I restored my 2007 Honda GL1800 3A Goldwing after it was flood submerged for 3 days following the August 2017 Hurricane Harvey. The $2000 restoration with many OEM parts required, among other things, a complete clutch rebuild where I discovered flood debris blocking the clutch housing's secondary trochoidal oil pump scavenge screen which I cleaned along with all engine & clutch cover oil passages to verify they weren't plugged. Everything works but unfortunately after about 50 miles of riding my bike I encountered a problem that according to the 2006 - 2010 Honda Service Manual is zero oil pressure due to a plugged primary oil pump filter screen. I could hear the primary trochoidal oil pump cavitation buzz so I immediately stopped the engine and took it home with my pickup. I checked engine cylinder compression and all meet spec so they're OK. I also checked the primary oil pump outlet pressure using a mechanical pressure gauge and verified there was no pressure while again hearing the primary trochoidal oil pump cavitation buzz.
I removed the Engine Oil Pressure switch and applied a high volume 150 PSI desiccated air flow backwards through the oil system (as well as forwards through the oil filter) and was able to restore oil pressure to the Honda Service Manual's specified 77 PSI requirement (without the oil pump cavitation buzz) but after 20 miles the oil pressure light came on again. I repeated the 150 PSI air pressure oil system purge and recovered the 77 PSI spec pressure again with no oil pump cavitation buzz.
The Honda Service Manual says the oil pump filter screen requires engine removal and splitting the engine block in half to gain access to clean the screen.
I contacted my local Honda dealer about the repair but they said it would be cheaper to buy a new replacement engine than have their mechanics attempt to repair mine.
I read the Honda Shop Manual and figured that I'd need about $1000 of special tools and another $500 OEM parts to disassemble/re-assemble the engine to clean the primary oil pump pick up screen. I will do this really, really complex tear down and reassembly only if the steps below don't work.
I am going to drain the engine oil for the 7th time and replace it with a 2 month soak comprised of 1 quart of Motor Medic Motor Flush (an engine cleaner composed of kerosene & diesel fuel) along with about 1 ounce of a diesel fuel enzymatic organic material dispersant/cleaner (Star Tron) to see if it will loosen the debris blocking the oil pick up screen enough to allow it to go through the primary trochoidal oil pump to the oil filter for removal. If that doesn't work I want to drill a 1/2 inch hole on the bottom of the Goldwing engine to allow me to use a bore scope and bristle brush to dislodge the suspected blockage.
That is where my question for the forum comes in. I've looked at the Honda Service Manual photographs and have identified where I believe I can safely drill the 1/2 inch hole but I need to know if there are any hidden oil passages in the engine block case that I would be drilling. I will be drilling in the port side of the engine case slightly forward of the oil pick up filter screen in an open area between the screen and the engine oil pressure relief valve housing.
I've attached a picture showing the drill location.
Can anybody please tell me if I will encounter any oil passages within the cylinder block case? If there are hidden oil flow passages in this area, can you suggest alternatives?
If nobody can help, I will probably still drill the hole to clean the screen. If I do hit a hidden oil passage, I'll tap the hole with threads and install a clocked screw with a hole drilled orthogonally through it to restore the hidden passage's flow. If none of this works I'll do the rebuild or swap the engine with one taken from a Copart auction bike.
Thanks for your assistance.
p.s. I've seen on YouTube where some people used water based cleaners combined with engine oil to clear an oil pump filter screen but I would never entertain doing that as it would likely cause lots of engine bearing wear.
I removed the Engine Oil Pressure switch and applied a high volume 150 PSI desiccated air flow backwards through the oil system (as well as forwards through the oil filter) and was able to restore oil pressure to the Honda Service Manual's specified 77 PSI requirement (without the oil pump cavitation buzz) but after 20 miles the oil pressure light came on again. I repeated the 150 PSI air pressure oil system purge and recovered the 77 PSI spec pressure again with no oil pump cavitation buzz.
The Honda Service Manual says the oil pump filter screen requires engine removal and splitting the engine block in half to gain access to clean the screen.
I contacted my local Honda dealer about the repair but they said it would be cheaper to buy a new replacement engine than have their mechanics attempt to repair mine.
I read the Honda Shop Manual and figured that I'd need about $1000 of special tools and another $500 OEM parts to disassemble/re-assemble the engine to clean the primary oil pump pick up screen. I will do this really, really complex tear down and reassembly only if the steps below don't work.
I am going to drain the engine oil for the 7th time and replace it with a 2 month soak comprised of 1 quart of Motor Medic Motor Flush (an engine cleaner composed of kerosene & diesel fuel) along with about 1 ounce of a diesel fuel enzymatic organic material dispersant/cleaner (Star Tron) to see if it will loosen the debris blocking the oil pick up screen enough to allow it to go through the primary trochoidal oil pump to the oil filter for removal. If that doesn't work I want to drill a 1/2 inch hole on the bottom of the Goldwing engine to allow me to use a bore scope and bristle brush to dislodge the suspected blockage.
That is where my question for the forum comes in. I've looked at the Honda Service Manual photographs and have identified where I believe I can safely drill the 1/2 inch hole but I need to know if there are any hidden oil passages in the engine block case that I would be drilling. I will be drilling in the port side of the engine case slightly forward of the oil pick up filter screen in an open area between the screen and the engine oil pressure relief valve housing.
I've attached a picture showing the drill location.
Can anybody please tell me if I will encounter any oil passages within the cylinder block case? If there are hidden oil flow passages in this area, can you suggest alternatives?
If nobody can help, I will probably still drill the hole to clean the screen. If I do hit a hidden oil passage, I'll tap the hole with threads and install a clocked screw with a hole drilled orthogonally through it to restore the hidden passage's flow. If none of this works I'll do the rebuild or swap the engine with one taken from a Copart auction bike.
Thanks for your assistance.
p.s. I've seen on YouTube where some people used water based cleaners combined with engine oil to clear an oil pump filter screen but I would never entertain doing that as it would likely cause lots of engine bearing wear.