RE: LOW / NO Oil Pressure / 1986 C4

[michael mars]

RE: LOW / NO Oil Pressure / 1986 C4

Ok, I just installed my rebuilt drive shaft, Gutted the cat, installed a new crossover Y pipe & KBD Targa mufflers.
changed the cap, rotor, wires, plugs, pcv, air, gas filter.
changed oil & filter. Car runs and sounds great!
except now I have no oil pressure.
Thats to say that it starts cold at 30 psi then drops to 3 or 4
-0- at idle. red light comes on. goes back up to 22 when driving.
This did not occure before i changed oil.
I used Castrol syntec 10 W 30.
This 1986 Corvette coupe just turned 100,000
I cannot believe the pressure switch ''just went bad''
Any suggestions would be welcomed.
Thanks
Mike
grentzer@msn.com

 

[8388]

I would first suspect the pressure sending unit. Then I would check the dist. gear. Also, are you hearing any unsual noises, like a slight knock ?

 

[G Winter]

Are you sure you used the right filter? I think the sending unit is next to the dist. You may have damaged it or the wire or maybe just loosened the wire. Do the lifters make any noise, at 5 lbs I would think they would. I hope you are lucky and it is the wire.

 

[michael mars]

There were NO knocks, No over heating, no smoke.
drove car 12 miles. drained out the syntec 10w 30 and put in pennzoil 20w 50
The first filter was a fram ph 30 I used a AC Delco pf 25 the second time.
I have not started the car as yet. I decided to do the front brakes as long as it was up.
Tomorrow will tell: I suppose there is a possibility i could have knocked a wire loose messing around with the dist. cap. I also noticed some gaget located by the oil filter.
I know 350 pressure switchs are next to the dist. But i have no clue as to what the other gaget is.

 

[8388]

There were NO knocks, No over heating, no smoke.
drove car 12 miles. drained out the syntec 10w 30 and put in pennzoil 20w 50
The first filter was a fram ph 30 I used a AC Delco pf 25 the second time.
I have not started the car as yet. I decided to do the front brakes as long as it was up.
Tomorrow will tell: I suppose there is a possibility i could have knocked a wire loose messing around with the dist. cap. I also noticed some gaget located by the oil filter.
I know 350 pressure switchs are next to the dist. But i have no clue as to what the other gaget is.

The sensor by the oil filter is the oil temp sensor.

 

[geekinavette]

Do you know if your oil filter bypass is plugged?

I will tell you from experience...do not EVER put a Fram oil filter on ANYTHING. That is the absolute worst piece of junk out there...they should all be removed from the shelves and destroyed. AC Delco is a good choice...Mobil1 even better, but considerably more expensive.

The filter bypass is plugged on mine, and I had a Fram filter on it that collapsed within a week...oil pressure suddenly dropped and would actually go down a little with increase in RPM before going up.

Bill

 

[Vettefan87]

The shop once hooked an analog gauge up to mine instead of it going to the readout. I am not sure where they hooked it up to, but the got a different reading then what the digital dash was saying. I doubt your motor has zero oil pressure, I think it is the sending unit also.

 

[michael mars]

There has to be pressure or I would have never made it the 12 miles.
I have to pick up the rotors today, I'll pick up a ''real'' oil pressure gage kit at the same time. not looking foreward to messing with that cap again
Any idea what the oil temp should normally be?
and how does one check for a plugged by pass.

 

[redvett]

There were NO knocks, No over heating, no smoke.
drove car 12 miles. drained out the syntec 10w 30 and put in pennzoil 20w 50
The first filter was a fram ph 30 I used a AC Delco pf 25 the second time.
I have not started the car as yet. I decided to do the front brakes as long as it was up.
Tomorrow will tell: I suppose there is a possibility i could have knocked a wire loose messing around with the dist. cap. I also noticed some gaget located by the oil filter.
I know 350 pressure switchs are next to the dist. But i have no clue as to what the other gaget is.

20W 50 is way to heavy of oil for your region 10W 30 is where you should be and the sensor by the oil filter is the oil temp sensor. I would stick with AC filters they are rated one of the best. Also if you didnt have oil pressure the engine would stop since the oil pressure (2nd one) keeps the fuel pump running as long as there is pressure. Its in case of an accident.

 

[michael mars]

LOW / NO OIL PRESSURE / 1986 C4/ Thanks

My Region has winter 9 months out of the year, however the summers are brutal too. I waited to do the 12 mile test before reporting results.
After switching to Pennzoil 20w 50 & AC Filter the car started @ 44 psi
ran @ 36 to 38 and held around 22 to 26 at idle.
I would guess to say that either the Castrol syntec was to thin, Or the Fram filter was defective. Either way, never use that stuff again!
Car runs and sounds great. New brakes made a world of differance.
Damn Car seems to be idleing faster now.. Whats With That!
I will tackle those half shaft U-Joints & rear brakes next month.
I'm burned out & broke.
Any way; Thanks to all of you who offered suggestions.
Later, Mike

 

[redvett]

My Region has winter 9 months out of the year, however the summers are brutal too. I waited to do the 12 mile test before reporting results.
After switching to Pennzoil 20w 50 & AC Filter the car started @ 44 psi
ran @ 36 to 38 and held around 22 to 26 at idle.
I would guess to say that either the Castrol syntec was to thin, Or the Fram filter was defective. Either way, never use that stuff again!
Car runs and sounds great. New brakes made a world of differance.
Damn Car seems to be idleing faster now.. Whats With That!
I will tackle those half shaft U-Joints & rear brakes next month.
I'm burned out & broke.
Any way; Thanks to all of you who offered suggestions.
Later, Mike

Check your owners manual there isnt anything in there about 20W 50 and in your climate your good for 10W 30 trust me. 20W 50 is way too heavy for your vehicle.

 

[redc4corvette]

Pennzoil I have 80 degree weather every day and I would not run 20-50.
Fram The poor thing.
Fill the oil filter befor installing it.

 

[michael mars]

Man!!
Your pretty cranky for an old guy who lives in Hawaii.
I always load the filter before installing it.
Won't use Fram again.
Coco nut oil is to expensive here, what do you recommend.?

 

[redc4corvette]

I am always cranky after a weekend at the races.

I run Vavoline 5-30 or 10-40 and the NAPA gold filter.
In the 94 I run mobil 1 and a K&N oil filter.