Low oil pressure in a 17 mile crate ls3
10-04-2016, 04:12 PM
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Low oil pressure in a 17 mile crate ls3 Details about the car: 1990 miata with a crate ls3 that I finally got running this year. Has a holley hp efi and a t56 behind it.
So like the title says, my crate engine has developed low oil pressure after 17 miles. When it's cold I'm seeing pretty good oil pressure, mid thirty's at idle (800rpm) but as it warms up it starts dropping (which it should) but after a little bit I'm seeing about 10-12psi at idle which is still inside the safe 10psi per 1000rpm but the problem is that when I get on the throttle it doesn't jump much, I was watching it pretty close and when I saw about 25 psi at 3000 rpm I brought it back home since I was just driving it around the block.
The entire time I've been driving I've had a person watching all the sensors on my laptop while I drive to make sure afr's are good as well as coolant temp and oil pressure. Up until the weekend the car has been driving great and everything was right where it should have been. However on friday I took the car out for a little bit and after maybe 5 mins of driving my buddy told me my oil pressure was starting to drop down. I pulled to the side of the road and went slowly up a hill, when I saw it drop down to about 10 psi I turned off the car and we grabbed my truck to pull it home. When I checked oil I had maybe a quart too much in there so I drained about a quart and then took it out on sunday. Same thing though, after the oil had warmed up the pressure started dropping down to levels that I'm really not comfortable with.
I still need to grab a mechanical oil pressure gauge to test and make sure the sensor is fine but in my experience, it's rarely the sensor. So I guess the question is what should I look into next? From searching a little bit the first thing that comes up is cam bearings, while it's possible that my engine was defective, I really don't want that to be the problem. Ideas on what else it could be?
So like the title says, my crate engine has developed low oil pressure after 17 miles. When it's cold I'm seeing pretty good oil pressure, mid thirty's at idle (800rpm) but as it warms up it starts dropping (which it should) but after a little bit I'm seeing about 10-12psi at idle which is still inside the safe 10psi per 1000rpm but the problem is that when I get on the throttle it doesn't jump much, I was watching it pretty close and when I saw about 25 psi at 3000 rpm I brought it back home since I was just driving it around the block.
The entire time I've been driving I've had a person watching all the sensors on my laptop while I drive to make sure afr's are good as well as coolant temp and oil pressure. Up until the weekend the car has been driving great and everything was right where it should have been. However on friday I took the car out for a little bit and after maybe 5 mins of driving my buddy told me my oil pressure was starting to drop down. I pulled to the side of the road and went slowly up a hill, when I saw it drop down to about 10 psi I turned off the car and we grabbed my truck to pull it home. When I checked oil I had maybe a quart too much in there so I drained about a quart and then took it out on sunday. Same thing though, after the oil had warmed up the pressure started dropping down to levels that I'm really not comfortable with.
I still need to grab a mechanical oil pressure gauge to test and make sure the sensor is fine but in my experience, it's rarely the sensor. So I guess the question is what should I look into next? From searching a little bit the first thing that comes up is cam bearings, while it's possible that my engine was defective, I really don't want that to be the problem. Ideas on what else it could be?
10-04-2016, 09:09 PM
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10-05-2016, 05:14 AM
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Did you swap/modify the pick up when presumably changing the pan?
P.s. is it a straight line car or for corners? You may have more oiling issues in future if the latter and have taken no precautions..
P.s. is it a straight line car or for corners? You may have more oiling issues in future if the latter and have taken no precautions..
10-05-2016, 12:15 PM
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That the same o-ring that's on the pickup? I did have to switch pickups with the new pan. And yeah, I'm for sure gonna run into oiling issues in the future since it's for corners, I wanna get the car running well and get some experience with it first and then when I'm ready I'll probably do a dry sump.
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10-05-2016, 12:30 PM
#8
That the same o-ring that's on the pickup? I did have to switch pickups with the new pan. And yeah, I'm for sure gonna run into oiling issues in the future since it's for corners, I wanna get the car running well and get some experience with it first and then when I'm ready I'll probably do a dry sump.
It's common for it to get pinched while installing the pick up if you put it straight on. This is a common problem that gets alot of people.
10-05-2016, 12:41 PM
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Really hoping that this is the problem, that would make my life 100x easier.
10-05-2016, 12:47 PM
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Me personally, I lube it up with motor oil on both parts and rotate in from the side.
I have not pinched one yet doing it this way. (knock on wood)
As mentioned check your oil and filter for bearing debris first.
10-06-2016, 03:39 PM
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10-07-2016, 01:04 AM
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Been a crazy couple of days mostly because of an aerospace summit I had to go for our mars rover team so I haven't been able to get out to the garage at all but I'll get out there tomorrow and drain the oil/check for debris.
10-08-2016, 02:25 PM
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Hahahaha you'd think at least!
Drained the oil this morning, as well as cut apart the filter. Filter just looked dirty but there weren't any problems other than that. The oil just looks dirty as well, nothing really in it. I took a picture of the drain plug because it has some very very fine metal goo on it but I'm guessing that's normal with break in. All in all it looks fine and I'm pretty sure that it's the o-ring since it's much more likely that I screwed something up than GM.
Drained the oil this morning, as well as cut apart the filter. Filter just looked dirty but there weren't any problems other than that. The oil just looks dirty as well, nothing really in it. I took a picture of the drain plug because it has some very very fine metal goo on it but I'm guessing that's normal with break in. All in all it looks fine and I'm pretty sure that it's the o-ring since it's much more likely that I screwed something up than GM.
10-09-2016, 03:01 AM
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Im pretty sure something is bad inside.
that amount of metal shavings isn't normal.
nor is the color of the oil.
with 17 miles the oil should come out the same as you put it in.
that amount of metal shavings isn't normal.
nor is the color of the oil.
with 17 miles the oil should come out the same as you put it in.