Brand new engine losing oil pressure
02-12-2013, 05:41 PM
#1
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Brand new engine losing oil pressure Needing some help..
99 C5 Brand new TSP 408 shortblock..Cold idle is 55-65psi and I have seen it reach 70+ with rpm. Also maintains good pressure until the oil gets over 180dg then it starts dropping towards zero. I can maintain some pressure with RPM and it does fluctuate accordingly. but at idle it wants do drop back towards 0. When the motor cools back down and I restart it pressure is fine again...
-verified pressure with mechanical gauge
-Barbell IS installed
-switched from break in oil to Valvoline VR1 50w made no differance
-katech timing chain (no shims on oil pump)
-original batwing style pan modified to clear the shimmed & trimmed windage tray, bent pickup tube & bracket to keep 1/4" clearance from the pan
-pump is melling HV/HP (used 2k mi in my previous motor) my new gasket set had 2 different size black O-rings... I used the thicker black one, it was snug going in but not super tight, the smaller black one was just a little smaller than the green. I felt I was very careful when installing it...
Is it possible that the o-ring could be too large?
the old cam retaining plate not sealing up?
Any help would be greatly appreciated before I start tearing it back down to check the o-ring
99 C5 Brand new TSP 408 shortblock..Cold idle is 55-65psi and I have seen it reach 70+ with rpm. Also maintains good pressure until the oil gets over 180dg then it starts dropping towards zero. I can maintain some pressure with RPM and it does fluctuate accordingly. but at idle it wants do drop back towards 0. When the motor cools back down and I restart it pressure is fine again...
-verified pressure with mechanical gauge
-Barbell IS installed
-switched from break in oil to Valvoline VR1 50w made no differance
-katech timing chain (no shims on oil pump)
-original batwing style pan modified to clear the shimmed & trimmed windage tray, bent pickup tube & bracket to keep 1/4" clearance from the pan
-pump is melling HV/HP (used 2k mi in my previous motor) my new gasket set had 2 different size black O-rings... I used the thicker black one, it was snug going in but not super tight, the smaller black one was just a little smaller than the green. I felt I was very careful when installing it...
Is it possible that the o-ring could be too large?
the old cam retaining plate not sealing up?
Any help would be greatly appreciated before I start tearing it back down to check the o-ring
02-12-2013, 07:38 PM
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There are 0 miles on the new motor, I did the initial start up and ran it at 2000 RPM then drained oil. Refilled it with break in oil again, I have started the car several times and let it idle while data logging and working on the tune. I was actually getting ready to take it for its first drive when the oil pressure started dropping,I let the car cool down and changed to Valvoline 50w w/no change. The car will maintain pressure even up to coolant operating temp, but it's only when the oil temperature gets 180+ that it drops.
02-12-2013, 11:45 PM
#7
The fat green ring that comes with a Melling pump, just may seal, even if installed all the way on.
How is your pressure? If ok, you should be good....at least for now.
Last edited by gMAG; 02-12-2013 at 11:51 PM.
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02-13-2013, 07:58 AM
#9
The photo is the correct way. It seems possible that adequate pressure can be achieved, even if the o-ring is installed all the way on, past the metal bulge.
The fat green ring that comes with a Melling pump, just may seal, even if installed all the way on.
How is your pressure? If ok, you should be good....at least for now.
The fat green ring that comes with a Melling pump, just may seal, even if installed all the way on.
How is your pressure? If ok, you should be good....at least for now.
I have about 130 miles on it now and no signs of low oil pressure. Things like this just scare me though lol..
02-13-2013, 12:29 PM
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[QUOTE=gMAG;17142689]I believe that he did verify with a mechanical gauge.
Did you install the o-ring like this?...(o-ring should sit on the outer metal ring, as shown)
Yes sir and I used the green O-ring with the same pump on my last motor with a H/C upgrade, Pressure was never at 60 at idle I remember seeing maybe 40. I did have the sewing machine sound that got louder as the car got warmer. After about 2000 miles I spun a rod bearing. When I took it apart I noticed a scar/slight cut on the green ring. that is why I thought putting the bigger one in would be a good idea on this motor. Btw I did take the pump completely apart and clean it before installing it in this new motor. The pump,pan, and front and rear covers are the only parts I reused on this motor
Did you install the o-ring like this?...(o-ring should sit on the outer metal ring, as shown)
Yes sir and I used the green O-ring with the same pump on my last motor with a H/C upgrade, Pressure was never at 60 at idle I remember seeing maybe 40. I did have the sewing machine sound that got louder as the car got warmer. After about 2000 miles I spun a rod bearing. When I took it apart I noticed a scar/slight cut on the green ring. that is why I thought putting the bigger one in would be a good idea on this motor. Btw I did take the pump completely apart and clean it before installing it in this new motor. The pump,pan, and front and rear covers are the only parts I reused on this motor
02-13-2013, 12:55 PM
#12
I believe the green O ring is too big. I used the OEM Blue with my SLP pump. It came with a black and green O-ring.
The sewing machine sound seems to be normal from the cam profiles with OEM rockers.
