Idle oil pressure was 50-52, now 39-41 after hitting a chunk of concrete... ideas?
07-02-2009, 08:16 AM
#1
TECH Fanatic
Thread Starter
iTrader: (9)
Join Date: Dec 2006
Location: Va Beach
Posts: 1,240
Likes: 0
Received 0 Likes
on
0 Posts
Idle oil pressure was 50-52, now 39-41 after hitting a chunk of concrete... ideas? Hit a wonderful 6" x 6" chunk of concrete on the shoulder of the highway when I pulled off to put my top back in due to a sudden rain shower.
Monitored oil pressure and all looked good... got off the highway to go to my buddy's and it drops to 35psi... so I pull over immediately and expect to see a cracked oil pan or filter... nothing. Drive to my buddy's where we jack it up and only damage is a nick in the front crossmember where it hit and a small nick on the oil pan. Oil filter etc. is all fine.
My car has 84,000 miles on it. I'm running a LS4 high volume pump, Amsoil 5w40 and a K&N oil filter. Ever since I took my oil cooler out I was seeing 49-53 psi at hot idle and 60ish hot cruise.
Now I'm still seeing the same at crusise and WOT, but my hot idle is 39-41... scratching my head here to see what if anything could have changed causing my idle oil pressure to drop like that.
Even when I had the oil cooler in place my idle oil pressure was always in the 47-49 psi range.
Started it up and backed it out to go to work today and the garage floor is total clean... I'm not loosing any oil anywhere and oil pressures look exactly the same everywhere but hot idle.
-Brian
Monitored oil pressure and all looked good... got off the highway to go to my buddy's and it drops to 35psi... so I pull over immediately and expect to see a cracked oil pan or filter... nothing. Drive to my buddy's where we jack it up and only damage is a nick in the front crossmember where it hit and a small nick on the oil pan. Oil filter etc. is all fine.
My car has 84,000 miles on it. I'm running a LS4 high volume pump, Amsoil 5w40 and a K&N oil filter. Ever since I took my oil cooler out I was seeing 49-53 psi at hot idle and 60ish hot cruise.
Now I'm still seeing the same at crusise and WOT, but my hot idle is 39-41... scratching my head here to see what if anything could have changed causing my idle oil pressure to drop like that.
Even when I had the oil cooler in place my idle oil pressure was always in the 47-49 psi range.
Started it up and backed it out to go to work today and the garage floor is total clean... I'm not loosing any oil anywhere and oil pressures look exactly the same everywhere but hot idle.
-Brian
07-02-2009, 08:42 AM
#2
How old is your oil? I've noticed now that it's gotten hotter around here. If I'm going down the interstate in my V6 bird for a long period of time. When I get off the exit it is a lil low on oil pressure. I know the problem is bc I'm coming up on time to change the oil to something thicker now that it's summer and not cold anymore.
Does it have normal pressure when you first start it up?
Does it have normal pressure when you first start it up?
07-02-2009, 08:48 AM
#3
TECH Fanatic
Thread Starter
iTrader: (9)
Join Date: Dec 2006
Location: Va Beach
Posts: 1,240
Likes: 0
Received 0 Likes
on
0 Posts
Yes... normal oil pressure at startup... everything is the same other than hot idle pressure.
The oil has about 3000 miles on it... it's Amsoil 5w40 synthetic.
The oil has about 3000 miles on it... it's Amsoil 5w40 synthetic.
07-02-2009, 09:04 AM
#5
TECH Fanatic
Thread Starter
iTrader: (9)
Join Date: Dec 2006
Location: Va Beach
Posts: 1,240
Likes: 0
Received 0 Likes
on
0 Posts
Amsoil 5w40 is hardly "broken down" at 3000 miles... plus... the change literally happened last night after hitting the concrete.
I'll most likely change the oil filter first and see what happens.
07-02-2009, 09:43 AM
#7
Trust me if it put a hole in your pan you would be asking what that knocking sound was. I'm just telling you from my experience with my car. If you dont see any serious damage then the concrete should have done nothing to change your oil pressure.
From what you just said, completely describes what my car is doing. Oh well what do I know
..
