Bad rust/corrosion on underside of car

Sorry for the vague and possibly stupid question but I’m a total idiot when it comes to cars and if I see anything out of the ordinary, I tend to panic.

I drive a 2005 Chevy Classic who seems in all other ways like a very reliable car. But I happened to take some pictures of the underside of my car and noticed some bad rust along the outer edge of the bottom. I’ve added my particularly garbage pictures just in case they might help in any way, first is as wide of a picture as I could get without my car being jacked, and the second is the worst spot I could find. Also I have no idea what this part would be called but if anyone has any ideas, throw them at me.

So to the best of your abilities, how bad is this? Still safe to drive? Expensive to repair? I’ve noticed no unusual feelings or noises. The rest of my underside seems to be mostly surface rust if anything, that is visible anyways.

Go easy on me, I know this probably seems like I don’t have enough information to even attempt posting but perhaps some insight from professionals may help ease my anxiety on where to go from here.

I’ve noticed on other posts you’ve asked if conditions of your car are “safe to drive”. I would like you to realize that on an Internet forum we can not see every detail of your problems. It is many times impossible to give you accurate reassurance on safety issues. Please don’t stop asking, because there are many things we can tell you that are unsafe, but we can not tell you with certainly that a certain condition is safe. What we can do is to say that from the small amount of information we have, it appears to be safe, and that is what I would tell you in this instance. If you have concerns about safety, it is wise to always bring it to a professional for inspection. To ask a professional about this may very well cost you nothing. It is nothing to feel stupid about. Stupidity is ignorance on purpose. Wisdom is ignorance being cured with information.

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You just happened to be taking pics of the underside of your car? I don’t think I have ever heard of anyone just happening to do that. As far as how dangerous this is, I can only tell you as a non mechanic, that I have driven much worse. As far as repair, it just is not economically feasible to repair rust like this on a unibody car of this age and value.

What city do you live in? Pittsburgh? Sante fe?

Having lived in the midwest rust belt for many years, I can tell you that rust repair can be expensive and futile. Rust never sleeps and there is always more than you can see.

Depending where the rust is, it is inconsequential or it is serious. The best plan is to have a professional inspect and advise. Some serious rust can be repaired but it is only buying you time. Plan you car replacement accordingly.


The OP needs to have this car put up on a lift for inspection and evaluation of the rust problem.


In what areas would you say rust could be inconsequential?

Fenders, floorboards, hood, roof. But not rocker panels, strut or shock towers, subframes. Holes in a fender or roof are ugly but won’t cause the car to collapse.

Rocker panels support the car - essentially the frame of the car - so rust here is bad. If the mechanic refuses to put it on a hoist because it might break, the car is hesded to the junkyard.

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More stupidity: I have no idea what a subframe is, unless of course its the same meaning as the whole frame of my car.

Do you know if my car model is unibody or frame on body? I’ve been curious about that and cant seem to find out through google searches for sure. Also would rust damage pose the same danger on either type of frame, or is one longer lasting (for lack of a better term) than the other?

Your car is a unit body with sub-frames for the front suspension and the engine support and the rear suspension.

Sub-frames are bolted-on structures that carry loads. If they rust through they must be replaced or repaired, if possible, by cutting away the rusted areas and welding patches in place.

If what they attach to - the unit body - is rusted badly at the attachment point, the car will likely need to be scrapped.

Please take this to a pro and have them actually inspect the car.

I will take it in. I know all these questions probably seems like I’m trying to avoid having it looked at by a professional, but that’s not the case. Just merely trying to ease the anxious part of me that thinks my car is going to crumple like a piece of paper on my work today.

Because your car–like almost all modern cars–is of unitized construction, it doesn’t have a conventional frame. As a result, certain components–many of which are located under the car and around the suspension–are the default “frame”.

The rust producing conditions and time are the main factors. You still have said what state you are in.

Your car probably won’t crumble under you, but that is not definitely. So have it checked out. You do not need a dealer, and you may find much better help with a local shop.

Michigan, sorry about that.

The danger is not just the car collapsing on its own, it is that modern cars have carefully designed and constructed crumple zones to absorb energy and limit the transmission of that energy to the occupants. Rust weakens the metal and is likely to make injuries more severe.

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