I have an 04 Fabia VRS and yesterday i serviced it and at the same time gave the engine bay a good cleaning with a damp cloth and then some black trim restorer, it came up great, however, beneath the plastic engine cover the engine itself if very dirty.

 

What are peoples thoughts about spraying it with some degreaser then jet washing it off?  I know it would do a great job, but I'm more interested if there is anything in the engine bay that can become water logged or damaged. 

 

Thanks, Matt. 

Cover battery and alternator

Then pressure wash until your hearts content

When I do it I bung a bit of cling film over anything obvious.

Never had a problem myself but make sure you cover all the electrics.  I have sprayed the stuff on cold before but start the engine before you wash it off and let it warm up.  Also watch out for air intake.

+1 on all of the above.

Jet washed mine several times and never had a problem. Have always put clingfilm over electrical connectors, alternator and battery for protection.

I think youll be fine just jetting away with youur diesel unless you have an open cone filter. If your jetting a petrol try to keep it away from coilpacks, ht leads, distributors etc.. Batterys are fine getting wet but dont go to mad

Not a problem if you keep your distance and essentially blast clean with a mist.

Be careful getting close up on what you think are stubborn areas as the jet will remove warning stickers, wiring clips, plastic grommets and all sorts and by the time you've noticed it's been blasted into an inaccessible part of the bodywork.

Hot water and laundry detergent does a good job of loosening grime if left to soak, use an old paint brush to agitate problem areas before blasting clean, you're car will smell like clean laundry for a few days :-)

Diesels will not have a problem as same as a marine engine! Petrol cover ht leads and leave engine running

All can be nice and dandy,

easy and quick to seal and mask up and go pressure washing around engine bays, under wheel arches etc.

 

But some engines can look like cr4p once the Aluminium has lost its nice coating, and the steel,, and some flaky paint is lost,

so bare exposed metal and corrosion sets in.

As seen on many used cars that have lovely clean engine bays at point of sale then are a Rusty Corroding mess one winter later.

 

So best take care, 

be aware that you are loosing Protective Grease & Oil and possibly wax.

 

Do not use Corrosive Detergents unless you can be sure of getting them all off and out of every place.

Re coat and grease and lube,

Use Rubber Grease on Rubber, not Petroleum Based Grease.

(Tesco Tyre & Bumper Restorer at £1.99 a can can tidy the plastics and rubber up nicely for 'Much Cheapness'.

& and with a nice Citrus smell.)

 

It can be easier to use Gunk/De-Greasers, which are the correct stuff for the job,

and spend some time with Elbow Grease rather than blasting with H20, 

heated H20 and other chemicals & the likes.

Take care with Detergents that are Sodium based (salt), most are.

 

george

Personally, I wouldn't but if you must, first remove the engine undertray and go for a blast round the block when you've finished jet washing, this  will get the engine quickly dried out.

Steam would be better. Sounds daft but steam is not as wet as pressure washing.

Modern cars are too dependant on electronics these days. They are designed to be waterproof but careless jet washing is an unnecessary risk for me.

 

I like a clean car but a dirty engine? Considering there is only me that ever see's it I'll live with the extra protection offered by all the dust and muck