rx7racerca

iTrader: (1)

So, I replaced the left side motor mount this afternoon, and as I was finishing and lowering the car after removing the jackstands, my floor jack slipped backwards off the crossmember, resulting in the oil pan landing on the jack pad.
There is a visible, crescent shaped dent, pretty much dead centre front to back, which is just ahead of the drain, and about exactly where the pickup is, iirc. I'm not sure how much it's dented, but it's at least a couple of mm, maybe more, I'm not sure of the exact proper contour, so it may be more, even though the car was most of the way down when it happened
So, is this a must-fix immediately? I don't want to mess around with restricted oil flow, but it is a PITA to remove the pan with the engine in the car, and I expect that likely the only proper fix is to replace the pan, not just remove it and try to massage out the dent. Thoughts?

diabolical1

iTrader: (3)

my initial thought from the photo is it should be okay. carry on with life ....

but ... as you mentioned, it may affect the pickup, and that would be my only concern. i've never given much thought to how close the pickup tube is to the bottom of the pan before now. as i said, from the photo, it doesn't look that bad, but it might be worth the time to look into it. if that checks out fine, then as long as there's no crack where it's dented, carry on with life.

j9fd3s

iTrader: (3)

pretty sure the pickup is at the bottom so not where the dent is

Redbul

iTrader: (26)

My pick-up was blocked by the oil pan dented up against it. In hindsight I should have paid attention to my oil pressure gauge. When I put a second oil cooler in with braided flexible lines, they buzzed like crazy. Replaced them with the solid OEM (R1) lines. No buzz.

When I eventually blew a corner seal, we then discovered the oil pan pressing on the uptake, when we stripped down the motor.

Did that contribute to the engine problem?.

There were other factors, but it likely the restricted oil flow contributed.

rx7racerca

iTrader: (1)

Yeah, I think the only way for me to be sure is to just remove the pan. PITA. Again (did it before Christmas, had a very slow leak after rebuilding the engine last year and using just sealant, no gasket on the pan). I will need to confirm the pickup hasn't been bent anyway - I'm pretty sure it drops down under the center iron, right where the pan is dented. In piston engines, the pickup is typically <5mm from the pan bottom, and they're easily restricted. Here, there's a mesh screen "cage", but I don't remember how close the pickup tube is to the bottom of the screen, so even though the screen can deflect a bit, the pickup could be too tight to the pan now. The pan's not cracked, so it is possible a few bangs with a rubber mallet could put it basically right anyway, and if not - I'll still have to order a pan.

cone_crushr

iTrader: (18)

I'll weigh-in here since you might need some rationale to motivate you to take unpleasant action. The right thing to do is remove the pan despite the time pain. Often we can evade the results of our mistakes, but this seems one of those cases where you have to face the music head-on. Indeed that dent is right where the pickup tube intake is located and appears (?) deflected ~1/4" (6 mm) which is about when you should be concerned about pickup restriction. How much risk are you comfortable with? If you're a gambler then move on. The odd that the pickup is significantly restricted is very low, but you should develop the skills of removing the pan (by loosening the motor mounts and tilting the engine) since sealing oil leaks effectively is a good arrow in your quiver. IMHO, using sealant only (no gasket) to seal a pan is the standard approach these days. Wipe the mating flanges with IPA to ensure the interface is CLEAN.

Certainly not what you want to hear. You're right though: hammering the oil pan back out will likely take care of it. Consider it an opportunity to add an oil pan baffle, although it's unclear how much they really help.

Cheers,

P.S. Why don't you have a 20 year badge @j9fd3s ?

j9fd3s

iTrader: (3)

lol! i have no idea!

Redbul

iTrader: (26)

He has been with Mazda for, like, 100 years. That's enough.

diabolical1

iTrader: (3)

just to put it out there ....

