I'm a VW guy and know very little about Dodges, but my new-to-me truck seems a little wimpy. It's a bone stock '97 5.2 4wd lsd auto with 225k miles, and when I'm driving it at about 60 and floor it, it seems like not much happens. I understand it's no powerhouse, but is there a common problem in these that would cause it to seem weak?

I've only had it two days and had to completely go through the brakes (broken line above the tank of course) so I haven't checked the plenum and much else, but I put new plugs in it and it starts and runs quite well.

Any fix or is it just weak?

 

Well as you stated, they aren't the biggest powerhouses to begin with but, the plenum affects so much that it needs to be addressed before doing anything else. Followed by doing something with the clogged catalytic converter and pre-cat O2 sensor.

Doing a full tuneup will help along with a new timing chain, double rollers are cheap at rockauto.

Best way to check the plenum is to take off the throttle body and look down with a flashlight and small dental mirrors...

Gears and size of tires matter too, I'd say you have 3.55 gears, what size tires are you running?

Edit:

I think the stock solenoids in the transmission are pretty terrible at WOT, others can chime in about that..

 

Take it to a muffler shop and have the catalytic converter pressure tested. When the cat is clogged the engine can't breathe, hence a loss in power. If the cat needs to be replaced then consider replacing the air filter and also the O2 sensors (O2 sensors should be replaced ~50-60K miles). Most people believe the O2 sensors should only be replaced if the PCM throws a code; however, their performance can diminish but still not throw a code. This results in problems with the emissions system.

 

I'm at work but I'll look into some of these things this weekend. My tires are 285/75/16 on stock wheels, as I recall, so they are obviously bigger than stock.

I have a feeling not much on this truck has been maintained, looking at the condition of the front axle u-joints, so I bet a tune up would do it some good.

 

All you're going to be doing is parts swapping. Pull the plugs and inspect them as well as the plug wires. Clean the plugs, and unless the electrodes are worn or there is other damage, why replace them? The same holds true with the distributor cap and rotor.

[rant]There is not such thing as a tune-up![/rant]

If the truck has not been maintained then it probably still has the original catalytic converter, and the OE cats were defective not even lasting 80K miles.

Try driving up a hill to see if the truck will maintain 50mph. If it won't then I guarantee the cat is plugged.

 

I've only put 11 miles on it so far since I'm waiting for the title to make me legal, but the road to my house is a hill and so is my driveway and I haven't noticed it struggling but I'll keep an eye out for that. I guess it does seem to kind of wheeze when it's floored, but the acceleration from a stop seems to be about right.

When I said tune up I mean it colloquially, as in plugs/wires/cap/rotor/fluids/filters etc.

 

One thing to keep in mind, blown plenum et al, these trucks weigh almost 5000 lbs. The 5.2 is not a huge engine to begin with. They will not be jackrabbits. Mine only drops a few mph's on hills, only until it drops a gear, then it will catch back up, but it is by no means "quick" or "fast". I drove a few when I was looking for one and they all seemed to have about the same "feel", even the 5.9L ones.

 

You could always do a leak down & compression test to see if it is worth putting a penny into first. I say this because a previous owner may have flogged it for years & it may just be worn out. I have had good power & oomph form 5.2 in the gen 1's & I can not imagine the newer units are significantly lower in power. Do the tests to see if it is worth it first, then maybe you will put money toward a new/rebuilt engine instead.

 

This feels like appropriate power in lower gears, just no passing power. By early next week I'll be able to put some real miles on it and maybe then I'll better be able to determine if it's truly anemic or if it's just that my standards were too high.

 

Get in the habit of shutting off overdrive at start-up, and then only turning it on at highway speeds on the flats. Turn if off again manually before pulling out to pass. That'll probably do the trick all by itself. In stock trim, these rigs tend to stay in overdrive far too long.

Also, ****** out that anti-drainback check valve in the transmission cooler line if there's one still there. There's a write-up in the FAQ/DIY section for that.