No oil pressure (need suggestions / ideas)
No oil pressure (need suggestions / ideas) 97 LS1 block
Stock Crank that was polished
Eagle rods, bearing's I think are at .0025-.0027 on the crank
Diamond Pistons
Stock lifters
Double roller
Fired the truck and turned it off . No oil pressure. We waited aprox 10 minutes before doing it again. We did this several times, swaping guages to confirm. Even using a clear oil pressure line. I would estimate a total 30 seconds max of run time between the test fires.
Pulled the front of the oil pump of and there is oil in the pump. Pulled the 4 bolts out of the pump and pulled it forward a little to confirm the spacer for the double roller is installed correctly. That checked out just fine and there was oil on it.
Based on those findings I am leaning towards the pump being good.
We tried firing it again for aprox 7-8 seconds thinking since nothing had oil, maybe it just needed to be run longer.
Are there any oil plugs similar to a freeze plug anywhere in the block that might not have been put back in?
Are there any other suggestions ideas?
I'm also guessing it would be wise to pull the pan and check a couple main bearings? By my figures total run time would be 35-37 seconds, nothing above 2k rpm. Max 1,200 total revolutions. There was a full tube of assembly lube used on the mains and about half on the cam.
Thanks in advance.
Stock Crank that was polished
Eagle rods, bearing's I think are at .0025-.0027 on the crank
Diamond Pistons
Stock lifters
Double roller
Fired the truck and turned it off . No oil pressure. We waited aprox 10 minutes before doing it again. We did this several times, swaping guages to confirm. Even using a clear oil pressure line. I would estimate a total 30 seconds max of run time between the test fires.
Pulled the front of the oil pump of and there is oil in the pump. Pulled the 4 bolts out of the pump and pulled it forward a little to confirm the spacer for the double roller is installed correctly. That checked out just fine and there was oil on it.
Based on those findings I am leaning towards the pump being good.
We tried firing it again for aprox 7-8 seconds thinking since nothing had oil, maybe it just needed to be run longer.
Are there any oil plugs similar to a freeze plug anywhere in the block that might not have been put back in?
Are there any other suggestions ideas?
I'm also guessing it would be wise to pull the pan and check a couple main bearings? By my figures total run time would be 35-37 seconds, nothing above 2k rpm. Max 1,200 total revolutions. There was a full tube of assembly lube used on the mains and about half on the cam.
Thanks in advance.
Well I just found this thread. https://ls1tech.com/forums/generation-iii-internal-engine/96161-part-number-oil-gally-plug-w-0-ring.html
I'm wondering if that might be my problem.
Any other suggestions?
I'm wondering if that might be my problem.
Any other suggestions?
I can't remember 
O-ring on the pump is solid though..
This thread talks about a plug on the front of the block too.. Any one have a part number for it? https://ls1tech.com/forums/generation-iii-internal-engine/92928-new-engine-being-built-should-i-prelube-if-so-how.html
O-ring on the pump is solid though..
This thread talks about a plug on the front of the block too.. Any one have a part number for it? https://ls1tech.com/forums/generation-iii-internal-engine/92928-new-engine-being-built-should-i-prelube-if-so-how.html
Last edited by LIL SS; Jul 18, 2007 at 01:16 PM.
Originally Posted by LIL SS
I can't remember
O-ring on the pump is solid though..
This thread talks about a plug on the front of the block too.. Any one have a part number for it? https://ls1tech.com/forums/showthread.php?t=92928
O-ring on the pump is solid though..
This thread talks about a plug on the front of the block too.. Any one have a part number for it? https://ls1tech.com/forums/showthread.php?t=92928
I don't know the part number, but, the front plug is a freeze plug insert that installs just to the right of the oil pump. So, you should be able to look & see if it's there. The plug on the back of the block is a dumbell shape w/o-ring; o-ring end out (cover side of hole). You'll have to pull the tranny & remove the rear cover to find it. Good-luck
Originally Posted by LS1-450
I don't know the part number, but, the front plug is a freeze plug insert that installs just to the right of the oil pump. So, you should be able to look & see if it's there. The plug on the back of the block is a dumbell shape w/o-ring; o-ring end out (cover side of hole). You'll have to pull the tranny & remove the rear cover to find it. Good-luck
Does the cover support it? Why would the o-ring be facing out?
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that plug in the back of the manifold is called the oil sending unit, that tells you what your oil pressure is . . . i know this cause mine snapped in half when i pulled off my LS1 manifold and i put my LS6 and i had no oil pressure. try that also
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Verdad Gallardo The hole where the oil sending unit goes had a M27-1/8 fitting for the oil line going to the guage. I know that's not the issue. Thanks for another idea though. The plate is also on the oil pan where the vettes have a sensor (by the oil filter).
Originally Posted by LIL SS
Does the cover support it? Why would the o-ring be facing out?
Yes, the cover supports it. Ignore the comment about the sender behind the manifold, it doesn't apply.
If you were able to look through the hole just right of the oil pump that has the freeze plug in it, you'd be looking right through the block if the barbell fitting & rear block cover were removed. The barbell fitting w/ o-ring needs to be installed in the back of the block, opposite the front freeze plug hole. Wish I had a pic....wait, I do have a pic, see below.
