Oil change with oil cooler

[alexmak]

I have an oil cooler installed (Breeze kit that includes thermostatic oil plate). When times comes to change oil/filter, what’s the best course of action for changing oil?

a) do I need to worry about oil in the cooler? I don’t think that within the last 2k miles I ran the engine hot enough to actually activate the the thermostatic oil plate to send oil to cooler
b) if I do need to replace oil in the cooler, do I just drain it by disconnecting one of the hoses?
c)is there anything else I need to know about changing oil with cooler installed?

(Thinking it might have not been the best idea to actually connect it but oh well…)

[CraigS]

In theory you should drain the cooler and it's lines. If you have AN fittings there it isn't to bad because they can be opened and connected again for ever. Of course catching the draining oil may be a challenge. I use one of those 2'x3' trays w/ the one inch sides under my main drain pan to catch the oil that drips out at unusual spots on my wife's car. And than 1/2 can of brake cleaner to wash it all down. Good luck.

[GoDadGo]

Heck, how many miles or better yet how many engine hours are you putting on the car between changes?
Unless you are racing your car or putting an extreme amount of mileage on it, I wouldn't worry about the residual oil in the cooler.
If you feel the need to do it make sure the engine is squeaky is clean, simply do a couple of dump, refill and drive oil changes to flush the system.

[alexmak]

Heck, how many miles or better yet how many engine hours are you putting on the car between changes?
Unless you are racing your car or putting an extreme amount of mileage on it, I wouldn't worry about the residual oil in the cooler.
If you feel the need to do it make sure the engine is squeaky is clean, simply do a couple of dump, refill and drive oil changes to flush the system.

BPE manual recommends doing oil change every 3k miles. I did the first one at 500, and now coming to 3000 miles, so decided to change the oil for easier calculations in the future. I’m not taking it to extremes just yet, more like a spirited driving, but overall it’s good to know what I should do with it in the future, even if I decide to pass on that this time

[Jim1855]

A good oil thermostat will, or should, allow some flow through the cooler to keep that oil circulating and warmer than just cold.

Anyone concerned with draining the oil from the oil cooler, lines and filter and then once the system is refilled starting the engine with nothing but air in the flow path?

Jim

[GoDadGo]

BPE manual recommends doing oil change every 3k miles. I did the first one at 500, and now coming to 3000 miles, so decided to change the oil for easier calculations in the future. I’m not taking it to extremes just yet, more like spirited driving, but overall it’s good to know what I should do with it in the future, even if I decide to pass on that this time

I am a huge fan of regular oil changes like you, but use the 5,000 miles or 6-month rule with a quality full synthetic motor oil for our daily drivers.

Mobile-1 Extended Performance

Once a year I do a dump and run on my wife's Challenger and my truck to flush them out. Both sport the 3.6 VVT V-6 Engines. 305 HP yields 30 MPG on the interstate for the Challenger and 26 MPG for the Ram 1500 which is less aerodynamic. I did the same thing for my C4 Corvette until selling it in 2018 and the engine was cleaner than clean. The Corvette had NO Ring Ridge when I pulled the heads to install a spark plug insert, but it proved to me that regular oil changes work.

https://youtu.be/svZX2BMSDEs

For the Cobra, since I'm still in the early stages of legal driving and under the 3,000-mile mark, I did my 1st oil changes at 100, 250 & 500 miles. Since I won't be doing a lot of long driving, I'll likely change the oil in the spring and fall, eventually changing over to Mobil-1.

Oil Is Cheap While Engines Are Rather Expensive!

[OVCobra]

You pretty much have to remove the cooler to drain the oil, blowing it out is not likely to remove the majority of oil in the cooler.
Following oil change remove the lines from the thermostat and prefill the lines and cooler (fill through one line until it flows out the other) to minimize air in the system on start-up.

A little extra work but as noted already, engines are expensive!

[J R Jones]

Oil, cooler, change topics:
I feel the oil change interval is more for your head than the engine. One does not shorten the wash cycle to get your cloths clean. If you want to know if you have contamination justifying short change cycles, have the oil analyzed. A short cycle will not be a comprehensive test. You can also inspect the filter element where any debris is more likely to be. Do you have reason to believe your engine builder has poor engine hygiene? Chinese sourced? If you really want to improve your oil, get a quality oil filter. Check reviews, two brands are much better than commodity filters.

Do you need a cooler? To reduce condensation in the engine and oil you want the oil to be 200F plus. Engine oil is safe to 250F, breakdown starts at 275F. You have to drive hard to achieve that.
I road raced a Sunbeam Tiger for a guy, with my SBF and my oil cooler. After practice and qualifying on pole Saturday, the owner showed up early Sunday to drive a warm-up session. He drove the car into a tree and broke the cooler. I had set a lap record in the dry, but it started raining after warm-up. I bypassed the oil cooler to take my chances. I won the race without overheating the oil.

How have you plumbed the oil cooler? Three reasons to filter the oil before cooling:
The filter reduces foam in the oil for better heat transfer.
The restriction in the filter is less with hot oil.
If you have debris in the oil you do not want it to accumulate in the cooler.
If you plumb the cooler from the bottom, draining is easier. If the cooler is mounted higher than the filter, the cooler will drain with the filter off.

I built a Mazda RX7 rotary with doubled horsepower. Those engines run everything hot, coolant, oil and exhaust. The OEM oil cooler and filter system were crap. I bought a Griffin aluminum crossflow radiator for short track racing and cut the right tank to make it a two-pass. I opened the left transfer tank and installed an oil cooler (extrusion). Water and oil plumbing was improved and airflow to the oil cooler was not an issue. Oil and water temperatures were coupled together, stable and never excessive.
jim

[cob427sc]

I have run coolers on several cars in the past and maybe because of my own stupidity never bothered to drain the oil out of the cooler when doing an oil change. The amount of oil is small compared to the overall volume in the engine. If I suspected there was contamination in the cooler (engine failure, etc.) it would be best to replace the cooler since there is no way you will ever be sure that all the contaminents are flushed out. Modern engines and oils push the oil change interval out much further than 3000 miles. I would live by the factory OEM reccommendations for both oil and intervals unless you are driving extremely hard or racing.

[rich grsc]

I have run coolers on several cars in the past and maybe because of my own stupidity never bothered to drain the oil out of the cooler when doing an oil change. The amount of oil is small compared to the overall volume in the engine. If I suspected there was contamination in the cooler (engine failure, etc.) it would be best to replace the cooler since there is no way you will ever be sure that all the contaminents are flushed out. Modern engines and oils push the oil change interval out much further than 3000 miles. I would live by the factory OEM reccommendations for both oil and intervals unless you are driving extremely hard or racing.
True, I wouldn't waste time trying to drain the cooler and lines. The 3000 mile rule is a hold over from before modern oil technology, some new vehicles are up tp 10,000 miles.

[alexmak]

Thank you everyone, I'll probably just leave the oil cooler alone for now. The documents that came with the engine from BPE state that oil needs to be changed every 3k miles.