I have been chasing an issue for a while and I have pinned it down to oil. Not the oil system, but oil. When my oil is fresh and cool, Stinky is quiet and smooth. I sometimes get nasty cackle under the hood, and sometimes not - but never when the engine is cooler. While monitoring AE, I see a pattern - Stinky's quiet when the Engine Oil Temperature is 180 degrees, 190 sometimes bring cackle and sometimes not, 200 degrees is obnoxious, and 210 degrees (on warm days and hill climbs) is practically frightening. Any time Stinky adopts the nickname "Noisy", the idle is less than ideal, but not bad.

I have all the fuel mods and my fuel pressure is stable, but I can see my IPR climb a bit to keep the same ICP as the oil heats/thins. While wrestling the web for the why, I stumbled onto yet another useful link (of course it's in my signature now). I read one line that raised an eyebrow: "the anti-foaming agents are depleted from the oil" Uh? Here is an excerpt from that website:

Recommended anti-foaming additives are Fleetrite with the Navistar P/N CH1824392 or Lubrizol 888. These are primarilly used to counter the effects of silicone sealers on the anti-foaming agents in the oil or if the agents become depleted from use providing the oil is still servicable and uncontaminated. An anti-foaming additive could also be used between oil changes if an oil-related poor running condition is suspected, especially on a long trip.
Under normal driving conditions the additive could extend the oil change interval to 6000 miles. For vehicles that are used for infrequent towing, using the additive at 3000 miles could extend the oil change interval to no longer than 5000 miles. Vehicles operated in dirty conditions, extreme weather conditions or constantly under heavy loads should stick to the 3000 mile service interval due to the other agents in the oil being depleted, and should only use the anti-foaming additive if performance problems occur between services.

I think this warrants a discussion. Your thoughts?

 

So do you get cackle when the oil is new, or only as it ages? I understand the temperature part but you were not clear on the aging effect. What oil do you use?

 

I use Mobile 1, and I've tried Rotella T6. The truck is quietest when the oil is fresh, but I blast through so many miles that I didn't track the decibel meter with the odometer. This is a recent discovery (since my loose injector issue was skewing my observations) and I'm just now sussing it out. I change oil at 5K (every three months).

 

hmmm. I'll have to pay more attention to mine but it seems I have no cackle, ever, oil hot or not. I am using Rotella 15/40 changing it around 4-5K. In fact, since my Frx and my bellowed up pipes I have marveled at how quiet my truck is. I am bone stock by the way. I do use a mixture of Optilube and Stanadyne in the fuel. There is a noticeable difference in noise reduction with the Stanadyne which I assume comes from the cetane improvement, she just whispers at idle.

 

I have been using T6 for about 3 years now. I have the oil tested once in a while. They keep saying to run it longer it looks good. I notice that at about 5000 miles it starts to run different and seems a little more noisey. So I keep changing it at at about 5000 miles. Makes me feel better if nothing else. I had a Tundra that i ran the Mobile 1 extended life oil 15000 miles between changes with a filter change at every 5000 miles with not one problem and great oil tests.

 

I didn't have good luck with T6 at all. I had changed to T6 last fall for the winter. Then this spring I was having to add a qt/800 or so miles. I changed at 7k miles and had added like 6qts of make-up oil. When I changed I sent a sample to Blackstone with the comments about the oil usage. They pointed to a possible turbo bearing issue, but other than that nothing jumped out.

At the oil change I went back to Rotella 15w-40....and now 4k miles in....have yet to add any make-up oil. Odd...and maybe the T6 was suffering from oil shear? Don't know.

 

Are you running any fuel additives? I noticed a noticeable tone difference adding 100:1 two stroke oil to the fuel.

You might try this oil additive:
http://www.riffraffdiesel.com/mm5/me...Store_Code=RRD

 

Have you looked at your perdels once warm. When I was having g my problem with injectors I noticed the idle got really bad as temps rose. I could watch the oil temp rise and the perdels would climb with it. The idle also got worse. After finally getting injectors that all like eachother my idle is smooth and engine is quiet. Also I am running bobs thermostat.

