I mistakenly poured coolant (50/50 premixed) into the oil resevour. I drove about 100 miles before realizing that I mixed up the oil and coolant containers. I noticed a lack of accelerating power about fifty miles in and while idling today it has been quite shaky. I had already planned on an oil change tomorrow. I am curious as to what sort of long term damage I may have caused by doing this though and what to look out for.

I plan on draining everything, running a bit of oil through to wash out any remaining coolant, then filling it up with oil. After that I planned on driving 500 miles and doing another oil change. Does this sound like a good plan or should I do something different. Also how much oil does it take for an oil change?

Thanks for helping me out with this bone head mistake.

 

6 quarts including oil cooler and lines. Otherwise 5. Whats an oil reservoir? Yes drain and fill twice as you would do on an auto tranny

 

Thanks for the information. Where you pour the oil into I have always heard referred to as the oil resevoir since some remains in that small area as a resevoir for when oil is used.

What kind of damage am I looked at from the driving I have already done and the driving I will have to do to go to the hobby shop on base (about three more miles).

 

Honestly, i would have suggested stopping right where you were when you found out about the mix up and having it towed home and not driving it again until everything was flushed out. Your engine could be messed up as it is, driving 3 more miles may blow it up 100%.

 

I figured it out after parking tonight. It's that severe that I can't drive it the three miles to be able to change the oil?

 

You were boiling water in your fuel. I am surprised you made it 100 miles.

 

So tow it to the shop, run a ton of oil through it. What kind of damage am I looking at and what kind of am I looking at? I'm not sure if I was too clear but there is oil in the engine. I was topping it off when I did this and poured I would estimate less than a quart of coolant into the engine. More likely half a quart.

 

Yah, that changes things lol, i thought you meant full of coolant, i was kinda surprised it was even still running. Even if its not that much, i would suggest not driving it, but thats just my opinion. I dont know the potential dangers of that much coolant in the oil. Ill wait for someone else to chime in.

 

That's a relief that my situation might not be as bad as previously thought.

 

I doubt there's any problem at all, a little water and ethylene glycol in the oil shouldn't cause any trouble over the short run, it would just separate out as a second phase when the engine is cool and mix into an emulsion when it heats up. But even the emulsion should still retain fairly good lubricating properties so I don't think you'll have any problems.

Just do as you planned, drain the oil really well (you should see the coolant come out first when you open the drain plug). Then replace the plug, add a quart of oil, then turn the engine over for a few seconds without starting it (you do this by disconnecting the spark plug wires). That will rinse the inside of the engine with fresh oil to remove any residue of the emulsion. Drain that quart of oil, if it looks really grungy you might want to repeat the procedure until the drained oil looks clean.

 

With only a small amount of coolant in the oil you may be ok. There's no way to predict the amount or extent of damage. Oil creates a film between moving engine parts, lurbicating and reducing friction. Take that away and as the friction builds heat, the clearances between moving parts becomes less and less building more and more heat. It breaks down the metal surfaces until something galls, siezes and breaks. Water and coolant do not mix with oil. You could have lots of tiny pockets of coolant all through the engine and system that will be hard to flush out.

If you haven't noticed any loss of revs or acceleration, again you may be ok. It may have not been concentrated enough to get in and displace the oil in critical areas. Sometimes damage can be very slight which only becomes more serious over an extended time. Not bad enough to cause a catastrophic faliure, just reduce the lifespan of a component. The sooner you get the coolant out, the better. You may want to replace the oil and run it 5-10 miles then repeat. Change the filter too.

 

Best case, you just accelerated your wear a small amount, much like letting your oil go way too long without changing. It may mean the engine will ultimately wear out 6 months or a year earlier, or might have no lasting effect.

Worst case, you sustained some bearing &/or seal damage from lack of lubrication, and have compromised the engine mechanically.

No real way to tell until you correct the situation; the loss of idle stability is worrisome.

If your engine temps remained reasonable & the car's not acting too weird, you probably didn't hurt things too much. Now that you know what happened, though, you want to correct it ASAP without adding any more runtime to the motor.

Definitely drain the oil system thoroughly & change the filter, refill, run up to temperature one time, then drain and change again for safety sake. There's always trapped oil that doesn't come out in just one oil change, & you need a few minutes' run time to push new oil through all the passages, especially the metering pump and its lines.

Use a flashlight to inspect your filler neck and if there is water-based crud built up in there, clean it out manually before changing the oil.

