glowing manifolds again? wtf?

[KAOS_3.0]

so I got the head gaskets on my 3.0, in the car, after I swapped it into the coug and they went out on me. all of that is fabulous and I drove the car around the block today and it's epic fast with all the cats gutted and the 05 UIM on there. only problem is, now the damn manifolds are getting hot enough to glow again. not at the elbows at the bottom of them like when Dom had me mis-wire my ignition signal connection, but right at the head. the back seems to be a little brighter, but I'm chalking that up to it just being darker back there. I'm pretty sure I got the plug wires on correctly too, as I numbered the wired before I took them off and the coil pack is also numbered.

any input guys? when I timed the engine, I followed all the proper instructions and even counted the teeth between timing marks to make sure everything was right. the trigger wheel is also on correctly as I scored it where the key way was before taking it off.

the only code I'm throwing is p1506, which I seem to remember being IAC overspeed error, which would make sense, because the 05 UIM currently has a 2.5 litre IAC on it (it's adapted with epoxy, the paper gasket, and ultrablack going to the gasket on the uim, so no, it's not leaking) as a patch till I can find the 05 one in storage. that shouldnt cause what I'm experiencing though, so I'm at a loss. it would trip a code if the mil eliminators where malfunctioning wouldnt it? or could they be causing some insane air/fuel issue? I havent tripped any air fuel or o2 related codes yet?

any ideas guys?

thanks in advance for any advice, it will be greatly appreciated!

 

[bhiggs89]

If the engine is running fine, then its not a timing problem, or a air/fuel problem. Whats all done to the exhaust? It seems like something is restricting the exhaust flow, causing the manifolds to heat up. Is there a decent amount of exhaust pressure coming out of the exhaust tips?

 

[KAOS_3.0]

the exhaust is: gutted precats, mil eliminators, stock y-pipe, gutted main cat, stock resonator, 2.5" axel back to 3" flowmaster delta 44 triple chamber and a rolled stainless 3" tip. no restrictions at all, you can feel the heat hitting you in the face of you stand behind the muffler. the car also still has functioning EGR via a corrugated stainless flex tube welded in between the Contour EGR pipe and the Taurus EGR flange.

the problem definitely isnt heat trapping, it seems to be high exhaust chamber temps. the manifolds are hot right as the gases exit the heads... the 1506 for IAC overspeed is effectively a lean code as well, so I keep wanting to think it's a vac leak causing an extreme lean condition thats causing overly high combustion temps. I'm trying not to run the engine too long so I dont burn up a valve.... but I would like it to trip another code so I'll know whats going on better...

 

[SJon85]

I had the IAC overspeed code for a while, and having the wrong IAC on isnt going to cause such an intense lean condition, especially the 2.5 iac on the 3L, as the ports are smaller on it. How is your idle, you should know if you have a vac leak. Also if the car isn't overheating, then I doubt its anything within the engine. As mentioned I would think the exhaust isn't flowing like it should be.

 

[KAOS_3.0]

the idle is crazy high to begin with, then it idles down, then the PCM makes a number of adjustments before finding a sweet spot, then when I hit the gas it goes back up to insane, it's really acting like a massive vac leak some place. it's not the egr pipe either, because the problem will happen at idle, and EGR only opens at mid throttle under load... perhaps the egr gasket to the uim, I did reuse that with some exhaust sealant on it. again though, not really significant enough to cause what I have going on. I'll keep a closer eye on the thermostat readings tomorrow though, good point. it did seem to be running a tad hot though...

 

[SJon85]

Ok that idling is because of your IAC I am pretty sure, get the correct IAC on and go from there. I have one sitting right next to me if you need it.

 

[KAOS_3.0]

yeah, I attributed the crazy idle to the IAC, but still, I cant really see that causing the manifolds to over heat? like, how lean could it possibly make it? when you unplug the IAC plug the IAC defaults to open, or else the car would just die when you let off the throttle. the manifolds dont glow orange when you unplug the IAC on any other car....

I need to go to storage anyway, I'll see if I cant find mine in there, if not, how much would you want for the one you have?

 

[KAOS_3.0]

could the mil eliminators be the cause of this? besides gutting the cats and switching on the newer UIM they are the only thing that is different.... there was also some discrepancy between the deign my father decided to use to make them and the "proper" design that floats around on here and neco...

I can get more specific if I dig up the instruction sets...

 

[KAOS_3.0]

no info on wether mil elims could even cause this issue? I went out and took out full coverage on the car yesterday so I can test drive it a little without being arrested or worrying about someone hitting me....

how much would you want for that IAC?

 

[striker2]

MIL elims would not cause this. unless perhaps you installed them on the upper O2s instead of the lower O2s.

 

[KAOS_3.0]

ok did some diagnosing today, and it appears to either be from an unsourceable vac leak or the IAC. I put a piece of paper between the IAC and the UIM and started the car, it ran fine if I kept the peddle open a bit. when after it had run a bit, I let off the pedle and it idled down the like 400 rpms or so. I was surprised it didnt just die, it tried, but it hung in there. I'm guessing this was air coming from the EVAP system? or maybe leaking at the paper in between the IAC and UIM? that or I still have a vac leak. at any rate, I adjusted the Idle screw on the TB till it would idle at 1kRPMS and then set in it with the ac and the stereo on for about 20 minutes or so. when I got out and checked the manifolds, they where just fine. it's scary the engine was running that lean, that it was torching the manifolds. I am truly impressed with the OEM exhaust valves in these engines now!

only code it's throwing now is 1504 instead of 1506 like before. this is obvious and not a surprise at all.

anyone remember which way each IAC is supposed to face? I went through this before (although it didnt cause this kind of a situation then) and I think I might have had the IAC on backwards or something? also, would it be insane to test drive the car some like it is now to see if anything else is screwing up?

also, brakes are still squishy, so I guess that issue wasnt vac related.... the car had new pads in the back and a base model bracket/rotor on the front passenger, so obviously the previous owner was doing something janky in the brakes department. probably didnt bother bleeding them. hopefully nothing is in the abs module. I dont have an abs light tripping on the dash though, so I'm going to assume I'm good in that department...

thanks for the input guys, we're getting this thing sorted pretty quick really considering all the mysteries of upgrading an engine and then shoving it in a non running car being sold for parts....