 

For years I have been wondering if the anti-foaming agent breaks down and if so...when? My lab says they aren't really able to check for that since each formula is different. I've thought about adding anti-foaming agent to the oil but not sure of the timing so I haven't tried it yet. Even so, my lab reports show that wear levels are very low so if the anti-foaming agent is breaking down it's not causing any more wear....just more noise.

My engine sometimes has the cackle when hot. Never when cold and hardly ever on new oil. On 6/28 I had to use my pickup to tow my fifth wheel up to the mountains since I had an issue with the 450. The oil in the pickup had 8112 miles on it at the time AND that truck also ran hotter than normal (later turned out to be a partially clogged radiator...). At any rate, when I got to the top of the hill and stopped to fill up water, the engine was quite noisy at idle....much more so than any other time in memory. I didn't have my AE connected so I have no clue what the temps were but I am sure they were above normal.

I then changed the oil and had the radiator cleaned. The tow home was much more enjoyable. No overheating...no noisy engine...no cackle. In case you are curious...that truck does not have AE in #8 ...they all are AD injectors. By way of comparison...both of my 2000 model year trucks have an AE in #8 and I've never heard those trucks cackle like my '99 does. Kinda baffles me though because the AE is so minutely different that I have a hard time believing that it makes any difference to the engine sound but I suppose it may have some sort of effect.

 

Rich, other thing you have to remember is that there are 2 timing tables, one base table, and one modifier table, that adjust things based on oil temp. I'd mention it to your tuner and let him see if theres any change in timing once oil rises above the 180* threshold. If there isnt, it may need a bit of an adjustment to account for the qualities of the hot oil.

 

I don't know about you guys, but I'm finding all of this interesting. I've had a couple of thought since this popped up - one was injectors and the other was oil. What if like JT250, I have one or two of less-forgiving injectors AND my oil choice asks them to be a little forgiving? That RevX looks interesting, and I've been using the Motorcraft fuel additive... but every diesel performance shop I've been in has Stanadyne in a pyramid in the middle of the floor. I'm thinking of getting some Stanadyne for my next fill-up. I've read the "don't add anything to the oil" speech many times, and it's hard to argue against it with a HEUI system. The wrong move can get expensive, but if that choice is wrapped in yellow tape....

The dealership service department and I are playing a game of passive-aggressive with each other right now and I'm feelin' grumpy - I either need a cookie and some warm milk... or to curtail their Buck$Zooka rations. It's sometimes hard to know who's being the *** (or the biggest). I have Stinky in for his 30,000-mile checkup on the HD4R100 to keep the warranty valid - this is the fourth time they had the truck for a week to do this and I'm picking it up tomorrow. You'll notice I made no mention of whether the work was done or not. In all fairness to them, I'm not their dream customer. Sure, I spend money... but they have to endure me. "Did you check the valve springs and push rods? What method did you use to tighten the injectors? You didn't flash the PCM, did you? Is it done yet? Is it done yet? Is it done yet?"

I think Cody and I discussed tuning one time, but the cackle is on one side now (I played musical sticks to isolate the problem). I have one side causing grief at this time, and the other side is fine. I need to determine if I want to go through the hassle of swapping a noisy injector (like I did last fall, which brought Frankenstinky to life), or find a chemical solution. I have one stick (confirmed root cause is injector) that gives me a Perdel of 3 when EOT is over 190 degrees - but it doesn't cackle. The loose injector issue really threw me off this trail for a long time and I'm just now getting back to it.

 

dont discount that you might be finding a issue with the oil itself. Have you moved to a different brand? Are you running synthetic?

 

Just me I guess but I like the cackle - If I didnt want cackle I would of bought a chebby. Mine sounds like a truck should

 

Following your tread. Change the oil no matter what the mileage is and see if it goes away. If it dose, change brands next time. I don't think the anti foaming thing will hurt your injectors but if you can cure it by changing oils I'd rather you do that!

 

Just to drop this here because I think it fits:

I heard plenty of success storys about switching to Delo. It quiets down the motor and makes the truck runs smoother. Primary because it's anti-foaming and other additives.