Oil Temp & Coolant Temp - Which Is More Important?

[Carlwalski]

Hey guys,


I feel like a dumb ass for even asking this but.............I don't care lol. Those who don't ask, never learn. What is the "more" important of the two or the temp to be the most concerned about, oil or water? I can't tell you what my oil temp is as my oil gauge is currently not working since install (loose wire under console, will get to it) so I'm not sure what my truck is actually reading oil temp wise. I've been getting confused/brain-farting mixing the two temps or basically thinking of them as one in the same lol lately. Is the water temp also know as the "Engine Temp"? I would have thought the oil temp would be more so the engine temp being more infused in the engine?

I guess if the water/coolant is only there to keep oil temps down, then when it does increase it can only do so because the oil temp has increased, thus making them one in the same, no? :dontknow: I must have been smoking some good hooch because I (for some unknown reason) took my water temp (90c/200F) as being my OIL TEMP. If 200F was my oil temp then I'd be perfect and in a good zone. I was looking at Tony's oil lines (still will but only for safety), oil coolers etc, might not need to now having not seen my actual oil temps yet.

 

[TNVIPER]

I removed my oil gauge to make room for what I felt were more important (A/F, fuel PSI. etc)...........I would think in most cases an increase in oil temp would cause coolant temps to rise.......on the flip side maybe oil temp would be more important if you road raced..

 

[SANTEEN]

My guess would be coolant temp

 

[bclark05]

I think that the coolent keeps the oil temp down, Hence the big a$$ radiator. As oil temp goes up coolent temp goes up, thermostat opens and fans come on, cooler coolent flows via water pump and oil and coolent come back down into operating range. Coolent temp more important.

 

[Yellow venom]

Hey Carl, if your oil cooler if working efficiently that is cooled by your A/F coolant it should be very close to the same (guessing give or take 5degrees F) there shouldn't be a real big difference,if your oil temp if alot higher then you should increase your oil cooler size IMO,I haven't drove my truck in well over a year now due to the engine/tranny build I did,but for what I remember they were always very close,not exact but close.
As for importance A/F coolant for sure being that almost all vehicles have a coolant temp gauge and not an oil temp gauge,IMO I say the more things you can monitor , the better you know whats happening under the hood and a little easier to trouble shoot if need be also.
One more quick note Carl,if your running out of room for gauge there is another option for ya,there's always single gauges out there that can monitor more then one thing too,just another idea for ya,Good luck.

 

[Carlwalski]

So basically in order for me to lower the water temps, I must address the oil temp which is basically what I've been researching all this time anyhow, maybe I wasn't on hooch lol. Are 200F water temps high or normal? Thanks for the input lads.

 

[JRSVIPR]

So basically in order for me to lower the water temps, I must address the oil temp which is basically what I've been researching all this time anyhow, maybe I wasn't on hooch lol. Are 200F water temps high or normal? Thanks for the input lads.

Carl, I believe temps. of 180-205 are normal coolant & oil.

 

[Carlwalski]

Hey Carl, if your oil cooler if working efficiently that is cooled by your A/F coolant it should be very close to the same (guessing give or take 5degrees F) there shouldn't be a real big difference,if your oil temp if alot higher then you should increase your oil cooler size IMO,I haven't drove my truck in well over a year now due to the engine/tranny build I did,but for what I remember they were always very close,not exact but close.
As for importance A/F coolant for sure being that almost all vehicles have a coolant temp gauge and not an oil temp gauge,IMO I say the more things you can monitor , the better you know whats happening under the hood and a little easier to trouble shoot if need be also.
One more quick note Carl,if your running out of room for gauge there is another option for ya,there's always single gauges out there that can monitor more then one thing too,just another idea for ya,Good luck.

Thanks mate! So you're saying that if my oil temp is around 180-200F and my water temp around 190-200F that this is normal and OK?

 

[Carlwalski]

Carl, I believe temps. of 180-205 are normal coolant & oil.

Thanks mate, it's reassuring to hear this.

 

[JRSVIPR]

Thanks mate! So you're saying that if my oil temp is around 180-200F and my water temp around 190-200F that this is normal and OK?

Yes, My truck has run in that range since new.

 

[Carlwalski]

Thanks again JRSVIPR!




I've been talking to Tony and was going to (still may) get an aftermarket cooler and remove the the factory exchanger. Not sure how much this will drop oil temps, I'm guessing around 15-30c (60-90F)? One thing I'm not sure on how to attack is the coolant line from the firewall. I was told to remove the exchanger to engine coolant line and then just run 1 line from the firewall to the engine then just remove the exchanger. Makes sense, just the coolant engine hose (C) diameter is much smaller than the firewall coolant hoses (D) diameter. I was told to run the engine end hose size and heat it up a little to squeeze over the firewall hose end. Any tips or input on this?

