low oil pressure..should i be worried?
09-26-2012, 04:57 AM
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low oil pressure..should i be worried?
I have the sr5 cluster and autometer oil pressure gauge. In my recollection, the oem gauge has always been in the middle when at wot in gear and thr autometer gauge around 50 psi.
Recently, the oem gauge sits around the lowest tick mark in the "normal" range and autometer says 25 psi at wot.
I don't see signs of an oil leak. This is recent.
Bad??? What should I look for and fix please?
Thanks
Recently, the oem gauge sits around the lowest tick mark in the "normal" range and autometer says 25 psi at wot.
I don't see signs of an oil leak. This is recent.
Bad??? What should I look for and fix please?
Thanks
09-26-2012, 06:24 AM
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Thanks Brian.
I don't think its the oem gauge being sporadin the past...25ic this time...I've had the oem sender/sensor come off and the needle drops to zero...simple fix.
What concerns me is that BOTH my autometer and oem gauges now tell me I'm about half the wot pressure I remember being at...25 psi instead of 50.
Is 25 ok? If not, what is it an indicator of? I will look at Rogers site today too.
On a one day biz trip and noticed on way to airport....this is all on my phone
I don't think its the oem gauge being sporadin the past...25ic this time...I've had the oem sender/sensor come off and the needle drops to zero...simple fix.
What concerns me is that BOTH my autometer and oem gauges now tell me I'm about half the wot pressure I remember being at...25 psi instead of 50.
Is 25 ok? If not, what is it an indicator of? I will look at Rogers site today too.
On a one day biz trip and noticed on way to airport....this is all on my phone
09-26-2012, 11:42 AM
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Thanks guys. Ok that sounds not too terrifying.
So, when it was 50 psi at 3000 rpm before, was that bad? Had been at that for over a year (while running right in the middle of the oem dash gauge (now running at the lower hashmark while at 25 psi at same rpm)....
Just seems odd that it would be low all of a sudden. I will check oil level when I land today.
So, when it was 50 psi at 3000 rpm before, was that bad? Had been at that for over a year (while running right in the middle of the oem dash gauge (now running at the lower hashmark while at 25 psi at same rpm)....
Just seems odd that it would be low all of a sudden. I will check oil level when I land today.
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09-26-2012, 12:38 PM
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Oil flow is more importiant than pressure. If pressure is all you want, switch to a thicker oil...that will get your PSI's up.
I hear a lot of people say (especially the older landcruiser guys)..."I lost oil pressure and spun a bearing". When in reality they lost oil flow and spun a bearing.
The problem with oil pressure vs flow is simple...it's easy to measure oil pressure and next to impossible to measure oil flow. So we've becomed conditioned to think in terms of pressure.
The only real way to see if you have oil flow is to take the valve cover off and rotate the engine by hand. You should see oil coming out of the rocker shafts onto the cam. Since this is the highest point in the engine, it's a good bet your bottom end is getting oil flow too since there fed through the same set of passages.
I hear a lot of people say (especially the older landcruiser guys)..."I lost oil pressure and spun a bearing". When in reality they lost oil flow and spun a bearing.
The problem with oil pressure vs flow is simple...it's easy to measure oil pressure and next to impossible to measure oil flow. So we've becomed conditioned to think in terms of pressure.
The only real way to see if you have oil flow is to take the valve cover off and rotate the engine by hand. You should see oil coming out of the rocker shafts onto the cam. Since this is the highest point in the engine, it's a good bet your bottom end is getting oil flow too since there fed through the same set of passages.
09-26-2012, 12:38 PM
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Ok I will check when I land in two hours and report back.
I added a quart about a month ago because the oil level was low on the dipstick (but psi was still high then). Hmmmm
I added a quart about a month ago because the oil level was low on the dipstick (but psi was still high then). Hmmmm
09-26-2012, 01:29 PM
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thanks everyone.
I am coming up on oil change time anyway, so hopefully that will do something too if it's still around by then.
I've run 10W30 in this truck for 10 years. New Timing chain/oil pump/oil pan reseal (oil pickup tube was not blocked) done less than 10K ago.
Again, the biggest surprise to me is that this is SUDDENLY happening now (both gauges indicated lower pressure by half) - which makes me think something changed recently - and I can't think of anything done to it recently that could trigger this in the last few days (again no oil leaks aside from the usual drop in the driveway I've had for a decade).
I'll do some more investigating suggested here and report back.
thanks again everyone.
Phil
I am coming up on oil change time anyway, so hopefully that will do something too if it's still around by then.
I've run 10W30 in this truck for 10 years. New Timing chain/oil pump/oil pan reseal (oil pickup tube was not blocked) done less than 10K ago.
Again, the biggest surprise to me is that this is SUDDENLY happening now (both gauges indicated lower pressure by half) - which makes me think something changed recently - and I can't think of anything done to it recently that could trigger this in the last few days (again no oil leaks aside from the usual drop in the driveway I've had for a decade).
