Oil change including coolers

[manuRx8]

Hi all,

Although the best way to change the oil in an Rx8 is a subject already treated, it is always in the air to extract the oil from the coolers.

The method of tilting the car left and right helps to extract the oil remaining in the ducts, but it does not manage to eliminate the liter of oil that is retained in the coolers.

The most radical solution would be to release the thermostats from the coolers, but it is delicate, cumbersome and in the long run could cause leakage and loss.

I think I have found the simplest solution to this problem. It had been a while and yesterday, I had to change the oil, I took the opportunity to try it and it works wonders.

With the hot car, you start a normal (and homemade) oil change by lifting the car from the right front side (with the jack), put on a safety stand, put the tray to collect the oil and remove the plug from the oil pan.

While it is emptying, remove the oil filter (I always change it with the oil).

Now the good starts:

You take a rubber tube with an outer diameter of 12mm (eg a gasoline tube) and fit it into the small hole in the oil filter base (to the left of the central hole)



(That hole is the return circuit of the oil coolers)

Then connect the other end of the tube with an air compressor (the compressor to inflate the wheels) and have it blowing for a while (1 or 2 minutes are enough). The air that enters goes directly to the radiators, pushing the oil contained in them and causing it to be discharged into the oil pan on the same circuit through which it had entered.



To ensure that all the ducts are as empty as possible, we change the jack on the left side (as is usually done in a conventional change) and while we wait for the rest of the oil to drain, we blow again.

Once it stops dripping, we change the jack on the right side (and put the safety trestle), put a new gasket on the oil pan plug and screw it back into place.

Finally we remove the blow pipe, fill the new oil filter with clean oil, moisten with oil your gasket and thread and put the filter (remember to tighten it only by hand)

Now we fill the engine with the new oil and we already have an oil change for a season.

IMPORTANT:

• Before starting the engine, remember to activate the starter 3 or 4 times (about 10 seconds) and always with the accelerator pedal fully (to prevent the engine from starting). This ensures that the ducts (and coolers) are filled with oil, thus preventing the engine from running without oil in the first instants.

• You should always check the level after the first start, since part of the added oil will have gone to fill elements or empty circuits.

If you are curious to see how much oil is removed from the coolers, you can do the maneuver in 2 steps. Before applying air, wait until the oil stops dripping, change the container or tray where you collect the oil for a clean container. Now you can blow and see how another liter of oil comes out, which means that the coolers are practically empty of oil.

In addition to how clean and simple it is, what I like most about this system is that the time needed to make the oil change is the same as that of a simple change, since the blowing operation is done while you are waiting to empty the crankcase completely.

Do you like it? Did anyone know a similar method?

[warpc0il]

Having removed the oil from the coolers, you have to ensure that you've then removed all the air before restarting the engine, otherwise there's a risk of oil starvation.

It should be sufficient to spin the engine on the starter, for no more than 10 seconds at a time, three or four times with the throttle pedal planted.

Personally I think it's a lot of effort for little gain and with oil so cheap I'll stick with doing a double change.

[manuRx8]

Having removed the oil from the coolers, you have to ensure that you've then removed all the air before restarting the engine, otherwise there's a risk of oil starvation.

It should be sufficient to spin the engine on the starter, for no more than 10 seconds at a time, three or four times with the throttle pedal planted.

Of course, after emptying the oil, whether the coolers are included or not, it is convenient to turn the engine, without starting, to ensure that the oil pump fills the oil lines (and the coolers if they have been emptied).
Thank you for commenting me, I will include it in the description of the process, that some sure did not know this detail.

Personally I think it's a lot of effort for little gain and with oil so cheap I'll stick with doing a double change.

As for the effort involved in emptying the chillers, I do not agree, since the blowing operation takes no more than 1 or 2 minutes, while waiting for the circuit to empty. And in addition the necessary resources are only a rubber tube and the pump to inflate the wheels.

To compare this effort with that of making a double oil change, does not seem proportionate. And that without taking into account the cost of oil, quite considerable despite what you say (minimum € 25 per change)

[13Black]

Similar to how I flushed my oil coolers and lines while the engine was out. Though mine was through pumping filtered paraffin round and round - ideally it'd be done with fluid warm enough to close the thermostats to ensure flushing the thin cores.

[PeteH]

I think it's a neat idea. Perhaps you could add that the oil level should be checked after cranking the engine, because that litre of oil which fills the oil coolers will have lowered the oil level in the sump.

(I'm wondering if it's possible to refill the oil coolers directly from the hose you just used to drain them? I.e. put a funnel in the hose and add a litre of oil. That should reduce the chance of having air in the system.)

[Phil Bate]

Or use a Pela pump on that port and draw the fresh oil up from the sump

[manuRx8]

I think it's a neat idea. Perhaps you could add that the oil level should be checked after cranking the engine, because that litre of oil which fills the oil coolers will have lowered the oil level in the sump.

