351 PCM direct drive leaking oil???

[codyandamber]

I have a tremendous amount of oil in my bilge. In has accumulated over the course of the last month. It is in an '85 mastercraft with a 351 PCM. What is the worst case scenario? I have it stored about an hour away so that is all the info I will have until next week. Let me know what you guys think. I appreciate it.

 

[snapperbait]

Re: 351 PCM direct drive leaking oil???

Worst case, leaking rear main seal, rusted out leaking oil pan, or leaking pan gasket.. <br /><br />Have to pull the engine for those jobs.. Have do a re-alignment too if the engine is pulled..

 

[Walt T]

Re: 351 PCM direct drive leaking oil???

Engine oil or transmission oil? The transmission oil will be red. Could just be a drain plug gasket or the tranny fill tube. Pulling the engines on these is simple. I can have that engine sitting on the ground next to the boat in 45 minutes. 30 if I lose 25 lbs. The tranny comes out with it and dont move the lower nuts on the mounts and it'll drop right back into place.

 

[DJ]

Re: 351 PCM direct drive leaking oil???

Suggestion: PCV (Positive Crankcase Ventilation) valve?<br /><br />Take it out of the valve cover and make sure it's not stuck.<br /><br />It all depends on where it is coming from. You can buy dye from the auto parts store and use a black light to track it down.

 

[codyandamber]

Re: 351 PCM direct drive leaking oil???

It was definitely motor oil. I do not believe it is a rusty oil pan. Again it is in storage right now and I do not have convinient access to it. When I did see it it was very limited. There seemed to be maybe a half quart in the bilge. I was in good clothes so I didn't get down to see if I could see exactly where it was coming from. It was nowhere on the high side of the motor. <br /><br />If it was the oil pan gasket is there now way to drop the pan a bit and put another one in it?<br /><br />Why would the rear main seal go out like that if it was used quite a bit this summer? Don't they usually go out when they dry up from not being used?<br /><br />What is there to align? If I bolt it exactly where it was will it not be aligned? <br /><br />Are there any better case scenarios of what it could be?<br /><br />I am going to look at it tonight to see if I can see where it may be coming from.<br /><br />Thanks for everything so far.

 

[snapperbait]

Re: 351 PCM direct drive leaking oil???

" If it was the oil pan gasket is there now way to drop the pan a bit and put another one in it?" <br /> <br /> Yes, you can do it that way.. I prefer to pull the engine.. For me, it's easier that way, and about the same with reguards to the amount of time the job takes, even with re-aligning it...<br /><br />Do you have an oil drain hose on it? That could leak..<br /><br />The crankshaft is prone to rust where the rear main seal rides, thats why the seals sometimes leak..<br /><br />As for reasons why the engine will be out of alignment, it's a long story, but it probably will be at least slightly... Anyway, good news is alignment is easy... It's a simple matter of making small adjustments for the purpose of matching up the drive shaft coupler to the transmission coupler using a .003" feeler gauge to make sure it's paralell... <br /><br />Here's a link to a page that has the alignment proceedure... you'll have to scroll down a bit. <br /> http://www.correctcraftfan.com/ftp/Velvet Drive Inst. Manual.pdf

 

[Trent]

Re: 351 PCM direct drive leaking oil???

Could be somthing as simple as a defective oil pressure sender. You need to clean the bildge and engine. Run and check for leaks.

 

[Walt T]

Re: 351 PCM direct drive leaking oil???

This is an inboard. Alignment is pretty easy. But were getting ahead of ourselves. Find out whats leaking first.

 

[codyandamber]

Re: 351 PCM direct drive leaking oil???

I cleaned the bilge and ran it. I wiped everything down that I thought might have a little oil on it. <br /><br />Afterwards, I saw absolutely not oil. I guess it is going to take a little more time.<br /><br />I will keep checking.<br /><br />Thanks again.