T444E CACKLE

[Blacktruck-1]

Well my employer just graced us with a fleet of 2001 4700 series Navistar powered service buckets and this is a different animal than the old DT466 I was driving.

Much more refined than the straight six and I can see out of the mirrors when stopped without revving the engine! Not as much across the board torque and the turbo lag off idle took some getting used to however when the turbo spools up the motor comes on pretty strong. Much smoother operation and a heck of a lot quieter. The I-6 would drone at certain RPM's

I have noticed that at around 2200-2300 RPM at light throttle the motor makes a stuttering sound that sounds similar to my DMax pilot injection cutting off except that it is reminescent of spark knock. The phenomenon is repeatable and consistent. I am curious as to which systems are shared by Navistar and Ford and if this could be the famous "cackle" that I'm hearing.

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Member# 5723

http://www.picturetrail.com/spankster

Onyx Black, Graphite Leather, All the goodies! '01 cc D/A LS 2wd order # Since 02/19 TPW 3/19 VIN 3/20
Arrived 03/29

DRIVING IT

[DmaxMaverick]

Blacktruck-1

That may be part of it, but when you hear a "cackle" you'll know it. I can't really explain the sound, it just "cackles". Maybe someone else can describe it.

[n3qik]

Blacktruck-1
The new engine dose have split-shot according to their web site.So it bight be what you are hearing.


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Ken Norman
1999 Chevy
2500 Series
Crew cab
short bed
6.5T and Auto.
Avg. 16.1 MPG city
Avg. 19.5 MPG highway
towing a 31' Golden Falcon travel trailer @ 11 MPG Highway
15000 miles and counting !!

[Blacktruck-1]

I dont believe the 444 uses Pilot Injection like the Duramax. It has the standard HEUI injection that is shared with the Powerstrokes. The noise i'm hearing is a loud pronounced "stuttering rattle" at a particular rpm and throttle position.

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Member# 5723

http://www.picturetrail.com/spankster

Onyx Black, Graphite Leather, All the goodies! '01 cc D/A LS 2wd order # Since 02/19 TPW 3/19 VIN 3/20
Arrived 03/29

DRIVING IT

[SteveO]

Blacktruck-1,

The 444T does use split shot injection, which is esentially the same as Pilot injection.. The current generation HEUI (Cat 3126, DT466, 444T, and a few others) is the older design and is louder, but it's still injects a small amount at the begining of injection and then the full injection to complete the cycle..

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2001 Chevrolet 2500HD 4x4, Crew Cab LB, LT, LB7-Duramax Diesel/Allison 1000 Series, Autometer Boost/EGT Gauges, Husky Floor liners, Vent Shades, 285/75-16 Brigestone Dueler AT's
The Diesel Page member #330

[Blacktruck-1]

Thanks SteveO--Is there a cutoff point at a specific RPM like the Max? My Chevy is either on or off, nothing in between. The Navistar seems to vary with throttle pressure.

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Member# 5723

http://www.picturetrail.com/spankster

Onyx Black, Graphite Leather, All the goodies! '01 cc D/A LS 2wd order # Since 02/19 TPW 3/19 VIN 3/20
Arrived 03/29

DRIVING IT

[dmax]

I don't think the split shot can be turned on or off by the description I read here...

http://www.intellidog.com/dieselmann/injector.htm

It looks like it's a mechanical function designed into the injector whereas the Duramax uses high speed solenoid actuation to do the same thing.

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Mike
Member No.2429
2001 2500HD GMC Duramax/Allison Summit White CC/SB Loaded, Amsoil Air Filter, PS2K Propane, Straight Piped, Allison Deep Pan, Transynd Syn ATF, SPA DG-111 Boost/EGT, Nordskog Digital Fuel Level, VentShades, Husky Mudflaps, 255/85-R16 Dunlop RV's PICTURES (http://uscom.com/~hoot/cars/duramax/gmc/)
1994 K1500 Blazer 350 Loaded, Flowmaster duals
Raised in Rockdale, Pa. Lenni Boy!

[SteveO]

Dmax,

That's correct.. The split shot injector is a physical part of the injector plunger.. The Single and split shot do have different programing, but there is an actual difference also in the two injectors..

The difference in the single and split shot is the plunger has some (what I call) "grooves" cut in the lower portion, which acts to pressurize a small amount, then the upper portion continues down and injects the main shot..



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2001 Chevrolet 2500HD 4x4, Crew Cab LB, LT, LB7-Duramax Diesel/Allison 1000 Series, Autometer Boost/EGT Gauges, Husky Floor liners, Vent Shades, 285/75-16 Brigestone Dueler AT's
The Diesel Page member #330