Engine bay cleaning

Giggidy

My mechanic suggested getting my BMW X5 engine cleaned by a pro, to get rid of all the gunk and oil build-up, so he can see where my car is leaking oil from. I have contacted a local mobile valeting service who offer this, when I asked if they cover the electronics, etc they said no only the alternator. Is this right? Just a bit nervous doing this in case my car's electronics get messed up

Martin_the_Unjust

If your engine is that covered in gunk and dirt that a mechanic can't see where an oil leak is coming from then possible water in your electrics from a procedure that has been carried out millions of times should be far down your list of worries.

Of course you could always get out there yourself with a load of rags.........

AdrianC

A BMW X5 is designed to be used off-road. It'd be a bloody poor off-roader if the engine bay electronics had a sulk the first time any water got anywhere.



Steam-cleaning engine bays is not unusual - and, yes, if you're trying to find the source of an oil leak, it's a very good idea to clean everything up beforehand.

Yes, an incompetent numpty can cause damage if he really tries. A pressure washer can lift paint if you try hard enough.

531063

Paraffin and a hose pipe 

cymruchris

https://www.halfords.com/motoring/engine-oils-and-fluids/engine-cleaner-and-degreaser/gunk-engine-degreaser-1-litre-678052.html

Give it a liberal coating of this first using a paintbrush to get into the nooks and crannies - then rinse it off with a hosepipe.

531063

cymruchris said:

https://www.halfords.com/motoring/engine-oils-and-fluids/engine-cleaner-and-degreaser/gunk-engine-degreaser-1-litre-678052.html

Give it a liberal coating of this first using a paintbrush to get into the nooks and crannies - then rinse it off with a hosepipe.

£8 for 1 litre Jesus!!!!!!!!!!!!!!!

EdGasketTheSecond

I would not let steam or water anywhere near a modern engine bay; do more harm than good. The only option is to do it the hard way with degreaser and rags; will take you all day to do a proper job.

MinuteNoodles

EdGasketTheSecond said:

I would not let steam or water anywhere near a modern engine bay; do more harm than good.

Only if you're an idiot who puts the lance of a jetwasher right on the connectors and keep it there. They're waterproof, take them off and you'll find they almost all have a little rubber gasket on the connector which is why they're usually a sod to pull off, they're not like they used to be in years gone by. For example on this typical connector it's the blue bit that's the rubber waterproof gasket:

shaun_from_Africa

MinuteNoodles said:

EdGasketTheSecond said:

I would not let steam or water anywhere near a modern engine bay; do more harm than good.

Only if you're an idiot who puts the lance of a jetwasher right on the connectors and keep it there. They're waterproof,

I'm a helicopter engineer by profession and all the connectors used on the engines and gearboxes are designed to be waterproof but it's amazing how many times there are electrical problems from corrosion inside the connectors where water has managed to find its way inside.
These are generally very expensive connectors with multiple seals and are designed to be used in areas where water, oils & greases will be prevalent yet they still suffer from water ingress.
In a car engine bay, it would only need for the connector to be slightly loose, a seal to be worn or there to be a tiny crack on the connector for moisture to get in and using a pressure washer, even if not directed at the connectors or other electrical/electronic bits isn't something that I would ever consider.

AdrianC

MinuteNoodles said:

EdGasketTheSecond said:

I would not let steam or water anywhere near a modern engine bay; do more harm than good.

Only if you're an idiot who puts the lance of a jetwasher right on the connectors and keep it there. They're waterproof, take them off and you'll find they almost all have a little rubber gasket on the connector which is why they're usually a sod to pull off, they're not like they used to be in years gone by. For example on this typical connector it's the blue bit that's the rubber waterproof gasket:

You did that deliberately, didn't you?

I need a 20A two-pin female Superseal just like that.

EdGasketTheSecond

MinuteNoodles said:

EdGasketTheSecond said:

I would not let steam or water anywhere near a modern engine bay; do more harm than good.

Only if you're an idiot who puts the lance of a jetwasher right on the connectors and keep it there. They're waterproof, take them off and you'll find they almost all have a little rubber gasket on the connector which is why they're usually a sod to pull off, they're not like they used to be in years gone by. For example on this typical connector it's the blue bit that's the rubber waterproof gasket:

Then how come my nephew's car wouldn't start after a pressure car wash; and that was only on the external of the car? Water had got into the engine bay from the pressure jet being sprayed around the bumper and grill and it had rendered the car unusable. We did get it going after about an hour of mucking around drying everything.