Hello

I have a 98 Dodge ram SS/T 5.9L 109k miles. With a Kenne Bell supercharger, headers, flowmasterexhaust exits to the passanger door.
Well I bought this truck used and didn't really test it out (kind of like buying a house without looking at it). I thought it had a simple spark plug misfire
and thought it would be a quickfix, I have already spent over $700 in labor for changing plugs mainly because the Kenne Bell supercharger is in the way the cap and rotor. A compression test was done,
cyl.1 150 psi.
cyl. 2 140 psi.
cyl.3 160 psi.
cyl.4 150 psi.
cyl.5 95 psi.
cyl.6 150 psi.
cyl.7 150 psi.
cyl.8 140 psi.
Cyl. 5 is the one that is low, I don’t know what the psi is suppose to be at. The shop said it might be a valve. So I’m tired of spending money on changing plugs, and would like to fix the problem, I’m still making payments on the truck so I can’t go the 408 stroker route( right now). First choice is to by a used engine ($800) out of a junked truck and change out gaskets; I know it will eventually go bad because of the boost. Second choice is pull my engine apart and find out what’s going on. I’m trying to consider cost, which way will be cheaper (I have a buddy mechanic that will be doing the labor, and wont be no where near the cost of pulg changes)? Now what my truck is doing is misfiring, And what I have also noticed is that when driving and the transmission shifts to a higher gear and the rpm drops under 2000 it shakes unless I accelerate to go above 2000 rpm or take of the O/D to shift into lower gear making the rpm go up it stops shaking, (don’t know if that narrows the problem). Also when at a dead stop and I slam on the gas it doesn’t move for about a second them it moves slowly. It almost lags at all speeds and seems like a slug (don’t know if that do to the Kenne Bell not having an intercooler) but the boost is always there, but builds rpm really slow, I can probably count to 100 before the rpm builds from 3000 to 4000 rpm LOL (im just used to my nitrous assisted ls1 T/A). Also if you have any advice in gasket brands in combination with my supercharger please comment because in order to change the head gaskets I have to pull of the supercharger NOT FUN, so I’d like to do it right the first time. I don’t know if it’s the heads pistons or what if you guys or gals have any clues let me know.

Sorry for the long story but I wanted to give detail Altough I know Im misssing the important things that I wanted to mention but oh well I guess I'll remeber later.
Thanks In advance for any help

 

Another question, Are 94-97 5.9 the same as 98, I seen that the spark plug heat range is different? The reasin I aske is because I have the kenne Bell computer that recailibrates the pcm so I don't know if that will be a problem?

 

the 360 are the same. i have taken alot of parts from my 97 and put them on my friends 98 and so far so good

 

Sounds to me like you would be better off saving money and pulling the head. Get it inspected. Replacing the valves/springs is cheaper and easier than spending $800 on a used engine which could last for three months or 3 years.

 

How many lbs boost is it making?
Compression should be 140+
Have you seen any change in the level of coolant in the overflow bottle?
Could be a headgasket leak, any detonation while running boost will take the stock ones out pretty fast. How much timing are you pulling from the ignition while under boost?

 

I thought it was a 6lb pulley, but sometime under full thortle it makes 8lbs. I haven'tlooked atthe coolant, but I'll keep an eye out for it. Sometimes while not in boost the truck will run good then when it goes into boost at feels like its being held back. I don't know what the timing is, the truck has a kenne bell computer on the fender suppose to recalibrate the pcm (I hear it's hold back for maaking boost). I know there suppose to come with a knock sensor, but when I bought the truck it didn't have it. I seen somescrew holesthat I think where from that sensor. I know headers get hot, but the ones on the passanger side look flamming hot under normal driving.

 

Another thing that I forgot to mention is that the exhaust always smells like fuel. It always gives my passanger's a headache since it exits in fornt of the rear tire. It has a cat, but don't know if that's something to do with the problem or running rich or what???

 

I know almost nothing about superchargers but going just from your symptoms I would put money on a bad cat and possibly a cracked head. The passenger side is the closest to the cat and when the cat goes bad it has a tendency to misfire on that side of the engine. I have also heard of the passenger side echaust manifold or header glowing red from the heat. Normaly with a bad cat your get a misfire on cyl8 or cyl 8 and 6. If it were me and some don't agree with my way of testing. I would pull the front o2 sensor out of the exhaust system and take it for a spin around the block. If their is a noticeable difference your cat is most likely bad.

 

Not taking it for granted but the previous owner claimed it was new and had just replaced it topass smog, and had a flowmaster installed. I looked under and exhaust looks new except the headers little rusted. If I were to remove the 02, can it cause any damage to anything? Any other way to test if the cat is bad?

 

Ok so I found out how a leak down test is done. But would I have to remove the valve covers, the k/b supercharger is going to have to be removed first right will??? Im starting to hate this k/b more and more.