*** HELP, buying a car with low oil pressure ***
05-05-2010, 08:13 PM
#1
*** HELP, buying a car with low oil pressure *** So I am 90% done with buying a 2001 SS from out-of-state, all factory, origional owner, 45k miles. I just found out the oil pressure is as follows:
COLD idle-- 60psi (normal)
HOT idle-- 25psi (low IMO)
What is wrong with this picture? I have had several LS engine combos and they have never idled lower than about 38psi when fully warm. Admitted, most had ported/shimmed pumps. I can;t figure out why it could be normal cold and then drop SOOOOO much when warm.
Is this a deal breaker? What could this mean? Is it just a weak spring?
Thanks
COLD idle-- 60psi (normal)
HOT idle-- 25psi (low IMO)
What is wrong with this picture? I have had several LS engine combos and they have never idled lower than about 38psi when fully warm. Admitted, most had ported/shimmed pumps. I can;t figure out why it could be normal cold and then drop SOOOOO much when warm.
Is this a deal breaker? What could this mean? Is it just a weak spring?
Thanks
05-05-2010, 08:23 PM
#2
TECH Fanatic
Join Date: Sep 2003
Location: St. Clair Shores Mi.
Posts: 1,265
Likes: 0
Received 4 Likes
on
3 Posts
My `98 has 140K and the pressure is the same (25psi hot idle) and I've never had an issue with it. IMO as long as the pressure climbs with rpm you should be fine.
05-05-2010, 08:51 PM
#5
I think you'd be surprised how low the oil pressure can go before it is considered "too low". I would say you should be ok with those numbers. Did you run a carfax to see if the miles make sense? You'd also be surprised to see how easy it is to switch out a cluster with lower miles for a one with higher miles. I ran a ton of carfax's (had unlimited when they still offered it) when I was looking for my truck and a few came back with odometer rollbacks......
05-05-2010, 09:06 PM
#6
They said they changed the "fluids". The car was traded in to a Toyota dealership and I know they used Toyota Oil...00279-DRM30, whatever the F*^% that is.
Carfax is clean. 1 owner. Miles check out 45k.
I think you'd be surprised how low the oil pressure can go before it is considered "too low". I would say you should be ok with those numbers. Did you run a carfax to see if the miles make sense? You'd also be surprised to see how easy it is to switch out a cluster with lower miles for a one with higher miles. I ran a ton of carfax's (had unlimited when they still offered it) when I was looking for my truck and a few came back with odometer rollbacks......
05-05-2010, 09:10 PM
#7
Mobil 1 is popular stuff, but it is thin when it is hot. If the car is running it, especially if its time to change it, that could contribute to the numbers you are seeing. That said, my 24,000 mile '01 is still 40-45 hot, all stock internally.
Like others have said, your pressure is still perfectly acceptable, even if it seems low. Used car maintenance means you'll be chaning the oil right away anyhow, which may be all that is required.
IMO, this shouldn't be a deal breaker, unless something else would lead you to believe the car has been abused....
Like others have said, your pressure is still perfectly acceptable, even if it seems low. Used car maintenance means you'll be chaning the oil right away anyhow, which may be all that is required.
IMO, this shouldn't be a deal breaker, unless something else would lead you to believe the car has been abused....
Trending Topics
05-05-2010, 09:17 PM
#8
The salesman just emailed me and said he thought the pressure was over 40 while he was "driving" it.
He also said he will have a mechanic check the pressure under accelleration tomorrow......but he has to make a work order so the mechanic's get paid to do it.
He also said he will have a mechanic check the pressure under accelleration tomorrow......but he has to make a work order so the mechanic's get paid to do it.
05-05-2010, 09:28 PM
#9
a lot of ls1 cars had weird oil pressure readings. my brothers was a 2000 and it read lower then mine did (2000 also). there were no ill effects though. but like mentioned before if its 10psi for every 1k rpm it should be fine. also if you ever do a cam swap put in a new oil pump and you will be fine.
05-05-2010, 09:40 PM
#10
Teching In
Join Date: Apr 2010
Location: Birmingham, AL
Posts: 39
Likes: 0
Received 0 Likes
on
0 Posts
Not sure that the input would help at all, but I have a 2001 SS and it has *slightly* higher pressure when cold, but even idling hot is always above 40psi. If you are that worried about it, no doubt an LS6 ported pump would do the trick. Everybody knows the oil pumps are shifty on the LS1's...
05-06-2010, 01:20 PM
#12
If it's not an oem oil sending unit, I can definitely see this happening. As long as their isn't any weird noises it should be fine. Hell you're going to be doing a cam swap anyways, right? See so you will be replacing the pump at the same time, 2 birds, 1 stone.
05-06-2010, 07:01 PM
#14
Soooooooooooooo the guy called me today as he was sitting in the car.
Engine temp just under the 210 mark
42ish idle
goes to 60 while revving.
Not sure how they got different results today but regardless I am not sweating it anymore. Thanks for all your help. Gotta love LS1tech!
Engine temp just under the 210 mark
42ish idle
goes to 60 while revving.
Not sure how they got different results today but regardless I am not sweating it anymore. Thanks for all your help. Gotta love LS1tech!
05-07-2010, 07:46 AM
#15
05-13-2010, 04:32 PM
#19
Staging Lane
Join Date: Mar 2010
Location: Knoxville, Tn
Posts: 65
Likes: 0
Received 0 Likes
on
0 Posts
I dealt with the same problem. 99% chance you need a different oil. I bought a daily driver in the winter with 168000 miles on it. The car was at 22psi after it was warmed up, and 50-60psi cold. It had Mobil 1 5w30 and a standard size K&N filter in it when I bought it. I put 3000 miles on it and decieded to go with what I normally use.
I use the German Castrol and Amsoil EaO64 extended filter. $75 for all of it if you change your own oil. My daily driven bird never seen less than 40psi at idle, and that is 90* days with the air on. At startup its 60psi, and at WOT I can peg the needle. This is a 168000 mile car without a rebuild. Your 45000 mile car should be fine.
The catch is my car on the old Mobil 1 would start up and hold 40psi, until I had driven it and began to set in traffic or in a parking lot, and then it would fall, and fall, and fall some more until it hit 22psi. If your serious, with money in hand, tell them you want that done. Pay for it if you must just to see. GC with the EaO64 filter. If it has a problem afterwards you need to walk away I believe.
25psi is low at idle for a car that doesn't have an aftermarket cam. I have never seen anything below 38psi in the southeast. That was at Rod Run while I sat in traffic for 4.5 hours in 92* weather with the air on waiting to hit the strip. Brutal as it was my oil guage never went below that.
I use the German Castrol and Amsoil EaO64 extended filter. $75 for all of it if you change your own oil. My daily driven bird never seen less than 40psi at idle, and that is 90* days with the air on. At startup its 60psi, and at WOT I can peg the needle. This is a 168000 mile car without a rebuild. Your 45000 mile car should be fine.
The catch is my car on the old Mobil 1 would start up and hold 40psi, until I had driven it and began to set in traffic or in a parking lot, and then it would fall, and fall, and fall some more until it hit 22psi. If your serious, with money in hand, tell them you want that done. Pay for it if you must just to see. GC with the EaO64 filter. If it has a problem afterwards you need to walk away I believe.
25psi is low at idle for a car that doesn't have an aftermarket cam. I have never seen anything below 38psi in the southeast. That was at Rod Run while I sat in traffic for 4.5 hours in 92* weather with the air on waiting to hit the strip. Brutal as it was my oil guage never went below that.
Last edited by Chaotic Deconstruct; 05-13-2010 at 04:38 PM. Reason: spelling
