Spraying a car underside with used engine oil....

[jshell]

Anyone do this anymore? It 'was' once a great way of preventing underfloor tin-worm, despite the environmental risks.

Just curious if the practice still exists, or is it universally accepted as unacceptable?

" (I'm not planning it before the flaming begins, it would ruin my driveway....)

[jagracer]

When we all drove British built cars we had no choice (you didn't need to spray it, the engine and gearbox took care of it) but if you do it now don't forget to drive it round a dusty area to help the oil adhere to the underside.

[mat777]

Haven killing all those motorcyclists.....

Try using something designed for the job, like waxoyl or dinitrol

[infradig]

You only have to look underneath my old Discovery to see it works ! The least rusty areas are those that have, over the years , received liberal coatings of ep90.

[jshell]

mat777 said:

Try using something designed for the job, like waxoyl or dinitrol

I'm not planning it at all, it was just an idle query...!

[Justin Cyder]

It's the very reason front subframes on old Mini's never rusted away while the rear ones always did. The double edged sword of British engineering right there!

Edited by Justin Cyder on Tuesday 11th December 10:28

[TonyRPH]

A friend of mine's dad used to pour old engine oil into the door bottoms, sills and other chassis box sections back in the 70's.

It used to stink like hell for a while but did the job - he had a car that was relatively rust free.

The upper bits still rusted though!

[Du1point8]

Friend of mine uses old sump oil on their grass cutters (both being 8ft+ wide, triple blade jobbies) as a way to stop the acidity of the grass getting to the metal of the mower.

seem to do quite well as both are over 15 years old and very little rust on them.

Not sure of the environmental aspect, but as they farm the land there, I assume its not that bad.

[alpinemauve]

Old oil used to a great wooden fence preservative too. Slap it on. Mind the roses.

[droopsnoot]

Worryingly I was chatting to a drunk bloke who works in the body department of a local luxury car manufacturer who shall remain nameless. He told me that the absolute best thing to use is warm gearbox oil. I must admit something of an argument ensued, he insisted it was the "best" thing. I did ask why his employers invested in all that fancy galvanising technique if all they had to do was slap a bit of old gearbox oil into the box sections, and strangely he couldn't tell me. Apart from I seriously doubt that it's "better" than something designed for the job, it smells absolutely awful.

[slimmyreed]

My RS6 did this for me all on its own. Oil pipe to the front gearbox oil cooler rusted through as is common with these and sprayed the underside with auto trans fluid. Luckily I noticed straight away and repaired it before the level dropped to a dangerous level. Nice coating of oil down the passenger side floor now though!