6.5 over boosting?

[craig12]

i bought 99 6.5 tb a week back, looks to be modded in a few areas from previous owners, and it seems to be hitting 15 psi boost when im towing about 6000 lbs car trailer on climbs, im thinking this cant be stock. Is there any way to adjust the wastegate? temp hit almost 230F going up one of the longer steeper climbs, is this related to the over boost im getting? the exhaust gas tempurature hits 8-900 F max on those steep climbs, which i assume isnt bad..?

 

[fastjohnny]

Does it have a Turbo Master instead of the factory vacuum controlled wastegate? If so, just loosen the spring tension. Those EGT's don't sound too high to me. At least you've got gauges telling you what's what!

 

[craig12]

its got a vacuum line going to where near the PMD was relocated, to a black box that has electrical connect that goes to a main harness it looks like

 

[WarWagon]

Could have a boost fooler installed.

I have run 14-15 PSI with the fuel turned way up. Did not have temp issues towing after fixing/upgrading the cooling system to near 1999 specs. (Single stat.)

You need to fix the cooling system - externally plugged radiator or bad fan clutch...

 

[craig12]

you may be right, but i think the heater core may be plugged, it girgles once in awhile. other then that hard driving emty it will never rises above 1/4 on the temp guage, just when i pegged it with a 6000 lb trailer on steep climb i it rose and kept rising, to 220-230ish, almost 3/4 on guage, after it leveled off it almost instantly went back down to 1/4 -3/8 on the guage,
truck hits 15 psi wastegate, not sure if this is safe or not on 99 6.5? i just heard there not meant for higher boost.

 

[craig12]

here what it looks like this doesnt look like a mechanical turbo master style to me

its annoying not knowing what 2 previous owner's ago did to the truck

 

[NVW]

It looks like the vac system is factory, can't tell for sure in the second pic but is the PMD mounted to a piece of aluminum on the intake? If so move it out of the engine bay. PMD Cable sells extensions.

Pull your rad and clean it real good with scrubbing bubbles as well as the oil cooler and condenser. I bet that is your heating problem. The EGT's are good.

 

[ak diesel driver]

after cleaning the rad do the fan clutch mod

 

[JiFaire]

Nice pictures, Craig. Welcome to The Truck Stop!!

Take a minute to fillout your signature as well as you can so we recognize your ride... click on the link in mine to get to yours.

You definitely have a stock wastegate assembly, but your 15psi boost isn't stock. That means either you have a reflashed PCM or a boost fooler...

Your water temps are high, which is a real issue. There are some threads around here that describe taking out the rad and cleaning it out good. Makes a LOT of difference. Like this one

http://www.thetruckstop.us/forum/showthread.php?12228

There are also some threads about modifying the fan clutch so it kicks in earlier:

http://www.thetruckstop.us/forum/showthread.php?t=12265

We'll probably need to know if you have either a boost fooler or a modded PCM at some point. You might look for a boost fooler:

http://www.thetruckstop.us/forum/sh...echnical-Library&p=61390&viewfull=1#post61390

 

[WarWagon]

Did you hear your fan kick in when it was hot? I ruined a good 6.5 over a bad fan clutch towing just like you describe above.
#1 thing you need to fix: cooling.
# everything else including high boost.

 

[625fireman]

The rod could also be rust frozen and not letting the vacuum can move it. See if you can move the rod up and down with the engine OFF.
After you take of the cooling issue first though.


OBTW Welcome to TTS.

 

[great white]

For sure someone's been in there and has at least messed with the stock system a bit. The VAC hoses have been replaced. Might have been simple maintenance for "cracked from age" stockers.

Since the hoses have been replaced, it's possible they're backwards on the wastegate solenoid (thing with teh blue wire connector). The wastage vacuum hose should be on the rear most nipple of the solenoid.

My 98 will peak somewhere around 10-12 psi (not really looking at the gauge at that point) with the throttle mashed and accelerating hard.

15 psi sure sounds a tad high.

Where's Sooke? You on the mainland?

I'm on the island.

 

[craig12]

i took a gander at where the pryometer guage was located on the exhaust and it was after the turbo so could that mean my exhaust gas temp was way higher then it was reading, and cause cause the engine temp to go up?, ill check the clutch fan as well,
the pmd is relocated on a heat sink, and someone installed a hood scoop directing outside air right at it.
the wastegate rod moves freely.
and im on vancouver island

 

[great white]

i took a gander at where the pryometer guage was located on the exhaust and it was after the turbo so could that mean my exhaust gas temp was way higher then it was reading, and cause cause the engine temp to go up?, ill check the clutch fan as well,
the pmd is relocated on a heat sink thing, and someone installed a hood scoop directing outside air right at it.
and sooke is on vancouver island

Ah, got it. Sooke is down by Vic.

I'm in Comox.

After the turbo? Is it installed in the elbow of pipe?

I can't see why anyone would install it there, that seems more trouble than the usual place in the exhaust manifold below the turbo....

 

[NVW]

Post turbo EGT is about 200* F less than pre turbo, rule of thumb is to back off at about 1000* F post turbo.

 

[625fireman]

I would bet than the lines are on the switch backwards then.

 

[craig12]

the vacuum coming from the turbo goes on the rear port of that black selenoid, front port goes to the vacuum pump, i checked the wiring and i seem to cant find anything like boost fooler. seems like my clutch fan may be shot, higher i rev it in Neutral it really doesnt push more air then it did at idle too much. and free spinning with engine off it seems to have "easy" spots when you spin by hand, i dunno tho, i dont mind the extra boost that much but as long as it doesnt lead to overheating and other problems, might go with a mechanical turbo master style wastegate that way i can easily set the max boost without this vacuum computer bs

 

[WarWagon]

You have to have a aftermarket program in it or the engine computer would de-fuel you at higher boost. Maybe it is de-fueling you.

 

[craig12]

i have a new problem now, i was towing about 6000-6500 trailer up a pretty steep grade, boosting around 14-15 psi basically the max of the gauge wasnt giving it all it had, Egts were safe, motor doesnt overheat, but all of a sudden the turbocharger completely cuts out, goes to 0 psi and speed drops a bunch and EGTs go way up and crams massive clouds of black, like 40-60 seconds later turbo kicks back in goes back to "normal", somethings definatly wrong, I dont think ive ever seen a diesel cram that much black out it must have a 9 # resistor or something looked at it looks red and says "beta 9a" if that means anything to you guys. I havent done much at all since i started this thread basically procastinating but i think a im going to install or make a mechanical spring style waste gate and go way down to stock boost pressure. Also it seems like im fighting the truck all time to keep the EGTs down like im not giving it as much fuel as i could be on the hills. this could be product of too much boost i think? like as far as i know when it hits 15 on the gauge it could very well being past that since thats max on the gauge.
and if i install a mechanical waste gate will it affect anything computer wise or fuel wise that may complicate things any more?

 

[ak diesel driver]

pcm is telling you too much boost and backing the boost off until things get under control again. Even with a TM unless you do a boost fooler or a chip your still going to have problems.