[Archived]

I love the challenge of fixing it myself and I am by no means a mechanic. These things are not hard to work on just big!!! Finding the leak is usually harder than fixing it. I chased one for 5 years on my Eagle coach with a 6V92 engine, and only found it because I had to remove the blower to replace an elbow from the after cooler. My leak was coming from a loose hose clamp on the crossover pipe under the blower drive at the rear of the engine.

Best thing to do is clean the engine real good with something like Gunk cleaner and then start tracing where leaks come from. Leaks are not always oil either. I had a pretty good leak on my power steering pump that just took an O ring to fix.

Now I have a small transmission fluid leak that I need to chase down when I have time.

[Archived]

If I spray the whole engine down with Gunk, is it safe to hose it off with a water hose without getting water into any of the “sensitive” parts?

[Archived]

Georges,

I have cleaned my engines over the years with excellent results. But I avoid the use of brute force. I spray it with a cleaner. I use Simple Green, but there are many others. I then use a small paint brush to work it in and loosen the crud. If the engine has been leaking and there is a big build up of oil, grease and grit it may require some scraping to get rid of the heavy stuff first. After working the solvent in with a brush I rinse it gently with a hose and a gentle spray.

I haven’t masked off any electrical connectors or devices, instead I just avoid flooding them with Simple Green and water. To avoid the cleaner from drying I do a section of the engine at a time. I work from the top down.

Apart from avoiding electrical connections I also avoid using a strong stream of water on the radiator. The radiator fins are fragile so if I clean the radiator I use a low flow or gentle spray.

Completely rinsing is vital. Almost all cleaners have the ability to attack something. Simple Green (unless it is the aviation formula) will attack aluminum for example. So I make sure afterI loosen the dirt I completely rinse. Usually a dirty engine requires multiple cleanings so after I have done the engine and I am sure it is rinsed I dry the areas I can get at, and if more crud remains I concentrate on those dirty areas.

Bottom line, just be careful around electrical connections and devices. Do not spray water all around, but direct it to where you need rinsing. If you get the fire detectors wet (some coaches have them on the roof of the engine compartment) you may set off the alarm. The alarm will stop eventually.

Use care if you clean the radiator. A strong spray can damage it.

I have heard folks use solvent, gunk, brake cleaner (nasty stuff to breathe), Simple Green, and even diesel fuel. I don’t know of any that don’t require a good rinsing, nor do I know of any you can use without consequences. Anything that removes crud and leaves a clean engine is going to require some care in use.

Once the engine is clean keeping it clean is relatively easy. A clean engine allows you to spot minor leaks quickly and if you do a visual inspection regularly you can catch common problems and address them before they become serious. If you have the 50DN alternator or OTR compressor look behind the clutch or pulley on those. They all show some leakage, but unless and until the leaks become serious you can easily judge them to be normal, but when the leaks grow you can easily see that it is time to do a repair.

[Tom]

Thanks Jon for your always helpful and sensible advice.

Now I just have to figure out where I can take it and make a mess, for some reason my wife doesn’t think its such a good idea to perform this procedure in the driveway!

[Bob]

I have cleaned a dirty engine on grass. The crud sinks into the ground and grass grows. Ooops. Excuse me, I have to answer the door. The EPA is out there. Just kidding.

I installed a sump in my pit. Anything that gets into the pit cannot get out unless I plug in the sump pump. The discharge from the pump runs through an oil trap I installed to collect anything that flows through my shop floor drains. I did not want to mess up the environment, much less my property. I wish I had an answer for where you could safely and legally clean an engine. The truth is the mess will not be any worse than the drips of oil I see in parking lots.

If you have a lot of built up greasy crud, use plastic or paper under the engine to catch it and scrape away as much as possible. That is going to be the greatest amount by far. If all that remains is some dirty spots on the engine that is going to emulsify and wash away. Emulsifying grease doesn’t make it go away, it just delivers it somewhere else which is what the cleaner or solvent is doing when it takes it off the engine.

[Elliott]

I normally clean mine on the concrete driveway. If you clean it off right away it will not stain. I have also learned that if you get oil drips on concrete you can clean it with oil dry and a 6 inch length of a 2×4. Just spread out the oil dry and scrub it with the 2×4 block until the oil dry granuals turn to a powder. Sweep it up and the stain is gone! Bad stains may take a couple of scubbings but it will come clean.

Makes the wife happy!!