Low oil preasure
Thread Starter
Junior Member
Joined: Dec 2015
Posts: 77
Likes: 0
From: Boyertown, Pennsylvania
Car: Firebird
Engine: 305 tbi
Transmission: 700r4
Low oil preasure
My oil pressure has been gradually going down. It idles just above the red and sits at about a little more than 15 most of the time but doesn't go much higher. Once I get past 1500 rpms the engine starts ticking. Any help is appreciated, really not wanting to have to dump money into rebuilding a 305.
Update: The oil pressure is at almost 30 when i start it up and the ticking was gone, but then gradually over like 10-15 minutes of driving drops to about 15 and the ticking came back. Higher rpms seem like they dont change it much at all.
Update: The oil pressure is at almost 30 when i start it up and the ticking was gone, but then gradually over like 10-15 minutes of driving drops to about 15 and the ticking came back. Higher rpms seem like they dont change it much at all.
Last edited by Mattkovitch; Feb 22, 2016 at 08:28 AM.
Senior Member
Joined: Jun 2000
Posts: 599
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From: Glenbeulah, WI
Car: 1988 Firbird
Engine: 406
Transmission: T-56
Axle/Gears: 4.10
Re: Low oil preasure
Does not sound good, what is the ticking noise? Lifters or a rod knock? Either way I suspect you will need a rebuild.
Joined: Oct 2001
Posts: 12,221
Likes: 1,141
From: Il
Car: 1989-92 FORMULA350 305 92 Hawkclone
Engine: 4++,350 & 305 CIs
Transmission: 700R4 4800 vig 18th700R4 t56 ZF6 T5
Axle/Gears: 3.70 9"ford alum chunk,dana44,9bolt
Re: Low oil preasure
Last oil change? Oil full? what brand of oil filter?
Joined: Mar 2014
Posts: 4,553
Likes: 806
From: South Ms
Car: 89 Firebird
Engine: 355 TBI
Transmission: 700R4
Axle/Gears: 10 Bolt.Posi-3.73s
Re: Low oil preasure
Try some 20w50 if its wore out this heavy oil may quiet it down some but you probably looking to rebuild or replace soon im afraid.
Joined: Jan 2010
Posts: 270
Likes: 17
Car: '86 Iroc Z & '91 RS
Engine: 305 TPI & 305 Qjet - Future LC9
Transmission: 700R4
Axle/Gears: 3.23
Re: Low oil preasure
Add a bottle of STP oil treatment - http://www.walmart.com/ip/STP-Oil-Tr...-15oz/16817398
Adds extra zddp needed for pre '87 flat tappet cams. Fingers Crossed.. and a Pray..
Adds extra zddp needed for pre '87 flat tappet cams. Fingers Crossed.. and a Pray..
Last edited by Camaro86IrocZ; Feb 22, 2016 at 02:33 PM.
Thread Starter
Junior Member
Joined: Dec 2015
Posts: 77
Likes: 0
From: Boyertown, Pennsylvania
Car: Firebird
Engine: 305 tbi
Transmission: 700r4
Re: Low oil preasure
Not sure what the ticking is. It's not loud or harsh, but just quietly there. And about the oil change that's the first thing I need to do, as I just bough the car about a month ago and haven't got it changed and Idk when they last did it. Really hoping I can fix it with some better oil or a new filter. If I do need a rebuild, how much does that usually cost? Any ideas?
Now that I think about it probably lifters causing the ticking.
Now that I think about it probably lifters causing the ticking.
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Joined: Aug 2014
Posts: 575
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From: Fort Collins, CO
Car: 1991 Firebird Formula
Engine: 5.7L TPI
Transmission: 700r4
Axle/Gears: 3.23
Re: Low oil preasure
I had a low-oil pressure issue on my engine where three of the four oil pump bolts had worked their way out. Perhaps not the source of your problem, but something to consider.
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Joined: Jul 1999
Posts: 17,268
Likes: 169
From: 51°N 114°W, 3500'
Car: 87 IROC L98
Engine: 588 Alcohol BBC
Transmission: Powerglide
Axle/Gears: Ford 9"/31 spline spool/4.86
Re: Low oil preasure
Pressure is a resistance to flow. When the engine is cold, flow is reduced and you see pressure. As the oil gets hot, viscosity drops and anywhere it can leak out will be easier. The chances of the oil pump being bad is very slim. That means you'll probably need engine work. The ticking is probably a lack of oil to the lifters and rockers.
Main bearings worn will cause an oil leak but will not cause noise until a bearing seizes onto the crankshaft.
Rod bearings wearing will generally cause a noise when they start to fail but will also make noise hot and cold.
Camshaft bearings can spin in the block and will wear causing a hot oil leak that won't show when the oil is cold. They will also not create a noise.
Buy a new oil filter to replace the one on the car. Don't worry about an oil change yet. Take the old filter and cut it open any way you can. Even a hacksaw can be used. Just cut the top off. Pull out the filter material and rip a chunk of it out. Squeeze that piece in a vise to get all the oil out of it then open it up to look inside. If there's lots of metal in the material, you have bearings going. All the temporary help such as thicker oil won't fix an engine in need of a rebuild.
Main bearings worn will cause an oil leak but will not cause noise until a bearing seizes onto the crankshaft.
Rod bearings wearing will generally cause a noise when they start to fail but will also make noise hot and cold.
