1989 4.3 litre v6 vortec mercruiser 4 stroke using lost of oil

[Josh.officer]

Hi, my old mans sea ray seems to he using lost of oil, for a for stroke I thought this seems strange as it must be getting used because it's not leaking anywhere, the rebuilt engine would of been lucky to do 50 hours, I put a litre of motor oil in prior to Christmas and 3 weeks later and a few long days boating And the dip stick so dry almost, so il add another couple of litres and it just goes on


Please help

 

[Walt T]

Re: 1989 4.3 litre v6 vortec mercruiser 4 stroke using lost of oil

Pull spark plugs and check condition. Compression test too perhaps.

 

[airdvr1227]

Re: 1989 4.3 litre v6 vortec mercruiser 4 stroke using lost of oil

Most likely it's not burning that much oil or you'd have a blue cloud from your exhaust. It's leaking from somewhere.

 

[alldodge]

Re: 1989 4.3 litre v6 vortec mercruiser 4 stroke using lost of oil

Hi, my old mans sea ray seems to he using lost of oil, for a for stroke I thought this seems strange as it must be getting used because it's not leaking anywhere, the rebuilt engine would of been lucky to do 50 hours, I put a litre of motor oil in prior to Christmas and 3 weeks later and a few long days boating And the dip stick so dry almost, so il add another couple of litres and it just goes on


Please help

What kind of boat is it?
Would it happen to have an oil cooler, not a power steering cooler but an oil cooler?

 

[Scott Danforth]

Re: 1989 4.3 litre v6 vortec mercruiser 4 stroke using lost of oil

Welcome aboard.

what kind of boat? when your boating, are you idling along, or traveling at WOT?

you state it is a fairly new motor, how was the break-in done? was it a complete rebuild?

What grade of oil are you using?

if the motor was not properly broken in, the rings could have not seated correctly. that would burn a bit of oil.

if the oil is thinned due to a failing fuel pump, that would cause it to burn some oil.

 

[Josh.officer]

Re: 1989 4.3 litre v6 vortec mercruiser 4 stroke using lost of oil

hi thanks for all your help. the boat is a 1989 Sea Ray Cuddy cabin, spark plug dropped through the piston at WOT A few years back, bought a second hand V6 Vortec 175 HP and married the two motors together new power heads pistons rings lower unit, gearbox, thermostat and gear linkages,had an electric fuel pump put in we had trouble with cold start, and the mechanic took out the valve from he fuel line to the carb thinking that was the problem but now the fuel drains back into the tank so the fuel pump pumps it back in to the carb, complete rebuild basically, newish spark plugs, i thought it must be leaking to but the motor is clean and so it the bottom of the hull were the billlige pump is so im sure its not leaking we use Caltex Havoline Synthetic Blend SN 10W-40 4L
• Havoline with Deposit Shield • Synthetic blend • SAE 10W-40 API SN oil, dads not concerned about it saying that ist doing alot of work and its normall for it to use alot of oil doing alot of work, but im not convinced

 

[Silly Seville]

Re: 1989 4.3 litre v6 vortec mercruiser 4 stroke using lost of oil

Color me confused, but a healthy 4-stroke engine does not eat or leak crankcase oil. There is something terribly amiss with your engine. Your dad SHOULD be concerned, or he may be replacing the engine again very soon!

 

[Bondo]

Re: 1989 4.3 litre v6 vortec mercruiser 4 stroke using lost of oil

Ayuh,.... Welcome Aboard,... Yer the cylinders honed when it was rebuilt,..??

Has it been run, Hard, to break-in the rings,..??

If it's passin' the oil, the spark plugs should show it with their colors,..

 

[Josh.officer]

Re: 1989 4.3 litre v6 vortec mercruiser 4 stroke using lost of oil

yes i am quite concerned, will take spark plugs out in the weekend and check them. i believe the cylinder and walls were honed when it was rebuilt

 

[alldodge]

Re: 1989 4.3 litre v6 vortec mercruiser 4 stroke using lost of oil

hi thanks for all your help. the boat is a 1989 Sea Ray Cuddy cabin, spark plug dropped through the piston at WOT A few years back, bought a second hand V6 Vortec 175 HP and married the two motors together new power heads pistons rings lower unit, gearbox, thermostat and gear linkages,had an electric fuel pump put in we had trouble with cold start, and the mechanic took out the valve from he fuel line to the carb thinking that was the problem but now the fuel drains back into the tank so the fuel pump pumps it back in to the carb, complete rebuild basically, newish spark plugs, i thought it must be leaking to but the motor is clean and so it the bottom of the hull were the billlige pump is so im sure its not leaking we use Caltex Havoline Synthetic Blend SN 10W-40 4L
• Havoline with Deposit Shield • Synthetic blend • SAE 10W-40 API SN oil, dads not concerned about it saying that ist doing alot of work and its normall for it to use alot of oil doing alot of work, but im not convinced

Sounds like your mechanic may have removed the anti siphon valve, and if so it needs to be put back in

 

[Josh.officer]

Re: 1989 4.3 litre v6 vortec mercruiser 4 stroke using lost of oil

yeah, that does need to happen, sttill doesnt solve this dam oil problem ! weathers supposed to be good in the weekend, and im not going to use it if its harming the motor !!!!

