My F350 runs great but sometimes after I've run it hard on the highway and come into a parking lot it starts knocking like a worn out cummins while idling. If I give it just a little throttle it is smooth again.
I just changed the oil and the pressure is good. I used the 5w40 rotella synthetic as always.
I'm thinking oil aeration. It's not bad bearings or oil pressure. This oil has less than 1000 miles on it so that can't be it and I don't have any leaks. How common is the cracked pickup tube on these? I've only seen it once and the truck was two years old. Maybe it's more common now.

Anything else that can cause this problem? I just did all my injector o rings, ICP o rings and replaced turbo. Like I said it runs perfect except for this occasional problem after I've run it at high rpm's on the highway and it smooths out within 5 minutes on it's own. That's why I'm thinking air is getting in the oil.

 

Sounds like your oil is getting aerated. Cause if your oil is getting aerated, it would not let the injectors open up good enough to put enough fuel in the combustion chamber, so that would make it knock. And with it running at idle for a few minutes fixes it, would mean it is circulataing the oil and getting the air out of it. IDK if you would want, but they make a anti-foaming additive you may want to try. But I say its aeration.

 

That additive won't fix an aeration problem caused by a leak in the system. It just helps with minor aeration caused by splashing connecting rods.

I wonder if there is anywhere else the oil can be getting air in it other than that pickup tube. I know what that means.

Pull the engine!

 

IDK if you knew the tube was bad or not, the way it seemed to be worded in your post is that you heard of it but didn't know if it was a common problem. But give me a minute and I will flip threw my books, be right back bud.

Edit: I went and got my school book on diesel (Almost a Diesel tech) and it says that oils, can have a Aeration problem do to contamination such as water. Also it could be a oil pump relief valve problem. Surface tension is also a factor. Plus a good additive would be made of Silicone polymers. Also I assume your oil level is proper? If tis not that could be the problem.

 

Check your fuel pressure when it's doing it.

 

I would NOT pull the engine just for a stupid cracked pickup tube. if i'm going to pull the engine it better be more drastic measures. if it were me i would cut the crossmember, then weld tabs to it so you can bolt it back in there when your done and then weld up around the tabs and a few times down the cut lines. this has been done many times on several trucks and have seen many miles and years afterward with no crossmember issues. in fact when you cut the crossmember out NOTHING moves at all. thats just my .02 on pulling the engine.

Now, is it romping when you bring it back down to idle after said runs??? i'd check the fuel pressure and hook a scanner to it and check all other inputs as well just for fun.

 

It's not romping, just a bad injector knock and it's not all the time. Most of the time though after I come off the highway running pretty high rpm's and warmed up good.

I am 2 quarts high right now on oil trying to see if it will cover the crack, if that's what it is. 2 quarts high in the crank case usually covers it and lessens the symptoms. I Was a Ford, International, Kubota, Case and Massey diesel mechanic remember.
So far the extra 2 quarts has only made it worse so now I'm thinking pickup tube gasket or o ring, whichever it has.

Not going to cut the crossmember. Boy that ruins a truck. I did alignments for a long time too and over the years without that thing helping to stiffen things up you will start to have problems. It's just not a good thing. My son and I can pull the motor in about 2 and a half hours. I still need to swap the oil pan anyway remember. It got cut real bad from the clutch cover and I had to silicone a 6 inch cut shut.

I just really hate pulling engines. Thats why I'm looking for other possible causes. Could it be the oil? Rotella synthetic. I noticed they changed the packaging again. It says t6 on it now. I guess it's the clean diesel crap. My new tractor is one of those. It drinks diesel and gives off water. And occasionally flames out the stack! At least it runs good for now.

 

I forgot, I can't run it with my fuel pressure gauge on for long. I have a really nice snap on test set and it's just beat the crap out of the needle on it. I just had to recal the gauge because of it. I set it at 70 psi, cold idle though by shimming so it should be fine. I checked it at a warmed up idle the other day while it was doing it too and it was right on 70.

