mx-6 oil filter Q
 

hi all

getting info for my first oil change on my recently bought FD

have searched and discovered that oil filters for the mx6 are bigger than the tiny stock filter for the 13B, (my bmw and ducati bikes have bigger filters than that thing!)

the search turned up a question that puzzles me...

aftermarket filters seem to have no anti-drain valve to stp the oil draining out of the upside down filter while the car is not being used, apparently mazda filters have this valve

however i read that if don't punch some holes in the top of the flter before removing it it will dump it's oil all over the engine...which would tend to imply that a vacuum is holding the oil in the filter and a valve isn't needed...if a valve is holding the oil in how would punching holes in the top of the filter help???

would prefer to fit the longer filter of the mx6 as there is no problem with space, but why haven't mazda rationalised their parts inventory by doing that themselves?....only reason i can see is to allow access to the coil end of the sparkplug wires

eric e

more questions than answers

haven't had any replies on my odd flush single arm NGK plugs yet but they start the car well so they can stay a little longer until i find out either more about them or the car starts running badly

I've heard you don't want to use the MX-6 size because it doesn't allow proper oil pressure. Myself I use a Purolator Pure One #PL14620 (that's the MX-6 size) with no problems. the pure one features an anti-drainback valve too.

I believe the older RX7 filter may work as well. I think the mount is the same... it may not fit due to space, though.
My RC51 has a bigger filter too.
Don.

thanks for the replies guys

the reduced oil pressure sounds interesting, if i do go the bigger filter way i will carefully note the warm idle pressure with the current small filter before the change and see if i can detect a drop

eric e

Many aftermarket filters have drain back valve and besides keeping the oil inside for better startup, there is the added benefit that less oil will spill when you change it out. It's important to have the valve I think.

I used Pure One for about 3 oil changes and now I am back to OEM. I think the OEM is slightly better than Pure One (for MX6) even if the size is smaller. I think there is a very slight oil pressure difference but it's not very noticeable. Pure One also carries a PL14622 that's direct replacement for OEM but it's very hard to find.

Many dealer has special on oil filter or you can get OEM from Mazdaperformance.com cheaply.

I have never bothered punching holes into oil filters in the 18 yrs that I have done oil changes. It's a waste of effort and it just makes things messy. If you go to a oil change shop or dealer, you'll find that none of the used oil filter has any holes and I don't see why there is a reason to do it. Get a oil filter wrench that works with a socket wrench bc the regular wrench won't work since space is tight.

finally got around to changing the oil and filter and as my JDM fd has dual oil coolers and theoretically lower oil pressure i decided not to risk lowering it further but installing a larger mx-6 filter

filter removed had no return valve and had completely drained of oil, not sure where the story about having to punch holes into the filter to release the vacuum came from...

eric e

the oil smelt pretty badly of gasoline, which seems to be pretty common with rotaries. thin oils must thin out even faster with gasolene finding its way into the sump!

best aftermarket filter is K&N... its like 20 bucks canadian...vs 5 bucksf or mazda filter.

The way i see it... a fileter is a filter.

the fact that mazda filters aare cheap and i replace my oil almost every other month... i dont' really care what filter i use as long as it filters.

oil filter is far more important than the brand of oil you use (assuming within the same weight of oil). OEM is pretty much the best thing to use. Don't bother with FRAM or some cheapo.

I wonder if the '89-92 2.2l filter (626/MX-6/Probe) will fit in an FD. It's basically the standard Mazda/Honda filter (NOT the teeny-meeny one used on Miatas/FDs) but about 1/2 inch taller. It's the biggest filter I could find that would thread on and has the proper O-ring seal diameter.

Anti drainback valve or not, if oil is going to flow one way or the other it is going to have to flow. It's not going to flow backwards against the oil pump (well maybe it will over a period of weeks or more), it's going to have to flow forwards, and again if it's going to flow forwards it's going to have to pull oil up through the system. It won't do that. It's simple siphon theory. Even without an anti drainback valve, the oil will not move because it's not so easy to pull oil through the system with gravity alone.

I have always had to punch holes in the oil filter, even with non-anti-drainback filters.