oil pressure dropping above 2.5k...
03-15-2009, 07:33 PM
#1
TECH Addict
Thread Starter
iTrader: (11)
Join Date: Feb 2005
Location: Brunswick, GA
Posts: 2,193
Likes: 0
Received 0 Likes
on
0 Posts
oil pressure dropping above 2.5k... cliffs at bottom
background:
so after i put my cam in (VRX4) i was driving and a couple different times i noticed the oil pressure drop to about the 20 psi mark for a brief couple seconds while i was just cruising at ~60mph in 5th or 6th gear. i didn't think anything of it because it was very brief and wasn't consistent. just thought it was an electrical thing.
so fast forward a bit. ive done some canyon runs with no problems or issues what-so-ever. so i signed up for a track day. i signed up late and got stuck with the slow beginners. after working through a lot of traffic i finally got some clear track...next thing i know i was at 6k rpms and my oil pressure was reading at the 20 psi mark and was solid. the session was over so i cruised around the track and exited keeping the rpms low.
i thought i'd let it all cool down for a few. i started it and pressure came back up. i raised the rpm's a bit and noticed that at 3k and above the oil pressure would drop down to the 20 psi mark. since that day its been doing that at 2.5k and higher.
so my friend and i diagnosed the problem as a failing oil pump. so i figured i may as well drop the oil pan and put in one of Improved Racing's oil pan baffles at the same time.
so i now have a Melling oil pump and baffle and still have oil pressure problems. any ideas?
Cliffs:
my oil pressure would drop above 2.5k to the 20 psi mark, i thought it was a failing oil pump so i changed my stock pump for a Melling and added an Improved Racing oil pan baffle...and i still have oil pressure problems with it dropping down to the 20 psi mark above 2.5k. Anyone have any ideas?
background:
so after i put my cam in (VRX4) i was driving and a couple different times i noticed the oil pressure drop to about the 20 psi mark for a brief couple seconds while i was just cruising at ~60mph in 5th or 6th gear. i didn't think anything of it because it was very brief and wasn't consistent. just thought it was an electrical thing.
so fast forward a bit. ive done some canyon runs with no problems or issues what-so-ever. so i signed up for a track day. i signed up late and got stuck with the slow beginners. after working through a lot of traffic i finally got some clear track...next thing i know i was at 6k rpms and my oil pressure was reading at the 20 psi mark and was solid. the session was over so i cruised around the track and exited keeping the rpms low.
i thought i'd let it all cool down for a few. i started it and pressure came back up. i raised the rpm's a bit and noticed that at 3k and above the oil pressure would drop down to the 20 psi mark. since that day its been doing that at 2.5k and higher.
so my friend and i diagnosed the problem as a failing oil pump. so i figured i may as well drop the oil pan and put in one of Improved Racing's oil pan baffles at the same time.
so i now have a Melling oil pump and baffle and still have oil pressure problems. any ideas?
Cliffs:
my oil pressure would drop above 2.5k to the 20 psi mark, i thought it was a failing oil pump so i changed my stock pump for a Melling and added an Improved Racing oil pan baffle...and i still have oil pressure problems with it dropping down to the 20 psi mark above 2.5k. Anyone have any ideas?
Last edited by SIK02SS; 03-15-2009 at 09:16 PM.
03-15-2009, 11:18 PM
#4
TECH Senior Member
iTrader: (96)
Join Date: Aug 2007
Location: Turnin' Wrenches Infractions: 005
Posts: 24,241
Likes: 0
Received 79 Likes
on
70 Posts
after my cam swap mine did almost exactly what you describe. i changed my oil and put a new filter on and it solved it. im sure with the oil pan removal you prolly already did that though. mine seemed to be a clogged filter.
03-16-2009, 10:22 AM
#7
Chris,
Hopefully it is not a damaged cam bearing. Has it been doing it since the cam install?
Low pressure would be related to the pushrods and lifters as well. Something is probably relieving the pressure I would assume, since you have a good new pump.
Hopefully it is not a damaged cam bearing. Has it been doing it since the cam install?
Low pressure would be related to the pushrods and lifters as well. Something is probably relieving the pressure I would assume, since you have a good new pump.
