# Engine cleaning risks



## Advanced Driver (Jun 24, 2006)

I've just seen this thread on another forum

http://www.honestjohn.co.uk/forum/post/index.htm?f=2&t=60986

It's interesting what 659FBE has said:
"Don't clean engines with any water based cleaners and never apply a hose unless you want long term electrical problems due to water penetrating electrical connectors and starting corosion."

What do you guys think? It all seems to make sense.


----------



## alanjo99 (Nov 22, 2007)

Water gets in anyhow when it rains - personally I don't use a PW - just hose pipe.

Always ensure you dont get water in /around fuse box etc 

Besides common sense - its fine !


----------



## Gleammachine (Sep 8, 2007)

Try to wrap clingfilm round any electrical areas where possible.


----------



## CupraRcleanR (Sep 2, 2007)

Gleammachine said:


> Try to wrap clingfilm round any electrical areas where possible.


Nappy bags are great. Try not to use used ones tho! Defeats the objective.


----------



## Gleammachine (Sep 8, 2007)

Gleammachine said:


> Try to wrap clingfilm round any electrical areas where possible.


Should have added whilst the engine bay is cold.


----------



## neilneilorange (Oct 9, 2007)

Most modern cars have IP rated connectors on them anyway so shouldn't really be a problem.


----------



## TOGWT (Oct 26, 2005)

Spraying high pressure water(or using steam) could be a problem, but *not using water-based car care products*, not sure I understand this one

•Spray electrical connectors with WD40 which repels moisture / water (avoid spraying on belts)
•Use cling-film or Saran wrap elastic covers to cover any sensors, electrical black boxes, electrical devises that could cause an electrical short-circuits if subjected to water spray.
•This will not guarantee that you won't cause a problem when cleaning an engine bay but it will greatly reduce the risks.


----------



## Mr OCD (Apr 18, 2006)

I've cleaned over 100 engine bays in the last couple of years and not had a problem with any of them... common sense prevails


----------



## mark1319 (Sep 9, 2007)

Still not sure about cleaning my engine bay, thinking to use the slow, but safe method just in case.


----------



## Jonsey89 (Jun 27, 2007)

I have jet washed mine many times with no precautions and not one problem.


----------



## Advanced Driver (Jun 24, 2006)

Engine_Swap said:


> I've cleaned over 100 engine bays in the last couple of years and not had a problem with any of them... common sense prevails


Ah, but what about in 5-10 years time? The OP seem to say that the problems were long term.


----------



## Destroyers (Aug 30, 2007)

Once the engine is running surely the high temperature should dry out any remaining water or condensation anywhere. Also remember the engine bay gets water in it anyway (otherwise it wouldn't need cleaning)


----------



## martyp (Oct 24, 2006)

I have cleaned my engine bays with AG Engine & Machine cleaner and now meg's super degreaser (much better). Not had any problems from doing it.

I used to put bags round fuse boxes etc, but I find it doesn't matter if they get wet - so long as you keep the water moving and not pointing it at the same area for too long.

I use a hose pipe on my car, but have cleaned diesel engines with a pressure washer - company vans!


----------



## glymauto (Feb 29, 2008)

I think you'd be very surprised at just how much water DOESNT get into the engine compartment when its raining.

I drove from Manchester to London in the pouring rain and parked up for about 1 hour before setting off back to manchester. Stopped on the services about 90 miles from Manchester (so that was a solid 300 miles at 70mph+) to fill up the washer bottle and the engine compartment was bone dry!

The engineers obviously design the bay to repel water from forward motion...but rain doesnt usually blast from above at 90bar pressure!

I'd use caution jetting or soaking an engine bay.


----------



## dominic84 (Jan 27, 2007)

> I think you'd be very surprised at just how much water DOESNT get into the engine compartment when its raining.


Agreed - water does not get into the engine bay like some people are suggesting! It's obviously not an air tight space which is why the engine gets dirty as crud from underneath and dirt and dust get in through grills etc but your engine is never going to be soaked when it rains.

