research the tank mods that were mentioned earlier in this thread.

 

If the 7.3 is bone stock, it is a slug compared to the 6.0. That's not to say we can help liven it up a little for him. But making sure everything on the truck is fine before adding some tunes is essential. That would be the fuel system, turbo setup, etc. Then, perhaps a chip if interested once that's all done.

 

If the wife had a diesel before - maybe it was pre-turbo, or maybe it was a small engine in a big vehicle.

The stock Superduty with a 7.3L should go from zero to 60 in ten seconds - just as fast as any Toyota economy car.

 

Definitely shouldn't take a couple miles to get to 55. I tow a 9k bumper pull with my stock Excursion 7.3 through the mountains here in CO and even going through the passes it doesn't take long to get to 55.
I'm going through a similar issue, but I don't think his is the same problem as mine. My turbo siezed up, but had the exact same symptoms. No power, but smooth idle and smooth thorughout the rpm range, no smoke, no codes, no oil in the intake or exhaust...I don't think it's a problem that would "fix itself" though.

 

If all things mentioned in the previous posts check out ok and no results it could be boost leak. Check all the boots to be properly seated and all clamps to be tight from turbo to intake manifolds. After recently getting my 2002 7.3L started after changing injector cups, I took it for a 36 mile drive at steady 65 mph. The truck was running great by the time I got home. The next day while driving it suddenly lost power. The symptoms were very similar to how you describe. I could get it up to 55 only it took a while. Mashing the pedal to the floor only created lots of black smoke to pour out of the tailpipe and not much else. I found several clamps not tightened all the way and the boots were loose. I ended up taking both CAC pipes off, cleaned the boots, then re-installed making sure all boots and clamps were seated and tighten. Truck is running great again.

 

I talked to my buddy tonight on the phone. He said that today he drove the pickup to town and back, about 20 mile round trip. He said it ran great, had good acceleration and good power. He said it started very hard though. It was about 20 degrees out, but he had it plugged in all night before. He thinks his block heater is not working, but he also said that it only took a minute or two for the heater to blow hot air.
I asked him when he first noticed the power loss. Maybe there is a clue here! Last summer he was on a camping trip. He stopped in a small town mom and pop gas station to get fuel, instead of one of the chain stations or truck stops he usually stops at. Not sure if that had anything to do with it, but it makes me wonder if he didn't get bad fuel? He rarely lets the pickup get under a half a tank of fuel, and when he filled up at that station he said he was just under a half a tank.
I have not had time to go see him and look the pickup over myself, so still just shooting in the dark by what he has told me.
Also, it is not smoking when he opens it wide. When it is losing power he can floor it and it does not smoke. He told me he was looking at buying a scan tool that is on sale at Orielly Auto parts. It is a Bosch OBD 1000 code reader. He is going to buy that to pull codes on his other vehicles, he was wondering if it would be able to be used on his diesel. Anyone know anything about these cheap scan tools?