woldson Posted May 5, 2009 Share Posted May 5, 2009 Screwdriver ear method. It will get louder the closer you get to the whine. Quote Link to comment Share on other sites More sharing options...
misterZ Posted May 8, 2009 Author Share Posted May 8, 2009 Screwdriver ear method. It will get louder the closer you get to the whine. Ok, haven't tried that yet but after some reading decided I want to tackle changing the oil pump; my Chilton manual makes it sound easy (3 steps I think)--rotate #1 to TDC, drain oil/drop pan, remove pump--fill new pump with fresh oil, install is reverse. After discussions w/ friends that have done this on their domestics, they cautioned me about alignment issues w/ the distributor and were surprised I don't have to pull the motor to get to the pump(?). How difficult of a job is this for a simple backyard mechanic (<-- term used loosely)? Most of the related posts to my problem on here (low pressure/whine) point to a bad sending unit or gauge; already performed the manual pressure gauge test and seems to validate the readings on my dash gauge. I still have some pressure but the whine still has me concerned and hope it's not tranny related. Quote Link to comment Share on other sites More sharing options...
misterZ Posted May 14, 2009 Author Share Posted May 14, 2009 How difficult of a job is this for a simple backyard mechanic (<-- term used loosely)? Most of the related posts to my problem on here (low pressure/whine) point to a bad sending unit or gauge; already performed the manual pressure gauge test and seems to validate the readings on my dash gauge. I still have some pressure but the whine still has me concerned and hope it's not tranny related. ^^ bump I've replaced the oil pressure switch and the gauge is now stable; pressure is ~15-20 psi at idle (engine warm) and ~40-45 psi under power. I'm still not convinced the pump is bad but I don't have a benchmark to compare my readings to. What is the 'normal' oil pressure range for the L28 (NA)? Btw--the whine noise disappeared after a fresh oil change using Mobil1 15-50w (previously had Mobile1 5-30w w/ conventional mixed from mechanic that diagnosed a bad pump as oil level was low at the time). Please help as I'm trying to ensure I don't blow this thing up driving it to DNI next week. Thanks in advance.... Quote Link to comment Share on other sites More sharing options...
Ferrariferg Posted May 14, 2009 Share Posted May 14, 2009 That sounds pretty low to me. My L28 NA has about 45 psi ,cold, at idle and not much different when warm. I'm using Mobil clean 5000 10w40. Quote Link to comment Share on other sites More sharing options...
misterZ Posted May 15, 2009 Author Share Posted May 15, 2009 That sounds pretty low to me. My L28 NA has about 45 psi ,cold, at idle and not much different when warm. I'm using Mobil clean 5000 10w40. So is the pressure suppose to hold steady or does yours drop at all when coming to a stoplight? Mine will fluctuate within the range stated above and occasionally drop below ~15-20 psi or go up as high as ~75-80 psi and stay for a period before settling in the middle ~45 psi. It's all over the place I tell ya... Quote Link to comment Share on other sites More sharing options...
Ferrariferg Posted May 15, 2009 Share Posted May 15, 2009 Mine never really moves unless I accelerate. When I let off the gas it will fall below 45 for a few seconds and then go right back up. Quote Link to comment Share on other sites More sharing options...
Careless Posted May 15, 2009 Share Posted May 15, 2009 misterZ, if you wanna change the pump, go right ahead... good insurance! ... but I'd like to mention that the oil cannot just disappear into thin air that fast. I mean... WHERE is the oil being burnt... it might be leaking passed something (i don't want to scare you though, so I'll keep shut) and being burned ever so slightly so that you barely even notice... the catalytic converter will cover up a slight oil burn but not two quarts between oil changes without a smell. it must be burning a touch passed the 5th and 6th cylinders, try running a slightly thicker oil? one weight increase? a compression test won't reveal a stuck oil control ring. but running a thicker oil for one oil interval will let you know if it's seeping passed a slight gap. Quote Link to comment Share on other sites More sharing options...
misterZ Posted May 15, 2009 Author Share Posted May 15, 2009 misterZ, if you wanna change the pump, go right ahead... good insurance! I don't mind and prefer replacing the pump if it's fairly easy to do; according to the service manual it appears simple enough ensuring #1 is TDC before dropping the pan and removing the pump--fill new pump w/ oil and allign the marks on the shaft(s) w/ the distributor. Is that all there is to it? Quote Link to comment Share on other sites More sharing options...
2eighTZ4me Posted May 15, 2009 Share Posted May 15, 2009 Chilton manual makes it sound easy (3 steps I think)--rotate #1 to TDC, drain oil/drop pan, remove pump--fill new pump with fresh oil, install is reverse. Why would you need to drop the pan? The oil pump mounts on the bottom of the front timing cover. 4 bolts and it's off in your hand ( and spewing oil everywhere). Get the motor to TDC, drop the pump, and then when reinstalling, just ensure that your spindle shaft is pointing in the 11:25 position looking down in the distributor hole and you're done.....No need to drop the pan. That's overkill.....thanks Chilton's! Quote Link to comment Share on other sites More sharing options...
misterZ Posted May 15, 2009 Author Share Posted May 15, 2009 Why would you need to drop the pan? The oil pump mounts on the bottom of the front timing cover. 4 bolts and it's off in your hand ( and spewing oil everywhere). .....thanks Chilton's! My bad, I read it again and it just says to drain oil and remove splash pan. My brain was focused on a picture of the oil pan bolt tightening sequence on the opposite page. Sounds/looks easy enough, thanks! Quote Link to comment Share on other sites More sharing options...
TimZ Posted May 15, 2009 Share Posted May 15, 2009 I've replaced the oil pressure switch and the gauge is now stable; pressure is ~15-20 psi at idle (engine warm) and ~40-45 psi under power. I'm still not convinced the pump is bad but I don't have a benchmark to compare my readings to. What is the 'normal' oil pressure range for the L28 (NA)? 15-20psi at idle and ~45psi under power sounds pretty much dead nuts normal for an L-series with a stock oil pump. It doesn't sound to me like there is anything wrong with your pump from that description. Quote Link to comment Share on other sites More sharing options...
misterZ Posted May 16, 2009 Author Share Posted May 16, 2009 It doesn't sound to me like there is anything wrong with your pump from that description. Most encouraging, thanks! I think I'll still replace it for piece of mind. Quote Link to comment Share on other sites More sharing options...
Careless Posted May 16, 2009 Share Posted May 16, 2009 15-20psi at idle and ~45psi under power sounds pretty much dead nuts normal for an L-series with a stock oil pump. It doesn't sound to me like there is anything wrong with your pump from that description. yeah thats what i was thinking too, but no harm in replacing it if done right, and having a spare pump is not a bad thing incase one starts to show fatigue... he can put the old one back in rather than say "ahh i'll drive it until the one i ordered comes in the mail" or something. Quote Link to comment Share on other sites More sharing options...
misterZ Posted May 17, 2009 Author Share Posted May 17, 2009 This car is possessed! It ran beautifully all day yesterday and oil pressure was ~65 psi at start up (within a min or two) and sustained that pressure all day under all drivings conditions. It only varied ±5 psi on deceleration/acceleration at stoplights. Quote Link to comment Share on other sites More sharing options...
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