CORROSION ON 740s
 

Whilst Volvo metalwork is better than most, it's a myth that 740s don't rust.

My front wheelarches severly corroded from the inside and both wings had to be replaced when the car was about 18 years old. Since then I have had minor rust (a) at the front and back edge of the reat wheel arches, (b) on the seam on the rear inside door frame above the sill, (c) on the inside of the front doors on the back window pillar and (d) non-structural parts underneath the engine

Anyone else had simlar problems?

Are there any 'weak spots' on 740s where they are prone to rust?

Bloody hell, thats very very unusual for a 740.

Snap! I replaced both front wings due to rust and dents, but one had been vandalised with a knife and the other had lorry damage so that was the main cause of rust there. But one of them did have bubbling around the arch too.
The driver's side front floor pan has been patched up a couple of times for the MOT because there used to be a water leak from the air-vent in the footwell and water was trapped under the insulation. Unfortunately, I didn't remove all of the insulation so I am going to be taking out the front seats, carpets, etc, to check the floor pans properly. There will be some more welding to do I'm sure.
Both battery trays. The one on the driver's side is really bad. See bottom of this thread for a photo: http://www.volvoforums.org.uk/showth...t=88950&page=6
The rear sills are starting to go now and also some other places. Oh yes, the windscreen suround has corrosion too now.
The crossmember underneath the radiator has almost completely gone.
However, it's all fixable, I think.

I don't know whether it's true that living by the sea is bad for your car?

I've just highlighted some areas that are most common from what I have seen. Some of these things are probably preventable. At the rear sills, check to see if there is any soil trapped in the wheel arch. Look carefully for this as it's hard to see. For the front floor pans, moisture can be trapped under the sound insulation. A leaking radiator probably causes the crossmember to corrode, I guess. And I would imagine battery acid must cause the severe corrosion of the battery tray. As I've said before, I've seen this last one on a young 940 too.

There is a bit of rust on the battery tray on my car. The top of one of the rear doors went as well. The bit on the door was strange. It's where the rubber seal is fixed. For now I have cut the lip off the door top and painted it. As soon as the weather improves I will re-stick the rubber seal on with double sided tape.

Unfortunately body repairs and windscreens that have been not done carefully can be the start of rust. My unfortunate task at the moment is repairing the windscreen surround on my old Citroen AX so a new screen can be fitted. All done because whoever did the screen in the past cut the paintwork.

I have seen some really rough early 740's and 760's in scrappys. They looked as if they had rusted from inside, presumably from water leaks.

My 1990 740 had rust on the metal between the tank and the spare wheel well. Rust on the tops of the doors (under the rubber covers). Under the driver's seat (LHD) due to a leaking heating valve. On top of that, the chassis (engine bay) was very very rusty (with a little hole!).

The Volvos don't rust myth still hangs around... They do, just a little later...

Corrosion.
 

I have two 1986 740s, a 745GL with 160k and a 744GL with 60k.

The low mileage car's bodywork would shame many ten year olds - it is near perfect.

The higher mileage 745 shows some corrosion on the battery tray (as OBV has mentioned), but no crossmember corrosion or sill corrosion. Neither car has any raw edge corrosion on any of the wheelarches.

The 745 has had some minor welding done on the front inner wings - alomost undetectable though, it also has its original tailgate which is still almost perfect.

Paintwork on both cars is also very good to excellent.

This issue has been discussed previously and I did post some information on Volvo's extensive use of galvanised steel in the 740 bodyshell. Which is why I tend to be surprised when I here of external rust on a 740.

The comments are interesting, we wouldn't be having this discussion about many other cars - they've gone! I sometimes find it difficult to believe my 740s are 26 years old in March and April 2012 - shall we have a party, my place this summer?

Prufrock.

Compared to many other cars Volvo 740's are very good. I have a twenty five year old, battered, scrap, parts car sitting on the driveway. Doors, sills, wheelarches are all original and rust free. It does have a couple of patches in the floor, but find me an Escort, Capri, Sierra, of even an Austin Montego (remember them)of the same year,which has not had rust repairs and I think you will struggle.

One of the changes in the 1989 upgrade was a fully galvanised body. Mine has zero rust after at least 15 years in the American Mid-Atlantic. I hear that prior years have more of a rust problem, but I rarely see any 700 series car that has rust.

Galvanised bodies began earlier than 1989, this was covered in a previous thread - here it is for everyone's convenience from my 1986 *M/Y brochure.

Prufrock.

*M/Y = model year.

I think 1986 was the year the 240 started having various panels galvanised too .