SIGforum
Modern vehicles-underside plastic covers?
June 25, 2026, 09:53 AM
P250UA5Modern vehicles-underside plastic covers?
quote:
Originally posted by HRK:
Think I'd just RNR the cover and keep it protected, do like P250's idea of a fuelmoto valve and a hose, you could drill a hole, and just put/pull the hose down for draining the oil.
My plan, on the Expedition at least, is to hose clamp the drain hose on each side of the undertray, have it positioned so I just have to slide the drain pan under it & open the valve. No messing with the hose, keep it in a fixed position. Maybe with a plug in the end to keep it 'clean'
Will see on the Legacy when I get under it for the first time, already have the Fumoto, just waiting on the first oil change to install it.
The Enemy's gate is down. June 25, 2026, 09:55 AM
P220foreverThe problem with mine is you have to take off the undercover to change the oil filter too. I can't just have a hole in it to drain the oil. I also found out that the metal screws holding it on in addition to the plastic screw rivets will unscrew themselves over time so I put Vibra-Tite on those. Haven't had to buy a new screw since.
June 25, 2026, 10:16 AM
P250UA5quote:
Originally posted by P220forever:
The problem with mine is you have to take off the undercover to change the oil filter too. I can't just have a hole in it to drain the oil. I also found out that the metal screws holding it on in addition to the plastic screw rivets will unscrew themselves over time so I put Vibra-Tite on those. Haven't had to buy a new screw since.
That's a pain.
My Expedition, it's a pain to get to [right above a crossmember with a 'tray' that drains to ground], but accessible with the cover in place
Subaru, right on top, spin on filter not a cartirdge.
The Enemy's gate is down. June 25, 2026, 01:17 PM
sredingMy wife's last two cars had these - I went through the hassle of removing them both one time - noted where the hole needs to be and used a 6" hole saw to cut a hole in the plastic shield. Her latest is a mercedes - she took it to the shop for some warranty work and the tech thought it was a great addition (or subtraction as the case may be)!
I reject your reality and substitute my own.
--Adam Savage, MythBusters
June 25, 2026, 01:33 PM
selogicMy Titan has a shield that has to come off. It had 6 bolts originally but now it's 4. Pretty easy to remove / install .
June 25, 2026, 01:35 PM
GeorgeairI've got cars with filter up top, but drain plug buried under similar cladding underneath. I'm thinking of going to the pump-out for every other or 2:3 times, and drain from bottom the other times. Not sure with good filtration that there should be anything in bottom of pan anyway.
Just sold a boat with a 350 block in it, and the filter also on top of the motor, near front. However, it was mounted screw-side DOWN, so you had to engineer a way to capture all the oil that was inevitably going to run out and over the mounting plate. Fun times.
You only have integrity once. - imprezaguy02
June 25, 2026, 01:36 PM
1s1kThese shields have made the quick lube places really lazy. Instead of pulling these shields they just suck out the old oil and put in the new.
June 25, 2026, 01:41 PM
Sharkey717quote:
These shields have made the quick lube places really lazy. Instead of pulling these shields they just suck out the old oil and put in the new
That’s crazy but 100% believable! Stuff like this is why I try to do this stuff myself!
June 26, 2026, 01:51 AM
NuclearI had a 2010 BMW that the local auto shop forgot to replace said cover. Below 30 mph or so, no problem. Above that it felt / sounded like something was banging around in the engine compartment.
June 26, 2026, 05:53 AM
mrvmaxYou can try Fumoto or Valvomax (I use Valvomax since they are veteran owned). For better filter access some bypass filters relocate the filters to a more accessible area.
June 26, 2026, 08:17 AM
chongosuertequote:
Originally posted by Sharkey717:
quote:
These shields have made the quick lube places really lazy. Instead of pulling these shields they just suck out the old oil and put in the new
That’s crazy but 100% believable! Stuff like this is why I try to do this stuff myself!
The only benefit is that means they can’t screw up the drain plug replacement.
Knowing what one is talking about is widely admired but not strictly required here.
Although sometimes distracting, there is often a certain entertainment value to this easy standard.
