turbonator
Member
just wondering what the limit is for engine oil temps? just installed a guage and seeing 190 at idle and 230-280 pushin hard... so whats the baseline here?
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engine oil temp... whats safe and whats meltdown....
- Thread starter turbonator
- Start date
schiker
Well-Known Member
Deutz, Kubota, and Yanmar all specify max sustained oil temp at 256F. But they allow intermittent to be higher but don't say how long is intermittent and can't remeber spec its 266F I think. Measured as avg oil pan temperature.
Now to try to understand that limit and what its means is something else. Oil temp takes a little while to top out at max temperature and a little slower to react. And oil doesn't catastrophically fail at higher temps than that but does suffer shorter lifespan if dino oil. If synthetic oil the numbers could vary higher too. I think the above specs insure factory maintenance schedule and a long warranty claim free life of 10,000 ??? hours. They don't elaborate. But a Yanmar applications engineer won't sign off on the application if they cannot maintain less than 256F oil temp with 100% of max normal application load for 1 hour.
I worked where we were making a big vaccum machine so we had to maintian max vaccum the customer could pull for 1 hour. That is kinda tough to do for a truck you would have to tow uphill for 1 hour.
Now to try to understand that limit and what its means is something else. Oil temp takes a little while to top out at max temperature and a little slower to react. And oil doesn't catastrophically fail at higher temps than that but does suffer shorter lifespan if dino oil. If synthetic oil the numbers could vary higher too. I think the above specs insure factory maintenance schedule and a long warranty claim free life of 10,000 ??? hours. They don't elaborate. But a Yanmar applications engineer won't sign off on the application if they cannot maintain less than 256F oil temp with 100% of max normal application load for 1 hour.
I worked where we were making a big vaccum machine so we had to maintian max vaccum the customer could pull for 1 hour. That is kinda tough to do for a truck you would have to tow uphill for 1 hour.
schiker
Well-Known Member
also have to look at all indicators togehter
You also have to look at all the heat rejection indicators together too.
The heat rejection balance test I have seen they will stop if any indicator can't be maintained during the 1 hour load test.
I have seen ECT exceed limit (think it was 230F for the Kubota but not sure - measured at top radiator hose coming out of the engine) in under 20 minutes while oil temp and other indicators were still ok. The engine actually shut itself off with a ECT warning light control. We put on a bigger radiator and retested and past the test. Another engine we had to add additional oil cooling. It depends on the application. I was surprised at how much air flow over the oil pan, oil filter, and valve covers helped cool the oil temp.
Anyway my point is if the engine is really hot and all indicators are high (IAT, ECT, EGT) then I would start to worry if oil temp was trending higher than 266F. Short periods of 280F is probably not going to kill your engine If other indicators are not being tested/pushed but it will consume more of the oil's additive packages I think.
Anyone want to guess where the pistons will scuff? Again saying other indicators are high too. I would say 300F is getting dangerous for more than 5 minutes??? But heat is time and rise rate dependant and don't think its a cut and dry figure. Sort of like ECT 2220F might not kill ya once if you just tickle it on the guage for a minute if everything else is lower and its not hot ambient.
You also have to look at all the heat rejection indicators together too.
The heat rejection balance test I have seen they will stop if any indicator can't be maintained during the 1 hour load test.
I have seen ECT exceed limit (think it was 230F for the Kubota but not sure - measured at top radiator hose coming out of the engine) in under 20 minutes while oil temp and other indicators were still ok. The engine actually shut itself off with a ECT warning light control. We put on a bigger radiator and retested and past the test. Another engine we had to add additional oil cooling. It depends on the application. I was surprised at how much air flow over the oil pan, oil filter, and valve covers helped cool the oil temp.
Anyway my point is if the engine is really hot and all indicators are high (IAT, ECT, EGT) then I would start to worry if oil temp was trending higher than 266F. Short periods of 280F is probably not going to kill your engine If other indicators are not being tested/pushed but it will consume more of the oil's additive packages I think.
Anyone want to guess where the pistons will scuff? Again saying other indicators are high too. I would say 300F is getting dangerous for more than 5 minutes??? But heat is time and rise rate dependant and don't think its a cut and dry figure. Sort of like ECT 2220F might not kill ya once if you just tickle it on the guage for a minute if everything else is lower and its not hot ambient.
turbonator
Member
thats a good answer.... has anyone looked at aftermarket coolers? i looked earlier and found 20 plate coolers, and thought they looked good, until i went out and counted the factory one, it has 32 or 36 plates...
I would say you are running hot.
Pistons scuff around coolant purge temps with high sustained load where shock cooling from the purge makes it happen. Least mine did.
250 degrees is the upper limit acceptable of where you want to be. You are starting to boil coolant at 16 PSI with oil going into a radiator that hot! Without a radiator involved 300 degrees is where conventional oil simply fails. Our AMSOIL vendor should be able to jump in here. Link to this number.
I have ruined 250 and 300 degree oil cooler hoses and still get 10K out of the oil on a Duramax verified with lab results. This is with a huge Killerbee oil cooler. Modern oil does get it's life cut down 50% by high, 300 degree, temps. No oil company is going to give you their results and the transmission temp failure chart is there to sell coolers.
You will have a small heart attack when you get the "Low oil pressure stop engine" DIC on a Duramax. I have. Synthetic oil was almost required for what I do and the temps here. I got less than 10K when things got hotter and the lab verified the standard oil was done.
Pistons scuff around coolant purge temps with high sustained load where shock cooling from the purge makes it happen. Least mine did.
250 degrees is the upper limit acceptable of where you want to be. You are starting to boil coolant at 16 PSI with oil going into a radiator that hot! Without a radiator involved 300 degrees is where conventional oil simply fails. Our AMSOIL vendor should be able to jump in here. Link to this number.
I have ruined 250 and 300 degree oil cooler hoses and still get 10K out of the oil on a Duramax verified with lab results. This is with a huge Killerbee oil cooler. Modern oil does get it's life cut down 50% by high, 300 degree, temps. No oil company is going to give you their results and the transmission temp failure chart is there to sell coolers.
You will have a small heart attack when you get the "Low oil pressure stop engine" DIC on a Duramax. I have. Synthetic oil was almost required for what I do and the temps here. I got less than 10K when things got hotter and the lab verified the standard oil was done.
The same co. that made the OEM cooler[Long/Tru-cool ] Makes a taller oil cooler that fits the lower bracket and has 1/2 pipe thread ports[L7B?]. They are made in Canada. Leroy /PMD Cable.com can get them. Member Bobbiemartin put one on his suburban and just modified the top bracket.
OrionThade
Member
I bought a heat exchanger from frozen boost, the 10" x 13". It is quite a bit larger than the stock cooler and has 30 plates. I need to get an oil temperature gauge to see what my oil temperature is. I'm running just shy of 12 quarts of oil, so I'm hoping that the heat stays relatively low with the added volume and larger cooler.
turbonator
Member
since we are re-locating under the bed, we are thinking of this cooler...
http://www.ebay.ca/itm/Derale-16-Pa...r_Truck_Parts_Accessories&hash=item5ae229430d
http://www.ebay.ca/itm/Derale-16-Pa...r_Truck_Parts_Accessories&hash=item5ae229430d
schiker
Well-Known Member
IMO 6 AN is too small for 15W-40. We made remote oil drains with 6 AN and they were slow draining. Hose has a lot of drag.
On a 4 cylinder stationary Kubota we installed one similar though. I saw a pretty good drop in oil temp and an ECT temp drop too when the oil cooler fan engaged. The application had a factory engine coolant to oil cooler.
On a 4 cylinder stationary Kubota we installed one similar though. I saw a pretty good drop in oil temp and an ECT temp drop too when the oil cooler fan engaged. The application had a factory engine coolant to oil cooler.
turbonator
Member
on the 6.2l block we are using the oil cooler lines in the block are only 3/8... i dont think it makes a difference to use AN-8(1/2) when the restriction is there anyways going in and coming out....:???:
schiker
Well-Known Member
Good point but rubber hose has more resistance to flow than compared to metal tubing. GM went with bigger ports and hose for some reason in later years. I think it was to encourage more flow through the cooler. Or maybe it was just the turbo and oil squirter (higher flowrate oil pump).
The oil is not thermostatically regulated just bypass pressure differential (thick oil has higher restistance to flow through cold cooler so its bypassed).
From all the literature I have seen on remote mount coolers and filters they suggest keeping distance to a miniumum.
Just food for thought I'd rather have oversized hose even if fitting orifice is smaller its a short lenght diameter restriction vs Lenght/Diameter ratio of hose.
The oil is not thermostatically regulated just bypass pressure differential (thick oil has higher restistance to flow through cold cooler so its bypassed).
From all the literature I have seen on remote mount coolers and filters they suggest keeping distance to a miniumum.
Just food for thought I'd rather have oversized hose even if fitting orifice is smaller its a short lenght diameter restriction vs Lenght/Diameter ratio of hose.
SmithvilleD
Active Member
I swapped in one of these 48 stacked plate oil coolers at rebuild time.
http://www.thetruckstop.us/forum/album.php?albumid=514&attachmentid=19416
http://www.thetruckstop.us/forum/album.php?albumid=514&attachmentid=19417
My application takes long-term uphill pulling & very high ambient air temps to push oil temps to maybe 230-240 max; it seems like to drive it any higher would also put engine coolant temps higher than I'm willing to run. I've only found one 109 degree day when towing about 12k that things got hot enough after 1 mile uphill I decided to ease up on the throttle. It does add some degree of overall cooling capacity, plus additional oil volume is a signficant temp buffer, slowing how quickly temps climb under heavy load/fueling.
I would also suggest a thermostat that diverts oil back to the block at oil temps under ~180 degrees is a good idea - particularly in colder climates. Without a thermostat, I needed to block a significant portion of the grille to keep oil temp warm enough in outdoor temps well below zero. Need to get & keep oil up to temp to boil out any water that condenses in the crankcase.
In retrospect, I wish I'd drilled out my block taps to the later block's fitting size (5/8" I think) & run -10 plumbing. I did use 45 degree AN hose ends at the cooler to lessen restriction there. The placement of the block taps behind the exh manifold didn't allow for gentle bends at the block connections.
Is it best to check oil temp in the pan, or after the cooler ? If its in the pan you will know how hot your bottom end is,but have no clue what temp the oil is that's actually going to the bearings. Or will it circulate enough that it will be about the same ?
schiker
Well-Known Member
Its my understanding that you are most concerned about the sustained oil temps and I guess the best indicator is the avg oil temp in the pan. It gets sucked from the pan goes to cooler first then filter and then to lubricate. Different locations will flash heat the oil at very high temps like the turbo and near the top ring and pistion crown. Other areas are probably cooler like the cam and rocker arms. It all drains back and mixes in the pan. As long as you don't shut down excessively hot and allow some cool down circulation the constant flow should keep oil ok safe for most people.
I use to think pan oil temp should get above 212F but not anymore. Assuming you drive long enough to get engine to operating temps for a good appreciable time. I think as long as oil gets to ~180F in the pan you should be ok. With the high heat of turbo and extra compression heat in the piston the oil will boil off water vapor from blowby locally in hot areas. And if you have a working CDR and pull out excess vapor it will help minimize contamination. Now gassers that have cooler pistons and without turbo might have more issues with cooler oil temps.
Another thought is you measure engine coolant temp at exit and worry about avg exit temp and that is what you are doing in pan. Note the Deutz engine is oil/air cooled and they just look at avg pan temp for testing. Seems I remember Deutz's oil temp sender is before cooler (which is oil coming from pan) is the warning light for high enigne temp (but can't remember when at what temp it turns on).
