98 Conti only year with plastic lower intake? having problems.

[gearhead291]

i having a problem with my 98 continental. it started with a misfire, i tried to cure it with new plugs ( motorcraft- gapped correctly) no help. checked all the boots on the coils. there only 2 years old. coils seem to be fine. wiring seems to be fine. so i figured maybe an intake leak, i take everything apart to replace all the gaskets (upper/lower/throttle body/egr) since it was about that time anyway (154K) i get it back together and it runs like hell, turns out the harbor-freight torque wrench i was using was wayyyyy off.so i loosen everything back up and do it again with a in-spec torque wrench. and it runs flawlessly....until it warms up. then back to misfiring and now the new symptom of idling high. i took it apart again to see if anything went wrong when i was re assembling and everything was fine. clean and ready for a good seal. so i get back together with no change in problems. its leaking right where the lower intake manifold runner control is, on both sides. i found this using some throttle body cleaner sprayed on while it was running. theres no reason why it shouldnt be sealed correctly, its at the correct torque spec and brand new gaskets with clean surfaces. its a 1998 and apparently had a plastic lower intake manifold, with the intake runner control. i looked at a 01 continental motor and it didnt have any lower intake manifold and didnt appear to have any intake runner control. im wondering if i can just use an 01 intake an bypass all the plastic lower intake crap. suggestions?

my intake (98) ...

01 intake...

 

[MooJohn]

I see no reason why going with an 01 (or 00; mine has no IMRC) intake would be any different than other methods of IMRC delete. The one-piece manifold would replace the upper & lowers you have now, solving the problem. I've read that the IMRC actuators themselves can be a leak source, when the rubber bushings get old and let air in.

It will affect the power delivery; you'd have to ask others who have done that on B-head engines to know exactly how it would change.


* Added *

It sounded simple but I can't find it in writing that the C head intake manifold will bolt onto the B heads. This thread mentions that fuel rails got relocated too (on the Mark, but probably applies to all B vs C head comparisons). I'll shut up and defer to those with actual hand-on experience

 

[gearhead291]

I see no reason why going with an 01 (or 00; mine has no IMRC) intake would be any different than other methods of IMRC delete. The one-piece manifold would replace the upper & lowers you have now, solving the problem. I've read that the IMRC actuators themselves can be a leak source, when the rubber bushings get old and let air in.

It will affect the power delivery; you'd have to ask others who have done that on B-head engines to know exactly how it would change.

well ive been doing a little bit of research since i posted this. apparently 99+ conti's have the (c?) heads. so the 99-02 intake doesnt look like it would work on my 98 b heads. i was also thinking that it could be the IMRC's themselves but i didnt think it was likely. i could pull them out again but i dont want to unless i have new ones, or a way to fix the old ones.

 

[gearhead291]

it looks like the older continentals have the same type of lower manifold with the IMRC's also, just not plastic its aluminum. but the intake is different, and i dont know if it will bolt up.


that is to say, i wonder if i could use 95-97 continental lower manifolds on a 98 continental engine.

 

[MooJohn]

Searching "lincoln imrc" on ebay found several sets of plastic 97-98 lower manifolds that might do the trick. They are definitely different in design from the 93-96 versions so while using the older aluminum lower might be out, at least your source for plastic lowers might be more broad than just Continentals -- and in the $100 range for the pair.

If the leak on yours is where the IMRC rod exits the manifold you might be able to repair yours with just new o-rings. Tried to find a how-to article but no luck on that yet. There has to be one out there.

 

[gearhead291]

Searching "lincoln imrc" on ebay found several sets of plastic 97-98 lower manifolds that might do the trick. They are definitely different in design from the 93-96 versions so while using the older aluminum lower might be out, at least your source for plastic lowers might be more broad than just Continentals -- and in the $100 range for the pair.

If the leak on yours is where the IMRC rod exits the manifold you might be able to repair yours with just new o-rings. Tried to find a how-to article but no luck on that yet. There has to be one out there.

thanks, i actually pulled a lower set from a 96 conti today that where aluminum. and exact same as my 98. i actually installed them on a 98 in yard and they are a perfect match. i went ahead and bought them, and the different style gaskets. but since i never want to deal with this again i do want to replace the o-ring where the rod exits the plenum. on the new lowers. im just not sure how to get it apart.

 

[gearhead291]

 

[gearhead291]

well after a while of cleaning prepping and disassembling, i got the new lowers ready for new o-rings, then to get them ready for the car. they are so small its crazy how it makes so much of a difference. so i'll be installing the new o-rings in the new (older style) manifold. and install everything tomorrow. hope everything goes well. anybody happen to know what torque spec the intake bolts are for a 96? since i will have 96 lower and all 96 style gaskets.

 

[bradyelich]

I tried to create a doc from service manual for you.

 

[MooJohn]

Was hoping to hear some progress -- rain coming tomorrow

 

[gearhead291]

Well got it back together and it's got a leak where the rod for the runner control exits, on the alternator side. It must not have seated correctly. Im wondering if the bearing itself is causing the air leak somehow. But it runs for now, had no issues with using the older style manifolds. Ill tear into it sometime again when i feel like messing with it.

 

[gearhead291]

I tried to create a doc from service manual for you.

Thanks that helps, ill use it when i do it again.