 

[Yellow venom]

Thanks mate! So you're saying that if my oil temp is around 180-200F and my water temp around 190-200F that this is normal and OK?

Yes:rock:,and if I were to guess I think the oil temp would be a tad higher temp the the A/F coolant.

 

[Chuck B]

The factory oil cooler is actually an exchanger. Heat is exchanged between the oil and coolant. Its primary function is at start up... coolant helps get the oil up to temps faster. Adding a cooler may or may not make a difference. The exchanger will always try and blend the temps of coolant and oil no matter what you do. You'd want to do some analysis of actual temps of both oil and coolant as it is entering the exchanger.

This exchanger is also used on the Ford GT. Read several articles on how efficient our exchanger really is and that it is being used in place of air coolers that most are familiar with/use.

 

[Carlwalski]

The factory oil cooler is actually an exchanger. Heat is exchanged between the oil and coolant. Its primary function is at start up... coolant helps get the oil up to temps faster. Adding a cooler may or may not make a difference. The exchanger will always try and blend the temps of coolant and oil no matter what you do. You'd want to do some analysis of actual temps of both oil and coolant as it is entering the exchanger.

This exchanger is also used on the Ford GT. Read several articles on how efficient our exchanger really is and that it is being used in place of air coolers that most are familiar with/use.

Hmmm, that's something I wasn't aware of, thanks for bringing that to my attention. I am having my oil gauge reconnected tomorrow, once it's in I'll go do some driving and see where my oil temp is at in conjunction with my water temp and report back with how I went. Would the lines Tony sells help reduce temps a little due to being heat restricting braid and not rubber? I'm getting them regardless for safety purposes, just curious is all.


Cheers!

 

[VIPR PWR]

I was wondering what those other hoses were -Maybe if I had really looked I would have figured that out ---This thread helped ---Now, is there a braided hose kit with A/N fittings for these ?

 

[Chuck B]

Hmmm, that's something I wasn't aware of, thanks for bringing that to my attention. I am having my oil gauge reconnected tomorrow, once it's in I'll go do some driving and see where my oil temp is at in conjunction with my water temp and report back with how I went. Would the lines Tony sells help reduce temps a little due to being heat restricting braid and not rubber? I'm getting them regardless for safety purposes, just curious is all.


Cheers!

Stainless lines do shed heat but it will be so insignificant... Remember your temp gauges are not reading by the exchanger. Doesn't tell much other than what they are reading....

Question will be once up to temps what is the temps of oil and coolant entering the exchanger. If the oil is hotter than coolant then (as I suspect) then your radiator is taxed further. This is actually an interest to me as during summer time temps my engine will reach temps high enough that the ECU will pull timing. At WOT it feels as if 2 cylinders suddenly dropped off...quite abrupt when it happens. My coolant temps and oil temp at the time it happens always shows coolant as higher than oil temp...but again these temps are not at the exchanger.

My guess would be that the exchanger is doing what its supposed to do....heat oil at start up and cool oil under normal driving. For those of us needing additional cooling probably best bet is via the radiator. Either by new flash turning on the fans sooner and faster speed or expanding capacity of the radiator. I think that would be best bang for the buck. Alternative or in addition to would be to add a oil cooler but question becomes to remove the exchanger or not. At the very least I'd want a thermostat control for the oil cooler.

Regardless, more analysis of our current system is needed before an answer makes the most sense. Thats one of the things I'm going to tackle once our summer heat hits in a few months. I plan on hooking up external temp readings and do some real world measurements.

 

[Chuck B]

Too add....obvious solution and one I looked at doing last year was to disconnect and loop the coolant lines at the exchanger then take the two oil lines and run to an air/oil cooler which I was going to mount on passenger side of radiator up in front. I also sourced a thermostat to control a fan which would be mounted on the cooler. Downside is oil temps will take longer to come to temp and I know that Aluminum blocks really really don't like to be run cold. After researching is when I learned more about our exchanger and why the factory used this over a regular cooler. So question becomes would adding a cooler and eliminating the exchanger really benefit in reducing oil temps. Would help take some load off radiator but again....need more info. Anyways...interesting topic.

 

[Carlwalski]

Stainless lines do shed heat but it will be so insignificant... Remember your temp gauges are not reading by the exchanger. Doesn't tell much other than what they are reading....