Hole is on the left of the block in the first pic & the barbell fitting is in the second.
Without the barbell fitting in place there will be no oil pressure.
Dumbell will be in tomorrow and the front plug is in stock so I will have them both tomorrow.. Boy am I glad I tried to fire it before all the front sheetmetal was in place. Had the inner fenders and radiator suport in place with a total of 6 bolts. Took me 1 hour 15 minutes to get the motor ready to pull today.. Just need to support the trans and chain it up.
Thanks in advance!!
Thanks in advance!!
Update:
Pulled the motor and installed the dumbell in the back of the block. Put it all back together. Since the front cover and crank pulley ect were installed from the previous night we though we would fire it again.
We have a clear line coming off the fitting that replaced the oil sensor in the back of the block. With no guage we routed it back to the oil fill on the valve cover with a funnel back in it. This way if there was any oil moving through the line it would drain back in to the funnel (valve cover).
Got it fired a few times 3 seconds (didn't want to stay running, 223/228 108/108, needs a little tuning I would imagine). It did not appear to be moving much of anything. We stuck the guage back on it and hit it again. Got a few 1 second fires then a good solid 7 second run. Still no pressure.
Pulled the front cover again The plug to the right of the pump is there. Pulled the pan down to access the pick up tube. When I unbolted it, I got some good oil drips. pulled the front of the pump off, again oil there.
Unscrewed the oil filter and it is full (dripping out like when you do a oil change).
The hole in the front of the block above the cam, I reached in there and felt no oil.
Pulled a valve cover and there is no oil on the rockers.
That's where we left it.
I'm under the impression there is a spring in the oil pump. What is it's function?
I'm wondering if the pump is moving oil but not much volume. Any truth to these?
https://ls1tech.com/forums/showpost....5&postcount=88
https://ls1tech.com/forums/showpost....5&postcount=93
Perhaps since I am running a truck pan and truck pick up tube, using the LS6 pump I have isn't a working combo? Using a blueish green o-ring.
Ordering a new pump tomorrow and I will be packing it with Jelly next week.
Any other tips ideas?
Thanks in advance.
Pulled the motor and installed the dumbell in the back of the block. Put it all back together. Since the front cover and crank pulley ect were installed from the previous night we though we would fire it again.
We have a clear line coming off the fitting that replaced the oil sensor in the back of the block. With no guage we routed it back to the oil fill on the valve cover with a funnel back in it. This way if there was any oil moving through the line it would drain back in to the funnel (valve cover).
Got it fired a few times 3 seconds (didn't want to stay running, 223/228 108/108, needs a little tuning I would imagine). It did not appear to be moving much of anything. We stuck the guage back on it and hit it again. Got a few 1 second fires then a good solid 7 second run. Still no pressure.
Pulled the front cover again
The plug to the right of the pump is there. Pulled the pan down to access the pick up tube. When I unbolted it, I got some good oil drips. pulled the front of the pump off, again oil there. Unscrewed the oil filter and it is full (dripping out like when you do a oil change).
The hole in the front of the block above the cam, I reached in there and felt no oil.
Pulled a valve cover and there is no oil on the rockers.
That's where we left it.
I'm under the impression there is a spring in the oil pump. What is it's function?
I'm wondering if the pump is moving oil but not much volume. Any truth to these?
https://ls1tech.com/forums/showpost....5&postcount=88
https://ls1tech.com/forums/showpost....5&postcount=93
Perhaps since I am running a truck pan and truck pick up tube, using the LS6 pump I have isn't a working combo? Using a blueish green o-ring.
Ordering a new pump tomorrow and I will be packing it with Jelly next week.
Any other tips ideas?
Thanks in advance.
Last edited by LIL SS; Jul 20, 2007 at 02:16 AM.
TECH Regular
Joined: Nov 2006
Posts: 426
Likes: 0
From: League City, Texas
The spring is attached to a poppet that regulates oil pressure.
Are you absolutely sure that you have the right o-ring on the pump pick-up? For some strange reason, GM used 2 different o-rings - one blue and one red. A lot of ppl on PT.net have had problems with the wrong o-ring. Also, you have an LS-1 block. Do you have an LS-1 oil pump and an LS-1 pick-up tube?
Are you absolutely sure that you have the right o-ring on the pump pick-up? For some strange reason, GM used 2 different o-rings - one blue and one red. A lot of ppl on PT.net have had problems with the wrong o-ring. Also, you have an LS-1 block. Do you have an LS-1 oil pump and an LS-1 pick-up tube?
OMG, what a nightmare. Sorry to see that issues remain. An LS6 pump will work. The problem could be the pick up tube. From the buldge/bubble/o-ring seat on the pick up tube, does the tube remain straight to the end (about 3/4" to 1" from the buldge/o-ring seat to the end of the tube) or does the tube have a step just before the end? Am talking about the end of the pick up tube that enters the oil pump. If the tube is straight from the buldge/o-ring seat to the end, it gets the blue (GM) or black (aftermarket) thinner o-ring. If there is a step @ the end of the pick up tube, it gets the green (thicker) o-ring. I'm going to the garage to look for spare o-rings & will post pics of the difference if I can find them.
