Aerated Oil

forddieseldoctor · October 25, 2014

I got a 96 F-350 with just shy of 200k on it. Came in from another shop. Rough idle hot, bucks when cold and lack of power towing Took it for a long road test, got it to buck a couple times and got a few recordings of it. The only thing that I noticed is that the ipr dropped about 5% less than 1 second before the rpm dropped. Also noticed that it had a lack of power at mid throttle, but once I got into it hard enough it cleared up. No codes present. Didn't run the oil aeration test or the crankcase pressure test.(They get weird about running trucks at wot at my shop) Swapped known good icp sensor, cam sensor and idm. All with no change in the way it ran. Fuel pressure was at 60 psi at idle and never dropped below 40 on hard accel. Boost was only getting to 7 or 8 psi. Ended up re-ringing the injectors. (Did find some bad o-rings.) Also replaced the wiring harness on the fuel bowl since there was no insulation left on the ipr wiring and I also replaced the fuel filter restriction switch for a leak. Took it for a road test and it had normal power, was building normal boost and I did still get it to skip once on accel from a stop sign. Customer needed it over the weekend. I recommended that he change oil since it was black as sin and there was no windshield sticker. He called the shop and said he didn't even get 10 miles down the road and that nothing was fixed.

Truck came back this week. I managed to find out that the customer is claiming he's towing 26k. The truck does not have a chip. I took it for a good long road test and after about 20 minutes I manged to get the real issue to show up. When you accelerate hard repeatedly the truck starts to run like crap and starts surging and looses power. Ran back to the shop, said the hell with it and went and hid behind the shop and did the oil aeration test. It failed miserably. ICP stayed at 2600 psi, truck ran like crap once it got the rpm's above 2500. Service manager called the other shop to tell them that we were gonna change oil and retest. They called the owner. Owner states that he changed the oil over the weekend as we recommended. I look at the filter and the color and condition of the oil on the dipstick and agree that it is fresh oil in it. Owner states that he used Rotella T 15w-40. Swapped in a known good ipr valve and reran the aeration test, with similar results as before.

I do believe that it is an aeration issue since when you let off of the throttle from running it at wot for anymore than a minute it stalls. I can't get the owner to let us dump his oil and put Motorcraft in it. I talked to another Ford diesel tech I know well and he told me to dump another gallon of oil in to overfill the crankcase and rerun the test. If it passes then I got a cracked pickup tube.

Is this something that actually happens? Anything else that can cause these results on the aeration test?

forddieseldoctor · October 25, 2014

Forgot to add. Running 33.5% max on ipr and 2700 psi at wot accel.

Keith Browning · October 25, 2014

Is this something that actually happens? Anything else that can cause these results on the aeration test?

I have never personally seen or heard of this happening but I suppose it is possible. Wayyyy back in 2005 there were a few engines that were built missing the oil pick up o-ring which will cause it to suck some air. Lucky me - I found one and it was the first pan I had ever removed. There was a TSB or an SSM on this.Speaking of oil pans, has this engine recently had a new pan installed? I hear that they rust. :haha2: Also wayyy back in time I had a customer with similar drivability issues that were also due to aeration. The oil pan was replaced and "regular" RTV silicone was used which is a no-no! ALWAYS use TA-31 (F5TZ-19G204-AB) Silicone sealant that is formulated to not deplete the anti-foaming agents in the oil. Remember that this is extremely important in ALL HEUI engines!When performing the Oil Aeration Test from the Diagnostic Guide Step 12a, the 1100-1750 psi specification should read 750-1250 psi (1.1-1.75V). If the ICP signal increases above 1250 psi (1.75V) after 60 seconds, then anti-foam additives may have become depleted from the oil. Change the oil and retest.

forddieseldoctor · October 25, 2014

I'll peek at the oil pan on Monday, but I'm gonna guess no. Since this truck is really clean. I can't get approval to dump the oil. It really sucks. I'm gonna be pissed when that's what actually fixes it after I've wasted a whole bunch of other time on it.

8WA Sman · October 25, 2014

I have customers that run Rotella T with no problems, some have over 300K on them. Did you put your known good ICP back in after repairs? Also check the ICP connector terminals.

I am also thinking I remember something about overfilling the crankcase to check for cracked pick up tube.

O I just caught the fact that it is a 1996/ no intercooler...did you check the back of the PCM for a board mounted chip?

Also make sure the CEL comes on in bulb check (KOEO) after the problem happens.

forddieseldoctor · October 25, 2014

I was thinking I should put a manual gauge on it and see what it read compared to the icp sensor. No I did not swap the icp sensor back in afterwards. Customer states no chip, but I did not tear enough crap out of the way to see the back corner of the pcm.

Buddy_M · October 26, 2014

I recall in the workshop manual about adding a gallon of oil, but to also add I believe they also had you raise the rear end of the vehicle about a foot or so in the air to help submerge the front end of the pickup tube at the front cover. For road testing you could probably get away with adding 4-6 quarts and run it down the road if needed, if symptoms disappear, it's likely a pickup tube issue.

Keith Browning · October 26, 2014

Going back through this thread - I think that if you still have not done so you will need to ACTUALLY run the oil aeration test. Be damned the people that you work with - you need to educate them that it is safe to run these engines at high idle (old diesel terminology reference) or WOT and perform the diagnostics properly.

