Rebuilt an '87 2.5 a few years ago with my son. Had to tow him home last night. It feels like it's funning on 2 cylinders, very sluggish. Last night I pulled of the airfilter, its was replaced a few months ago, it was full of oil, the breather was also wet and going down the intake throttle. I expect the plugs are foweled. What would cause this the PCV? Can the PCV be elimiated and just put on a breather w/filter? Any thoughts?
Thanks,
Tayne

How many miles on the engine?

Usually that means you have a lot of blow-by - from worn out rings and cylinders with too much taper. If you dont feel like rebuilding the engine you can always just clean/change the plugs and keep on running it.

How many miles on the engine? How many miles between oil changes lately?

You can't eliminate the PCV valve. It's there for a reason to make sure stuff gets reburned back into the intake.

Likely oil has passed by the valve stem seals and is flowing up into the intake. You're likely looking at some minor head work, possible ring job on the pistons.

Edit: beaten to it.

[This message has been edited by Fiero84Freak (edited 11-30-2010).]

that would suck! We just rebuilt it 3 yrs ago. new pistons, bore and rings. I expect is has 20K on the new engine max. Anything else cause it? How is the best way to test for it? leakdown or compression test?

A compression test would be good. Then put some oil in the spark plug hole and test compression again. Check the compression on all the cylinders each time.

Just a thought.... are the coil packs working properly? This wouldn't cause the oil issue, but if one goes out, the car will run like crap.

PCV, see cave, emission in general engine
DIS, see cave, dis in l4 engine

What kind of spark plug? use standard resistance plug in DIS. DIS hate some platinum and performance plugs.
Which cyl has stuffed plugs? 1-4, 2-3, or all?

PCV
valve cost $2-5 so just replace it.

Want kind of ring you use when rebuild engine?
That much Blow by is likely bad oil rings or valve seals if it not the PCV system.

------------------
Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)

The Ogre's Fiero Cave (It's also at the top and bottom of every forum page...)

I hate to say it but that much oil in the air cleaner is caused by the rings. I know, I had the same problem on my Duke with 100K on it. I was able to hone the cylinders and replace the rings on mine, did it without removing the engine. It wasn't really that hard to do. Drop the pan, pull the head.
Mine had a broken ring on #4 piston and fortunately it didn't really do any major damage to the cylinder wall. I was able to hone out the cylinders and after replacing the pistons because #4 was damaged, put it back together with new rod bearings and it's been good for 30K so far.
If you go this route, make sure you cover the crank journals with rags and wash everything down thoroughly before re-assembly.

I know it's not the ideal way to do an engine but I just need the Duke to last another year or so until I can afford a SBC swap.

Edited to add: Start the engine and remove the oil fill cap. If the air is pumping out of there, it's the rings. I was getting lots of pressure and oil mist from there. Mine was so bad that the dipstick was being pushed up from the pressure in the crankcase.

[This message has been edited by TONY_C (edited 12-01-2010).]

I have seen a pluged up converter cause oil to be in the air filter. It was putting a lot of pressure in the crankcase and shoved the oil into the air filter. It did not run to well either.lol

Great information, Thx... I haven't done anything with it yet. We have 3' of snow on the ground. I will look @ it on Saturday and report back. See if air is coming from the Oil cap and pull the plugs and all. How do you test for a plugged Cat? Over the past 3 years replace everything but the exhaust stuff. When I did then engine I did a swap with a newer 2.5 it had a little bit more horsepower, was doing a ring job on it when I bent a ring scrapping the wall, So my ring job ended got a bit more pricey had putting in over-sized pistons and rings.

Its a Dis, not sure which plugs yet. I believe the ring were Chrome Premium, but don't recall for sure

Thx
Tayne

Update. all spark plugs were fouled. Got it started ran some sea foam thru it. but it was still running rough. Found the oil was low. put in 5 Qts it was empty. started it then noticed all the oil coming out the front of the engine! several quarts if not all at my feet! Oh joy! Haven't had time to jack it up yet and see where it is leaking.

quote Originally posted by tayne: Update. all spark plugs were fouled. Got it started ran some sea foam thru it. but it was still running rough. Found the oil was low. put in 5 Qts it was empty. started it then noticed all the oil coming out the front of the engine! several quarts if not all at my feet! Oh joy! Haven't had time to jack it up yet and see where it is leaking.

Is pumping out because the blow by is creating such pressure that it's probably leaking at the oil pan/timing cover RTV seal. Is it streaming oil mist out of the oil fill when it's running?

not sure. I need to jack it up and see were its leaking. But in a very short period maybe 5 min. I had several qts of oil. Leaking from the from of the engine. I might have time tomorrow to see where its leaking. I will post my findings

Well it's good that it's leaking from the engine 'cause that's where the oil is supposed to be.

When changing oil filters it's important to wipe off the sealing surface of the engine. While you do that you should also double check to make sure there isn't a rubber o-ring gasket from the last oil filter on there. If you wipe it and look at it, it should be pretty clear if you're seeing a nice shiny metal surface, or there is a rubber gasket stuck to it.

Of course the other thing to do is look for that gasket when you pull the oil filter off.

Anyways if there's a rubber o-ring gasket stuck there in addition to the one on your filter, that's going to leak.

Considering how much oil is coming out of your engine, that would be my first place to look.

quote Originally posted by tayne: The body is an '87 and the engine is a '90

Maybe he's got a balancer motor, like 88 Fiero. Very easy to mess up the Filter cap.

If so... get a new cap. Dorman has it.

------------------
Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)

The Ogre's Fiero Cave (It's also at the top and bottom of every forum page...)

i did not see that. I thought it was a 87 2.5

Hey Tayne, just a thought, if your engine does not work out I have a good running used '87 Fiero 2.5 that I'd sell fairly cheap. And I'm about a hour from you.

It looks like my son want to scrap it after all the work we put into it. Lots and lots of new parts. Anyone want to buy it as is?

Do one thing first - unplug the MAP sensor from it's electrical connector and see if that makes it run a whole lot better.

MAP sensor is the #1 thing the ECM uses to figure how much fuel to put in the engine. Way too rich sounds like perhaps the MAP is wacked out. Unplugging it forces the ECM to use the other sensors. If unplugging the MAP makes it run better first check to make sure you have vacuum at the MAP line. If you do then your MAP is most likely bad.

will due. I think the big issue is the huge oil leak shooting out the front of the engine. I believe it is from back pressure maybe a clogged Cat. It is also fouling the plugs, which is causing it to run poorly. I expect even with the exhaust disconnected it will still require the front of the engine to be resealed to fix the leak. This is the reason he wants to scrap it. He doesn't want to tear apart the engine, and I don't want to mess with it. I even have a 2.8 and tranny in the garage we could swap, but I think he is done playing with it

If you are not going to fix it please sell it dont scrap it ! Post it in the mall here, or sell the good parts off it first. Every one that gets scrapped makes it that much harder to keep the rest of ours on the road.

I would buy the front and rear bumpers and all the trim mouldings and marker lights if you decide to part it out !

Mine did something similar to this with a cracked piston. So much blowby it overwhelmed the PCV system, and forced oil out of lots of places it doesn't normally come out of.

Dont have enough space to store it while I sell parts off it. I have too many project cars and not enough parking. I have my Kitcar/Fiero project and my younger son's mustang. Then two cars that need to go ASAP (no parking, and they love to ticket non-working cars). I would love someone to buy the whole car.

If I had the money and means and the price was right I would buy it from you for a engine conversion, but I already have 2 others waiting for swaps. Put a price on it in the mall section, somebody will save it !

just posted it in the for-sale section