buellrunner

Hey all,

I just got my 90C2 back from the mechanic after an oil change. I noticed that when hot, the oil level gauge slowly makes its way to the top of the level, and then very slowly moves past the full mark (only 1-2mm past).

I guess they put a bit too much oil in the engine....

Can this cause damage to my engine? I really don't feel like draining out oil....
being a dry sump system, I figured that an over or slight under fill would be fine..

Any help would be cool..

tbennett017

I am pretty sure you can siphon or draw oil out of the tank filler with a hose and a pump. (loonnng turkey baster) The oil level gauge is very sensitive, and 1/2 quart might bring it into spec.

There is lots of discussion here on an overfill situation.. Do a search.

Christer

Most of the time when my car has been serviced, the oil level goes to the top or thereabouts when very warm...I have never had a problem personally...so if you don't notice any oil being thrown back out, I would just not worry about it....there must be other things to worry about right?

Indycam

An overfill is not good , the oil can get into the intake and get into the cylinders .
When this happens , your car will blow great big clouds of smoke and the engine can knock badly .
The stress on yourself and the motor are something to miss .
If you put an oil drain pan under the oil drain plug and just crack the drain plug , oil will drip out . If you watch the amount of oil that ends up in the drain pan over time you can snug up the drain plug when it looks to be about one quart .

buellrunner

Hey Indycam,

This doesn't sound very good at all...Even a little overfill can cause this type of problem? A bad knock?

Not good...

boxsey911

The best tip I heard recently about rectifying an overfill came from 'Computermedic' (Dave). When the engine is cold drain, from the engine plug as you'll only get a small amount come out (unlike if you undo the oil tank drain plug ). Then just put the required amount back in when you warm the car up to operating temperature.

TR6

Check your dipstick (with the engine fully warmed and running). If it is just at the high mark on the dipstick or even just a hair over, I don't think you'll have a problem. And at that level, the gauge would be reading full. It might just be the difference between the oil being all the way full vs. truly overfilled.My only concern/question about this method is that if you drain all of the oil out of the engine case, when you start the car, will this cause oil starvation to the bearings, etc, until oil is pumped from the tank back into the engine? Of course, I guess this is no different than when you change the oil, right? After an oil change, is there no oil in the bottom of the engine case until it starts pumping from the tank?

boxsey911

I also assume it's the same as doing an oil change but without draining the tank aswell. The guy that it was recommended it to (who also had experienced the overfill problem) found it worked for him.

But I guess with less volume in there (and it being cold) you could probably just drain a little off to be on the safe side.

Indycam

"will this cause oil starvation to the bearings, etc,"
It will not .
The oil tank is where the engine oil pump , pumps from .
In a dry sump system , an oil pump pumps the case "free" of oil . That oil pump is a scavenger pump . It sucks oil from the case and puts it into the oil tank . The oil pump that oils the engine feeds from the oil tank .

Indycam

I would use the drip method from the drain plug behind the shark fin because its easy to get to and the drain pan is where you can see it .

GG Allin

That happened to me at an autocross a couple years ago. I thought I had blown my engine.

Indycam

"I thought I had blown my engine."
Exactly how sick did you feel at that moment ?
What thoughts / curse words were going on in your head ?
How long till you were ok again ?

GG Allin

Well, I shut 'er down right away. Went around back and saw oil dripping from the exhaust. At that point I went looking for my mechanic. Figures from 5 to 10K were running through my head. I even consulted Rennlist before I found out what happened.

https://rennlist.com/forums/964-forum/201230-smoke-and-oil-coming-from-exhaust-pipe.html

Indycam

"Even a little overfill can cause this type of problem?"
Yes . The top of the oil tank is vented to the intake . If the oil sloshes into the vent hose , the oil gets sucked into the cylinders .
I run my oil gauge at the bottom of the ok range when the motor is very hot .
With the needle at the bottom of the ok range , I know I have plenty of oil , putting in more than that is not going to make anything better .

"A bad knock?"
Motor oil has a low octane number , so when you try to burn it , it sounds like an old diesel .
Its not a sound you want to hear from a freaking expensive motor .

"saw oil dripping from the exhaust."
Ouch ! That had to hurt .