Here is an important excerpt from the HPOP diagnostic guide:

"IPR with low duty cycle (less than 8% @ idle) and engine running, indicates a restriction in the drain circuit. This restriction is taking the place of the IPR valve, driving the IPR duty cycle lower, with higher than expected ICP. The excess restriction will be in the reservoir, front cover, stuck IPR valve, or debris above the edge filter. The drain path through the reservoir and front cover can be visually verified. Typically the pump or IPR must be replaced to repair this concern. Do not replace both components at the same time.

This often occurs after the oil pan is resealed where excess sealant is forced through the lube system (short circuit check valve) and trapped at the edge filter of the high pressure pump. In mid 1995 the edge filter moved out of the IPR, upstream into the pump.

Brad Clayton · October 26, 2014

I'll peek at the oil pan on Monday, but I'm gonna guess no. Since this truck is really clean. I can't get approval to dump the oil. It really sucks. I'm gonna be pissed when that's what actually fixes it after I've wasted a whole bunch of other time on it.

I worked with a couple of Navistar engineers that had this little bottle of magic that would make even the shittiest oil run as if it were brand new CJ oil. All it took was a thimble full of fluid added to the crankcase.

Too bad we can't get our hands on some of that!

Keith Browning · October 26, 2014

Pixie oil? Lolololol!!!

Bruce Amacker · October 26, 2014

I've personally seen:

-The IPR return restricted on a 7.3 after a pan was changed from rust that was in the old pan. The tech inverted the engine to replace the pan, dumping gunk/rust that was in the bottom of the old pan into the block area, where it migrated into the IPR return, causing very low (3-4%?) IPR and high ICPV. The fix was pulling the HPOP and cleaning the IPR return passage/edge filter area.

-Same thing on another 7.3 from too much RTV on the new pan.

-The wrong RTV used on the pan, causing aeration of the brand new oil (again, 7.3), the symptom was wildly fluctuating ICP going into an intermittent stall after 10+ minutes run time. The truck ran perfect for 10 minutes or until the oil started to warm up, then ICP would start swinging like a roller coaster from 3-400ish to 2000ish, stalling at 300ish. After much grief, changing the oil fixed it. The shop (local to me) changed every part of the HP system before I got there.......

The pixie juice is anti foaming additive Fleetrite/Navistar CH1824392, and appears to still be available: http://www.truckpaper.com/list/PartsSearch.aspx?PartNum=CH1824392

Good Luck!

:grin:

forddieseldoctor · October 26, 2014

Going back through this thread - I think that if you still have not done so you will need to ACTUALLY run the oil aeration test. Be damned the people that you work with - you need to educate them that it is safe to run these engines at high idle (old diesel terminology reference) or WOT and perform the diagnostics properly.

Here is an important excerpt from the HPOP diagnostic guide:

"IPR with low duty cycle (less than 8% @ idle) and engine running, indicates a restriction in the drain circuit. This restriction is taking the place of the IPR valve, driving the IPR duty cycle lower, with higher than expected ICP. The excess restriction will be in the reservoir, front cover, stuck IPR valve, or debris above the edge filter. The drain path through the reservoir and front cover can be visually verified. Typically the pump or IPR must be replaced to repair this concern. Do not replace both components at the same time.

This often occurs after the oil pan is resealed where excess sealant is forced through the lube system (short circuit check valve) and trapped at the edge filter of the high pressure pump. In mid 1995 the edge filter moved out of the IPR, upstream into the pump.

I did run the oil aeration test this last time. I got about 2500 psi almost the whole time I had it pegged at wot. It did start to run like crap over about 2500 rpm and anytime I ran it back down to idle after having it at wot for more than 1 minute it stalled no matter how slowly I tried to let it back down to idle.

I get complained about having the motor running too fast if I do a koer test on a 6.7. And I take them outside and do that or the other retards I work with complain about the smell in the shop.

Fordracer · October 27, 2014

Bad fuel or gas in fuel can cause it to fail the aeration test.

jimmy57 · October 27, 2014

"I get complained about having the motor running too fast if I do a koer test on a 6.7. And I take them outside and do that or the other retards I work with complain about the smell in the shop."

I guess you work with a bunch of celibate techs. Surely the sound and smell of coitus also bothers them.

DieselD · November 3, 2014

I get complained about having the motor running too fast if I do a koer test on a 6.7. And I take them outside and do that or the other retards I work with complain about the smell in the shop.

I had that in the past too, I had a pretty good method to shut them up. I would intentionally rev a smoky bastard multiple times to fill the shop once they started bitching. They figured it out real quick just to keep their mouth shut when I was working on a diesel.

or maybe I was just being a dick! :haha2:

forddieseldoctor · November 7, 2014

Well. After chasing my tail all I know is that it's not actually making foam. What I don't understand is what is causing the icp to jump from 1200 to 2000 psi once the engine crosses the 2500 rpm mark in park. It didn't matter how fast or how slow I ran the throttle up. I did verify it with a manual gauge.

Ended up bugging hotline and after a bunch of other testing and swapping every sensor off of this thing onto my personal truck they told me that it needs injectors. Whether it's actually what's causing it or not I may never know cause the truck left today... un-fixed. :facepalm: