Oil cooler, 496 HO
 

Where is my oil cooler located on my 496? I follow the hard oil lines from the oil filter and they run on top of the manifold beside the head and goes towards the back of the motor. I have a high oil temp issue at higher rpm's. Would like to pull the cooler if possible and clean. Any insight?
Thanks, Tim

Underneath the exhaust manifold on the port side. Hard to miss unless you cannot get your head down there to see.

Oil cooler
 

Thanks, I thought it was under the manifold but like I said I followed the oil lines and it lead to the back of the motor. Ill look again tomorrow when I get to the boat. Hope its accessible!

Before you go to the trouble of fighting it out of the boat, you might want to unhook the raw water hose coming into the heat exchanger and the hose going out of the raw water pump. And then you would adapt a garden hose up to something larger clamp it into the heat exchanger end and back flush out the water side of the cooler.

https://www.google.com/search?site=&source=hp&ei=7Zw5Wd7pHsi7jwSg3obYCQ&q =496+oil+cooler+diagram&oq=496+oil+cooler+di&gs_l= mobile-gws-hp.1.0.33i22i29i30k1l5.1938.8179.0.9540.20.20.0.2. 2.0.228.3068.0j12j5.17.0....0...1.1j4.64.mobile-gws-hp..2.18.2970.3..0j35i39k1j0i131k1j0i20k1j0i22i30k 1.hFGLOewlVIQ#imgrc=3AZhfgWyhG09pM:

No need to pull to flush. Remove incoming hose off oil cooler. Remove hose from heat exchanger to oil cooler. Flush from HE hose to oil cooler. With the PS hose off the oil cooler you dont backflush crap back thru the system and youncan see what comes out of the oil cooler.

I backflush all coolers/heat exchanger. Clean out HE cooling tubes, inspect HE endcap gaskets every fall layup.

Ok thanks. Ill give that a shot and keep you posted on how I made out. Will I be able to see anything come out of the hose at the raw water pump? Will I know if its backed up at all? Or am I back flushing it to see if it fixes my problem and then have to buy a new cooler?

Possibly pieces of impeller.

Ok. Fingers crossed. Ill let yous know how I make out. Thanks

Well back flushing the oil cooler didn't work. Thinking I need to flush the heat exchanger. The water temp on the starboard motor is 10ish degrees higher then the port and the oil temp is 20ish degrees higher also. And thoughts and recommendations on how to flush the heat exchanger?
Thanks guys!!

Essentially the same way. 2 hoses go to exhaust. Put water in those. One or the other don't matter. Water goes out thru big hose coming from oil cooler-raw oump. One thought. Did you repl water pump impeller-housing?

Yep, when was the seawater pump serviced last? Heat exchanger endcaps ever been off? The endcap gaskets are a known problem area. They deteriorate and come apart. The cooling tubes internally can be cleaned with stiff wire, .17cal bore brush, compressed air etc..... Engine coolant flows around the tubes and seawater flows thru them.