I'll do some more investigating suggested here and report back.
thanks again everyone.
Phil
09-26-2012, 02:26 PM
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Oil flow is more importiant than pressure. If pressure is all you want, switch to a thicker oil...that will get your PSI's up.
I hear a lot of people say (especially the older landcruiser guys)..."I lost oil pressure and spun a bearing". When in reality they lost oil flow and spun a bearing.
The problem with oil pressure vs flow is simple...it's easy to measure oil pressure and next to impossible to measure oil flow. So we've becomed conditioned to think in terms of pressure.
The only real way to see if you have oil flow is to take the valve cover off and rotate the engine by hand. You should see oil coming out of the rocker shafts onto the cam. Since this is the highest point in the engine, it's a good bet your bottom end is getting oil flow too since there fed through the same set of passages.
I hear a lot of people say (especially the older landcruiser guys)..."I lost oil pressure and spun a bearing". When in reality they lost oil flow and spun a bearing.
The problem with oil pressure vs flow is simple...it's easy to measure oil pressure and next to impossible to measure oil flow. So we've becomed conditioned to think in terms of pressure.
The only real way to see if you have oil flow is to take the valve cover off and rotate the engine by hand. You should see oil coming out of the rocker shafts onto the cam. Since this is the highest point in the engine, it's a good bet your bottom end is getting oil flow too since there fed through the same set of passages.
There are no rockers on a 3.0.
09-26-2012, 02:51 PM
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you can have as much flow as you want. But its the resistance to flow which creates the pressure. And the oil pressure is whats nessacary to float the crank, rods and cams so you don't beat the snot out of your bearings/internals. This of course all depends on the engine. Your rules of 10psi per 1000rpm is a good baseline, but you should get ahold of the proper numbers for your engine. My 7mgte has a factory oil pressue of 4.3 psi at idle. Its kinda scary seeing your oil pressure gauge almost at 0 before you get used to it.
Before I changed my oil pump, I would get 22~24psi highway cruising. After I changed it I'm getting 26~29. Over time they will eventually wear out and become sloppy. Just like everything else. Just one more option.
Before I changed my oil pump, I would get 22~24psi highway cruising. After I changed it I'm getting 26~29. Over time they will eventually wear out and become sloppy. Just like everything else. Just one more option.
09-26-2012, 03:30 PM
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[QUOTE=nothingbetter;51978393]you can have as much flow as you want. But its the resistance to flow which creates the pressure. And the oil pressure is whats nessacary to float the crank, rods and cams so you don't beat the snot out of your bearings/internals. QUOTE]
If it was that simple, then everyone should be running 90wt gear oil and we would have lots of oil pressure.
New engines, and yes I would consider the 22re new engine technology since it's an OHC engine, have very tight tolerances. There doesn’t need to be any "floating" of the bearings. Last engine I did, I platigaged the bearings at .0023 hundredths of an inch. That is only enough rooms for a thin film of oil to get in there.
Again, oil flow is more important than oil pressure.
If it was that simple, then everyone should be running 90wt gear oil and we would have lots of oil pressure.
New engines, and yes I would consider the 22re new engine technology since it's an OHC engine, have very tight tolerances. There doesn’t need to be any "floating" of the bearings. Last engine I did, I platigaged the bearings at .0023 hundredths of an inch. That is only enough rooms for a thin film of oil to get in there.
Again, oil flow is more important than oil pressure.
09-26-2012, 03:57 PM
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update....
Ran at idle for a few then checked oil level...nothing on stick!
Also noted that at startup, a metallic "rat tat tat tat" for a second, then its gone (dry oil pump gears?).
Pressure still low. Drove a block to gas station, put in a quart of oil, and now pressure is where it was before this all started, and no rat tat tat sounds at startup.
I put a quart in a month ago because dipstick was dry when I checked.
No oil leaking so I must be burning it now? 274k on motor.
Ran at idle for a few then checked oil level...nothing on stick!
Also noted that at startup, a metallic "rat tat tat tat" for a second, then its gone (dry oil pump gears?).
Pressure still low. Drove a block to gas station, put in a quart of oil, and now pressure is where it was before this all started, and no rat tat tat sounds at startup.
I put a quart in a month ago because dipstick was dry when I checked.
No oil leaking so I must be burning it now? 274k on motor.
09-26-2012, 06:01 PM
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A quart or less low on oil will not cause pressure to drop, if it is truly that low you more than likely have worn main bearings, check the pressure with a gauge connected to where the OEM gauge screws in and check it like that to be sure. Time spent diagnosing the problem properly, will save you time and money, just because Joe Bob's car had the same trouble and a muffler bearing fixed his, it may not fix yours, if you get my meaning.
