More interesting to me is that my lines are a zinc/brass color and not the silver that the pics above indicate.
They are completely corrosion-free, even after spending their first two years submerged in the wet, salty roads of Maryland.


About to do that.
It is over 100°F here, so it should be a good test.

when was the last time you replaced them ? or is it still the original one ?

cuz I think Mazda made changes to the lines ... same as the Canada ones now. maybe thats why ?

Never replaced them. They are the original '04 lines that came with the car.

hmm ...

so does that mean they went "cheap" on the 05s, the salt ate the "cheap" lines alive and they have to issue a recall(for Canada at least) and replace them all again ?

oh well, I know my lines has rust all over them :(

Move to California, my lines are spotless!

If not, just get the rust off and put a coating on.

Just did this mod today. I went for a short 4-5mile drive and recored the temps. I then did the same drive after the mod same speeds and temp 30 mph and 71 deg. The results wrere as follows using a IR thermometer on the outside of the cooler.
Before: DS-169 PS-155
After : DS-147 PS-140
15-22 deg drop in cooler temp is not bad for free. :)

C Ya L8r - That's good to know - thanks! Anybody have any problems with road debris hitting the coolers, etc after doing this mod? Just wondering why Mazda didn't have the openings bigger in the first place.

Jeff - any word on your "move where the food is - nothing grows here" desert test? :)

Thanks for doing the research on this!

Great to see mate, and thanks for posting actual temp results!!

I knew my guesstimation was about right, and I was not imagining things..

Yes, even for this slight reduction in temps it has to be worth it.

I can not though agree on the other mod which virtually exposes the oil cooler by 85%..can't be good for rocks, stones and road/wheel water and mud.

Ash

wow nice results from cyal8r, was waiting to see some hard data, anywhere near 20deg reduction in temp is AWESOME. your engine will be happy.

MazdaManiac - all the lines i normally run into are brass-ish but they seem to have a coating on them cause it doesnt look like any immediately recognizable metal. I'll start looking to see if i can find a pattern.

kevin.

Nope . There is no more chance of debris than before the mod as the holes are at an inverse angle to the direction of said debris .

As to why Mazda didn't do it - they probably just didn't think it was necessary ....

Now we need someone to measure oil temps before and after. My test proves tihis mod mkes the coolers more efficent. But thats not to say overall oil temps will drop 15-20. Also 30mph is pretty slow but I wanted a route where I wouldn't have traffic variables.

personally id imagine higher speeds will show a decent gain as well, air flow undisrupted of the "exhaust" air will definitely get more cold fresh air thru the cooler faster.

the fact it did anything at slow speeds is pretty good considering such a lack of air velocity.

as for why mazda didnt do it... probably so animals couldnt hop in.

kevin.

:lol:
Yeah, like little pussy cats, snakes, lizards, small crocodiles, baby giraffes..
Mazda has to cater for ALL nations and continents you know...:uhh:

lol, but seriously im sure it had some kinda link to not wanting stuff to get in easily...maybe to prevent people being able to pop the hood by grabbing the cable or something(if you pull hard enough it breaks the plastic clip piece and pops the hood up)?

kevin.

The strange thing is that there is a reacll in Canada for the oil cooler line corrosion...and one of the fixes was putting in fender liners without any cooling holes....I said NO THANKS....and left my stock ones with the bis assed holes I cut in them :)

Yup

Cool mod!! Was wondering if any of you knew the actual part number for those OEM splash shields. A curb reached out and grab one of mine the other day and I need to replace it, and plan on doing this mod while I have the wheels off anyways. Searching for "front wheel well inner vented splash guards" (or any combination of those words) doesnt seem to help. Or I just am using the wrong part names. Thanks in advance

I guess you are sorted "Scarslett...late reply.

Anyone else done this mod recently??...
I am just interested to know ...being your Hot Summer is a happening now!!

wow thats a pretty cool diy mod, wish i would of known of this when i was putting on my new rotors, too bad they dont make small fans we could just put behind the oil coolers, that would be bad ass:cool:

I did it, but won't be testing the temps. It was worth it to see the oil cooler lines. The drivers side had some rust, but the passenger side was clean. I'm going to buy some spray grease from Amsoil and coat those and a few other areas under the car. Once before and after winter should help with long term corrosion.

i was just thinking if you cut out most of the backing and if u put in some wire mesh to cover the hole that should help with keeping road debris out of the coolers, wouldnt that work and alow alot more air flow

Yes, probably OK for Summer, but I would be concerned during Winter or wet roads, too much water or snow or mud over your oil coolers would not be good, then there are your horns and some electrics. I guess you could insulate or waterproof spray these would help.

But hey, I have been thinking perhaps a quick replacement type plastic shield, one Open mesh type for Summer and the original slit vents for Winter?

Subscribed. Never new about this. Probably a winter project while its setting in the garage.

nice, i will do this this weekend :)

I'll have to do this soon.
If I do this in the next few weeks, I'll make sure to monitor the actual oil temperature and post my findings.