Good morning everyone,
I have years of leaked oil and dirt caked onto the bottom half of my engine. I would like to clean it off. Do you all have any advice on how to do this or what to look out for? My questions are mainly about the use of water going over the top of the engine, but also disposal of the water after cleaning. But any other product or method advice would be helpful.

 

if you clean it yourself, its pretty much impossible to catch the rinse water unless you have some sort of industrial scale facility with wastewater capture that you can drive onto...

best thing is to find a steam cleaner business, who has this all setup.

don't worry about the electrics, if they are all in decent condition, they will survive the spray, just don't blast things like the distributor directly with high pressure. I've used foaming Gunk brand engine cleaner successfully, park somewhere where the drainage won't go down a storm drain, and won't do any damage (a funky corner of the field behind my house is what I've used) spray down the sides of the COLD engine, go at it with a parts cleaner brush, hose off with cold water, and repeat if you missed stuff, then let dry thoroughly in the sun before restarting.

 

I use an electric hi pressure washer at home, works very well, uses little water. Volvos are very tolerant with engine washing. I cover the 240 distributor with a plastic bag, spray all the rest but take it easy on the electrical connections, injectors, etc. The pressure washer is much better than just hosing the engine with water! Go to a self serve wash bay if you have one where you live if you don't have a washer at home... Engine degreaser works on COLD engines so you cant drive very far, or in some field to do this.

 

yeah, i meant the back of my own property, where I can run a long garden hose.

 

important update: New problem

Yesterday I took the 240 to a local drive-in self-service car wash. I covered up the distributor and its cables. I sprayed the engine down with a Gunk equivalent. Rinsed it off with the sprayer. Put everything back together. Engine started up. Drove off. All was well.

Today. After a short drive to my office (about 1.5 miles) the oil pressure light came on. I did a cursory check of the oil. I did not have a cloth to wipe the stick. But it looked good. I had my wife check the floor of the garage, but no spills there.
She told me to be careful because it might be a bad oil pump.

I started looking around and found a different Volvo forum talking about a similar issue and the comment was made that the problem is very, very rarely a bad oil pump, but rather something else in the system. Is this just a coincidence, or is something that happened when cleaning the engine?

What would you look at? Is there a sensor that might be bad? Is there something that triggers the oil pump to turn on that might be bad? Could my dashboard warning light be malfunctioning? I don't have my manual with me, so there may be a simple diagnostic flowchart there, but I thought I would check here in the meantime.

 

Most likely you knocked off the wire off the sensor. It's on the passenger side low, to the front, bet that's the reason...

 

more specifically, its on the exhaust side of the engine block just forward of the oil filter, and just above the back of the alternator, its a single wire sensor. I believe its a black wire, and I think its a 'faston' aka spade lug connector.

 

Not sure what happened. The light did not come back on on my way home from the office. It has not been on since. I checked the sensor and it looks good. Perhaps most importantly, the engine sounds really good, as far as I can tell. A phantom warning?

 

bad insulation on the wire ? flaky sensor? IIRC, the sensor is grounded when there's insufficient oil pressure, and open circuit when its good.

never had that oil pressure sensor fail on 3-4 volvos, but thats not saying much ... I remember a very similar sensor on a VW Jetta developing a oil leak but IIRC, it still worked OK