You are right, you should always check the level after the first start, since part of the added oil will have gone to fill elements or empty circuits.

(I'm wondering if it's possible to refill the oil coolers directly from the hose you just used to drain them? I.e. put a funnel in the hose and add a litre of oil. That should reduce the chance of having air in the system.)

You could try but, since the circuits are designed to work with pressurized oil, the passage of the oil by gravity may be too slow.

[manuRx8]

Or use a Pela pump on that port and draw the fresh oil up from the sump

Possibly it also works, we should try it; although I prefer to send all the used oil to the sump and then extract it from there.

Besides, returning the oil from the radiators to the sump (in reverse) causes that oil to pass through the pump's inlet filter and I believe that it could drag part of the dirt stuck to it, depositing it in the sump and then we will eliminate it with the old oil.

[warpc0il]

All good points.

Just to complete the picture, it makes a huge difference if you drain the oil while it's really hot.
Not only because it's thinner, so drains faster and flushes out more muck, but also because the crude thermostats on the oil coolers remain open.

Refilling with preheated oil (just stand the can in a bucket/sink of hot water) also helps the new oil flow and helps prevent it from backing-up in the filler neck, which could otherwise cause it to run into the breather system on the pre-06 cars.

[Doblegota]

Or use a Pela pump on that port and draw the fresh oil up from the sump

Possibly it also works, we should try it; although I prefer to send all the used oil to the sump and then extract it from there.

Besides, returning the oil from the radiators to the sump (in reverse) causes that oil to pass through the pump's inlet filter and I believe that it could drag part of the dirt stuck to it, depositing it in the sump and then we will eliminate it with the old oil.

Un abrazo fuerte amigo!

(In rebuild engines)

With a thermal pellet could be completely removed the small amount of oil inside rotors and all the central parts of the e-shaft pumping through the other hole of the oil filter cup with a small electric oil pump using fresh oil. Yes, you will spend one liter of new oil that is used for washing process.

refilling from the oil filter cup to the coolers could be also fine thinking that there is a good filter in the sump. I have already opened 3 engines myself and oil pump and the filter of the neck that sucks the oil from the sump were totally fine without debris. In the case that something was wrong in the filter neck it would go to the oil filter.

Of course to add oil we go to the natural way. It was only to avoid any kind of air in the system.

Un abrazo! See you soon!



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[13Black]

Removing the oil thermal pellet is waaaaaaay too much faff for minimal gain.
It also won't drain the rotors at all.

[plas87]

Easiest thing is to use a siphon pump. I extracted around 4 litres, topped up with 4 litres, drove around for 30 minutes and repeated the same process. Viola, 8 litres of fresh oil!

[Doblegota]

Removing the oil thermal pellet is waaaaaaay too much faff for minimal gain.
It also won't drain the rotors at all.

Oh no! I was only saying with the thermal pellet is fully open all the time not like OEm method that it needs heat to move the internal spring


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[13Black]

For the thermal pellet to be open then the oil/engine needs to be cold. I would imagine it gets flushed regularly during cold running.

[Doblegota]

True! So wrong in my head!

Ajajajajaj

[manuRx8]

Easiest thing is to use a siphon pump. I extracted around 4 litres, topped up with 4 litres, drove around for 30 minutes and repeated the same process. Viola, 8 litres of fresh oil!

The easiest? I'm sorry, but I do not understand it: a minimum of 30 minutes for the first change, another 30 for the second change and another 15 for the filter change. What added to the 30 minutes of walk between changes give me 1 hour and 45 minutes. To which we must add about $ 25 of oil thrown away, since in the end you do not have 8 liters of fresh oil, in the engine you have 4, at most 5 liters.

The method I propose, but using the siphon pump and including the blow to expel the oil from the radiators would be 15 (filter) + 5 (blown) + 30 (change oil), in total 50 minutes. And besides, you save $ 25 of the 4 liters of oil to throw (and reduce the ecological impact of those 4 liters)

[TerryH]

Definitely an interesting addition to the oil change, definitely worth a try. Even without the jacking from side to side. Easy to see how much more you get out buy changing the container before you blow it out.

What pressure did you use on the air line?

How far did you insert the pipe into the filler neck?

[manuRx8]

Definitely an interesting addition to the oil change, definitely worth a try. Even without the jacking from side to side. Easy to see how much more you get out buy changing the container before you blow it out.

What pressure did you use on the air line?

How far did you insert the pipe into the filler neck?

As I indicated in the first message of the post, I checked and left something more than a liter, so I guess the radiators will have been empty or almost empty.

About the blowing pressure I did not notice, but it does not need a lot of pressure, with what gives the inflation pump is more than enough.

Relative to the tube, I introduced it a couple of centimeters, just enough so that the air does not leak. I used a piece of tube that I had left over when I installed the Sohn, it was a rubber tube for gasoline, with thick walls, which came in very fair and therefore seal well without having to introduce it much.