I noticed that most dealers use engine flush when changing oil. This is supposed to help drain out the oil and clean out the sump.

In the case of the RX8 I understand that the oil in the oil coolers is not drained. So I am wondering what effect these additives have on the engine oil as a large part of the oil still remains in the system with this additive.

Mazda specifies that we should not use additives in this vehicle.

skc

 

I wouldn't use oil additives or engine flush, since the Renesis is a high rpm engine i.e very high precision, using flush might messed up the precision a bit. I used to use them quite often in other cars but after watching BMI VTEC Club, the Spoon CEO mentioned problems with additives.

 

Viksing, this is something that the dealer uses during oil change. I am wondering if I should stop them from using this additive next time.

skc

 

Normally I would only use oil flush if I'm switching between brands otherwise I wouldn't do it. However as I mentioned above oil flush MIGHT messed up clearance in high precision engine so I wouldn't recommend it but what do I know. If I'm not mistaken flush oil is just very low viscosity oil, I wouldn't use it if possible.

 

I've used the engine flush treatments with great results. they are especialy good at removing old burnt deposits.
I wouldn't like to use them on the 8 as you have a large percentage of oil left in the oil cooler that isn't changed and the treatment would be left in this oil. I don't think my dealer uses the oil flush but I had better check.

 

My dealer has used 2 litres Protec Engine flush during my 20k service but none in my 30k service.

skc

 

It would be pretty strange if local dealerships were doing this sort of thing "off the cuff". I would have thought they would have publications to follow when conducting a service.

That being said, I checked my past services and there has never been any mention of an Engine Flush in the paperwork.

WTF? I smell something fishy.....

 

I've never seen mention of oil flush on my service receipts either.

Given that Mazda effectively carries the risk of this motor for the first three years I find it hard to believe that they would allow dealers to do something that would harm it. Perhaps it's an isolated case of a dealer who believes an oil flush should be carried out on all engines regardless of their particular build?

 

It may well be a dealer thing or even a tech going on with this routine.

It has not caused any problems on my car however, I will quiz them today on it and make them aware of the fact that all oil is not drained and this may discourage its further use on other cars as well.

skc

 

No mention of engine flush on my last couple of services.

 

Proof that it's apparently safe. This 12A engine has 511,000 miles on it and is engine flushed on a regular basis.

https://www.rx8club.com/series-i-tech-garage-22/want-long-lasting-high-mileage-renesis-73873/

 

I quizzed the dealer today on its use. They have stopped using this product on the RX 8 now. The last time they used Protec on my car was 12 months ago.

skc

 

Great news skc... I have to go in there tomorrow - I am already not to happy about the oil...

 

Now they supply Prozac to all the previous customers who are depressed that something naughty happened to their engine.

:D

Cheers,
Hymee.