Just purchased a 1999 Durango 5.9 with 128k on it and this thing is a dog! I was expecting the 360 to have a little more kick. Plugged in the obd2 and no codes came up. Just changed the oil, pcv, and air filter (as i read sludge is a problem with this engine). The plug wires look relatively new but that doesnt mean much for the spark plugs. Any thoughts or ideas to help me out?
Thanks guys!

 

well for 1 the sludge problem is a load of BS 99% of people claiming sludge on this forum (and most likely the rest of the internet too) are idiots, and wrong. and of those who do have sludge 100% of them is from poor maintenance GUARANTEED!

now, idk what type of vehicle you are coming from, but if you are coming from a sports car then, yes the durango will be a dog, if you are coming from another truck, then i would start w/ new plugs/wire/air filter (full tune-up basically), make sure the plugs are copper core champions gapped to .040 and that the cap and rotor have brass contacts on them. this is the obvious starting place with any new vehicle (imo)

btw, where did you read about the 5.9 having sludge problems????? most people who come on here claiming that bs has the 4.7

 

Well im coming from a 4cyl ranger haha so my expectations are not that high, but my dad has a 1999 v8 jeep and that thing is waaay faster. But if i recall i read the article about the sludge on carcomplaints.com and as you said all the responses are to simply change the oil to high mileage and keep on top of the pcv valve. (as i did) Well i will go do the plugs etc today and gad them to .40, and hopefully that will help. Im simply concerned with making sure this engine has some life left in it rather than its actual performance. Also have you heard of people installing tranny coolers to reduce the wear on the typically hot running dodge tranny. Any thoughts on that one?

 

I also just bought a 1999 Durango 5.9 SLT 4WD with 148,558 miles on it. I also own a 1999 Dakota 5.9 RT with 118,718. Both have the same engine, heads, cam, etc. My Dakota runs like a raped ape...it just flat out goes. The durango on the other hand is not as fast.... A few factors are the vehicle weight...the rear end gear ratio...the trans gearing....and the fact it has another diff up front.....My Dakota is a whole lot faster but it could not pull itself out of a wet paper bag....My Durango on the other hand is not fast but it can pull like hell....And as far as the sludging problem...the 5.9 didnt suffer from that problem....the 5.9 has a special quirck of its own....under high rpm racing or high rpm towing...rapid deceleration causes a momentary loss of oil pressure...easy fix

 

I agree with 325 the 4.7 does have sludge issues...its just my opinion but i think dodge engineers could have come up with a much better temp range for this engine to operate in...just my 2 cents

 

i never said the 4.7 has sludge issues, i said alot people THINK it does, i have a 4.7, 95k miles and 0 sludge, there IS NOT SLUDGE PROBLEM WITH THE ENGINE!!!!!!!!!!!!!!

the sludge problems in any engine is due to LACK of maintenance not a design flaw for the engine

btw, the the temp range for the engine was selected for emissions reasons thanks to the government

 

Take a look under your hood, look for a sticker on the radiator support that looks like a software update. Also being a 99 and 138 on the ticker it could have been neglected. Clear the comp (battery cable off/or scanner), cap/wires/plugs, see what you come up with

 

Same thing here in comparison:


I went from my custom built Durango 5.9L that was a pulling machine built for torque and speed. The Durango was fast as hell and would pull away from just about anything!

Then I went to a Ram V10. It has 8.0L motor over the 5.9L motor so I was thinking well I have 2000 lbs more but look at the Liter difference its ok, well my Durango would walk away from my truck but the truck out pulls the Durango hands down. Also the Durango had a 3.92 gear ratio as the truck has a 3.55 gear ratio. Durango had 31" tires and Ram has 33" tires. So my next thing is to drop gear ratio, I am going to a 4.10 ratio which will put me to just above that of the Durango's 3.92 ratio and with the added Torque I should walk away from the Durango. The Durango trans were a 46RE and truck has 47RE but gearing is the same.

Also the 8.0L motor is a low rpm motor verses that of the low to middle rmp 5.9L engine. Just saying, ya got to compare apples to apples as dakota59rt is stating.

Regardless, the Jeep might have 3.92 gear ratio and yours might have the 3.55 gear ratio.

 

Heck, I've been pretty happy with my 5.2... lol

 

I think the 5.2, 5.9 and 4.7 all have sludge problems. Dodge engines are well know for sludge battles.

:-0

IndyD