 

[dazk14]

Re: 1989 4.3 litre v6 vortec mercruiser 4 stroke using lost of oil

What is the air temp you are working with?
10w-40 is likely to burn more oil and thin out quickly - reed shear.
Merc oil is 25w40 and would be better.
Chevron Delo 400 Straight 40wt is excellent depending on temps and can often drastically reduce oil consumption,... while improving oil pressure, which can be an issue with rebuilds where the new bearings aren't fitted properly.

Edit: If you don't want to completely change the oil, then add Lucas stop leak - in addition to topping with 40wt.

It's about a quart and has a viscosity improver (read high wt) and also helps to rejuvenate worn valve seals - although with 50 hrs it certainly shouldn't need it.

 

[Josh.officer]

Re: 1989 4.3 litre v6 vortec mercruiser 4 stroke using lost of oil

I can t from memory tell you the oil pressure or temp but I do have some Lucas stop leak sitting in my garage that I bought a while ago will put that In on Saturday, take it out for the day and I will completely drain the oil and replace it with the brand that you recommend

 

[dazk14]

Re: 1989 4.3 litre v6 vortec mercruiser 4 stroke using lost of oil

I can t from memory tell you the oil pressure or temp but I do have some Lucas stop leak sitting in my garage that I bought a while ago will put that In on Saturday, take it out for the day and I will completely drain the oil and replace it with the brand that you recommend

Looking for air temps, not engine. You may as well give seawater temp as well.

 

[alldodge]

Re: 1989 4.3 litre v6 vortec mercruiser 4 stroke using lost of oil

I don't see the weight of oil would cause what your experiencing. Both oils are 40W when engine reaches temp and your using way to much for it to be an oil issue. Break in periods in most cases suggest non-synthetic oil for first 20 hours then shift to synthetic, but this would not cause what your seeing IMO. Stop leak stuff is snake oil in most cases and are mainly sold to folks who have old engines which are trying to get some more life out of an old motor.

As Bondo mentioned pull the plugs and advise what you find.

 

[dazk14]

Re: 1989 4.3 litre v6 vortec mercruiser 4 stroke using lost of oil

Pulling the plugs is always a good idea.

10w-40 in a marine engine, will not be 40wt for very long. It will get thin fast.

Snake oil...I know what's in the Lucas and specifically specified the Lucas. It sounds as though you do not know the product.

 

[Josh.officer]

Re: 1989 4.3 litre v6 vortec mercruiser 4 stroke using lost of oil

Will pull the plugs this Saturday take some photos report what I find, what does anyone actually think it could be ? The motors next to knew !?

 

[alldodge]

Re: 1989 4.3 litre v6 vortec mercruiser 4 stroke using lost of oil

Will pull the plugs this Saturday take some photos report what I find, what does anyone actually think it could be ? The motors next to knew !?

With that kind of oil loss I would lean toward broke rings or someone forgot to install valve seals when assembling the head.

 

[aerobat]

Re: 1989 4.3 litre v6 vortec mercruiser 4 stroke using lost of oil

10w-40 is likely to burn more oil and thin out quickly - reed shear.
Merc oil is 25w40 and would be better.
Chevron Delo 400 Straight 40wt is excellent depending on temps and can often drastically reduce oil consumption,... while improving oil pressure, which can be an issue with rebuilds where the new bearings aren't fitted properly.

please be very careful on giving such hints ... like stated above a 10w-40 is at operating temperature nor thinner neither thicker than a 25w-40 and with putting thicker oil inside you deal with a long time since the thick oil reaches critical engine parts to be lubricated.

there is a reason why the world developed multiviskosity oils and we do not use oils like 50 years ago. and uncounted boats run 10w-40 without any issue...

i promise just putting 25w-40 will not solve the problem of the op.

@josh : you must clarify at any cost if your engine is leaking or burning oil - that are two different stories ! are you sure you read the dipstick correctly ? a very high oil burn should result in blue smoke.

i recommend you a quick test - start the engine and pull off the oilfill cap. do you see/feel a strong blowing out of the oilfiller when the engine idles ? (blowby...)

cheers

 

[Josh.officer]

Re: 1989 4.3 litre v6 vortec mercruiser 4 stroke using lost of oil

New oil filter and a thicker grade of oil seemed to have done the trick, thank god will monitor it though, thanks guys for all your help