I found a mid eighties Monte Carlo that's in decent shape but the frame is rotted through in a couple of spots. Is there any fixing to this, or would the whole frame need to be replaced? It's a full frame car but it's rotted behind the front passenger tire about eight inches long going towards the rear of the car and wide enough to put all my fingers in. It's also rotted out behind the rear driver tire just behind the rear axle. Possibly more places also but I can't see under the car very well. Would this car be better off being sent to salvage? What would it take to save this car

Well, unless your planning on a total resto or even a partial a frame replacement is a lot of work. If you have any rust holes at all the frame should be junked. Thats an accident waiting to happen repairng something like that but it's your call. If you have any reputable shops around you, take it to them and get a professional opinion. Good luck.

This can be repaired quite easily with the body off the frame, or pick up another frame, repair it, and swap the body over. You will need to look the underside, floorpans, etc. of the body over very carefully because rarely is the frame this rotten and the body still be saveable with these metric chassis cars.

Take an ice pick or a small screwdriver and poke any questionable spots probing for soft areas. Undercoating and carpet will hide a lot of ills. I could almost guarantee that this car is a lot worse underneath, if the frame is rotten, than the upper half of the body looks.

Yep, looking at rust is like looking at an iceberg. You only see 1/10th of it.

Thanks for the advice guys. I think it would be best to just scrap the frame. Are these frames heat treated or could a pro shop weld it without weakening it?

Frame is just mild steel, no heat treat, anyone with a welder that knows how to weld could do it.

These frames rotting is a commo0n problem with them.....There are repair sections available for the rear area, not sure about the front.

__________________
Home Handyman Forum I Shade Tree Mechanic Forum

There's (IMHO) not enough return on your investment- unless you have an emotional attachment of some sort- to justify the amount of work, time and money needed to properly resurrect a car as common as the metric Monte Carlo if it's badly rusted.

A better option might be to pass on that one and hold out for a better candidate. In your area this may be hard to find- those salty winters will have taken their toll on anything driven in the snow!