Just bought a 99 slt 5.2. Had A 98 slt plus 5.9 before, bit of a downgrade but it will do for now.

Anyways, the guy I bought it from had it sitting for almost a year. This is my first 318 so not too sure what to expect from it power wise. It starts on a dime, seems to run pretty smooth. Trans is good, shifts well. I'm not looking for crazy 0-60 times, but when an 03 windstar has better acceleration I get a bit concerned.

I haven't done anything yet with except a new air filter, coolant flush and oil change.

Just not sure where to start. Plugs and wires are a given, from what I've read and past experiences with my 5.9 iridiums seem to be the top choice.

But I don't see plugs making such a drastic change. Throttle body seemed surprisingly clean, so what next?

 

I've never driven a Windstar, but remember it has something like a 3liter engine with a much lighter body weight compared to the Durango. So I don't know if the 318 Durango is truly slow or just compared to your expectations. I've been in other minivans that are pretty quick off the mark

Any how, one of the things I would check is compression in each cylinder. Also jack up the wheels and make sure nothing binding - I had once bought a car where the parking brake was not releasing properly.

 

In my experiance the only plugs that worked well with the engines in the D where the cheapo champion coppers. that's whats most recommended around here too

 

A few things to get you started and not break the bank!

Clean Throttle Body, Clean IAC (don't push the plunger in)
Change Plugs with Champion Copper Plugs (Part Number: Champion 436) $2.09 a piece
Change wires, cap, and rotor (and I don't mean brakes like the guy at Autozone thought)
Run a can of seafoam through the TB BEFORE changing your plugs

These items should help a little bit, and if it is having any hesitation on take off from acceleration, change your TPS, $30 bucks and is easy to do, don't think you are having that problem though, but I say run seafoam to clean out the stuff that may be in there from sitting, and did you take out the old gas and put in new gas? That year old gas could be bad gas and not burning correctly or slowing down the rate of fuel pumped through the injectors

 

Thanks for the tips everyone. Went and grabbed some champion plugs, and a cap and rotor kit.

Got the throttle body cleaned up, new rotor and cap in, but only 6 plugs. The guy before me put some new champion plugs in at one point, but that was definitely a longgg time ago, the truck has 200k on it, and they look like they've been on there for 150k of its life. Never seen so much build up on plugs in my life. Noticed when taking them out he had actually only replaced the front 4 plugs Managed to get the front 4 out no problem, and with some issues managed to get the 2 back ones out on the passenger side. Ive exhausted all ideas i can think of to get the other back 2 off but no luck, anybody have any ideas?

Truck does seem to idle considerably smoother now, but those 2 plugs obviously have to go. Also haven't picked up any wires yet. Any particular set seem to be preferred for these trucks?

 

I exhausted every idea as well but ended up using a breaker bar, extension, and a swivel socket. I don't remember exactly how I did it but I used those tools. Hope that helps.

 

From my experiences when you are dealing with changing plugs, wires, cap, rotor..etc, sticking with what is factory style is highly recommended. I however, tend to go against the grain a little. I bought a 93 Jeep Cherokee off my cousin a couple years ago, I love to watch "The Powerblock" on Spike TV, and had been seeing a lot of advertisements for E3 spark plugs. You will have die hard fans of copper plugs, but I honestly noticed a little difference in fuel economy..2 mpg, added with a CAI, Accel cap and rotor, and Autolite plug wires, but still those seemed to work ok. I recently did a top end rebuild on my wife's 01 Grand Prix, it blew intakes, and replaced plugs and wires..but I went with a platinum plug, and 8mm wires..averaged 32 mpgs on a recent trip to Indianapolis, 260 mile round trip. When I go to change plugs and wires on the Durango, it will more than likely be E3's, and MSD 8mm plug wires...larger the wire, the less resistance, thus better spark, might not be a bad idea since you did the others, to replace the coil too, if it has 200,000 miles, it's probably due as well

 

i promise the gain in MPGS you say was from the e3 plugs was NOT, it was from the thing being that badly in need of a tuneup and any plug that you put in would have done that.

E3 plugs are a flawed or not thought all the way through theory that give you 0 gains unless you are looking for a lighter wallet.

 

On the 318 5.2L I would buy a Cylinder head rebuild kit, replace the springs , push rods. Remove the stock air filter and put a 10 inch edelbrock filter on it. Still will pass smog and visual since there is not MAF on the Durango. Then run a half bottle of seafoam through the engine to clean it out any gunk, replace the spark plugs with Bocsh +4 plugs. On the throttle body remove the MAP and clean it and the insert they tend to get gunked up with carbon. (wire brush and brake cleaner works great and make is shine). Now take your EGR off and clean it by soaking it in Brake cleaner for about 10 minutes then queue-tip it and blow dry with air. Note Seafoam will make your truck smoke like a 3 pack a day addict but afterwards your truck will be running smooth.

 

o there is soooo much wrong with what you are saying jack

1) spark plugs, these engines will not run right for long w/ bosch plugs in them, stick with standard copper core champions

2) i would never use a wire brush on the map sensor, they also tend to be pretty trouble free sensors

3) there is no EGR valve on these trucks

4) seafoam should be done BEFORE spark plugs