A true thermostatic oil temp control is a good idea to help bring engine temps up quickly and hold temps more uniform through out the engine. Especially with our air cooled oil. Engine block mounted ECT cooled oil gets some thermostatic temp control and ECT might even warm oil until stats open. And in those cases it doesn't cool the oil any cooler than stat temps ~180F minimum I have seen for a Diesel. Radiator oil cooled oil would get a little less thermostatic control but still some except in cold climates that need a cold air damn in front of radiator.
I use to think pan oil temp should get above 212F but not anymore. Assuming you drive long enough to get engine to operating temps for a good appreciable time. I think as long as oil gets to ~180F in the pan you should be ok. With the high heat of turbo and extra compression heat in the piston the oil will boil off water vapor from blowby locally in hot areas. And if you have a working CDR and pull out excess vapor it will help minimize contamination. Now gassers that have cooler pistons and without turbo might have more issues with cooler oil temps.
Another thought is you measure engine coolant temp at exit and worry about avg exit temp and that is what you are doing in pan. Note the Deutz engine is oil/air cooled and they just look at avg pan temp for testing. Seems I remember Deutz's oil temp sender is before cooler (which is oil coming from pan) is the warning light for high enigne temp (but can't remember when at what temp it turns on).
A true thermostatic oil temp control is a good idea to help bring engine temps up quickly and hold temps more uniform through out the engine. Especially with our air cooled oil. Engine block mounted ECT cooled oil gets some thermostatic temp control and ECT might even warm oil until stats open. And in those cases it doesn't cool the oil any cooler than stat temps ~180F minimum I have seen for a Diesel. Radiator oil cooled oil would get a little less thermostatic control but still some except in cold climates that need a cold air damn in front of radiator.
schiker
Well-Known Member
I should have put a approximately ~256F as max sustained. I went back and looked at a long thread I posted on the dieselpage with some specs and somewhat related data with some good input from others too.
I think the noted solution to the Duramax overheating vs the additional oil cooling was a new improved intake. The new intake allowed the turbo to be more effecient and allowed more mass of air to help cool the piston/engine which reduced heat load on engine coolant and oil too.
If I can't or shouldn't post to link another forum I'll pull out my contributions to the thread (but there are quite a few posts). I am Hubert in this thread and schiker on dieselplace by the way.
11 ish pages of info....
http://www.thedieselpageforums.com/tdpforum/archive/index.php/t-32992.html
I don't think additional oil cooling is a must have for most but if you tow heavy with extended grades then you might should consider it. And if you add a large cooler a true thermostatic control might also be a good idea.
I think the noted solution to the Duramax overheating vs the additional oil cooling was a new improved intake. The new intake allowed the turbo to be more effecient and allowed more mass of air to help cool the piston/engine which reduced heat load on engine coolant and oil too.
If I can't or shouldn't post to link another forum I'll pull out my contributions to the thread (but there are quite a few posts). I am Hubert in this thread and schiker on dieselplace by the way.
11 ish pages of info....
http://www.thedieselpageforums.com/tdpforum/archive/index.php/t-32992.html
I don't think additional oil cooling is a must have for most but if you tow heavy with extended grades then you might should consider it. And if you add a large cooler a true thermostatic control might also be a good idea.
Duramax engines also run hot when working/towing esp in our temps. The 2005 was plagued with several issues including GM running the turbo in the choke region even with a good intake. Several changes were made to later models including to the oil/water heat exchanger. The 2008's run hot, but, don't overheat and shutdown. The big oil cooler was a benefit to me.
I would guess the frequent oil cooler line failures we experience are due to high oil temps.
However as hard as I run my 6.5 towing in the temps out here, 110+ F, the cooling system improvements were enough without a need for a larger oil cooler. I would boil off a quart every 500 miles though - A larger cooler may have helped this. Squirter blocks may be harder on the oil.
I would guess the frequent oil cooler line failures we experience are due to high oil temps.
However as hard as I run my 6.5 towing in the temps out here, 110+ F, the cooling system improvements were enough without a need for a larger oil cooler. I would boil off a quart every 500 miles though - A larger cooler may have helped this. Squirter blocks may be harder on the oil.