Any suggestions re appropriate manner to clean underneath my XJ-S. There is a lot of build up of muck, dirt mixed with grease residual.
Years ago I had a 1954 Vauxhall Velox, surprisingly no rust. My garage then steam cleaned taking into consideration brake lines etc.
Is steam cleaning safe or should I avoid and live with 35 years of accumulated muck. I regularly use high pressure hose underneath my regular car a 2020 Mazda CX-5, but that car hasn’t the build up my Jag has. As an aside the XJ-S has been under sealed by previous original owner.
Hope this is not a stupid question.

Mike

 

Mike,

Personally I would do it. It sounds as if you have a lot more than just wax / underseal under there.

By properly cleaning it, you may remove some of the wax protection. BUT you will help to expose any cracking old undersealing that may be permitting moisture to sit under it and letting the car corrode. You also may have chipped and cracked paint on teh subframes. You may also have oil leaks from engine, gearbox, diff, power steering etc.

As long as you go into this understanding that it will highlight the need for some residual maintenance and further painting, protection and undersealing, I think it's the right thing to do.

Good luck

Paul

 

Thanks Paul. There are professional steam cleaners in my town, car is extremely sound for age, but as you say, a thorough clean may or may well show up some hidden gremlins, be than as it may, the car is rare, immaculate contours and I want the underneath looking as good and sound. Todate there are no oil leaks or rust evident but that could be hidden as you say.

 

Agree with Paul.

Just ensure they stay WELL clear of the rear cradle, particularly the inboard items, diff, brakes etc. Seal damage from Hi-pressure "whatever" will require that cradle out to rectify.

Good luck.

 

As all above have noted, the steam cleaning is only the easy part of the preservation process. You absolutely must, afterwards, properly re-protect the underside. This will almost certainly mean testing the old underseal for having gone hard and removing that part of it that is no longer adhering to the metal, merely hiding it to make water traps.
Once all sound, resealing with a top non-hardening wax-type protecting layer. BUT, as important is spraying wax and protection into the box sections: sills, chassis rails above the rear axle; front top and bottom rails; checking the front shock absorber strengtheners and seeing if they have corroded the inner wing below the shock fixing in the engine bay; exhaust tunnels inside the boot; sending a probe over the inside of the rear wheelarch; removing the rear seats and doing the sills under the rear side windows, and VERY important, under the rear seat squab metalwork where the rear axle radius arms are welded to the metal on the outside. For the box sections you have to drill 10mm holes for the spray probes. Personally I recommend spraying the boxes first with AquaSteel (this stuff is absolutely wonderful) and then, after 48 hours with wax (eg dinitrol or similar):
https://aquasteel.co.uk/
https://www.dinitroldirect.com/produ...ection/cavity/

 

When working at the Jaguar shop I had mine done at a local shop.
They did a fair job and I was satisfied with the price.
I didn't have any electrical issues because care was taken to protect.
There were still some spots that needed more attention but still worth it.
After that we had an E Type come in for sympathetic restoration.
It was pretty filthy everywhere in the engine bay.
The shop owner was too cheap to spring for the shop I used.
He decided to do it in house.
We drove the car onto a big sheet of plastic and stuffed it all around to make a pond.
I don't remember if we used an actual steam cleaner or just a pressure washer.
Anyway, we all wound up soaked to the bone, the shop was a mess and the wet/dry vac was next to useless.
Since all the electrics were being replace that wasn't a problem.