nxfirebird

i rebuilt my gen 6 '98 502's this spring, honed all stock, didn't add anything to them simple rebuild, fresh rings bearings, springs etc..

both motors run like stink, love it BUT my port motor is pumping it's oil out at a fast rate, more than a quart a mile at any RPM.

it's not burning it, and no oil in the boat. i thought it was a the oil cooler, and it was oily, but i change that last week and put a new one on. i know a friends mark 4 block had casting shift and cracked between the oil galley and the water jackets.

does the Gen 6 block have an oil passage close enough to do the same thing? was there something i missed on this motor in assembly? i'm lost.

MILD THUNDER

iTrader: (3)

If you are losing that much oil, there would/should be a oil slick noticeable in the water behind you when the engine is running.

If its not in the bilge, then it must be going out the exhaust. You replaced the cooler, so Sounds like it might be time to tear it down again.

hunster

If there's no water in the oil , gotta me spitting it out somewhere. No oil in the bilge?

oldandslow

you could take the belt off the water pump and the drain plugs out of the block. If its leaking that bad you should get a drip before the headers get hot. sure sounds like the oil cooler though.

HiPerf2000

iTrader: (2)

If the oil cooler was bad, wouldn't it work both ways and you would see water in your oil ??

oldandslow

Higher oil pressure than water pressure usually keeps the water out. eventually water will work back while not running but im sure he has not run it much.

cabin fever

John,
I plugged the oil cooler on mine, dropped it in the water, and put some air to it, to check. Pretty simple check,
but if you replaced it, probably not it.

I did read about some core shift on Gen 6 blocks. I'll see if I can find the info I was reading.

sorry to hear your still have problems.

-Shane

cabin fever

sorry John. I was thinking of something else. Here is the info I was talking about. Seems like its more a gen6 vs dart heads thing.

http://www.offshoreonly.com/forums/g...ater-leak.html

nxfirebird

like i said not a drop! i'd love it if it was, all those are easy fixes!



at idle when in gear you can see a little trail behind that motor.
we're thinking that if we pull the motor we'll knock out the frost plugs, use a bore scope and oil primer and start looking for cracks.... or i just had the thought, i could drain the water leave out the plugs and run a primer on it.. at the rate it's loosing, like old and slow said, it should run out quick if there's a crack.



i think i will do that just for peace of mind, my luck is that i got a worse new cooler than the oil one!

Thunderstruck

Who installed the rings?? Upside down rings will turn the motor into an oil pump.