IACV full of oil, Failing emissions test, and other crap.

[91LTDProject]

well I've replaced my O2 sensors, and that cut all my emissions numbers almost in half, then I swapped out the platinum plugs after reading bad things on here about them for NGK V power copper plugs, and my hydrocarbons went up 50ppm. Car seems to jerk while running on the dyno, and only on the dyno, feels like a misfire. So I let the car sit and idle till it was hot, and got out the infa red heat gun. The cylinder closest to the firewall on the left bank (dunno #'s) is 75 degrees cooler than the average of all the other ones. That plug also had alot of buildup on it compared to the rest of the plugs when I pulled them out, will get a pic on here when I get home. Also, my cars been Idling in park around 1200rpm lately. i had this problem in the summer also and I pulled off the IACV and blew it out with brake clean and compressed air, and it stopped. Tha was in July, and now its doing it again, so I pulled it off to clean it again, and a ton of oil poured out onto the valvecover and exhaust manifold. Cleaned it out, put it back on, didnt fix the problem. The plastic hose from the filler neck to the throttle body has suction into the fillerneck. Maybe somethin wrong with pcv system? I dunno, cars pissin me off. Opinions???

[mrltd]

Sounds like a PCV issue...Check all of the hoses, the valve, and the screen. The one hose under the upper has a tendency to collapse.

[87mefull]

Did you replace the pcv screen, gromet, and the pcv valve? If the screen is clogged, it causes excessive crankcase pressure to build up and forces oil everywhere. You pretty much have to lean ontop of the upper intake and use a woodscrew to get the screen out. If I were you though, I pull the upper intake because the ports probably have oil in them also and the screen is easier to get to it with it out of the way. Its worth a shot plus cleaning the upper might solve the other issues also.

You replaced the headgaskets on your 91 right? If the pcv screen doesn't fix the problem, you could have a broken oil control ring on one or more cylinder. If the 5.0 overheated before and cooked the headgaskets, it most likely damaged or weakend the rings. Had the same problem with my previous car. Owner ran the radiator dry and cooked the headgasket, oil was forcing itself out the headgasket and the pcv was covering the maf in oil. Had good compression, so I replaced the headgasket, timing belt, etc. Ran great for 2 weeks then it almost overheated, blew the main seal, etc. Oil control rings on cylinder 2 were cracked.

[91LTDProject]

I checked the hoses when I had the upper off to swap on the H.O Intake. They were all in good condition with no cracking. The pcv valve was replaced in February, and I took the screen out, took it apart and cleaned all the carbon out, and put the filter back together. Should have just replaced it, but time was pending and I had to go to the Ford dealership to get a new one. I blew it back out when I swapped intakes cause I forgot to pick a new one up. I'll re-check everything tommorow I guess. And no i've never touched the heads on it. The gaskets are still good.

[mrltd]

Didn't say anything about cracked hoses, I specifically said collapsed. The one hose that goes from the neck to the edge of the plenum has a habit of collapsing because of the U bend in it. Check for suction at the PCV valve.

[91LTDProject]

Sorry mike, you'll have to excuse me, I dont clue in sometimes. I just went out and checked the hoses. None are collapsed, and there is suction at the PCV valve.

[gadget73]

Sounds like blow by to me too. Might wanna try some seafoam through the PCV valve to clear out the intake. How many miles are on this motor?

[91LTDProject]

85,000 miles. I Had my H.O upper for a month before I put it on, and it got cleaned very well. When I pulled the lopo off, I spent about 30 minutes with a toothbrush and a can of carbon cleaner scrubbing the lower intake out. I run a seafoam equivilant through the motor once every 6 months, spraying it through the throttle body.

[gadget73]

Hm, you shouldn't have that kind of blowby at that mileage. Is the PCV grommet still pliable and fitting tightly? If not, get a new one and wrap a turn or two of electrical tape around the PCV valve. Might also want to put a bit of black RTV around the grommet where it sits against the intake so it seals nicely.

[91LTDProject]

The grommet fits tight into the manifold, and the pcv fits in the grommet fairly tightly. When I have some free time, i'm gonna pull the IACV back off and see whats happening. Theres also the other problem I'm having. I replaced one non-functioning O2 sensor, the other working at 70%, and replaced my platinum plugs with copper ones after everything i've read here. gas mileage stayed the same around town and got worse on the highway. After I replaced the 02 sensors, i ran it on the dyno, and it droppd all my numbers by quite a bit. Now that I replaced the plugs, its failing the e-test again, and my real e-test is gonna be coming up soon.

[fomoco01]

My 91 CV lopo motor did the same thing. Even the same cylinder would carbon up the plug real bad.Id pull it and clean it every 4 or 5000 miles. A guy told me he thought it had over heated at some point and the oil rings were stuck causing real bad blowby. When I finaly did my HO swap I took apart lopo motor & found my pcv screen was completly clogged. I think thats what caused my problem cause I never had it hot. If you just somewhat recently had upper off I guess thats not your problem. Sorry wish I could be help but I just dealt with it cause I didnt have to worry about any E-Test