So I have had problems with from the day I got the truck. Very slowly making progress. Getting up to speed usually takes a minute. Sometimes it take a little longer to shift gears almost like I'm always pulling something. There is usually a poping noise randomly. It starts to shake pretty bad usually after I get up the speed and the let my foot up a bit to maintain it. Overdrive helped a good bit but i had the engine replace and it doesn't effect it as much anymore. It seems to run a bit hot but gage never reads hot. Before i had the engine replaced it leaked oil something awful. So i was wondering what might happen if i added a little blue def to the coolant. I've had the transmission looked at, they said it wasn't that. Fuel pump. Distributor coil and more. 3 1/2 mechanics later and Idk what to do. The engine was supposed to fix it. Ideas?

 

You mean 5.9 not 5.7 You might want to have the fuel pressure checked. Was the plenum gasket addressed? Blue def is for emissions on a diesel and it doesn't go in the coolant. When the distributor was replaced did they set the fuel sync? Any codes?

 

No 5.7. Plenum is part of the engine right? Idk about the fuel sink thing. No codes but light comes on for a day and then goes off for a few days.

 

There was no 5.7 in a second gen. 5.7 is a Hemi and wasnt offered until 2003. You either have a 5.2 or 5.9.

 

Unless someone out a later engine in your truck, and managed to get the computers all working together, you don't have a 5.7. You have either a 3.9, if you have a 6 cylinder, or a 5.2 or 5.9 V-8. The plenum is basically on top of the engine between the valve covers. Blue Def is meant to keep catalytic converters clean on diesel engines. It's main component is urea, basically cow pee. You do NOT want that in your cooling system as it will upset the chemical balance of the coolant. The anitfreeze part never really goes away but you have anti-corrosion components that keep the steel and aluminum parts from counteracting and eating the engine away from the inside.

There are a lot of things that will slow you down. First off, you do realize you have a truck, right? If you expect it to handle like a car, you'll be disappointed. Lot's of things can cause drag. Brakes dragging, universal joints seizing up, front end out of alignment and so on. First off, you need to know what engine you have. The 5.7 looks quite a bit different than earlier engines. The 5.9 is different inside but looks a lot like small block V-8's from Chrysler since the late 1960's.

 

No you were right. 5.9 I always get it backwards. And I realize that blue def was made for diesel or i would have just tried it without asking. It's not a sluggish like it's a truck duh sluggish it's sluggish like can't catch a breath, can't catch the gear, shake and sputter sluggish. When i first start it it takes me a solid 5 mins floored to get up to 50 sluggish. So what about the catalytic converter. Is that simmering it could be? That's ridiculous difficult to get to right?

 

I think the cat is the first thing I would be looking at, if you aren't getting codes for anything else...... The cat is part of the exhaust, and its just past where the two pipes from the manifolds come together. Unfortunately, I think everything is welded together there.... (if not with a welder, then, with rust.......) so, getting a peak inside ain't easy. You could try physically removing the front O2 sensor, (right in front of the cat) and going for a drive, see if things are any better... But, getting that sensor out isn't exactly a piece of cake either.

Could try just unplugging the sensor...... and see if anything is different, but, if your truck drives like a slug, even when the engine is cold, I don't think you are going to get lucky.....

 

So before i do all that the reason i think it's not...
It's got some weird correlation with the ac. When it's struggling to get up to speed the ac stops blowing cold and doesn't blow nearly as hard. As soon as it picks up the gear the ac snaps back.

 

I wonder if it's a charging issue

 

Is it just redirecting the air to the defrost vents? If so, that's a pretty standard problem with these trucks, with low vacuum, which a clogged cat will give you..... the problem is even worse.