Oil Pressure

go.stfu · 04-19-2007, 02:44 AM

I just bought an '89 n/a for $1.2k and noticed that the oil pressure is very low and the acceleration / top-speed is worse than that of the '85 n/a I just killed.

The front axle (and pretty much everything close) is coated in oil; however, there are no drips under the car when parked and the oil level doesn't drop.

1. How much would a small leak drop oil pressure?
2. Using dye in the oil after cleaning - what are some known '89 leak probs to look for?

Thanks =]

supramacist · 04-19-2007, 03:05 AM

Remove your exhaust manifold and your upper and lower plenum and have a look at your head and how it connects to the block.

There are drips..., just look a little further back like under the doors. You could have a bad rear main seal and if that's it you'll be smoking the clutch also, because it will be oil coated.

The dye won't do you any good unless you clean all of the oil from the engine as best as possible and then maybe. But chances are it
lt'll light up like a rave anyway.

Do you find yourself overheating?
Check the underside of your oil fill cap and see if there is like a white milky residue. If there is your'e about to blow a head gasket.

I had all of the symptoms you are talking about for weeks before mine finally blew out.

go.stfu · 04-19-2007, 03:09 AM

Thanks for the info.

No signs of overheating yet -- I'll check the cap + head tomm. morning.

IHateHacks · 04-19-2007, 03:12 AM

Oil pressure at idle at full operating temperature should be more than 4.3psi. See your stock gauge? See the mark inbetween the 40 and 0 mark? Thats 20psi, at idle with the engine fully warmed up it should be exactly inbetween the 20psi mark and the 0psi mark which would be 10psi. That is where mine sits at idle with coolant temp at 190F. During acceleration with the engine fully warmed up, it should start to climb as soon as you hit the throttle. And should level off a hair below 40psi around 4K rpm, never really looked at my oil pressure above 4k too busy watching the road.

At stone cold start up it should register within 3 seconds and should read 40psi within 10 seconds.

You might want to try a heavier viscosity oil like 10w-40.

supramacist · 04-19-2007, 03:13 AM

Also Make sure your valve covers are tight. You won't lose oil like that from them but maybe a bit.

You're welcome. Let's hope I'm wrong for your sake.

I had been running 10w 40 in mine.

mrnickleye · 04-19-2007, 03:29 AM

Before removing parts, go to the $0.99 store (or similar) and buy 4-5 cans of engine degreaser, and 5 cans of brake spray cleaner . Spray degreaser all over the engine and let soak for about 30 min. Then wash away degreaser with brake spray.

All cars with lots of miles and time on them will leak.

After repairs are made, they won't leak for a very long time.

I haven't seen a drop under mine in 2 yrs.

Read thru this thread, and do the stuff to get the upper t-belt cover off.
http://www.toyota-supra.info/forums/...ead.php?t=5768

The cam seals leak, and are not too hard to change. Check t-belt fot wear and oil contamination.

Front crank seal leak. Power steering hoses and pump seal leak. Parts Plus has quality hose for about $100 (toyota is $323).

VC gaskets leak. Distributor/cam sensor O ring, and internal seal leak.

Check in the FAQs section for info on these repairs.

Head gaskets seldom leak alot of oil. USUALLY just seepage.

see my signature.

supramacist · 04-19-2007, 03:36 AM

I was pumpimg a quart every 100 miles out of my head gasket took it to toyota and they still couldn't tell me where it was coming from.

When mine finally blew I took off the exhaust manifold and there was a solid quarter inch gap between the head and the block. I don't know how I made it home other than I had a can of starting fluid.

I don't know how the car ran even other than the exhaust manifold was covering the leak enough to make it so.