From what you just said, completely describes what my car is doing. Oh well what do I know
.. Trending Topics
07-02-2009, 09:47 AM
#9
TECH Fanatic
Thread Starter
iTrader: (9)
Join Date: Dec 2006
Location: Va Beach
Posts: 1,240
Likes: 0
Received 0 Likes
on
0 Posts
Trust me if it put a hole in your pan you would be asking what that knocking sound was. I'm just telling you from my experience with my car. If you dont see any serious damage then the concrete should have done nothing to change your oil pressure.
From what you just said, completely describes what my car is doing. Oh well what do I know..
From what you just said, completely describes what my car is doing. Oh well what do I know
..I'm going to change the oil and filter and see what happens... after that I'll just drive it and forget about it.
07-02-2009, 09:51 AM
#10
TECH Fanatic
iTrader: (12)
Join Date: Jun 2007
Location: earth
Posts: 1,438
Likes: 0
Received 0 Likes
on
0 Posts
Oil breaking down makes the effective viscosity go up... which would make pressure go up.
Amsoil 5w40 is hardly "broken down" at 3000 miles... plus... the change literally happened last night after hitting the concrete.
I'll most likely change the oil filter first and see what happens.
Amsoil 5w40 is hardly "broken down" at 3000 miles... plus... the change literally happened last night after hitting the concrete.
I'll most likely change the oil filter first and see what happens.
I wouldnt worry to much about it. You still have plenty of oil pressure and its the same when driving.. Maybe your sending unit was slightly sticking and reading high idle and the hit from the block freed it a bit... lol who knows.. Do the easy things. Change the oil and filter and see if the pressure goes back into your comfort zone.
07-02-2009, 10:04 AM
#11
TECH Fanatic
Thread Starter
iTrader: (9)
Join Date: Dec 2006
Location: Va Beach
Posts: 1,240
Likes: 0
Received 0 Likes
on
0 Posts
Funny thing is that my comfort zone is actually lower... if I change cams this winter I'll go back to a ported LS6 pump. Don't need all the pressure of the LS4 w/o the oil cooler and track use.
We'll see what happens w/ some fresh oil and a new filter.
We'll see what happens w/ some fresh oil and a new filter.
07-02-2009, 11:51 AM
#12
TECH Enthusiast
iTrader: (5)
Join Date: Mar 2004
Location: New Orleans, LA
Posts: 556
Likes: 0
Received 0 Likes
on
0 Posts
Completely WAG. Well, slightly WAG.
I just replaced my stock oil pump with a ported/polished LS3 unit, with a different spring. My oil pressure is significantly higher now.
Perhaps when the concrete jarred the engine, it slightly moved the spring inside your oil pump and caused it to regulate at a slightly different pressure???
BTW, I wouldn't worry too much about it. When we removed my engine, there were several gouges in the pan where I'd run over curbing at the track at over 100mph. Looked scary, but there were no problems. It's a pretty stout pan.
I just replaced my stock oil pump with a ported/polished LS3 unit, with a different spring. My oil pressure is significantly higher now.
Perhaps when the concrete jarred the engine, it slightly moved the spring inside your oil pump and caused it to regulate at a slightly different pressure???
BTW, I wouldn't worry too much about it. When we removed my engine, there were several gouges in the pan where I'd run over curbing at the track at over 100mph. Looked scary, but there were no problems. It's a pretty stout pan.
07-02-2009, 12:05 PM
#13
Im pretty sure mine is 35psi hot idle. but i only have a TSP ported LS6 oil pump
07-02-2009, 12:22 PM
#14
TECH Fanatic
Thread Starter
iTrader: (9)
Join Date: Dec 2006
Location: Va Beach
Posts: 1,240
Likes: 0
Received 0 Likes
on
0 Posts
Completely WAG. Well, slightly WAG.
I just replaced my stock oil pump with a ported/polished LS3 unit, with a different spring. My oil pressure is significantly higher now.
Perhaps when the concrete jarred the engine, it slightly moved the spring inside your oil pump and caused it to regulate at a slightly different pressure???
BTW, I wouldn't worry too much about it. When we removed my engine, there were several gouges in the pan where I'd run over curbing at the track at over 100mph. Looked scary, but there were no problems. It's a pretty stout pan.