I didn't see your model mentioned, but if you have a front-mounted oil cooler, I would strongly consider removing it & draining it separately. The oil cooler only opens under higher-temperature conditions, the rest of the time it's bypassed by a thermostat at one end. Because it spends a lot of time mostly closed off, all manner of crud collects in there & it doesn't drain at all under normal oil-change conditions.

Other than that, all you can do is see where you stand once you've fully exchanged your oil out. If you don't have an oil-pressure gauge, you might consider getting a pressure check after all has been flushed out and filled - that will tell you if your bearings or oil pump were damaged.

Good luck.

 

It is an 81 GS. The only time the temperature rose when hitting 90+. I have an oil pressure gauge, what is a healthy oil pressure? I am pretty sure I have an oil cooler, how do I go about cleaning it?

 

Also there is only 63k miles on the original engine, does that lower the chance of significant damage? I hate that I have done this to such a great engine.

 

Also would you guys suggest having my engine flushed before changing the filter and adding oil?

 

I dont see how its even possible to mix up where oil and coolant goes!

 

You need to read his post more carefully. He didn't put it in the wrong opening, he accidentally switched his oil and coolant containers.

James if you want to do a quick job and save oil, do it the way I suggested. But also change the oil filter, which I forgot to mention, and check the oil every hundred miles or so to see if there's any residual emulsion on the dip stick or around the oil filler tube. If so, do another oil change.

If you want to do a thorough job, follow DD's instructions. I would recommend DD's method, just to be sure.

Healthy oil pressure depends on the gauge and a few other conditions, but on the stock gauge with the engine revving it should be around 60 lb. per square inch.

 

I plan on doing the best thing possible no matter the price. I would rather pay the money for extra oil and filters than for a rebuild. My oil pressure is normally just over 60, since this happened slightly more but not an extreme amount.

How do I drain and clean the oil cooler? thanks for all the help guys.

 

If you have a Front-mount cooler (I'm not sure if 81's still did or not) you'll see two braided hoses leading from the left side of the engine to a device below the radiator that looks like a smaller radiator. Tha'ts the front-mount oil cooler (FMOC, for short).

The only way I know of to clean it is to dismount it, place it in a pan on end and let it drain completely dry.

If you don't have that device, but instead have what looks like radiator fins below your oil filter, then you have what's known as a 'beehive' oil cooler, and you won't need to worry at all about draining it.

I tend toward overkill on procedures - - I'm an engineer by trade and therefore professionally paranoid - - if your pressure is still good (~60psi at road speeds) and you don't see frothing or weird milky stuff on your dipstick after the first change of oil & warm-up, you're probably fine.

 

The FMOC has large plug on the bottom that holds in the oil thermastat. I belive it can be removed and the oil drained without taking the entire cooler off the car.

I would change the oil with something cheap the first time while keeping the current oil filter on the car. Start the engine and bring the oil up to temp so the oil thermstat opens. I would then drain the oil and change the filter. This time use your normal quality oil. Run it for a day and then change the oil and filter again.

 

I drained the oil, cleaned out as much of the emulsion as I could from the feed neck. The dipstick had a good amount of emulsion on it and cleaned it off. I replaced the oil with my usual oil and cranked. She idled rough while warming up, gave off some white vapor from the exhaust as well as emitting some clear liquid which I assume was the coolant. After heating up to operating temperature the idle smoothed out and stayed at 1k (my usual) with a very slight wobble to the needle but still staying on the steady bold 1k tack mark. My oil pressure was roughly 40-45 while idling at 1k and 60 when I pulled the choke out a little and let it go to 2.5k rpm.

I was not able to let it cool to check for more emulsion due to the auto hobby shop closing. I checked the dip stick and it was clean however I would imagine that when warm I wouldn't see the emulsion any way. It opens back up on Friday and I will check for more emulsion, drain and refill again and replace the filter. One of the workers at the shop suggested I do a flush on it however I do not trust them too much. What do you guys think of doing a flush to try to get rid of more emulsion?

 

What do you mean flush?

 

I would also suggest using a product called sea foam. You dump in your oil run it for a Lil a while then dump your oil. Its actually a whole treatment that you split between you're fuel Tank, oil and run some through your intake manifold. But it helps absorbs moisture all out should soak up any water or coolant left in the engine

 

If you can do it for you for free but I live near Dodger Stadium but please check on the west forum for locals; Im sure Alex Rodriguez can recommend someone from your base.

Dont flush it as pressure can cause damage to the internals. Instead, just do drain and fill 2X as I noted previously and adding a seafoam to your oil per 007FC is not a bad idea at all; I hope you know where the filler is by now lol.

 

I ran new oil through it several times, did a full oil change. She is now running very well with good oil pressure . Thanks for all the help guys.