Problem may also be that if the oil filter wasn't filled prior to installation, perhaps the time spent running the engine was long enough only to feed the pump & fill the filter; not long enough to build pressure........maybe?
Edit: Here are the pics.
Blue o-ring left is for straight end tube, green 0-ring right is for stepped end tube. Both o-rings are the same O.D., the thickness of the green o-ring makes the O.D. appear to be larger, but it's not. Couldn't find the black (aftermarket) o-ring, but it's the same size as the blue o-ring.
Problem may also be that if the oil filter wasn't filled prior to installation, perhaps the time spent running the engine was long enough only to feed the pump & fill the filter; not long enough to build pressure........maybe?
Edit: Here are the pics.
Blue o-ring left is for straight end tube, green 0-ring right is for stepped end tube. Both o-rings are the same O.D., the thickness of the green o-ring makes the O.D. appear to be larger, but it's not. Couldn't find the black (aftermarket) o-ring, but it's the same size as the blue o-ring.
Last edited by LS1-450; Jul 20, 2007 at 10:23 AM. Reason: added pics
Staging Lane
Joined: Nov 2006
Posts: 96
Likes: 0
From: Auburn,AL War Damn Eagle!!!!
Just wanted to give my 2 cents...I went threw this same **** with my 99 Z28, Installed my new cam and all that good stuff, left the old pump on figuring it worked fine before, started it up, the oil pressure spiked than went to 0psi. I over thought thinking about all this same stuff you are and the FU#%ER ended up being that pressure spring in the oil pump hung up letting all my oil pressure out! Since I had the shitty 99 pump still on there I ordered the TSP Ported LS7 Pump and have had no problem yet.
Long story short it always seems to be the *most* obvious fix ever but Most of us always tend overlook it and spend hours replacing something that is absoutly fine..
Long story short it always seems to be the *most* obvious fix ever but Most of us always tend overlook it and spend hours replacing something that is absoutly fine..
I had the same problem... I checked all of the plug and stuff.. I just ended up putting a new GM LS6 (not ported) in and it fixed my problem.
I have read that the Oil pressure bypass valve and spring has been a problem with sticking. I also have a engine that was pulled from a 99' Z28.
Bad or pinched O-Rings have been the cause of many oil system problems as well as the pickup being to close to the bottom of the pan.
I have also heard that many will leave it running for a few min's and then the pressure will return.. that is insane ! I could get myself to leave the engine running that long with out pressure.
I have read that the Oil pressure bypass valve and spring has been a problem with sticking. I also have a engine that was pulled from a 99' Z28.
Bad or pinched O-Rings have been the cause of many oil system problems as well as the pickup being to close to the bottom of the pan.
I have also heard that many will leave it running for a few min's and then the pressure will return.. that is insane ! I could get myself to leave the engine running that long with out pressure.
All good info, and thanks again..
I have ordered a pump, a LS6 o-ring and a truck o-ring. There is a different part number for the truck o-ring per my GM dealer. I'm going to put the LS6 pump and truck o-ring in and see what happens.
I figure this time I will pull the valve covers, spark plugs, leave the front cover off, disconnect injectors and turn it over for a minute or so once the new pump/oring is installed. I have seen oil pressure build from turning over a few other motors with the coil packs disconnected. Given there had run in the last few days and there was oil through ought the motor, but I'm hoping that will help. If it doesn't build pressure then, I will try the LS6 o-ring to see if that makes a difference.
This is a big PITA but again thanks to all that have been giving ideas.
I have ordered a pump, a LS6 o-ring and a truck o-ring. There is a different part number for the truck o-ring per my GM dealer. I'm going to put the LS6 pump and truck o-ring in and see what happens.
I figure this time I will pull the valve covers, spark plugs, leave the front cover off, disconnect injectors and turn it over for a minute or so once the new pump/oring is installed. I have seen oil pressure build from turning over a few other motors with the coil packs disconnected. Given there had run in the last few days and there was oil through ought the motor, but I'm hoping that will help. If it doesn't build pressure then, I will try the LS6 o-ring to see if that makes a difference.
This is a big PITA but again thanks to all that have been giving ideas.
Wanted to give a heads up on the situation. Got the Fbod and Truck o-rings. Major difference. The truck uses the red o-ring and it's external diameter is the same as the blue one for the F-bod but the thickness is much greater.
Put the o-ring and new pump packed with petroleum jelly in. Pulled the plugs and injectors. Turned it over and with in 4 seconds I had oil pressure 20 psi and with in 10 it was 30 psi with just a free crank.
Tomorrow I'll get the pulley on belt ect and fire it up. Very happy right now
Put the o-ring and new pump packed with petroleum jelly in. Pulled the plugs and injectors. Turned it over and with in 4 seconds I had oil pressure 20 psi and with in 10 it was 30 psi with just a free crank.
Tomorrow I'll get the pulley on belt ect and fire it up. Very happy right now