 

Aeration would get worse with high engine RPM that is a possibility. Another oil change would rule out the oil but I doubt the Rotella is an issue unless you have fuel dilution.

Also just adding 2 quarts won't rule out the cracked pickup tube. You have to jack the back of the truck up a foot or two since the cracks occur up toward the front of the tube.

What is ICP pressure when its acting up? IPR DC?

BTW please remember you are the one asking for help so statements like this "I Was a Ford, International, Kubota, Case and Massey diesel mechanic remember." don't do much for us........ Just saying it cause I know others are thinking it.

 

Tj

IIRC he has installed inj's from his 97 cali.

ranch
Fuel system needs to be tested under a load.

On a wag, iam with air in fuel or fuel pressure loss.

.02
Bill

 

I did try jacking the back up and duplicating the problem. It won't do it in the driveway though. I have to run it pretty hard.
The injectors I used turned out to be AA not the AB's I thought was in that truck. Apparently someone swapped the motor on it at some time and it's not a california anymore.

I don't have a way to check the oil pressure since it's eec4 on this one but I can check the duty cycle. I sold off my old breakout box right before I got this truck too! I'll take my meter with me next time I go to town and check it when it acts up. Maybe it is the ICP. I could only hope right.
I wish I could use the one off the 97. They aren't interchangeable are they? They look a good bit different. One has the edge filter and one doesn't.
Maybe I don't even have a problem. I'm too picky sometimes about my own stuff. It could just be crappy fuel and I'm being paranoid.

I'm going to go pull the oil filter and get that extra two quarts out of it now. I'll dump it into a glass jar and see if any fuel or other junk settles out. I doubt that's it but ya never know. When I sealed up the oil pan cut in the back, I hosed it off with brake cleaner and used the gray Ford rtv on it. I might have messed up the oil with that too.

Last week when I first started looking into this problem I took off the fuel pressure regulator and cleaned it good. This one has the little filter canister hanging on it. There was some little bits of paint and dirt and what looked like rubber in it but it's all clean now. The screen was about plugged but it's clean now too. I think most of that came from my kid borrowing fuel out of it with a garden hose!

 

Now I am starting to believe the oil is the culprit. I was just doing some research on the net and I new the labelling had changed on the rotella 5w40. Now it says T6 synthetic on it and also has new ratings.
It says it meets CJ-4, CI-4plus, CI-4, CH-4, CG-4/SM
No mention of meeting the performance requirements of Ford or international.

The new ratings are for the low phosphorus, high moly content, safe for EGR and DPF systems.

The required rating for the OBS powerstrokes is CF-4/SH or CG-4/SH or higher.

From my brief research just now any oil rated SM is not good in ant older engine including the powerstrokes. I can't find any mention of it being backwards compatible to the SH rating either.

I wish I had one of the last bottles of rotella synthetic. I could swear it was SJ rated which is supposedly backwards compatible.

Any thoughts?

Last time I remember the engine doing this I was running delo syn in it because I couldn't find the rotella in the store. Am I on to something maybe?

 

You are barking up the wrong tree.
They are higher.
The lower #'s and/or letters are previous blends.
Higher #'s/letters are latest blends.

Bill

 

Look up the SM classification online and see all the things said about it. I wasn't looking at forums either but mostly govt sites and test labs.
I don't know. The regular rotella still has the CF-4 but it is also SM now for the low emission engines.
I think it might be worth further looking into at least. These engines are hydraulically activated and it does not take much to mess up a hydraulic system.

I might have just found my problem though. I hope. I need to stop relying on what my kid tells me. He was putting the oil filter back on and I asked him if the bypass valve was still there. He said if you mean the black o ring then yes.
Since I didn't know what he was talking about I crawled under and looked and the bypass was hanging half out of the bore and it is the staked in one! Last time we changed the oil I asked him if it was staked in or had a snap ring. He said snap ring so I believed him.
That is fixed now. I just restaked it. I'll see what happens today driving it.

 

Lube package has change because of ULSD fuel.

Bill