04-19-2007, 02:44 AM	#1
go.stfu 3" Exhaust Join Date: Nov 2006 Location: Atlanta, GA Posts: 80	Oil Pressure I just bought an '89 n/a for $1.2k and noticed that the oil pressure is very low and the acceleration / top-speed is worse than that of the '85 n/a I just killed. The front axle (and pretty much everything close) is coated in oil; however, there are no drips under the car when parked and the oil level doesn't drop. 1. How much would a small leak drop oil pressure? 2. Using dye in the oil after cleaning - what are some known '89 leak probs to look for? Thanks =] __________________ 1985 manual (r.i.p) -- 1989 automatic (new) http://www.cardomain.com/ride/2635827

04-19-2007, 03:05 AM	#2
supramacist 1000whp postwhore Join Date: Apr 2007 Location: Escape from the Prison Planet Posts: 1,356	Remove your exhaust manifold and your upper and lower plenum and have a look at your head and how it connects to the block. There are drips..., just look a little further back like under the doors. You could have a bad rear main seal and if that's it you'll be smoking the clutch also, because it will be oil coated. The dye won't do you any good unless you clean all of the oil from the engine as best as possible and then maybe. But chances are it lt'll light up like a rave anyway. Do you find yourself overheating? Check the underside of your oil fill cap and see if there is like a white milky residue. If there is your'e about to blow a head gasket. I had all of the symptoms you are talking about for weeks before mine finally blew out. Last edited by supramacist; 04-19-2007 at 03:11 AM.

04-19-2007, 03:09 AM	#3
go.stfu 3" Exhaust Join Date: Nov 2006 Location: Atlanta, GA Posts: 80	Thanks for the info. No signs of overheating yet -- I'll check the cap + head tomm. morning. __________________ 1985 manual (r.i.p) -- 1989 automatic (new) http://www.cardomain.com/ride/2635827

04-19-2007, 03:29 AM	#6
mrnickleye 1000whp postwhore Join Date: Jun 2005 Location: Mojave Desert, Calif. Posts: 1,705	Before removing parts, go to the $0.99 store (or similar) and buy 4-5 cans of engine degreaser, and 5 cans of brake spray cleaner . Spray degreaser all over the engine and let soak for about 30 min. Then wash away degreaser with brake spray. All cars with lots of miles and time on them will leak. After repairs are made, they won't leak for a very long time. I haven't seen a drop under mine in 2 yrs. Read thru this thread, and do the stuff to get the upper t-belt cover off. http://www.toyota-supra.info/forums/...ead.php?t=5768 The cam seals leak, and are not too hard to change. Check t-belt fot wear and oil contamination. Front crank seal leak. Power steering hoses and pump seal leak. Parts Plus has quality hose for about $100 (toyota is $323). VC gaskets leak. Distributor/cam sensor O ring, and internal seal leak. Check in the FAQs section for info on these repairs. Head gaskets seldom leak alot of oil. USUALLY just seepage. see my signature. __________________ Had a Red 1989 N/A. Automatic. Sports Pkg. w/wing. TEMS, and some nice MODS. Sold to a friend 10/08/08. Last edited by mrnickleye; 04-19-2007 at 03:45 AM.

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04-19-2007, 03:12 AM	#4
IHateHacks 20psi boost Join Date: May 2006 Location: New Haven/Hamden Posts: 793	Oil pressure at idle at full operating temperature should be more than 4.3psi. See your stock gauge? See the mark inbetween the 40 and 0 mark? Thats 20psi, at idle with the engine fully warmed up it should be exactly inbetween the 20psi mark and the 0psi mark which would be 10psi. That is where mine sits at idle with coolant temp at 190F. During acceleration with the engine fully warmed up, it should start to climb as soon as you hit the throttle. And should level off a hair below 40psi around 4K rpm, never really looked at my oil pressure above 4k too busy watching the road. At stone cold start up it should register within 3 seconds and should read 40psi within 10 seconds. You might want to try a heavier viscosity oil like 10w-40.

04-19-2007, 03:13 AM	#5
supramacist 1000whp postwhore Join Date: Apr 2007 Location: Escape from the Prison Planet Posts: 1,356	Also Make sure your valve covers are tight. You won't lose oil like that from them but maybe a bit. You're welcome. Let's hope I'm wrong for your sake. I had been running 10w 40 in mine.

04-19-2007, 03:36 AM	#7
supramacist 1000whp postwhore Join Date: Apr 2007 Location: Escape from the Prison Planet Posts: 1,356	I was pumpimg a quart every 100 miles out of my head gasket took it to toyota and they still couldn't tell me where it was coming from. When mine finally blew I took off the exhaust manifold and there was a solid quarter inch gap between the head and the block. I don't know how I made it home other than I had a can of starting fluid. I don't know how the car ran even other than the exhaust manifold was covering the leak enough to make it so.