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Post by r0llinlacs on Jan 29, 2015 12:23:58 GMT -5
So I have a 98 with the 3.0 6G72 and I don't have the owners manual.
What is the proper oil weight? I've read someone recommended 10w-40, I've been putting 10w-30 in it and the oil pressure seems low after it warms up? I'm not really even sure what the oil pressure should read with this vehicle. When cold and during warming up it reads between 30-50 but after warm up it drops as low as 15 at idle? It hovers around 25 when warm and driving.
Am I using the wrong oil weight and what should my oil pressure read? I've never owned a vehicle with an oil pressure gauge so I have no idea what it should be reading.
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Post by ES_97Sport on Jan 30, 2015 12:50:30 GMT -5
So I have a 98 with the 3.0 6G72 and I don't have the owners manual. What is the proper oil weight? I've read someone recommended 10w-40, I've been putting 10w-30 in it and the oil pressure seems low after it warms up? I'm not really even sure what the oil pressure should read with this vehicle. When cold and during warming up it reads between 30-50 but after warm up it drops as low as 15 at idle? It hovers around 25 when warm and driving. Am I using the wrong oil weight and what should my oil pressure read? I've never owned a vehicle with an oil pressure gauge so I have no idea what it should be reading. For the 3.0L and 3.5L - all years - the specified oil weight for normal duty (not towing, wheeling, etc) is 10-30W. Depending on what the conditions are I run 10-30 or 10-40. 10-30 in my stock '03 Limited 3.5L. Either 10-30 or 10-40 in my stock '97 LS 3.0L (mostly its what I have handy is the deciding factor) - unless I'm going out to Moab in which case I run 10-40. I don't run anything lighter than 10-40 in my big '97 Sport (in either the 3.0L or 3.5L) - ESPECIALLY in the summer or out in Moab - but that thing weighs in at almost 6000K empty so the engine gets a lot of stress. That's pretty much where my pressures stay. About 50-55 psi when cold. Warmed up and on the highway at 3K RPM its about 45-50 and at idle warm its about 10-15. Same for my 3.0Ls and 3.5Ls. I don't have the FSMs handy so I can't give the official readings but this is what I've seen since I bought my first Sport. After about 500K miles on my 3.0L everything was about 5-8 PSI lower. What I recommend for oil is full synthetic. Not the blend - FULL synthetic. The best high mileage filter you can find - one designed to be changed every 10-15K miles. I use the Fram unit and it seems to do well. Oil weight shouldn't be any lighter than 10-30W and no heavier than 10-40W. If you're in some place like Phoenix, I'd stick with 10-40 year around. If you're in north Montana you might want to go one step lighter than the 10-30 in the winter. The viscosity of full synthetic is different than normal motor oil, so you have to be careful going with lighter oil. I run the High Mileage Mobil 1 full synthetic in my two stock Sports as they're over 150K. Price isn't any different and it can't hurt anything. The new 3.5L in my big Sport is still under 100K so it gets the regular full synthetic. Edward |
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Post by colted on Jan 31, 2015 10:58:17 GMT -5
hmmnn......I have never used the 10W-30 oil, been using Valvoline 5W-30 HM Maxlife syth blend then went to full synthetic Valvoline 5W-30 HM Maxlife....can't complain, engine runs really smooth & quiet....morning lifter ticks is a come & go.....maybe I'll try the 10W-30 next COI.....  |
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Post by r0llinlacs on Jan 31, 2015 11:14:14 GMT -5
Depending on what the conditions are I run 10-30 or 10-40. 10-30 in my stock '03 Limited 3.5L. Either 10-30 or 10-40 in my stock '97 LS 3.0L (mostly its what I have handy is the deciding factor) - unless I'm going out to Moab in which case I run 10-40. I don't run anything lighter than 10-40 in my big '97 Sport (in either the 3.0L or 3.5L) - ESPECIALLY in the summer or out in Moab - but that thing weighs in at almost 6000K empty so the engine gets a lot of stress. That's pretty much where my pressures stay. About 50-55 psi when cold. Warmed up and on the highway at 3K RPM its about 45-50 and at idle warm its about 10-15. Same for my 3.0Ls and 3.5Ls. I don't have the FSMs handy so I can't give the official readings but this is what I've seen since I bought my first Sport. After about 500K miles on my 3.0L everything was about 5-8 PSI lower. What I recommend for oil is full synthetic. Not the blend - FULL synthetic. The best high mileage filter you can find - one designed to be changed every 10-15K miles. I use the Fram unit and it seems to do well. Oil weight shouldn't be any lighter than 10-30W and no heavier than 10-40W. If you're in some place like Phoenix, I'd stick with 10-40 year around. If you're in north Montana you might want to go one step lighter than the 10-30 in the winter. The viscosity of full synthetic is different than normal motor oil, so you have to be careful going with lighter oil. I run the High Mileage Mobil 1 full synthetic in my two stock Sports as they're over 150K. Price isn't any different and it can't hurt anything. The new 3.5L in my big Sport is still under 100K so it gets the regular full synthetic. Edward Yeah, it gets cold here so I usually try to stay on the thinner side in the winter. But if it calls for 10-30 then I'll keep using it! I couldn't find an owner's manual anywhere on the internet so thanks for the reply! Also, would you say oil pressure around 30-35 while warmed up and driving is okay? I was also kind of thinking oil weight would have a direct impact on oil pressure? IE thicker oil = higher pressure? Kind of like how pressure is higher when the engine is cold and the oil is thicker? If 30-35 while warmed up and driving is low, would using 10w40 instead of 10w30 help raise the pressure? |
