I went to change the oil only to have all the oil pour out when I took the filter off. This is the second time this has happened. Is it possible the cooler is clogged? I usually unscrew it and all the oil is drained out. Thanks

 

If the cooler was clogged, but not completely closed up, your oil pressure would probably be very low.

 

No problem with oil pressure, maybe I’ll try a different filter, I’ve been using Bosch.

 

The oil filter is full of oil, it will do that just like unscrewing the cap on a bottle you hold upside down.

I've found that if the car sits for a week or so before changing oil then there is no mess, if you change the oil soon after shutting off then a large mess is made. You can help allevioate the mess by punching a hole in the top of the filter and waiting a few minutes before removing it... about as much time as it takes to jack the car up, slide the drain pan under it, and remove the drain plug.

I usually only change the filter every fourth or fifth oil change.

 

if the filter has an anti drainback valve, it'll make a mess. next time take a screw driver, awl, or punch and punch a hole in the top of the filter. give it a few minutes to drain, and presto, no more mess.

BTW the difference between the regular Bosch, and the long life Bosch is how much the filter filters. the long life filters to 40 microns, and the regular filter is 20 microns. if you're changing your oil frequently, you want the one that filters better, the regular one

the other good option is the Wix, it also filters to 20 microns.

the other brands, including Mazda, don't have complete specs.

 

I read in the manual somewhere your suppose to make a hole in the top of the old oil filter, before you remove it, this will let the oil drain out of the oil filter.

 

This is what I did as a flat rate tech in Mazda dealership on RXs. Pull car in for oil change service ,punch hole on top of filter,put up on lift and drain oil. Change oil filter last- plenty of time for filter to drain down making no mess on removal. This worked well,except one time went to lunch in middle of doing a service on a 83 GSL and came back,put oil in and started it up- forgetting I had punched a hole but did not yet change the filter. Couldn't turn key off fast enough...lost rest of day washing that car,underhood,all over,car in next stall,my work bay,toolbox and same for next work bay,toolbox,workbench....NEVER forgot that one little step again! Every time I punch a hole in filter on my SE while changing oil,I think about that day. I can laugh about it now ...

 

lmao, i remember on time we had had the oil cooler out, and the hose got kinked on the way in. we didn't notice, except the car didn't run right, and then *pop* oil everywhere...

 

Thanks everyone, the thought of punching a hole in it never occurred to me, since every other car I’ve ever owned has been pointed the other way.

 

This is a very good, simple explanation.

I'm very curious why you wouldn't change the filter every oil change though...

 

I let the car sit and then drain the oil really good first. The filter is empty
by the time I undo almost every time.

You can alternate changing the filter every other oil change on most cars
as long as you keep to regular intervals. On an unknown or overly long
duration between changes I would change the filer. I use the mobil 1 filters,
well made and black just like the MAZDA filters. I think they are made by the
same outfit that makes the K&N ones as well. Not cheap.

 

i looked into oil filters a bit, and there seem to be two tests that are relevant.

the first is how much crap the filter can hold, most filters have a blurb about a 330g.

the second is how well it filters. they range from 20 microns to 50 microns.

so for example Bosch has two filters, a 3300 which is a 20 micron filter, and then there is a distance plus, which is a 40 micron filter. if both filters can hold 330g of stuff, then the 20 micron filter will fill up more quickly.

so i've been using the Wix 51356, its fully documented, 21 micron filter. the Bosch also is fully documented. those are the only two i was able to find full information on. info is specific to these filters too, didn't look at anything else. i believe when the filter is "full" that it just bypasses, so no filter

 

I change the oil every 1000mi or so. I do filter cuts hen I do change the oil, and the element is always clean. (I use NAPA filters, which are Wix)

Well, usually. The last filter cut I did had a lot of chunks of iron in it. That's not so good. Not driving the car anymore until the engine has been out and disassembled/inspected. There aren't many places that big chunks of iron can come from so the prognosis is not very good at all. A lot of the 12A side housings I acquired over the last year have had sections where the hardening was actually flaking off of the rest of the iron, and what I am finding in the oil filter is about that size.

Well, it has been five years since I built the engine from a conglomeration of well-used parts, and its life has been rather hard.