I would recommend as other's have suggested that you cover any sensitive electrical components and go easy with the pressure washer, also watch out for cars with recessed spark plugs and some cars which have a warranty clause about pressure cleaning engines.


----------



## TOGWT (Oct 26, 2005)

Engine Compartment Steam Cleaning: 
The engine compartment is deigned to resist water ingress, it is not waterproof / watertight. Rain or water splashed up into the engine is at very low pressure, very different from a pressurised hose or steam

High-pressure steam cleaning can force solutions into the engine harness sheath and associated cables, causing unusual problems that would not have occurred otherwise. Once steam is applied to a cold metal surface it condenses and becomes water that may be in a place that it cannot be easily removed from.

Modern vehicle engine harness multi-plugs and related sealing measures are not designed for the discharge velocity and force of typical commercial steam cleaning units. Further, cleaning solutions with the high-pressure discharge can leave conductive and often corrosive residues deep within the harness and cables. 
Most engines are rarely so encrusted with automotive residues and dirt that normal, low-pressure degreasing methods fail to provide proper, efficient cleaning. High-pressure engine water / steam cleaning are unnecessary and should be restricted to extreme cleaning jobs, such as commercial trucks, off-road vehicles, etc.

*Engine Bay Detailing - *http://forums.bimmerforums.com/forum/showthread.php?p=11062018&posted=1#post11062018


----------



## ericgtisuffolk (Apr 26, 2007)

I have never had a problem with wet electricals before,but I only use a hosepipe and not a pressure washer.


----------



## Muncher (Apr 3, 2006)

On the VX220 and the Elise the engine bays are pretty much open to the elements, when it rains, the engine gets wet with no problems.


----------



## Paulm31 (Jul 27, 2006)

aha! that must be why i saw a 220 broken down on the side of the A1 this morning :lol:


----------



## AW8 (Dec 11, 2006)

Used hose once - and had issues but tbh this was years ago and I failed to bag electicals. Also got water down into the spark plug bores.

I have cleaned all my car engine bays since with elbow grease using old toothbrushes, paint brushes ( with mask tape over metalwork of same), old damp cloths & maybe with a little dab of WD40, (not on rubber) or whatever cheap left over polish I have kicking around. Any soiled/greased areas can be lightly rinsed by light spray of tap water via an old household glass cleaner bottle.

Then if you wish apply you can polish accesible paint surfaces &/or apply dressing of choice.

Not pebble beach standards granted but tbh daily driver engine bays can be well maintained to an acceptable std this way & without any resultant electrical probs etc.

The initial clean on a prior neglected bay is always the hard bitand can leave a few battle scars to hands but after that it's just a case of a quick wipe over & dress if you wish.


----------



## markcoznottz (Nov 13, 2005)

Muncher said:


> On the VX220 and the Elise the engine bays are pretty much open to the elements, when it rains, the engine gets wet with no problems.


Didnt the vx220 used to have problems with water getting onto the plug leads and causing misfires? It still common practice in the valeting trade to soak engines in TFR and steam clean/ pressure wash them. Amazing that it doesnt cause more problems further down the line, or maybe it does...


----------



## Wol (Mar 31, 2008)

i dont see any real problems with jetting an engine,unless ofcourse any components/covers/protection etc are faulty ofc.

i detail engines on a daily basis. in the last 2 years ive had only 1 problem and funnily enough it was actually on a diesel engine, not a petrol engine like you'd expect. after about 1hr it had dried enough and cranked straight up


----------



## Stebo (Mar 12, 2008)

The older shape megane is a disastor to clean the engine bay. The Shape of the engine means that water lies down round the spark plugs which about a week after washing the engin bay leads to the spark plugs needing changed. I managed to do it three or four times before realising that it was cleaning the engin bay that was causing it. Eventually smeered a barrier of greese around that area of the engine (under engine cover)


----------