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Post by ES_97Sport on Feb 3, 2015 18:02:27 GMT -5
... Yeah, it gets cold here so I usually try to stay on the thinner side in the winter. But if it calls for 10-30 then I'll keep using it! I couldn't find an owner's manual anywhere on the internet so thanks for the reply! With full synthetic I wouldn't go below 10-30. Even in -10 to -20 temps after sitting outside for a weekend the synthetic doesn't thicken up like regular motor oil. Now, if I were living in northern Canada and it was -30 all winter long, I might drop it on notch. At what RPM? You are correct. It takes more force to push a higher viscosity oil through the the passages and spaces between parts so the pressure reading will be higher. Yes, it would raise the pressure but not much. There really isn't that big a difference between 10-30 and 10-40 - which is kind of the point. If you're thinking it'll go up 10 psi ... that's not going to happen. The point of oil pressure (besides just getting the oil where it needs to go) is to keep bearing surfaces from contacting one another. For instance, oil flows between the crank journal bearing surfaces and the main bearings. The oil between those surfaces keeps them from contacting each other, but the pressure has to be high enough that the force of combustion on the crank doesn't force contact between the crank and bearing surfaces. Same for the rod bearings. A higher viscosity (thicker) oil helps with this - which is why the recommended oil for high stress/towing is 10-40 - also because it's harder to push thicker oil out of the way than thinner oil. It also helps as an engine gets older and the tolerances increase. The 'thicker oil' takes up that little extra space created by wear and tear evening things back out. Closer tolerances, lighter oil. Wider tolerances, thicker oil. Something else to know - the filter you run affects oil pressure as well. Its generally not a good idea to run whatever is on the bargain rack when you buy your oil. Edward |
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Post by r0llinlacs on Feb 3, 2015 19:10:01 GMT -5
Also, would you say oil pressure around 30-35 while warmed up and driving is okay?At what RPM? Just cruising RPM, 1200-2000. |
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Post by ES_97Sport on Feb 5, 2015 13:54:58 GMT -5
Also, would you say oil pressure around 30-35 while warmed up and driving is okay?At what RPM? Just cruising RPM, 1200-2000. Yep. That sounds about right. Edward |
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Post by r0llinlacs on Feb 6, 2015 16:17:50 GMT -5
Just cruising RPM, 1200-2000. Yep. That sounds about right. Edward Alright, good! Thanks for confirming! |
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Post by tirill on Feb 8, 2015 2:23:26 GMT -5
Well......In my 2000 Pajero Sport with the 3.0 litre 6G72 engine I have done some tests with engine oil. First of all the oil pressure reading on the gauge in the car has ALWAYS been very low!!! I higlighted that for the dealer when the car was in for the first service when it was only a month old. The delaer come back with "The pressure is very normal" and I had to be happy with that answer even if I didnt like it. The pressure at around 2000 rpm (=normal cruising ) is around 35 psi/2,5 Bars. When the oil is cold it is 1 bar higher. In my experience the oil pressure of an engine like that shall be around 60 psi/4 bars. It might be the oil metering device, that is not looking to reliable to me, but I have never tried to check it up. As I live in Sweden with temperatures down to 15 Deg F. To be able to start the car without an electric engine heater I have used an Semi Synthetic oil 10W-40 during all years. I would like to use an Full synthetic oil but as the pressure then probably falls further I have ended up with this compromise. I have heard that U shall not experiment with different oil types on an old engine, as different additives can release carbons etc than is no good for the engine. So I am happy with my oil even if the pressure should be slightly higher. I change the oil and filter once a year, and the mileage then is between 15000 to 20000 km. The oil is most often quite clear then. I have never had any problems with "ticking" valves etc. The oil pressure meter is anyway good to have as the oil warning lamp is an LEVEL switch, that comes on suddenly even if there is 25% space to the low level mark on the dipstick. Then U can see on the meter that the pressure is normal. The upper picture shows the pressure after a "cold" start The lower picture show the pressure at warm engine at 2000 rpm. Attachments:
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Post by r0llinlacs on Feb 8, 2015 12:44:48 GMT -5
Yeah, looks like about what mine reads!
