Has anyone else had corrosion bubbles on the trunk lid right above the chrome trim? I have gotten 2 small bubbles and it looks like it creeps out from under the chrome trim. Are there any steel part that connect to the aluminium below the trim that could cause cathodic corrosion? Jag here in CO has never heard about corrosion and will only cover corrosion if it is penetration. Car is 5 years

Thank you in advance
Martin

 

This is a well-known corrosion point on these cars, and if the car is still on warranty, should be sorted out and paid for by Jaguar. It is classic crevice corrosion.

Have you any at the leading edge of the trunk lid ? There is a lip on the seal that the lid closes down onto in a wping action. Grit collected there, (washed down by rain), eventually wears away the paint and corrosion starts and then creeps round to the top side. Modification is to cut off this lip with a Stanley knife blade.

 

Thanks Fraser Mitchell
The paint is worn off at the leading edge of the trunk but not any corrosion - I will touch up the paint and cut off the tip of the seal - thanks for the advice. The car was bought in Massachusetts - a moist environment - but I am now in Colorado where it is dry and the dealer here has no idea what he is looking at and has never seen any corrosion - and states as the manual that the corrosion warranty only covers penetrations within 6 years. Has anyone else had this covered under the corrosion warranty??

 

Hi MTW

Jaguar did a lot of warranty work on this corrosion problem in the UK. Some guys have reported warranty work only recently on cars up to 2006. Jaguar are not sympathetic if the car has not been maintained by main agents, as per my car !

You need to cut off the lip of the seal so the trunk lid does not touch it. I had mine done by the paintshop, as a lot of skill is needed to make a neat cut. As regards your other spot, I think early cars were not assembled correctly so the paint film on the trunk lid was penetrated above the rear light plinth by a fastener. However, I am not totally sure this is the exact reason.

 

Thanks Fraser Mitchell,
The Jag dealer asked me to go and have it looked at at a local collision center - specialized in Alu. If they would consider this corrosion and typical corrosion for the XJ then they would cover it - it does help to be a giant pain in the b...

Martin

 

Paint shop took the chrome trim piece off and could conclude that the trunk lid has been repainted earlier and the 2 bubbles are caused by steel contaminants under the paint. The manager suggested that not all facilities have a separate department for aluminum and specks of steel accidentally could have contaminated the paint job. No big concern – it will be touched up. Was told the corrosion only was an issue on the earlier models and by 2006 the issues was straightened out.

 

Have a look at this webpage: -

QUALISINO — TECHNICAL ARTICLES — Filiform Corrosion

 

What the website describe is the normal corrosion you see on aluminum caused by atmospheric oxidation, expedited by chlorine ions if available, and that can be the case as well for my car if there has been an entrance in the paint(The deal breaker with Jag is that the lid has been painted before and the paint is not original). Untreated aluminum will corrode/rust as well as steel the difference is that the corrosion product - aluminumoxid - is so dense it will mostly protect the base metal from further corrosion in that area opposed to steel where the corrosion product is very porous and only slightly will impede further corrosion. My dealer is under the impression that aluminum does not rust - period- very unfortunate! It is possible to treat - anodize the aluminum and create aluminum hydrooxide which is a very dense and durable "aluminum oxid" I don't know if the base material of our cars is anodized? The biggest issue with aluminum is cathodic corrosion where aluminum due to its low electron potential will be sacrificed in the process of protecting a metal as steel, with a higher electron potential, against corrosion. I thought some uninsulated fasteners in the trunk lid were causing cathodic corrosion on my car this was fortunately not the case. Zink as is used for galvanizing actually has about the same electron potential as Aluminum.

 

Aluminium coorodes under the right conditions, with presence of salt a major accelerator. hence it is barred from use by airports. They use very expensive alternatives. Carrier aircraft see a lot of salt spray and have to be specially protected and inspected compared to normal airforce planes.

 

I repaired the 2 bubble and found 3 additional under the trim piece. This corrosion had nothing to do with contaminant under the repaint since the 3 other once were far in under the trim piece where the lid had not been repainted. This was simple aluminum corrosion - cleaned the corrosion off - used a self etchning primer(esentially the way AL is anodized) - then painted it. The trim piece was very intuitive to get on and off but man it took properly close to 15min to reinstall the glass over the parking light - extremely badly designed - it needed to sit in just the right way to stay - fortunately I installed new bulbs so I dont need to deal with this for hopefully a long time.

 

Have you cut that lip off the rear screen seal yet ? I know its absence will show a gap, but it's better than another paint job.

Since I had my trunk lid redone and seal cutoff in June 2010 I have had no further paint issues with the trunk lid. I keep inspecting the car, though !!

 

Yes I cut off the lip - forgot to write about that (properly due to the thoughts associated with installing the stupid glass over the license plate light). Advice: I tried to cut the lip with the trunk closed but it was far easier to get into the trunk and hold the Stanley with a steady hand - no one will ever notice the tiny undulations in the cut.

 

All cars seem to have little design errors in them to annoy us. My previous car, a Rover 75, had a plenum chamber at the back of the engine compartment, used for air entry to the heater, via a pollen filter. Only thing was they forgot about rain water when designing the car ! So, (obviously), as some late stage of development, they must have realised water was going to get in there and put drains at the bottom of the chamber. Advice on the owners club was to rod these out about every 6 months.

OK it was only a 10 minute job, but chaps not in the know (i.e not in the Owners Club), would join up and post on why they were hearing the sound of water sloshing around when they went round corners !! Damp/puddles in the car too, eventually, plus a flooded ECU. Not good news.

Paintwork was extremely good though.