-JALLEN
"All I need is a WAR ON DRUGS reference and I got myself a police thread BINGO." -jljones
June 26, 2026, 09:10 AM
P250UA5quote:
Originally posted by chongosuerte:
quote:
Originally posted by Sharkey717:
quote:
These shields have made the quick lube places really lazy. Instead of pulling these shields they just suck out the old oil and put in the new
That’s crazy but 100% believable! Stuff like this is why I try to do this stuff myself!
The only benefit is that means they can’t screw up the drain plug replacement.
I've heard, but not experienced, that some won't do it with a Fumoto, or similar, installed.
Even to the point of a guy took his into the dealer for service & they removed the Fumoto and put a standard drain plug in.
The Enemy's gate is down. June 26, 2026, 09:41 AM
egregoreI wonder how these 10- and even 5-minute, "stay-in-your-car" oil change places deal with covers that have multiple screws and push pins. There was a thread here a few years ago about somebody taking a Sawzall to one.
June 26, 2026, 10:43 AM
Fly-SigThe pump method removes as much oil as removing the drain plug in my car. Within a couple of ounces. Not every engine will necessarily be like that, and of course the diligence of the person doing it is a factor. But I have no concerns about leaving too much dirty oil behind.
June 26, 2026, 09:14 PM
oldbill123Pump wont remove all oil in a 21 Subaru Forester. Might get 2.5 quarts
June 27, 2026, 09:09 AM
Fly-Sigquote:
Originally posted by oldbill123:
Pump wont remove all oil in a 21 Subaru Forester. Might get 2.5 quarts
My Crosstrek was easy enough to get under and use a Fumoto, so I never tried it. My wife's Audi though gets within a couple of ounces. Getting under the low convertible is
impossible without a lift.
My suv, though has a ridiculous air cleaner housing blocking access to the oil fill cap and the dipstick tube. I negotiated a reasonably priced service contract with the dealer. I hate trusting them with even an oil change.
June 27, 2026, 09:02 PM
Speedbird@OP; Were similar in age and I've been doing PMs and light to medium repairs since ~1989. The under chassis trays are not awesome, but a necessary evil. Manufacturer would not spend a dime if they didn't have to right? So, there's a valid reason i'd say.
Anyway, think about my approach. I only do this kind of maintenance when the weather is nice... not too hot, not too cold. Every 6 months +/-. Dead of winter, middle of sweltering summer = nope. Maybe one oil change runs short, maybe the next long. I use top shelf oil and parts, so I think it works out just fine. Does my engine REALLY know if its been 7k or 8k or 10k?
Astrick, I would also speculate, assuming you can get the filter off without removing the pan; suck the oil out the dipstick method is probably still easier and for 99% of us driving an average car won't make any meaningful difference.
June 27, 2026, 10:21 PM
Sharkey717quote:
posted June 27, 2026 09:02 PM Hide Post
@OP; Were similar in age and I've been doing PMs and light to medium repairs since ~1989. The under chassis trays are not awesome, but a necessary evil. Manufacturer would not spend a dime if they didn't have to right? So, there's a valid reason i'd say.
Anyway, think about my approach. I only do this kind of maintenance when the weather is nice... not too hot, not too cold. Every 6 months +/-. Dead of winter, middle of sweltering summer = nope. Maybe one oil change runs short, maybe the next long. I use top shelf oil and parts, so I think it works out just fine. Does my engine REALLY know if its been 7k or 8k or 10k?
Astrick, I would also speculate, assuming you can get the filter off without removing the pan; suck the oil out the dipstick method is probably still easier and for 99% of us driving an average car won't make any meaningful difference.
Good points! Extraction def has its perks. As for car manufacturers paying for the bottom cover my belief is because of the fuel economy mandates by Obama is what forced the manufacturers hand because they had to. My thought anyway. The comment about how quick lube places do it in minutes is an excellent point! I’m getting salty with my age I feel like so many places in every industry are rushing and not doing what they say they are!
June 28, 2026, 05:26 PM
ChowserI do the extraction method on my daughter's Subaru Impreza. Oil filter is also up top. It extracts over 4 qts so it’s getting almost all of it. i just used it on her boyfriend's Chevy. Except his oil filter is underneath. My alfa and past bmws have not had a dipstick so I always had to lift the car
Not minority enough!