i have a 986 and recently i noticed a problem with the paintwork.
just under one of the side vents, the one where there's the fan of the engine i noticed i had a small air bubble under the paintwork, and after a couple of weeks another two bubbles appeared next to it, all in the same spot. there doesnt seem to be rust, just a small bubble. i looked carefully for similar marks on the whole car but there doesnt seem to be any more except just that spot. any of you guys expereinced this problem? could it be the hot air the fan sends making a reaction on the cold bodywork at this time of year?

 

My Dad started to get little bubbles in the clear coat of his A8...came to find out the dealer had repainted the quarter panel without telling us because they damaged it during a service. The little bubbles occurred because the paint was not allowed to cure properly before applying the clear coat - something that further validates they were in a hurry to repair and repaint so we wouldn't find out. Well, we did find out and we got a nice chunk of change because of it.

 

the thig is its not just in the clear coat, its the paint itself

 

I have found bubbles in the paint in exactly the same place as you. I had a closer look by removing the vent. Please see my post on boxa.net in the UK here: http://www.boxa.net/forum/index.php?...0&gopid=522159&

How did you deal with yours?

 

i didnt yet seanpaterson.
i still get the occasional bubble, i scratch it off and touch it up with some paint. i would like to respray that area but i dint want to do so before i solve the problem!!

 

I had this issue once on a car that wasn't supposed to have any paintwork. I didn't spot anything on the pre inspection. About a month later the rear quarter started to show small bubbles. The problem was traced back to the repair method. The used lead but did not get the flux fully neutralized. It turned into a nightmare.

 

If you have a look at my thread over on boxa.net (link above), I've got some images showing where the problem starts. It's rust coming through from the inside of the panel. I found rust had formed on both sides of my car, but only causing bubbles in paint on one side.

On the inside edge of the vent hole, there's a strip of 2in wide black foam. I ripped this foam off along the lower edge(pretty well stuck on). The rust was under the foam, and I'd assume that over time, water and grit had been held against the panel by the foam and caused the corrosion.

I've since treated both sides, but the bad side will need the rust cut out, a patch welded into the panel, and then filled and sprayed.

 

the thing is that i noticed that thebubbles occur after a long ride. if i spend a while not using it, no more bubbles appear, as soon as i take it out on a long trip, i guess the body panel gets hot, cause of the fan, and thats when bubbles occur. i'm assuming it has got something to do with the fan.
seanpeterson im not being allowed to enter the site.

 

Must be that you need to register to see the post. I'll cut and paste it onto here, so hopefully you'll be able to see all of my first post. Think about it, the fans drawing air in, which will be cool, and have you ever heard of warmth from the engine causing paint to bubble on a car?

If like me you own an old 986(mines an S '98) my post may be worth reading and give you somewhere to check.

During a wash at the weekend(the car not me!), I noticed some bubbles in the paintwork under the drivers side engine air vent. Bubbles about the size of a fingernail:


Resized to 87% (was 800 x 600) - Click image to enlarge




So today I visited a bodyshop for advice, and they confirmed what I had feared. This is rust, coming through from the inside of the panel. Having had this confirmed I decided to take the vent cover off and investigate further.

Resized to 87% (was 800 x 600) - Click image to enlarge




Once you have the vent removed, what you find is that the entire aperture has what I can only describe as a sort of 'black automotive expanding filler' around it's inside edge. It's about 2in wide and half inch high. I peeled/ripped this off the lower edge of the vent(where the rust was).


Resized to 87% (was 800 x 600) - Click image to enlarge


About 2/3 of this came from the driver's side, the rest from the passenger's. You can see the orange rust on it.



Once I had removed the foam from the effected area this is what I found:

Resized to 87% (was 800 x 600) - Click image to enlarge


This is the worst quality image, but you can see the orange rust on the inside of the panel in the mirror. Probably an area about half the size of the palm of your hand. It coinsides with the lowest point of the vent. Seems the foam(not sure what it's puropse actually is) was holding moisture and grit against the panel and it's rusted through(is still solid to touch, even with pressure, but rust must have worked it's way through).

On inspection of the passengers side, the was some rust on the inside of the panel, but maybe only a thumbnails worth.

Not realy sure what to do next. I'm quite happy to spend money on mechanicals whan neccesary, but not big amounts on body work. A proper repair would require cutting the rust out, welding in a patch, filling, and painting 2 panels for good color match . I'm the kinda guy that does 'everything' on the car myself.

It's an old car, I bought it knowing it had been a cat D, has a number of little blemishes to the sharp eye. These things don't bother me, but my concern with this is it geting worst. The rust isn't in an accident repaired part of the car - the foam mentioned above is definately original. I can do the cutting and welding myself, could even put a fibre glass patch in there instead of a welded patch, but not wanting to spend on two panels being resprayed at the mo..

So what to do?? I can rough sand the rust on the inside of the panel, rust treat it, and back fill it. And then keep an eye on it and hope for the best! Anyone know of any very good 'rust eater' type treatments??!!

 

finally i feel i can share my problem with someone. thats exactly where i have my problem as well.
i keep touching it up with some paint from the outside but the bubbles keep re appearing.
so you think its worth removing the vent and checking from the inside?
do you reckon it'll be better to remove that part of the foa then?
thanks a lot!

 

You should definately remove the vent and have a look! If it is rust, in time it will only get worse. Unfortunately the rust is likely to be under the foam, so you will have to rip this off. It's well stuck and fairly tough stuff.

The only real cure for rust coming right through the panel, is to cut the bad section out, weld a plate in, fill and paint. For now I've just ground the rust away on the inside of the panel with a dremel, and treated with special paint. Plan to do the cutting in a couple of months.

Let me know what you find, and I'll keep you updated as well.
Sean

 

hey seanpaterson, i did what you told me to do and found exactly that, rust! so i removed part of the foam, which as you described was quite tough, and saw that there was rust with a small mirror.the good thing is that it didnt seem to be penetrated too much. so i scrathed it off with a scrpaer, then went over it with a small wire brush, doing everything by touch as you obviously cant see! i then went over it with some red oxide paint, i hope it works!
thanks for the info,
hopefully it will reduce the problem a bit, though i know that once rust starts forming its hard to get rid of unless you cut the panel off as you said.

 

Glad my instructions were of some help. Just out of interest, what year is your car? To the best of your knowledge, has the vent area ever had any accident repair? And Malta has a hot climate right? You don;t have salt put on the roads over winter do you? Malta was probably the last place I would have expected to hear of a rusting Boxster! Very different Story here in Scotland UK.. It's April, and it's been 2'c out today, with persistent rain and sleet!

 

its a 1999 model. no we dont have salts thrown on roads here, we're soon gonna start needing to throw ice to cool them down a bit lol! in summer it reaches 40c! at the moment its 23c.
as far as i know it only had a slight repair on the front mudguard, doesnt seem to be any new paint anywhere else.