I just replaced my stock oil pump with a ported/polished LS3 unit, with a different spring. My oil pressure is significantly higher now.
Perhaps when the concrete jarred the engine, it slightly moved the spring inside your oil pump and caused it to regulate at a slightly different pressure???
BTW, I wouldn't worry too much about it. When we removed my engine, there were several gouges in the pan where I'd run over curbing at the track at over 100mph. Looked scary, but there were no problems. It's a pretty stout pan.
As far as jarring... I've jarred the car way worse during off course exursions at VIR
Drove it to get lunch today... was 50ish at idle when semi-warm. When fully warmed up w/ oil temp at 213 degrees I was steady 40 psi.
Like I said... I'm going to change the oil and not worry about it.
07-02-2009, 05:17 PM
#15
Thicker is Better (that's what your mom said) Run a thicker oil, dude. 10W-40 or 10W-50. I had the same problem with Royal Purple 5W-30 then switched back to regular 10W-40. Oil pressure went back to normal right away. Also, I saw less oil consumption over 3000 miles. Thin oil and hard driving don't seem to mix, but that's just my experience.
07-03-2009, 06:42 PM
#16
Could be it... or it could be that I haven't paid close attention to my oil pressure in this continued high heat we're having until now. Maybe the oil does thin out as it ages... the oil is 11 months in the car and 2500ish miles.
As far as jarring... I've jarred the car way worse during off course exursions at VIR
Yeah the LS4 pump has a different internal mechanism that moves more oil with each revolution.
Drove it to get lunch today... was 50ish at idle when semi-warm. When fully warmed up w/ oil temp at 213 degrees I was steady 40 psi.
Like I said... I'm going to change the oil and not worry about it.
As far as jarring... I've jarred the car way worse during off course exursions at VIR
Yeah the LS4 pump has a different internal mechanism that moves more oil with each revolution.
Drove it to get lunch today... was 50ish at idle when semi-warm. When fully warmed up w/ oil temp at 213 degrees I was steady 40 psi.
Like I said... I'm going to change the oil and not worry about it.
07-06-2009, 02:01 PM
#18
TECH Fanatic
Thread Starter
iTrader: (9)
Join Date: Dec 2006
Location: Va Beach
Posts: 1,240
Likes: 0
Received 0 Likes
on
0 Posts
Well after swapping the Mobil 1 5w30 and the Mobil 1 filter I'm seeing a lowest of 35 psi hot idle after ******* the car in 90 degree weather. Normal hot idle seems to be 38ish. Hot cruise is 57-60 and WOT is around 80-84 at redline.
I'd think if something was jarred loose I'd not be able to hold oil pressure at all. I'm going to just monitor it for a bit unless anyone has a better idea.
I'd think if something was jarred loose I'd not be able to hold oil pressure at all. I'm going to just monitor it for a bit unless anyone has a better idea.
07-06-2009, 02:40 PM
#20
TECH Fanatic
Thread Starter
iTrader: (9)
Join Date: Dec 2006
Location: Va Beach
Posts: 1,240
Likes: 0
Received 0 Likes
on
0 Posts
I replaced the 11 month old Amsoil 5w40 and K&N filter w/ Mobil 1 5w30 and M1 filter this weekend.... as expected, the pressure went down a few PSI w/ the 5w30 oil vs. 5w40.
I don't track the car anymore and no longer have an oil cooler installed so I actually want lower pressure... just not for no apparent reason.
I'm just going to watch it closely and see what happens... if it changes again then I know something is up... as it stands right now this could all be from the hot weather and return to a stock non-vented hood.
When I first pulled my oil cooler it was in February and since watching the oil pressures closely then I haven't paid much attention. So... the lower presssure I'm seeing could be from the hot weather and a hotter engine bay, but I can't be certain.
I don't track the car anymore and no longer have an oil cooler installed so I actually want lower pressure... just not for no apparent reason.
I'm just going to watch it closely and see what happens... if it changes again then I know something is up... as it stands right now this could all be from the hot weather and return to a stock non-vented hood.
When I first pulled my oil cooler it was in February and since watching the oil pressures closely then I haven't paid much attention. So... the lower presssure I'm seeing could be from the hot weather and a hotter engine bay, but I can't be certain.