Trending Topics
03-16-2009, 10:49 AM
#8
oil sensor.
that's what i would be checking if i were you.
before headers install, mine always cruised at 40 psi, but i realized that the oil sensor was broken in half. once i replaced it, it kicked it up to 60 psi, when i'm driving. ;]
that's what i would be checking if i were you.
before headers install, mine always cruised at 40 psi, but i realized that the oil sensor was broken in half. once i replaced it, it kicked it up to 60 psi, when i'm driving. ;]
03-16-2009, 11:34 AM
#9
TECH Addict
Thread Starter
iTrader: (11)
Join Date: Feb 2005
Location: Brunswick, GA
Posts: 2,193
Likes: 0
Received 0 Likes
on
0 Posts
now that i think about it, i think one of the wire coatings may have been a little melted from my headers. but i don't see how that would be rpm affected...
03-16-2009, 11:48 AM
#10
TECH Addict
Thread Starter
iTrader: (11)
Join Date: Feb 2005
Location: Brunswick, GA
Posts: 2,193
Likes: 0
Received 0 Likes
on
0 Posts
no. i did some canyon runs and drag racing with absolutely no drop in pressure (on the gauge). it started the day or 2 before we finished the tune, but it was in-consistent so i didn't think anything of it. it did it twice at different rpm's under different conditions but was only for a couple seconds each time.
i'm also thinking maybe the pickup tube filter is clogged. i was so set on the oil pump going out that i didn't think to look. but also i replaced the drain plug with a new one from chevy dealership and it didn't have a magnet on it, so i ordered a new one w/magnet.
03-16-2009, 11:55 AM
#11
TECH Resident
iTrader: (4)
Join Date: May 2003
Location: Diamond Bar, CA
Posts: 859
Likes: 0
Received 0 Likes
on
0 Posts
no. i did some canyon runs and drag racing with absolutely no drop in pressure (on the gauge). it started the day or 2 before we finished the tune, but it was in-consistent so i didn't think anything of it. it did it twice at different rpm's under different conditions but was only for a couple seconds each time.
i'm also thinking maybe the pickup tube filter is clogged. i was so set on the oil pump going out that i didn't think to look. but also i replaced the drain plug with a new one from chevy dealership and it didn't have a magnet on it, so i ordered a new one w/magnet.
i'm also thinking maybe the pickup tube filter is clogged. i was so set on the oil pump going out that i didn't think to look. but also i replaced the drain plug with a new one from chevy dealership and it didn't have a magnet on it, so i ordered a new one w/magnet.
03-16-2009, 01:51 PM
#13
Check the oil pressure sensor just in case, but you really have to bump it to damage it. Since the intake was not removed, I surmized that it was untouched. If you can get an external oil pressure gauge on there, it would eliminate if it is a gauge problem. I don't think it is though, by your description of events. It could be the pick up is too close to the pan and is losing the ability to flow the oil it needs. SBC had this issue and we would weld the pick up tube with 3/8" air gap from the pan. 
Now you have a reason to build a 408, since you need to pull the engine anyway.
Sorry, just trying to lighten the mood.
Now you have a reason to build a 408, since you need to pull the engine anyway.
Sorry, just trying to lighten the mood.
Last edited by 12secSS; 03-16-2009 at 03:08 PM. Reason: Crap! I can't type for shit!
09-02-2009, 10:47 AM
#17
Did you check the oil pressure sender?
The pickup tube is another thing to check. Flush it out with compressed air or water to make sure it's not clogged. Also, did you use a new o-ring where the pickup tube bolts to the oil pump? It's easy to tweak the o-ring creating an improper seal and causing it to leak when the pressure is higher. You should always replace it with a new one.
The pickup tube is another thing to check. Flush it out with compressed air or water to make sure it's not clogged. Also, did you use a new o-ring where the pickup tube bolts to the oil pump? It's easy to tweak the o-ring creating an improper seal and causing it to leak when the pressure is higher. You should always replace it with a new one.
09-02-2009, 12:25 PM
#18
11 Second Club
iTrader: (10)
Join Date: Feb 2006
Location: Sterling Heights, MI
Posts: 2,215
Likes: 0
Received 2 Likes
on
2 Posts
i ahve the same problem but its only when i romp 1st gear. around 3500-4000 my pressure drops to 20psi, and in the shift to 2nd it shoots up to 65+ and stays there till im out of the throttle. I had this problem with the stock pump, built the new motor with a new melling, new pickup tube new pushrods/lifters and all new bearings and i STILL HAVE THE SAME ******* PROBLEM!
