94 Concorde - need some tips

[ShelbyZD]

Well, I picked up my newest car yet the other day. heh.. Its a 94 Concorde with a 3.5L. There seemed to be very little wrong with it for the price he was asking. So I did some checking up on the car (last 2 previous owners) and found out the car was all that the seller had made it up to be. SO, I got it for a steal at $600C.

I wont go into detail on all the problems (about a dozen minors) but there are a few that are more important.

1. The engine fan stays on all the time.
2. Engine has a stumble at idle.

I have not had the time to check the plugs/wires but that will be the 1st thing I do when I get the time.

I understand that there is a restrictor in the intake hose... so I plan on getting rid of that. Also, I dont know about the exhaust.. it's terrible restrictive. I'd surely like to get rid of those tiny downpipes. Any tips in general would be appreciated. :nod:

[turbovanman²]

Everything you do will be custom made. The intake hoses from the air box are pretty good so i would leave those alone, just make or fix the stock air box or put a cone filter there with a box to shield the hot engine air.
DP's will be custom so I would redo those, 3 inch to the back and a nice muffler, IE Flowmaster or ?
Wires, get Aurora for sure, no one makes any decent wires for that and all you'll be putting back in is Carbon core crap. Run some Iridiums.
The stumble is most likely the coolant sensor hence the fan on all the time.

The waterpumps like to leak so watch that, not a hard job but replace the timing belt while your at it, plus the tensioner pulleys tend to get noisey, dealer only.

The injector harness's go on these, again, dealer only and you'll get intermittant miss's that you can't trace.

Check the inner tie rod end bushings, they always go bad, replace with the Poly 2 piece design.

[22mopar]

these things are known for having the upper intake gasket fail causing idle problems. I just did one today.

[shadow88]

Well, I picked up my newest car yet the other day. heh.. Its a 94 Concorde with a 3.5L. There seemed to be very little wrong with it for the price he was asking. So I did some checking up on the car (last 2 previous owners) and found out the car was all that the seller had made it up to be. SO, I got it for a steal at $600C.

I wont go into detail on all the problems (about a dozen minors) but there are a few that are more important.

1. The engine fan stays on all the time.
2. Engine has a stumble at idle.

I have not had the time to check the plugs/wires but that will be the 1st thing I do when I get the time.

I understand that there is a restrictor in the intake hose... so I plan on getting rid of that. Also, I dont know about the exhaust.. it's terrible restrictive. I'd surely like to get rid of those tiny downpipes. Any tips in general would be appreciated. :nod:

Problem #1 is most likely caused the the high-sdie pressure transducer is bummed. If the a/c still works, grab a new one. If not, just unplug it.
It's on the passenger side under the car, it's the only pressure switch on an aluminum tube.

Problem #2 Most likely lower intake manifold gasket failure, pour water on it to see if it leaks. Expect 2 lower intake bolts to break, and you'll need 2 new fuel rail gaskets as well.

Yes, there is a noise reducer in the airbox-to-throttle body tube. Easy to remove. I hear it's good for 5-10 hp.

[Vigo]

The lower intake manifold is the one that causes problems. The upper one is basically foolproof unless you tear it or something, they dont leak unless you do something wrong.

If that doesn't fix the idle, i would look into that injector harness thing. i Have only heard it referenced once before, but i suspect it might be the cause of my problem.

if that doesnt pan out, check out the list of stuff i've checked on the top of my Intrepid page to give you a 'to-do list' for diagnostic. not listed in order of importance.
http://www.cardomain.com/ride/2223179


The restrictor is probably worth something, but if you do remove it, make sure to do something about the tube between the airbox and fenderwell too. Take it out and look at it and you will understand.

Bottom line, though, is that the intake pipe at the rear of the engine bay that feeds the 2 throttle bodies is the ugliest thing known to man for an engine with such a high rpm powerband.

I dont really feel like typing much right now but the point is that the stock 3.5 longblock has massive potentialfor bolt-on power if you deal with the intake and exhaust. PM me if you want to talk about it.

[22mopar]

The lower intake manifold is the one that causes problems. The upper one is basically foolproof unless you tear it or something, they dont leak unless you do something wrong.

If that doesn't fix the idle, i would look into that injector harness thing. i Have only heard it referenced once before, but i suspect it might be the cause of my problem.

if that doesnt pan out, check out the list of stuff i've checked on the top of my Intrepid page to give you a 'to-do list' for diagnostic. not listed in order of importance.
http://www.cardomain.com/ride/2223179


.

Are you kidding, in the past 2 months, I've had to fix 3 upper intakes over the past 10+ years, I can't count how many upper intake gaskets were leaking. I've only had 1 lower intake causing problems.

[JDAWG]

dig around www.dodgeintrepid.net And I mean dig cause most of the peope there cant even change their own oil so there is alot of useless stuff. Heres a thread on performance stuff. http://www.dodgeintrepid.net/forums/showthread.php?t=24020 You can swap heads and intake for newer designs and pick up some power. You can also put different gear sets in the trans.

[22mopar]

just fixed another 3.5 w/ rough idle this morning. problem was the injector to intake manifold gasket $5 part, 30min labor $100 in my pocket.

[Directconnection]

After doing the heads on my car('96 3.5), I totally put the details out of my mind. Was NOT a fun experience working on that engine in 0 to 10 degree temps.

But, one weird thing about my car... it likes to eat plugs and wires. Every winter, when it's cold out, the car stumbles when it first runs, and then comes out of it after 5 seconds. Put in new plugs...good for another year. I bought 2 sets of wires since owning it too. The cheapies.... had the hemi boot rip right off the wire and stupid me threw away the reciept just the year before thinking I'd never have to replace them.