Engine Mechanical problem
1985 Pontiac Fiero 6 cyl Two Wheel Drive Automatic
Hi, so I have a 1985 fiero GT with a 2.8 liter V6. The car had a loud clatter from the valves and low oil pressure, About 25-30 psi on the dash guage.
I removed the covers and found a very loose rocker arm. I then removed the intake mainfold and found 6 rockers arms that had collapsed with broken retainer springs and some with the seats displaced. Thinking that this was the cause of the low oil pressure I replaced them all, set them and put the engine back together. And ran it.
First time out the oil pressure was still low aroung 25-30. And when I peak in the valve cover from the oil cap, I can't see any oil spurting on to the rocker arm at all.
Second time out the oil pressure never dropped below 40 and comes up to 60 on the road but the rocker arm I can see is still to dry.
What do I do, replace the oil pump or does this sound like a spun cam bearing, clogged passages. What would take out 6 lifters? I'm trying to, like everybody, save some cash. I can get to the oil pan easily, is there any way to tell from the bottom if its a spun cam bearing?
Remove valve covers and distributor, you can get a long shaft that connects to drill, spin oil pump, you should see oil from pushrods going over rockers.
Parts are available from " thefierostore. Com".
If not, then possible clogged galley, oil pump pickup, or excessive main/cam bearing clearence. The lifters may also be clogged
How is oil pressure at idle?
Also set valve lash at 3/4 turn after 0 lash.
You might also try an engine flush, where you pour contents of can into engine, let it idle for 20 minutes and then change oil.
January, 6, 2010 AT 10:07 PM
The oil pressure at idle is around 35-40 psi, and hits 60 at around 2000 rpm.
I will pull the rear valve cover and distributor and do as you said. The lifters are new so I doubt they are clogged.
What volume of oil should I expect at the rocker arm with the drill?
If oil begins to show up at the rocker arm, does this mean the pump is bad?
January, 8, 2010 AT 7:30 AM
If you have 35-40 psi at idle you have no problem. If you had 7psi or less, then you would have a problem.
The oil will " dribble" out the pushrod ends when spinning oil pump.
If oil dribbles out pushrod end while spinning pump, you are good, that is what the 2.8 is supposed to do.
Spin pump for 2 minutes, after no more than 1 minute, you should see oil out the pushrod ends, all 12 of them.
The main and cam bearing clearence is critical to oil pressure, so if you are getting a correct oil pressure reading, then most likely you have sludge buildup, clogging a galley.
However, I would not trust an electrical oil pressure gauge, use a mechanical gauge screwed into oil pressure sender hole for accurate readings.