The sewing machine sound seems to be normal from the cam profiles with OEM rockers.
02-13-2013, 01:36 PM
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The black one I used was actually larger than the green... is it possible for one to be too big even though it goes in ok? Thats what i dont understand and why im hesitant to just take it apart, but seems like the first place to check. For god sake its not a flux capacitor its a damn o-ring!!! it fits and seals or it doesn't lol but nothing is as simple as it seems with this car �� & even though it seems far fetched to me, so far that is the only thing I have been told could be causing this besides bearing clearances.
02-13-2013, 03:39 PM
#14
I used the green one.
A little lube, and it went in correctly.
Pressure is at 70 cold/43 hot idle.
As long as the o-ring is large enough, and it is not pinched or ****-eyed, all should be well.
If you believe that it is installed properly, you can move on, and other things can be looked at now.
A little lube, and it went in correctly.
Pressure is at 70 cold/43 hot idle.
As long as the o-ring is large enough, and it is not pinched or ****-eyed, all should be well.
If you believe that it is installed properly, you can move on, and other things can be looked at now.
Last edited by gMAG; 02-13-2013 at 03:50 PM.
02-13-2013, 08:34 PM
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I used the green one.
A little lube, and it went in correctly.
Pressure is at 70 cold/43 hot idle.
As long as the o-ring is large enough, and it is not pinched or ****-eyed, all should be well.
If you believe that it is installed properly, you can move on, and other things can be looked at now.
A little lube, and it went in correctly.
Pressure is at 70 cold/43 hot idle.
As long as the o-ring is large enough, and it is not pinched or ****-eyed, all should be well.
If you believe that it is installed properly, you can move on, and other things can be looked at now.
given the odd symptoms what would be the next areas to check?
How can I tell if the pump is the problem?
02-13-2013, 09:00 PM
#18
Before doing anything else (restarting the engine, oil pump, checking any components), I would check the oil for sediment/chips. This way, you can verify that there is no imminent damage to your bearings/metal. If there IS any metal (bearings, oil pump, etc), you'll find it in the filter, or in the oil.
Start by emptying the oil into a container which has a new plastic bag covering it. Let the container sit for an hour, to allow any sediment to fall to the bottom. Slowly, empty most of that oil into another clean container, leaving just a little oil in the first container.
Swirl the first container around, checking in the sunlight for any bearing material/metal.
Also, check the drain plug for ferrous metal sticking to it.
Also, cut your oil filter open with a pair of wire cutters, and inspect for any metal/contaminants in the filter material.
If you don't see any evidence, you can continue on with your troubleshooting, with the assumption that your bearings are not wearing.
If no metal in the oil, it can safely be reused.
At the least, this will give you some peace of mind.
Start by emptying the oil into a container which has a new plastic bag covering it. Let the container sit for an hour, to allow any sediment to fall to the bottom. Slowly, empty most of that oil into another clean container, leaving just a little oil in the first container.
Swirl the first container around, checking in the sunlight for any bearing material/metal.
Also, check the drain plug for ferrous metal sticking to it.
Also, cut your oil filter open with a pair of wire cutters, and inspect for any metal/contaminants in the filter material.
If you don't see any evidence, you can continue on with your troubleshooting, with the assumption that your bearings are not wearing.
If no metal in the oil, it can safely be reused.
At the least, this will give you some peace of mind.
Last edited by gMAG; 02-13-2013 at 09:07 PM.
02-13-2013, 10:40 PM
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Before doing anything else (restarting the engine, oil pump, checking any components), I would check the oil for sediment/chips. This way, you can verify that there is no imminent damage to your bearings/metal. If there IS any metal (bearings, oil pump, etc), you'll find it in the filter, or in the oil.
Start by emptying the oil into a container which has a new plastic bag covering it. Let the container sit for an hour, to allow any sediment to fall to the bottom. Slowly, empty most of that oil into another clean container, leaving just a little oil in the first container.
Swirl the first container around, checking in the sunlight for any bearing material/metal.
Also, check the drain plug for ferrous metal sticking to it.
Also, cut your oil filter open with a pair of wire cutters, and inspect for any metal/contaminants in the filter material.
If you don't see any evidence, you can continue on with your troubleshooting, with the assumption that your bearings are not wearing.
If no metal in the oil, it can safely be reused.
At the least, this will give you some peace of mind.
Start by emptying the oil into a container which has a new plastic bag covering it. Let the container sit for an hour, to allow any sediment to fall to the bottom. Slowly, empty most of that oil into another clean container, leaving just a little oil in the first container.
Swirl the first container around, checking in the sunlight for any bearing material/metal.
Also, check the drain plug for ferrous metal sticking to it.
Also, cut your oil filter open with a pair of wire cutters, and inspect for any metal/contaminants in the filter material.
If you don't see any evidence, you can continue on with your troubleshooting, with the assumption that your bearings are not wearing.
If no metal in the oil, it can safely be reused.
At the least, this will give you some peace of mind.
I also posted this on the corvette forum. hopefully is it ok to link another forum lots of insightful suggestions from both so far, thanks to all...
http://forums.corvetteforum.com/c5-t...post1583117939