Today I was towing a 3K lb trailer and 1500lb horse to the vet, on the way there no problems ECT and EOT were at the highest 12 degree spread with a 30 mph tail wind. About halfway home with now a 30mph head wind the EOT was 221 and ECT was 211, then the wrench light came on while going up a slight hill and the boost was 30.1 on the SGII, I pulled over and shut her down and she restarted with no problem and the light was out and there were no codes on the SGII. What do I need to look for?

 

Greater than 30 psi boost is on the verge of a overboost condition. The PCM may have been about to defuel to try to save your engine. from potential damage.

 

Is there anyway to prevent this from happening?

 

My truck was going into limp mode puling trailer before I replaced turbo due to overboost. Had to shut off and restart to clear.

 

Watch MAP, Baro, and EBP for a while. Should be within .5 of each other with key on engine not running. See if anything odd is happening when boost is up.

 

Thanks Woodlander and Rusty I will keep an eye on things and hope the turbo isn't going bad. I will be towing the horse trailer around again in the next couple weeks.

 

Your turbo has stuck VGT vanes, no question about it. Classic symptoms and cause, well known problem. You need to pull the turbo, take off the hot housing side and inspect the unision ring, the vanes, and the housing. If you are lucky it's sooted up and and has minor rust and you can just clean it. You may have serious rust pitting (mine did) and need to replace the turbo. You can drive it forever like this if you don't need low end power, don't tow a trailer, don't need tow/haul engine braking and don't need the best fuel economy. The PCM is quite quick at going into limp mode on overboost so you shouldn't hurt anything. FWIW I towed a quite heavy trailer around 2500 miles with this problem, I was just into the trip when the problem first hit, so I got quite good at going up hills very slowly so as to not provoke the wrench god...

Brian

 

Over 28 psi boost is not good. Turbo or vgt solenoid or both. More than likely turbo. Three times on the truck I no longer have.

 

Thanks for all the help, looks like after I take the horse to Colorado I will pull the turbo and see what it looks like.

 

I bought a new 03 turbo for $899 and an now whistling down the road

 

I will think about that Woodlander!

 

The only real way to keep the wrench light from happening is to keep your foot out of it when pulling a load. Heck even the big rigs don't try to pull the rocky Mountains in high gear. LOL

 

Sorry, double post.

 

I agree with you there, just try to tell the wife that, she drives the Superduty like she drives her Screaming Yellow Mustang!!

 

I agree on using the proper gear but if everything is working properly your foot on a hill with a load should give no cel's.