4.3 oil level reading over full

[4jh1zz]

Just replaced 4.3 motor (rebuilt) . The dip stick shows approx 1/2 inch over full. The mechanic that replaced the motor said he always put a quart extra in for brake in period. Has anyone ever heard of this or is it BS. Just before the last motor froze up I was getting fluctuating readings.

[mcoffey]

I have never heard of this practice before though I guess it is plausible. It is common for a new engine to burn a bit of oil until the piston rings seat in. I personally have never seen one burn a whole quart though.
I have probably replaced 20 engines in my time from various rebuild companies and we always just kept an eye on them and added oil as needed.

With that said, I also have never seen 1 extra quart cause any damage to an engine this size. I am familiar with the 4.3 in a S10 and Astro and they hold about 4 3/4 quarts so 1 extra is not that big a deal. Now add an extra to a small engine that only holds 1 or 2 then you got issues

[seapuppy]

well...as stated...it's not normal.....but it won't hurt anything....but ...and I use that sparingly....keep an eye on the oil pressure...if it runs high...then stop and check the oil levels...if it starts going up for no reason..then you need to smell it for gas...if it starts foaming up and looking like a mocha coffee..you blew a gasket somewhere...

SP

[9Ball]

I hate to disagree but!!!!, no offence to SP but, I have been a Engine Mech most of my life from Gas Eng to diesel, and jet engines. I have NEVER seen any engine manufactures do this…. This not a good idea!!!! The engine engineers "Usually" set the oil level at 1" below the Pan rail of the engine block, if it is too high it could cause foaming and poor oil Lubrication and blowby (the blowby will get sucked into the Carb and cause problems or vent overboard. Not a good idea to run a engine with a QT over full! Just my 2 cents!

Todd

[seapuppy]

9ball....it's ok to disagree.......you are correct about blowby and foaming....however ...we in SCCA racing would run an engine hard and never saw foaming happening...we'd run alot of oil (only cuz we had a sump)...I for some reason was thinking of something else......had to re-read the oringal posters comment.........

appreciate your comments....

and welcome to the zoo...4h...


SP

[ss3964spd]

Complete and utter BS from the mechanic.

The extra oil will do nothing good whatsoever and could possibly cause issues. If the oil level is high enough the spinning crankshaft and connection rods will splash through the oil, causing foaming (aeration). Aerated oil isn't an especially good lubricant.

Piston rings, if the correct cylinder wall finish for the rings is used, should be pretty much seated (broken in) when the engine is first cranked with the starter. If the new engine goes through an extra quart of oil during break in it simply wasn't assembled correctly.

A clarification on the 4.3 though; the crankshaft centerline is exactly where the oil pan rail meets the block, so the correct oil level in the pan is well below 1" down from the rail. Since the 4.3 has a 3.48" stroke, add an extra inch for counter weights, the correct oil level is quite far down

Dan

[seapuppy]

Be nice Dan

Sp

[shrew]

About the only variation on this theme i've heard is some guys who claim they cahnge their oil at the end of the season and leave it one quart low. Then top off the oil in the spring during commissioning. I still have no idea what that would achieve. However, there is a huge difference between 1 Qt low and 1 Qt over. I've heard nothing but bad things when there is too much oil.

[ss3964spd]

Sincere apologies, Steve, I in no way meant to offend anyone at all.

Sorry if my posting came off as abrupt.

Dan

[seapuppy]

Originally Posted by ss3964spd

Sincere apologies, Steve, I in no way meant to offend anyone at all.

Sorry if my posting came off as abrupt.

Dan

no worries....to make a point....(not about you dan)...the oil pan may have a about a half a qt more than is required...the half in. extra on the dip stick is probably about that much oil......now if it were a full inch or more....it could cause airation due to spinning shaft.......
but only a half a qt isn't going to be a big issue...


just an opinion cuz I routinely run my cars at a half qt over at times....

never had an issue....

SP

[shrew]

[QUOTE=4jh1zz;18339] The mechanic that replaced the motor said he always put a quart extra in for brake in period. Has anyone ever heard of this or is it BS. QUOTE]

1 Qt., not 1/2 a Qt. I'm not sure if that makes a difference.

[vffb507]

I must say.. I ended up replacing a 2.8 in a car due to overfilling... Caused frothing and promptly removed a bearing for me.... I thought "it was no big deal" as it was only a little ways over full (can't remember now how much on dipstick)... Pain in the *****... But I did come out of it learning alot about engine tear down, remove and replace.. And a whole lot about engine bay wiring etc!! So looking back it was a good experience, just would been nice to not be so darn inconvienent and semi expensive.. ($1000 during my late college years)

[4jh1zz]

I finished the 5 hour brake in period with the oil reading over full as instructed by the mechanic. I hope I have not damaged anything. I think from reading all the post I should have pumped the oil down to propper level. Changing oil tomorrow with the propper amount going back in. Anyone have a recomendation for the best oil to use. The boat is used mostly in hot weather (70 to 95 F.)

[mcoffey]

Well I am sure this reply will start a debate about "proper" oil and "shearing" of regular oils

I use Amsoil 15W40 Heavy Duty Diesel and Marine. I use it as the Mercruiser 20W40 is hard to find and the places that do have it charge an arm and a leg for it. The Amsoil is full synthetic, meets all Mercruiser specs, is available at many local and online stores and only costs $1 per quart more (did I mention it was full synthetic)

My brother has been using this same exact ol in his 1985 Chapparel 200XLC with the 5.7 4bbl 260HP engine since he got the boat back in 1990. Never had a single engine issue with it so must be working OK

[jamanati]

My $0.02. Run it at normal full level. If it burns while breaking in, then check and fill.