I can't get a solid reading on the dipstick unless the oil level is below the first notch though... when it's "full" or between the two notches, I can't tell what the level is because when I pull the dipstick out of the tube, it smears the oil all over the dipstick. It may be an aftermarket dipstick but I'm not sure what the OEM dipsticks look like.
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Post by colted on Mar 13, 2015 12:57:25 GMT -5
just had a change oil and my monty is now running Valvoline Maxlife High Mileage Full Synthetic 10W-30.....  |
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Post by ES_97Sport on Mar 16, 2015 16:39:40 GMT -5
... First of all the oil pressure reading on the gauge in the car has ALWAYS been very low!!! ... Define 'very low'. Unless you have a good, diagnostic oil pressure gauge (NOT something that's meant to go on your dash) hooked directly to the engine diag port and the readings are not within the FSM specs - there's nothing wrong. About where mine sits - same when cold. You do realize that pressure doesn't necessarily mean anything? There are high volume pumps and high pressure pumps and high pressure/high volume pumps. Your engine can get adequate volume at low pressure - that doesn't mean something is wrong with the pump or engine. And frequently manufacturers use pumps with more pressure than is actually needed so lower pressure isn't necessarily a problem either. I'm sorry, but 'an engine like that'? What? How in your 'experience' have you determined that 'an engine like that' should be around 60 PSI? I'd also like to know what 'an engine like that' is supposed to mean. There are two functions of an oil pump - volume and pressure. Volume is the amount of oil a pump pumps in n amount of time. Volume is cooling and lubrication. Obviously the pump must be able to pump enough oil volume for the engine - it has to fill all the passages, etc. More importantly, it has to pump enough to cool the bearing surfaces, etc. or they're not going to last. Pressure is the pressure the oil is under - AT THE PUMP EXIT or wherever the diagnostic oil pressure port is located. Pressure does a few things - it gets the oil into the little passages and crevices, keeps the lifters pumped up and more importantly keeps the bearing surfaces from contacting each other. There are a HOST of reasons for having more of the former and less of the latter and less of the former and more of the latter and they're ALL based on internal engine design. They are NOT based on the displacement, the physical size, or any of the other things people use to lump dissimilar engines together with. (usually they start off with 'an engine like that'....) Year ago, maybe, probably. Now? No. Unless you're talking about a 40 year old engine with half a million miles on it.... All current oil - synthetic, blend or regular - have detergents and additives in them that pretty much make that a moot point. You are making way too much out of this. A couple PSI one direction or another is meaningless. First of all, full synthetic oil is better for your engine even if you DO get a consistent couple PSI drop. One of the reasons guys that wheel without dry sump systems use full synthetic is if you happen to suck air in the oil system and loose pressure briefly, full synthetic oil will withstand the pressure exerted by the bearing surfaces and withstand the heat and not coke. As for cold, full synthetic flows better at extremely low temperatures than blend or standard oil which means you will get BETTER protection at start-up. At start up you basically have NO pressure so worrying about 'pressure' is pretty ridiculous. It will continue to flow better at low temps as the engine warms up and if the engine doesn't get to operating temperature. IMHO, you're chasing a problem that doesn't exist. Unless the dealership says you have low oil pressure and they can prove it's pump related there's nothing for you to do or worry about. Use a good full synthetic 10-40w and a good high mileage oil filter and move on. Edward |
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Post by colted on Apr 6, 2015 17:38:14 GMT -5
just had a change oil and my monty is now running Valvoline Maxlife High Mileage Full Synthetic 10W-30..... Update on my use of this 10W-30 oil...good news!!!!..no drips or leakage so far, my Monty is no longer marking his territory like most Jeep SUVs,LOL |
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Post by ES_97Sport on Nov 22, 2016 18:41:25 GMT -5
Per FSM:
Oil pressure with the engine at normal operating temperature and the correct oil level.
At idle: 29 kPa (4.2 psi) or more
At 3,500 r/min: 294 - 686 kPa (43 - 100 psi)
Remove oil pressure sender on the oil filter housing. Fitting is a 1/8" metric - STRAIGHT - thread, not tapered.
This is the fitting type:
AutoMeter Metric Adapters 2269
This kit contains the correct fitting (and it works well, too):
OTC Tools 5610 Trans-Eng Oil Press Tester
Edward
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