Over fill with oil

[PH4]

What are the consequences of adding too much oil (overfilling) a 2.25 engine? What, if any, damage may result? Answers appreciated.

[vansdonk]

I have always heard that over filling oil is almost if not worse than not having enough oil. Probably wrong on this. An old MG mech said that they put those lines on the dip stick for a reason. And they call it a dip stick for a reason....LOL I would try to stay as close to max as I could.

[PH4]

I have a brand new engine that my mechanic installed and may have overfilled with oil to the point it is spraying under acceleration from the oil filler breather cap. It has less than 400 miles on it and I want to know if it could have possibly harmed/damages something. I am not happy as it is a brand new engine.

[Donnie]

I have a brand new engine that my mechanic installed and may have overfilled with oil to the point it is spraying under acceleration from the oil filler breather cap. It has less than 400 miles on it and I want to know if it could have possibly harmed/damages something. I am not happy as it is a brand new engine.
it should leak out soon, no really a little over full will not cause problems unless it is high enough to get churned by the crankshaft, in which it will foam up, that it pick up air bubbles then your lube quality will diminish.... if U R of major concern, just drain some out >>>>>>>>>>>..

[Jeff Aronson]

If you have a rebuilt engine, it will be quite tight and thus might force oil out at a greater amount. I'm still surprised that it's backing up through the oil breather, though; just how much above the dipstick is the oil level? Oil coming up that direction is usually problem with crankcase ventilation. Is there a PCV valve on the motor? Is it hooked up correctly?

If it's more than 1 quart, I would just open the oil pan drain plug and drain out the correct amount. If it's not much above the dipstick level, I would have your mechanic check out the engine.

Good luck,

Jeff

[ArlowCT]

Is there a chance that the baffle between the block and fill tube was not installed? Not having this may lead to oil spraying out the filler tube. Hope it all turns out OK.

[PH4]

There is no PCV valve on the engine and the baffle was installed on the engine. I am a bit perplexed.

[Jeff Aronson]

How much extra oil is in the engine? Can you infer it by the dipstick markings? What happens when you have to correct amount of oil? Does it still push oil out the breather cap?

Jeff

[PH4]

We have checked and double checked the oil level. It appears to be occuring when truck is going above 30mph. Mainly occuring when traveling 55mph. Last Thursday on way to 45 minute trip oil caught on fire on the exhaust manifold. Fortunately, if you can use that term, it was small and able to be put out with a can of soda. The mechanic has checked and double checked the baffle and he says it can only go on the engine one way. It is shooting oil from vent cap on valve cover and vent cap on oil filler. I am extremely displeased as this is a brand new/rebuilt high performance engine. The seller of the engine(not RN as at the time they only had one engine complete with all ancillaries) has no idea why this is happening. Any help much appreciated. My mechanic also installed the exact same engine on my friends truck at the same time with no problems. Any and all help, is as always, greatly appreciated.

[49coe]

If you are blowing oil out both vents, my first thought would be an extreme case of blowby. A leakdown test may provide you with some answers, or at least rule some things out.

[PH4]

What is blow by?

[SafeAirOne]

What is blow by?

Blow-by occurs when combustion air from above the piston is not properly contained by the piston rings and "blows by" them into the crankshaft/sump area of the engine and then out any orifice leading to the sump area, such as the oil fill tube and breather.

Out of curiosity, are you sure the oil is coming from those areas? There's a member of this board who seemed to be having the same trouble (minus the fire), but the oil turned out to be coming from the distributor base/shaft orifice.

[PH4]

I am pretty sure it is coming from both the oil filler tube and the vent cap on the valve cover. Would a compression check show anything? Either it was installed incorrectly or I was sent a bad engine. I need to figure out which one. If the baffle was installed correctly, what if anything could it be other than a bad engine?

[Jeff Aronson]

A compression check might help answer some questions; basically, you want to see even compression at each cylinder - maybe around 120 - 130 lbs. If you had a bad cylinder, the compression would be either much higher at one or much lower.

IF the oil is coming out through the breather cap, then the problem has to be with crankcase pressure. Are you sure you don't have a crimped oil delivery line at the back of the head?

If the oil is being forced out only at higher rpm, that would further lead to the question of what pressure is buillding up and why. Have you ckecked the oil pressure valve at the oil filter? Have you checked the oil pump inside the oil pan? If the release valve inside the pump is not working, then you could build up too high a pressure.

Also, your installer should hook up an oil pressure meter to determine the oil pressure at the filter. It should be no more than 40 psi at warm startup, 60 psi at highway speed when cold, reducing to 40. At hot idle, 20 psi is common. If your pressure is much higher, then you've helped narrow down the likely causes.

When the mechanic removes the oil pan to look at the pump, he should check the bearings, too. It's rare that engines are so tight that oil gets overly pressurized as you're implying.

Good luck,

Jeff

[49coe]

A compression check will only tell you if there is something amiss with a cylinder, not what the problem is. A leakdown test works by putting the piston at TDC and then blowing compressed air into the cylinder through an adaptor that goes in the sparkplug hole. It has a guage that will tell you how fast the air is leaking out of the cylinder, i.e. alot of leakage = problem, not much = fine. The test has an added benifit of showing where the leak is occuring by listening where the air is escaping. Sound of air leaking in oil breathers = rings, cracked piston, or blown headgasket to an oil galley; Carb = intake valves, exaust= exaust valves, radiator= blown headgasket to waterjacket, etc. Good luck.

[Jeff Aronson]

You're quite right with your procedures and with the conclusions they would help you reach. However, if you don't do the compression test, you don't know whether to take the next step with a leakdown test; I just wanted to recommend getting that diagnostic process started.

Perhaps all I'm suggesting is that there's an anomaly here - something is causing high crankcase oil pressure. So I'd be looking for a cylinder[s] with excessively high compression to see if that helps with a diagnosis.

Has your mechanic read the oil pressure in the engine yet? Does it exceed normal limits under higher rpm?

Jeff

[LaneRover]

I say look for a crimped or semi blocked oil return line which would be very quick and pretty easy I think.