Camshaft bearings can spin in the block and will wear causing a hot oil leak that won't show when the oil is cold. They will also not create a noise.
Buy a new oil filter to replace the one on the car. Don't worry about an oil change yet. Take the old filter and cut it open any way you can. Even a hacksaw can be used. Just cut the top off. Pull out the filter material and rip a chunk of it out. Squeeze that piece in a vise to get all the oil out of it then open it up to look inside. If there's lots of metal in the material, you have bearings going. All the temporary help such as thicker oil won't fix an engine in need of a rebuild.
Re: Low oil preasure
"All the temporary help such as thicker oil won't fix an engine in need of a rebuild."
There isn't much in a can that is a long term fix for low oil pressure or a tick..
There isn't much in a can that is a long term fix for low oil pressure or a tick..
Thread Starter
Junior Member
Joined: Dec 2015
Posts: 77
Likes: 0
From: Boyertown, Pennsylvania
Car: Firebird
Engine: 305 tbi
Transmission: 700r4
Re: Low oil preasure
Thanks for the help. I'll try looking for metal chips in the oil. If I do need a rebuild, does anyone have a ballpark figure of what that will cost?
Joined: Sep 2005
Posts: 27,918
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Car: Yes
Engine: Usually
Transmission: Sometimes
Axle/Gears: Behind me somewhere
Re: Low oil preasure
does anyone have a ballpark figure of what that will cost?
IOW, if you get to that point, DON'T do it to your existing block. Put a "bore kit" in it. And a good set of heads. Those crappy "swirlies" aren't worth the time of day either, any more than a 305 is.
Moderator


Joined: Jul 1999
Posts: 17,268
Likes: 169
From: 51°N 114°W, 3500'
Car: 87 IROC L98
Engine: 588 Alcohol BBC
Transmission: Powerglide
Axle/Gears: Ford 9"/31 spline spool/4.86
Thread Starter
Junior Member
Joined: Dec 2015
Posts: 77
Likes: 0
From: Boyertown, Pennsylvania
Car: Firebird
Engine: 305 tbi
Transmission: 700r4
Re: Low oil preasure
Thats what i thought. if I need a rebuild, then I'm just gonna run it till its dead while i save and then swap a 350 into it. How hard is it to find a good running junkyard 350 anymore? Or is there a better place to get one?
Thread Starter
Junior Member
Joined: Dec 2015
Posts: 77
Likes: 0
From: Boyertown, Pennsylvania
Car: Firebird
Engine: 305 tbi
Transmission: 700r4
Re: Low oil preasure
Augh well I guess I'm engine swapping this summer. Here's another question, what can I do to make this motor last as long as possible? Would thicker oil and an oil additive help? And how long do you think it'll last?
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Posts: 1,390
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From: Bright, IN
Car: '86 Bird, 96 ImpalaSS, 98 C1500XCab
Engine: LG4, LT1, L31
Transmission: 700R4, 4L60E, 4L60E
Axle/Gears: 3.73 Tors, 4.88 spool, 3.73 Eaton
Re: Low oil preasure
[QUOTE=Mattkovitch;6009672]...Would thicker oil and an oil additive help? ...QUOTE]
No and No.
No and No.
Joined: Mar 2014
Posts: 4,553
Likes: 806
From: South Ms
Car: 89 Firebird
Engine: 355 TBI
Transmission: 700R4
Axle/Gears: 10 Bolt.Posi-3.73s
Thread Starter
Junior Member
Joined: Dec 2015
Posts: 77
Likes: 0
From: Boyertown, Pennsylvania
Car: Firebird
Engine: 305 tbi
Transmission: 700r4
Re: Low oil preasure
Any ideas on how to make the engine last as long as possible, while I get some money together for a 350 swap
Supreme Member
iTrader: (1)
Joined: Aug 2007
Posts: 1,390
Likes: 0
From: Bright, IN
Car: '86 Bird, 96 ImpalaSS, 98 C1500XCab
Engine: LG4, LT1, L31
Transmission: 700R4, 4L60E, 4L60E
Axle/Gears: 3.73 Tors, 4.88 spool, 3.73 Eaton
Re: Low oil preasure
Don't let it lug at low rpm. Raise the idle speed. Don't rev it over 3000.
Joined: Jan 2010
Posts: 270
Likes: 17
Car: '86 Iroc Z & '91 RS
Engine: 305 TPI & 305 Qjet - Future LC9
Transmission: 700R4
Axle/Gears: 3.23
Re: Low oil preasure
Could also be an exhaust leak, injector click noise, bad oil pressure switch making the gauge read off.. So hard to tell thru internet posts,, Make a vid so these guys can hear it for a better diagnosis..
Thread Starter
Junior Member
Joined: Dec 2015
Posts: 77
Likes: 0
From: Boyertown, Pennsylvania
Car: Firebird
Engine: 305 tbi
Transmission: 700r4
Re: Low oil preasure
I was hoping you're right, but I don't see it being probable as the ticking sound development right after the Gage started reading low oil pressures.
Member
Joined: Jan 2011
Posts: 446
Likes: 1
From: Saratoga Area, New York
Car: 1990 Formula Firebird
Engine: 305 TBI (LO3)
Transmission: WC T-5 out of an 88 T/A
Axle/Gears: 10 bolt, 3.42 & Torsen Posi
Re: Low oil preasure
Does it have the proper oil level? It was asked earlier in the thread but I didn't see an answer.
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