Dodge Ram runs like a dog

My 98 dodge ram 5.9 has suddenly dropped all its guts it seems, will ping an rattle if trying to shift gears and takes about a mile to get up to 50 mph. it has always had a slight ping but will do it a lot more now. ive tested the intake for leak,wasnt that.It has a hard time gaining speed,push pedal down and it sounds like it is just sucking air.when i start truck i can hardly hear it idle.doesnt run hot,smell rich or lean, but it drives like i am pulling a extremly heavy trailer with the brakes set.drive this truck 80 miles a day for work and will have to leave early for a while till i can figure this out, any help ?  

Are you positive about the intake??? sounds like exactly what my '98 did when the intake gasket finally went. Those magnum v8's ALL leaked from the factory buy Dodge never recalled it. that pinging you hear? mmm hmm! yep, vacuum leak. the DAJ dealer will sell ya the fix kit(new thicker gasket and longer bolts) pretty cheap and it's not that big a job.  

Why not stop using 87 octane??? As engine gets older, carbon build up and increases effect CR a bit and when fuel knocks you are loosing a lot of power. I'll bet that if you use 89 or better, power will increase towing and MPG with it too. I do not use 87 in any of my FI cars here. All at least 89 and some 93 and it is cheaper to drive them on better fuel because they use less of it. 87 was designed for 8 to 1 compression in mid 70's and some modern engine with higher CR do not tolerate it well at times. Especially towing.  

Well from everything i have read about the dodge, i was sure thinking that was it as well,done the vacume tests,several times,sprayed ether everywhere possible,not even a hint of idle change.if i try to accelerate going down the hiway it will actually slow down some, i have to back off the pedal a bit an let it gradually get up to speed, push pedal down an its like it is just sucking nothing but air,ping ping ping and after letting back off it slowwwwwly gets up to speed, i kept doing it out of frustration and the engine light finally came on,test says its wires and plugs, i dont buy that but installed new ones for sure.Nothings changed at all.I am like you, i still think intake,will keep informed,and thanks !  

Will try the better octane as well soon as this tank is empty,wich wont take long the way this things running,ty  

sounds like yer cat converter is plugged when ya say it like that. The oxygen sensors on those trucks will go bad and never trip a check engine light. Why? I have no idea. just last month a friend of mine with a '97 Ram passed emissions testing then less than a week later had the same symptoms you have. new O2 sensor, cat, and an intake gasket and it runs like a new one. I'll bet you a nickel when you go up a steep/long hill on the highway your AC suddenly stops blowin out of the dash and comes out of the defrost.?!? am i right?  

The first place i went was the muffler shop to have the cat replaced, was 150 bucks,and after the fella put truck up on rack,he said he would take my money and be done in 30 minutes but there is nothing wrong with converter. so i listened to him an limped home, but yes blower does come up thru dash on acceleration,has since ive owned the truck?  

The blower vent switching is from loss of engine vacuum to keep it routed to vents. See if you can get access to a vacuum gauge though and see what vacuum you have at a idle.  

almost all the magnum V8's had a leaky intake gasket from day one. Dodge wouldn't recall it because it wasn't a safety issue and most owners didn't have a major problem until well after the warranty was out. Now 10 years down the road you gotta eat it.  

how many hrs on intake gaskets replacements ?  

not sure what the book charges, probably around 8 (s.w.a.g.) ....with some good tools, an extra hand and all the parts/supplies we did one in about 8 hours including a beer run, a side trip to the junk yard (to replace a lost bolt, ooops) and numerous b.s. sessions  

worked all weekend, will have to get gaskets installed next weekend,have 3 days,hope thats my problem,looks as that should be it according to all i have read.truck will barely reach 50mph on level road,any hills slows to 30,push pedal and it will actually run slower.Im getting the vacume gauge tomorrow,but the pcv valve on mine is on left hand side of motor,i plug both and check vacume on opposite side and wet finger it will blow bubbles and not suck air,looking down into intake there is sign of oil though, so its not doing as people have said on pulling vacume when pcv is plugged,that or i am missreading what they are saying  

Well i am still sputtering around,top speed 45 on flat ground,changed plugs, wires, rotor, cap, pcv valve,checked vacume with pcv plugged and valve cover plugged as well i have about 2pds of pressure,no suction there so plenum gasket good according to what i have read.have 50 pds of fuel pressure on injector bar, cataletic converter is tight,no noise,temp readings indicate it is fine, HELP ????  

let's back up a second. if there is an extreme vacuum leak such as at the intake, the motor will run lean. you can still have a bad cat converter. they may not make any noise (assuming you mean like a rattle). what do the oxygen sensors look like (you should either 2,3, or 4 depending)? does it show any codes at all?  

On vacuum here, lets talk inches of vacuum (not PSI)at idle and going down road (hook up with a long hose and run into cab)