JerryB

I would love to see a picture of this turbo!The mounting flange is a tad different on vgt style turbo! Doubt it would even fit.If you have a waste gated turbo and you have replaced it with a standard turbo the result is the same if the engine sees any more than 33 psi boost it will derate!In this case you (MAY) be able to remove the sensor from the manifold and plug the hole and install the boost sensor in a plastic bag on the fire wall so the puter never sees the boost! down side is your boost gauge wont work!Put in a real gauge

The turbo does mount differently and I forgot to mention we used a different exhaust manifold. At the local parts store I get the traditional turbo for $595 but for the VGT they asked me $2875 and Mack wanted $3850 so please excuse me for suffering from sticker shock.

When I can find the boost sensor I'll try removing it like you suggested before I spend the big bucks for the vgt and do all the work of switching it back again. Thanks guys I do appreciate any and all advice.

Gentlemen I had a VGT turbo go out so I replaced it with a regular single speed Mack turbo now I have low boost pressure and weak engine. Is there anyway to correct this besides putting back on a VGT turbo?? According to the manufacturer the new turbo should produce at least the same amount or a little more boost as the old.

Gentlemen thanks to you each and every one. the Houston Mack dealer shop had supposedly done the checks but today I idled the engine up to about 1100 RPM and started spraying all the air intake system and air to air condenser with soapy water and the turbo outlet hose going from turbo to condenser was bubbling like a bubble bath at the far end of metal tube. I put on a new hose clamp and upon testing the engine is back to it's old self. Thanks again I wouldn't have thought after paying over $500 I would have had to check it. my shop receipt says they had checked it already so I didn't suspect it.

Gentlemen my 04 Vision CX613 w/460 ASET and has 450,000 miles is running high exhaust temp, up to 1200 degree. I carried it to Mack in Houston and had air to air, turbo, egr gate and waste gates checked, no problem found and no codes present. Checked pyro and put in new pyro sensor.

symtoms:

1. when bringing up to operating temp it smokes black smoke like freight train

2. engine coughs like gas burner when accelerated and sometimes white smokes from exhaust only when accelerated

3. fuel mileage has dropped about 1.25 mpg

Thanks in advance for any help. Jerry

You need to have the Calibration # off the EUP installed in the trucks ECM. You can run truck with out doing this but it wont run its best.

Thanks Mackpro68.

My 2004 Vision w/460 Mack engine was giving electrical fault code 8-5 so I've replaced the number 5 EUP. Could someone tell me if there is anything I need to do now before I run the engine as normal? TIA--Jerry

I will say this one more time!!!

THE TURBO CAN COME OUT OF TUNE and Will not throw a code Have it recalibrated and make sure its going full stroke!Have em watch the lever and push it full stroke if need be!The computer remebers the stroke in the recal sequence.Have em use the advance display in the vmac 4 program and make sure the egr flow and turbo are reaching their targets! The two wire plug you speak of throws a 270 code if faulty (compressor discharge temp code.)

Thanks guys. When I said I had it scanned I meant that I have carried the truck into Mack again yesterday and had it scanned. I was listening to you the first time and did have the turbo and gates check performed. Thanks again--Jerry

Thanks guys. It still shows no fault code on dealer scan but today it seems to be running normal. I tried the self scan using mode and reset buttons but all that comes up is a single reading of < 1.2 > in the top right corner of display.

I have cleaned all terminal and connections from batteries out. There is a sensor w/2 wire connection in the aluminum air tube going from turbo to charge air that upon removal looks dirty with slight heat damaged wiring. Do either of you know what this sensor controls? Thanks again--Jerry

I see several replies to other power loss problems but none of them address my problem. I have a 2004 Vision/w 460/18sp @ 370,000 miles on it. With engine cold in morning it black smokes heavily from exhaust and has normal power, but after the engine reaches normal operating temp the smoke clears and engine loses power. Accelerating from dead stop the foot throttle has little effect but when I release the accelerator then mash again there is some power increase (not nearly normal power) and slight rpm gain. Traveling down highway the accelerator somewhat responds after several (3 to 5) seconds of dead pedal after being mashed but will not reach but around 1400 rpm with manifold pressure tops out @ 24-25psi. I have changed the fuel and air filters plus pressure checked the air to air. The only need so far has been replaced the EGR valve and EGR cooler with overhead run again 50,000 miles ago,

The dash board shows no fault light and I have had a computer scan done at Mack which show no fault present. I know absolutely nothing about computer trucks so does this make sense? is it possible there is a fault code present but the Mack tech did not/cannot find it? Any help will be greatly appreciated so thanks guys--Jerry