Oil pressure drop
11-07-2009, 02:51 PM
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Oil pressure drop If I roll on it from second gear depending on the amount of throttle I give it throughout the gear my oil pressure will drop to zero and my "check gauges" light will come on. The dipstick was just above the add mark. Any guesses as to what causes this sudden drop in pressure?
11-08-2009, 07:15 AM
#3
Make sure the oil is full and if so and you dont hear and valves rattling it may be your gauge. I am having a similar problem now, over the last two weeks I noticed my gauge was going up and down and yesterday it stopped moving at all and is at 0. From what I have read and found it is a some what common problem for the gauge to go out and if there is really no oil pressure the motor will idle bad and be very loud with valve train noise.
Hope this helps. Good luck
Hope this helps. Good luck
11-08-2009, 08:36 AM
#4
98's are NOTORIOUS for the pumps going bad. Mine was still working fine at 70k when my cam was swapped but a Melling M10296 high volume pump went in anyway. Be careful so you don't toast some bearings. Sending units are known to go bad too but if OP otherwise reads good I suspect the pump.
11-08-2009, 01:22 PM
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Notorious is a HUGE overstatement.
'98-'00 all used the same pump. A '98 is no more or less likely to have this issue than a '99 or '00. And very few actually go bad in relation to the amout of LS1s that were produced for those three model years.
A notorious problem would be something more like power window motors.
From the sounds of the OP's problem, I'd first change the sending unit and see if the problem goes away.
'98-'00 all used the same pump. A '98 is no more or less likely to have this issue than a '99 or '00. And very few actually go bad in relation to the amout of LS1s that were produced for those three model years.
A notorious problem would be something more like power window motors.
From the sounds of the OP's problem, I'd first change the sending unit and see if the problem goes away.
11-08-2009, 01:34 PM
#7
Really not too bad. The crank pulley is usually the biggest PIA. Don't know if they mention it but go to GM and get a new o-ring for the oil pickup tube and make sure you don't drop a OP bolt in the pan. That is a PIA LOL Also a good excuse to put a underdrive pulley on since it off.......
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11-08-2009, 01:44 PM
#8
[QUOTE=RPM WS6;12479401]Notorious is a HUGE overstatement.QUOTE]
Then we just disagree. I have read about several trashed motors on here due to crapped OP's. I had one on my 99 z-71 at 115k but caught it early.....
If it does crap the consequences are much worse than window motor
And my experince with bad sending units they read weird all the time if they are bad not just WOT. Just my .02 which aint worth that since it is free
Then we just disagree. I have read about several trashed motors on here due to crapped OP's. I had one on my 99 z-71 at 115k but caught it early.....
If it does crap the consequences are much worse than window motor
And my experince with bad sending units they read weird all the time if they are bad not just WOT. Just my .02 which aint worth that since it is free
Last edited by SOMbitch; 11-08-2009 at 02:47 PM.
11-08-2009, 05:23 PM
#9
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Back on track, try the oil sending unit.
...and to change an oil pump = all day, unless you have a lift and some air tools. ~ Craig
11-09-2009, 09:24 PM
#10
Not trying to be arguementative but comparativley they seem to fail at a much higher rate on these motors than any other I am familliar with. Maybe notorious is too strong a word but it happens enough it does not surprise me anymore. It is in fact quite rare on SBC genI/II stuff unless something went through the pump.And it is also why almost everybody swaps them out with a cam change.
I wouldn't have one of these cars if they went out as much as window motors LOL. Gonna be doing my second one of those real soon....
OP I hope it is just an oil pressure switch.. GOOD LUCK!!!!
I wouldn't have one of these cars if they went out as much as window motors LOL. Gonna be doing my second one of those real soon....
OP I hope it is just an oil pressure switch.. GOOD LUCK!!!!
12-17-2010, 02:21 PM
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Notorious is a HUGE overstatement.
'98-'00 all used the same pump. A '98 is no more or less likely to have this issue than a '99 or '00. And very few actually go bad in relation to the amout of LS1s that were produced for those three model years.
A notorious problem would be something more like power window motors.
From the sounds of the OP's problem, I'd first change the sending unit and see if the problem goes away.
'98-'00 all used the same pump. A '98 is no more or less likely to have this issue than a '99 or '00. And very few actually go bad in relation to the amout of LS1s that were produced for those three model years.
A notorious problem would be something more like power window motors.
From the sounds of the OP's problem, I'd first change the sending unit and see if the problem goes away.
also you should use oil w/zink so you dont wipe camshafts.delco oem water pumps so they dont fail at high rpm.oil sending units also fail but not often. ive got some w/600000 miles and still running strong
12-17-2010, 11:47 PM
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Sorry there has been no correct info given to the OP in this thread. OP, you likely have a thrust bearing issue, meaning your motor is basically on borrowed time. The drop of oil pressure specifically when you roll onto the throttle is from crank walk. Your bearings and crank have chewed each other up, meaning both are trash. Want proof? Here ya go.
https://ls1tech.com/forums/racers-lo...ew-engine.html
https://ls1tech.com/forums/racers-lo...ew-engine.html
12-18-2010, 11:06 AM
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Dude you are sadly mistaken, I have 23 in a fleet and out of that 23 ive replaced all the oil pumps. every one failed around 160000. if you dont change the pump you will buy cam bearings,camshaft, lifters gull some rockers. if not worse. 25 years a GM Master . first sign is low oil pressure cold.
also you should use oil w/zink so you dont wipe camshafts.delco oem water pumps so they dont fail at high rpm.oil sending units also fail but not often. ive got some w/600000 miles and still running strong
also you should use oil w/zink so you dont wipe camshafts.delco oem water pumps so they dont fail at high rpm.oil sending units also fail but not often. ive got some w/600000 miles and still running strong
1) LS1s don't use a flat tappet cam. Therefore, you don't need the oils with high zinc content. You are thinking of older engines here, before the switch to roller cams.
2) When a '98-'00 pump does fail, there are rarely warning signs and there is no set mileage (some of them failed on almost brand new engines). The pressure relief spring sticks and all pressure is lost.
3) If you had 23 of 23 LSx engines with oil system failures, you are working in a Bermuda Triangle of fleet vehicles. That's a 100% failure rate, and if it was that common then it would happen to everyone. Yet here we are, 12 years later, and somehow tons of these engines are still roaming about with stock oil pumps.
Last edited by RPM WS6; 12-18-2010 at 11:13 AM.
