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Yup It Was A nightmare. ya had to be there to grasp the situation.It was embarrassing to say the least.Is the best words to describe it!

B61 Unfortunatley 3 Mechcanics didn't design and build this engine . Things would be a whole lot diffrent if they had. Don't forget this engine has been the back bone of the mack line for the last decade and all the stuff on it is bolton to get by reg's stuff the core engine is still good ole mack stuff. The coolant system however evolved, got changed to put up with the egr heat its been a dogs breakfast of problems since.They how ever have worked thru MOST of the problems! if 68 will send you all the sb for the coolant probs ensure you got ALL the upates Thermastat housing and plumbing reroutes ect the water pump is a quicky but make sure you get the right one! Hope ya get everything sorted out man. These engines can be made to hang in there, Problem is not everyone has the time, money or patients to get them there.

Trent two diffrent animals!22- 28 is spec on a v8 A good hot runing v8 500hp will be 28 -32 I beleive his is a 400!A 400 I would expect to see 22 24 maybe 25 max!If the fuel is stock!

Al the boost gauge was plumbed in the right spot the cross over is where to do it!You should be seeing 22 to 28 psi under a decent pull! You either got one hell of a leak or the turbo is not working right you should be trailing plumes of black smoke behind ya if theres a leak that big. Is the fuel pump robert bosch? if you don't have smoke .I would check the lda valve on the back top of the pump take the hose off at the engine end and suck on it if it will not hold a vacuam the diphram inside is fubar. Also if the engine has an air throtle make sure the dam thing is opening right up!

Worst part is if its the egr cooler your going to have to replace it now!If you do ! cap off that valve as Jerry did!

The pyro heating up indicates not enough air yes the leak has alot to do with it! BUT was this problem there when you changed out the turbo before?The turbo can look and feel fine but if thr wrong compressor wheel was installed at rebuild it will get warm! Check the gap around the compressor wheel if it has a big gap say 1/32 of an inch its got the wrong wheel on it Ive see this happen on rebuilds before. just somthing else to look for.

Time to plug off that egr valve!

You should put the driver on your truck !Then you can blame him for everything, It will make ya feel better. Off subject! No falt codes with the egr plug Jerry correct ?

Naw I'll be, awhile doin this, got to pick the time !As for the ecm I m going to gamble on the no change needed aproach. ive been off for a few weeks had my hand fixed couple of weeks to go.

Well Im going to find out ! I'll race ya!

Its been my observation that the puter don't care about the egr valve position! It looks for the target if it don't see the value it simply opens the valve more! If the egr cooler is pluged what code do you see?? I have had egr valves fail with no codes!!!I ve seen pluged egr coolers no codes! you can hear they arent working right. I was thinking the same about the plate we have several trucks I got in mind for this! If the flow is not there it simply opens the egr valve in turn it doesnt let the turbo spool but if there is a plate there like I said before, theres no place to go but out!!!!????

Yes!I beleive you can still get It! aint cheap!

Mack diffs can also have inter wheel power divider simular to the power divider setup these make alot of racket aswell.

And hopfully they will find somthing, we have done this before found to be low and had no resolve! Unfourtunatly the dealers hands are tied, you can't just try this and try that without having permission to do so!

Theres one thing about this Jerry you will not have any problems with the egr cooler cracking with no flow it will never get hot! I do know that if the egr valve is stuck open or closed or if the egr cooler is pluged the computer won't tell you theres a problem so pluging off the valve at the manifold does make some sence.no flow in the egr tube will tell the computer to open the egr valve but with no where to go but out, there you have it!

Ask this question two years from now We'll know more jury is out !Hopefully the bugs will be by that time too!

What's the difference between the ASET, AC and AI engines...? Ac is tractor AI construction truck two diffrent egr concepts! you need AC.

All external problems ,exhast gaskets, turbo problems, coolant pushing problems! most of which have been finally cured BUT has your prospect truck had all these up dates???? That would be your worry!The later 2005/6 trucks mostly had exhast gasket problems the fix is spacers and update gaskets you got to know what to look for! maybe you should take the hint move up to 2001 or past 04 to 2005/06 Or stay put!!!!

My guess would be the throtle lever is broken try replacing that first!

I agree with Rob here replace that HL switch somthing told those relays to shut down All at once ,that relay arangement,(The Update} was ment to take the load off the HL switch, Maybe it got installed a little to late to save the switch!

Hope fully exhast gaskets only! Don't kid yourself they make most of the money off the parts and what they swindle out of the dealers! Not offthe sale of the truck!

If you inframed it and did not remove the fly wheel yo may be ust getting a dirty flywheel sensor!

I Just didn't want to say it! Its a truly bad Business move if thats their plan! Just makes us all look bad!

Thats disgusting !Some one droped the ball on that one!

The codes sum for the newer stuff are posted here ! http://www.nortrux.c...hp?area_id=1003