Stupid Oil Overfill Incident

Inniswhe · 05-25-2010, 06:28 PM

I had my oil lines/tank drained and removed to refinish the tank and paint my 84 911. Car was put back together and I refilled the oil tank. This is where I did something stupid.

I thought that with the oil lines removal I would have had the oil basically fully drained so I put 11quarts ( I believe an 84 hold 13 quarts total) before I started the car which I now know is too much. It has been 18months since I drained so memory has faded . I am pretty sure I drained everything though.

I only ran the car for a couple of minutes but it appears oil overflowed out the filler neck I believe and ran onto the floor in my garage. I can see oil in the filler neck with the cap removed so it is obviously overfilled with lots of evidence of oil spillage in the area.

I am wondering exactly what would have happened here. Is it a case of air in the lines to the oil cooler causing my levels to be too high .

I never got any smoke so I am not sure if oil was sucked into the airbox. I am cleaning up the mess and will have a look in the airbox to see that was carried over.

Do I just drain some oil out and fire her back up, let her warm up and recheck the levels/top up after a proper warm-up ?

newms · 05-25-2010, 06:41 PM

I would assume that until the thermostat opens your lines and cooler are empty. Perhaps you can warm it up until it opens and then check level... likely need to add that 12th and 13th quart.

John W. · 05-25-2010, 07:13 PM

Did you remember to drain the crankcase - sorry for asking?

vash · vash's Garage

Quote:

Originally Posted by john w.

did you remember to drain the crankcase - sorry for asking?

this?^^^^

89cab · 89cab's Garage

If the oil sending unit was removed it could of failed or was bent when reinstalling back into tank.This would give you a false reading at your gauge.I hope this helps.

Inniswhe · 05-26-2010, 03:13 AM

I am quite sure that I drained the crankcase oil at the time ( 18 months ago). The thermostat being closed is what I also suspect is the issue.
A 13L oil capacity less 3L that is held in the oil cooler piping circuit = 10L in the engine/tank. I put in 11L so the bulk of the extra liter in now on my floor .

I did install a new oil sending unit and it appears to be operating as it is showing full to the max. I can see the oil in the filler neck so I think I need to drain about a liter out which may be messy. I may see if I can get a cheap manual vacuum pump to suck it out.

I just hope there wasn't a bunch of oil sucked into the intake.

boxster03 · 05-26-2010, 03:55 AM

U should work for BP

Winter · 05-26-2010, 06:20 AM

Why don't you drain all the oil - everything - and start over? At least then you can keep a tab on how much you've put into the car. Oil is cheap, but perhaps you can reuse what you drain to save a buck or two.

Good luck.

---

Tom '75 targa

NoLift911 · 05-26-2010, 06:27 AM

I did the same thing to my 84 (minus the oil spill and overfill) I removed my lines and oil cooler for a refurb (they hold a few quarts) and on the refill figured the thermostat would not open till it got hot so I did not add in a ton of oil to compensate.

I only put in 10 initially (10.5 is what I normally do on a oil/filter change) after all drained - ran the car until it got hot - checked the level and slowly added 2.5 more quarts. Seemed to work out. I think one more hot/cooldown cycle and I will be back to where I was.

Forza · Forza's Garage

Quote:

Originally Posted by Winter

Why don't you drain all the oil - everything - and start over? At least then you can keep a tab on how much you've put into the car. Oil is cheap, but perhaps you can reuse what you drain to save a buck or two.

Good luck.

---

Tom '75 targa

+1 start over

BoxsterGT · 05-26-2010, 10:02 AM

The engine will run w full pressure with 8 quarts in the system, so drain a couple quarts out, clean up the mess & run it until warm.

The important part is the oil level when fully warm & the t'stats open.

In the summer heat, don't fill above the half way mark on the dipstick.

Above this on a 90 deg day usually results in "Mosquito control".

BTDT

Len

Inniswhe · 05:51 PM

I went back tonight to try and sort out the mess. I removed 1.5 liters of oil initially and checked the dipstick ( cold) and the level was down on the stick ( still near the full mark).

I then started the engine. It started to smoke right away. Last night when I ran it for only a couple of minutes I had no smoke just oil in the compartment and the floor.
I let it run tonight for a few minutes but it smoked a huge amount . I hoped it would clear up but no luck . It started to run rough as I assume the spark plugs are fouling.

I shut it down and noticed the oil level rose on the stick so I removed another 1.5 L so now I have 8L in the engine. There was no longer overflow when I ran it tonight but I doubt the engine warmed enough for the thermostat to open so I suspect there will be a significant drop in oil level when it does.

Now what do I do to address the smoking issue? I looked through the Bentley to try and figure out where the oil gets drawn to . There are three oil lines off the top of the tank but I could not find much info in the bentley book about the routing. THere are two large lines that I understand are breather lines and a small line with what appears to be a vacuum diaphragm attached. All three lines lead in behind the air intake.

Do I need to remove the airbox assembly and try and remove all of these lines to clean them out . Is there a standard approach to dealing with this. I really hope I have not done major damage like damaging the main seal which I read can happen with an overfilled engine.

Any help is appreciated and I will continue to read the archives.

Vincent Hill · Vincent Hill's Garage

The Extra Oil is in your Airbox. Pull off the air filter lid anc clean out the box and then when starting it up, Spray carb cleaner which will pick up the oil and burn in the engine and in a short time SHOULD Stop smoking!

NoLift911 · 05-27-2010, 08:29 AM

I doubt you damaged anything - its just a mess. X2 on the airbox removal and cleaning - you will see where the oil is...

BoxsterGT · 05-27-2010, 09:56 AM

Thoroughly clean the intake box, pull your muffler & run the engine.

Most of the smoke will be gone in minutes, as the oil ended up trapped in the muffler.

Once you are sure the engine runs clean, put on the muffler and take a nice long drive out in the country where the mosquitos are thick.

In ten mins all will be back to normal.

Len

Inniswhe · 05-27-2010, 12:02 PM

I removed the air filter exposing the interior of what I believe is referred to as the the air box. It is clean and dry.
Maybe I am not clear on what others call the "airbox".

I believe the inlets from the oil tank ( both overflow and ambient air line are downstream of the airflow sensor in the throttle body are they not ? It is hard so see in there as the connections are on the backside.