What are symptoms of partially clogged CATS or Supercharger pending failure....Help!!

phils89sc

Registered User
I posted a message here recently about alot of blackish grey smoke dumping from my 89 SC's exhaust under heavy acceleration. Well, I didn't get any responses, so I will try it again. I am pretty sure it is either bad catalytic convertors or my supercharger is finally dying on me. At any rate, my problem happens at higher RPM's in usually 2nd gear and 3rd (by the time I hit high RPM's under full throttle in 4th gear, I am usually push about 135 mph, hehe!!). What happens is I get alot of black smoke coming from the exhaust, and whenI look at the boost gauge (however innacurate the factory gauge is...), it reads almost 15 psi (way too high). Now, I have to say that I have stock everything, except for a 70mm MAF, and removed air intake silencer. When I get to this higher RPM and the smoke starts pouring out, the supercharger whines very loudly and the power drops off kinda like she is straining or pulling something. I shift into third and the power comes on good till about 4k rpm's and them drops off like in second, again, very high boost levels (could be spark know too I guess, even though I am ALWAYS running 93 octane). Another symptom I have is that when on the highway, my gas mileage is sort of crappy (about 21-22 mpg tops). My first SC (also an 89) got almost 30 mpg (28-29) on long highway trips using cruise control, so this seems strange. I just changed the plugs and wires to Borg Warner wires and Autolite double platinum plugs set to .054" gap a week or so ago, but this was pre-existing before that. I was thinking either my cats are partially clogged or my supercharger is failing (seems that the whining and the power drop off/smoke happen at the same time).

Also, I ran a code check on the ECC a few days ago, all 11's clear across the board, no codes period, KOEO, KOER, or stored codes at all were picked up. She idles very well too , but exhaust smells sort of sweet, but not like rotten eggs or anything. I was thinking about punching out the cats, but they seem sort of difficult to get in to.

I would appreciate any advice/help you can offer.

Thanks

Philip Stocker
 
Black smoke means you are running rich (extra fuel). This is somewhat normal. Ford runs them rich to save the engine, if you run any forced induction into detonation, you will kill the motor quickly. Partially clogged cats will run HOT, as in glowing dull red at night.

Gray smoke means you are burning oil. Maybe the engine is worn out. Have you checked the supercharger fluid? It should be at the bottom of the threads on the fill hole (it has an allen head screw on the right side of the snout.

Horsepower peak is at 4100rpm so power does drop off.

Does your boost gauge sit on 0 when the engine is off?

Have you changed the fuel filter?

Jeff
 
The engine has 230k miles on her....

She might be trying to tell me that it is time for an overhaul. As for smoke, I thought blue was oil? She never puffs out blue smoke, not even if I rev it up when in neutral and at a stop. She does have oil leaking from the valve covers. Maybe I should just remove the engine and put on new head gaskets while I have it out. Don't have the time to rebuild it, need another engine for that. I hate taking out engines from these cars. I love the SC's, but when the have problems, the suck to work on,:( !!!I am sure not too many would disagree with that. Almost makes me want to go back to a 5.0L, almost, but not quite.
 
Ya, blue= oil it was late. Gray or white could be the first sign of headgasket failure. Do a compression check. You didn't answer if you had changed the fuel filter. If the filter is clogged or the pump is weak it might not be supplying enough fuel, you run lean and the noise you hear might be detonation.

Jeff
 
About fuel filter....

I just recently in the past couple months changed the pump and filter (filter twice). I don't think it is either one. I cannot hear any audible detonation from the engine, but it might explain the smoke though. I really hope it is nothing serious. Soon I plan on buying an exhaust system for it. Probably use Flowmaster mufflers and high-flow resonator. Gotta get a 92 and later fuel tank to do that though, kinda pointless doing that with an 89-91 exhaust system as long and bended as it is.

Thanks for the advice,

Phil
 
symptoms

I would look at the O2 sensors as well as cats for the poor fuel mpg and put the original 55mm MAF back on to see if it will stop running rich. Good Luck
 
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