Question will be once up to temps what is the temps of oil and coolant entering the exchanger. If the oil is hotter than coolant then (as I suspect) then your radiator is taxed further. This is actually an interest to me as during summer time temps my engine will reach temps high enough that the ECU will pull timing. At WOT it feels as if 2 cylinders suddenly dropped off...quite abrupt when it happens. My coolant temps and oil temp at the time it happens always shows coolant as higher than oil temp...but again these temps are not at the exchanger.

My guess would be that the exchanger is doing what its supposed to do....heat oil at start up and cool oil under normal driving. For those of us needing additional cooling probably best bet is via the radiator. Either by new flash turning on the fans sooner and faster speed or expanding capacity of the radiator. I think that would be best bang for the buck. Alternative or in addition to would be to add a oil cooler but question becomes to remove the exchanger or not. At the very least I'd want a thermostat control for the oil cooler.

Regardless, more analysis of our current system is needed before an answer makes the most sense. That's one of the things I'm going to tackle once our summer heat hits in a few months. I plan on hooking up external temp readings and do some real world measurements.

Good reading there brother. If I take heat readings at the exchanger, which to be honest I probably won't but what would be the point of that as we always take them from the gauge, where ever that sensor is located. I would have thought it would have been a good idea to stick with and track temps using our gauges, like we would in the truck. If it's hotter or cooler at the exchanger makes no difference does it? As it will still show those fluctuations at the OEM sensor. If the braided hose takes 5-10F I'd be happy, lol, all helps. I can't wait to see what my oil temp is actually reading. Turning the fan on early at cruising and idle speeds saps around 20hp and I was told not the best thing to do. Sean Roe told me this. If you run an aftermarket oil cool AND the exchanger, how does that work? You have 2 lines for the oil trying to get to 4 fittings, no? :dontknow:

 

[Chuck B]

Good reading there brother. If I take heat readings at the exchanger, which to be honest I probably won't but what would be the point of that as we always take them from the gauge, where ever that sensor is located. I would have thought it would have been a good idea to stick with and track temps using our gauges, like we would in the truck. If it's hotter or cooler at the exchanger makes no difference does it? As it will still show those fluctuations at the OEM sensor. If the braided hose takes 5-10F I'd be happy, lol, all helps. I can't wait to see what my oil temp is actually reading. Turning the fan on early at cruising and idle speeds saps around 20hp and I was told not the best thing to do. Sean Roe told me this. If you run an aftermarket oil cool AND the exchanger, how does that work? You have 2 lines for the oil trying to get to 4 fittings, no? :dontknow:

The point would be is the exchanger transferring heat from oil to coolant or coolant to oil. Example: Coolant temp is 200 and oil temp is 185. At those readings oil would appear to be cooling (exchanging heat) with coolant at the exchanger. However I suspect the opposite is true that actually coolant is actually cooling the oil at the exchanger. Its an important difference...

Facts are....my truck has trouble maintaining constant temps in our summer heat. Regardless of what those temps are at the gauges I can easily run up temps far enough to cause the ECU to pull timing. Granted, I've never actually overheated but fact that temps reach a point that engineers determined was serious enough to pull timing is a concern to me. I think the easiest solution is as previously stated....via the radiator by either reprogramming the fans and/or additional capacity.

 

[Chuck B]

Good reading there brother. If I take heat readings at the exchanger, which to be honest I probably won't but what would be the point of that as we always take them from the gauge, where ever that sensor is located. I would have thought it would have been a good idea to stick with and track temps using our gauges, like we would in the truck. If it's hotter or cooler at the exchanger makes no difference does it? As it will still show those fluctuations at the OEM sensor. If the braided hose takes 5-10F I'd be happy, lol, all helps. I can't wait to see what my oil temp is actually reading. Turning the fan on early at cruising and idle speeds saps around 20hp and I was told not the best thing to do. Sean Roe told me this. If you run an aftermarket oil cool AND the exchanger, how does that work? You have 2 lines for the oil trying to get to 4 fittings, no? :dontknow:

While I don't know for sure about 20hp I do know I'd prefer to either add electric type fan or better yet additional capacity of the radiator over using factory fan for additional cooling. Yes, exchanger has 4 fittings but remember 2 are for coolant (in/out) and 2 for oil (in/out). you would run the cooler in series with the exchanger. Knowing what the actual temps are determines if you leave the coolant lines connected or not. Again...is coolant cooling oil or is oil cooling coolant at the exchanger while at full temp. Another possibility...as temps rise does this flip?