Autozone will rent you tools (the one time i did it, was more of a loan than an actual rental - i left a deposit and they gave it back when i returned the tool. maybe it's an actual rental now, i don't know), and i would imagine other big chain parts stores might do the same if there are no Autozones near you. it might be worth your while to look into if they rent cameras or borescopes and see if you could use that to answer the questions at hand. tape some plastic wrap to it and see what you can see. it will cost you nothing (or next to it), but time.

there was a time when you had to PM Mario (mar3) to get them changed. i don't know if it's a different person now, but if you want it, it shouldn't be too hard find out from one of the higher level mods. i've been lazy, but i guess i should look into getting mine, too.

j9fd3s

iTrader: (3)

it feels like it! why back in my day the dealership had a row of FC's for sale, in the front!

rx7racerca

iTrader: (1)

I have a boroscope, which I've used only twice, and I can't believe it didn't occur to me to drain the oil and have a peek right away. Duh. Thanks for the reminder.
I'm pretty sure I'm going have drop the pan to bang it out or replace the pan, but I can definitely have a look to see how it looks at the pickup before removing the pan.

TonyD89

iTrader: (10)

I almost chimed in to say I bought one, 3.9mm in dia, 5' long, works with my cell phone, $40, so I chimed in now.

rx7racerca

iTrader: (1)

Just back from a short vacation, so I'm back on this.
My boroscope is a less slim, and less flexible handheld, with its own display, vs. the ones commonly plugging into a cell phone - I had a hard time getting it to turn tight enough to see the pickup and screen at all, and could not get it to see the bottom of the screen/pan interface, only roughly the top 2/3 of it. That said - the screen on the pickup was mushroomed a bit from its hemispherical shape, so it's safe to say the pan is making some sort of contact, and I was right not to run the car. I've ordered an oil pan gasket. I'm hoping I can get away with banging out the dent, I had to order in a pan gasket to my local Mazda dealer (the only one within ~100km), and the cost was CDN $107, which is ridiculous, but shipping from Atkins or Racing Beat plus USD conversion was going to be close to that anyway, and take longer to get here.

cone_crushr

iTrader: (18)

You seem rather committed to pan gaskets. I'd suggest that they're obsolete and a PITA since you now have 4 surfaces to seal rather than 2. Won't you be using oil resistant RTV to seal the interface regardless?

rx7racerca

iTrader: (1)

I skipped the pan gasket (but had it leftover) when I did the rebuild last year, reasoning that it never leaked significantly from the pan or anywhere in 30+yrs, and if Mazda skipped it, I could too. But it did leak, very slowly, despite my being very careful with my sealant, after the rebuild, so I redid the pan in the car back in December, and there was no leaking. It seemed the RTV had squeezed out in fine lines at some of the edges of irons and housings. So yeah, in my limited experience (also with piston engines), a pan gasket seems useful - although it is a pain to carefully lay a bead on two surfaces.
I didn't get the pan off the car yesterday after all, got busy changing winter tires to summers on my daily driver 6, and trying unsuccessfully to track a clunk in the front end under throttle load/unload, including clutch release or engage. Likely an engine mount, but couldn't see any visible problem.

cone_crushr

iTrader: (18)

Thanks for relaying your experience. Agreed that sealing pans can be challenging, but knowing some tricks can improve chances of success. Briefly,

1) Use oil resistant RTV. Some swear by 'Hondabond', but either grey or black Permatex 'Tough stuff' is excellent as well. Don't cheap-out here.
2) Final wipe all faying surfaces with alcohol after removing all oil/grease with kerosene/brake-clean.
3) During initial pan fastener torque-up, only hand tighten when 'wet' to prevent RTV squeeze-out. then, after cure has started (time depends on ambient humidity), increase torque level to 1/2 final level. After ~6hrs, apply final torque.

Admittedly, these steps can be a bit of a PITA, but as you know, leaks suck.

While being your own mechanic is the best answer, the work can stackup. Sounds like you need a lift or Quick jack.

TonyD89

iTrader: (10)

The one I posted is, and isn't, as flexible as one might think. The metal head at the front is a little over an inch long and stiff right behind it. I wouldn't bend it more than a 1-1/2 radius. You can't look back up in a piston engine to look at upper cylinder wear. I don't know if they make attachments to do so.

I bought it for a DIY homeowner project, plumbing, worked great.
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