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View Full Version : Lowish boot, highish EGT..need advice



biggreendiesel
12-18-2007, 08:19
Hi folks,

I could use some advice on this one.

The Truck:
96 K2500 4wd 103k miles
97+ Cooling mods
180 degree thermostats
97+ intake with K&N
4" exhaust post turbo (no cat)
4.10 gears
PMD replaced with Heath's set up 5k or so ago after mine failed.
Stock ECU

The Issues:
Truck has always had lowish boost (2-4 psi under load, never higher than about 5psi peak..maybe 6 but only very very briefly) and moderate power. However it did fine towing my relatively light 3500 lb trailer.

More recently, the boost seems slightly lower than before and the egts higher. My post-turbo EGT gauge can get into the 900s pretty easily if I put my foot into it for a bit - even when I am not towing on flat ground. Highway temps not towing are ~500-600.

It seemed to get worse following the pmd replacement, but that could just be me. Note that I did not have anything calibrated with the pmd...just replaced the old unit with the new one.

Power is better when it's cold outside, but that is usually true.

Otherwise truck is great. Starts right up, consistently runs quite cool (coolant temps 185 degrees) with low tranny temps as well. I'd love any thoughts / advice folks might have.

Hubert
12-18-2007, 09:32
First check air filter and change accordingly.

Still probably a bad wastegate solenoid or vaccum problem (leak or maybe a bad pump). Fix first then look into boost fooler or just go with turbomaster spring control. Get boost to peak up to max 10 psi under load ( at about 2200 -2400 rpm) with either wastegate controls mentioned and see if you like performance better.

Post turbo I want to say 800F is a better safe limit sustained EGT. Get boost up a little more and EGT should be more in check.

Don't worry about boost at idle or cruise it will only be 0-3 psi normally. But it should react pretty quick and change according to load and fuel rate. If you are not getting up to 6-7 psi easily on hills or towing something is wrong and probably a wastegate issue.

Hubert
12-18-2007, 09:34
You can look at vendor list or net at kenedy's or heath's website for more info on boost control gadgets.

Hubert
12-18-2007, 09:40
I am assuming its an "F" engine (no EGR stuff). I can't remember all the different truck options.

Fill out your signature and that will help others give better advice.

Miles, upgrades, condition etc.

biggreendiesel
12-18-2007, 12:15
No EGR present.

Robyn
12-18-2007, 12:55
Are you still running the vacuum controlled wastegate system??

I have a turbo master on mine with a chip that is programed to allow for more boost without tossing codes.

Mine will see a quick 7 psi right off the line and then once the load come on it will come up to 10 psi and possibly 11-12 on a long hard pull.

The factory system can do about 7 max but all the components must be in top shape.
Vacuum pump working at its best. Wategate actuator working properly
wastegate solenoid (On LH VC near the back) working properly too)

If your exhaust is in good order and the turbo and the air filter system are good 10 should be easy.

Robyn