Mechanics: What happened to my car?

Factual Questions
1

Ok, I’m sure everyones is sick of me and questions about my car. Oh well. Some of you may remember a few weeks ago I asked about an itermittent oil pressure warning light and what I should be doing about it. Well, I’ll tell you a story:

Before I went on vacation, I was on call everyday. Even though I knew I should’ve been taking my car in to be looked at, I didn’t. I went on vacation and the person who was housesitting for me was given my car. A week into my vacation I get an email saying the car is running really rough, check engine light is on, blah blah blah, so I tell him to park it. Fast forward to when I get back to town. Car starts up, but sounds kinda like it’s running on only 3 cylinders. “Uh oh”, I think to myself, “I really should’ve got that oil light thing checked out”. So I drive it directly to my mechanic’s and leave it there, expecting very bad news.

The next day they tell me it’s ready for pickup. So I pick it up. They tell me that the crankcase was full of water (not coolant, water) and gas. 10.5 litres of it. The car was running rough because the friggin crank was trying to run submerged. They drained it, replaced the spark plugs and oil filter, did an engine flush and refilled the oil. They don’t know what caused this. They suspect frozen PCV valve or something. Can anyone tell me what likely caused this and what I should do to prevent it happening again? How much life have I taken off this engine because of this?

The car:

1998 Toyota RAV4 AWD 136,000km
I live in the arctic and most trips are short (meaning the engine probably barely thaws out)

Ideas?

2

Oh yeah, that’s easy:

And there’s your cause. Moisture from the air condenses in the engine, and the engine never gets hot enough to evaporate it out. It just builds up. Gasoline condenses in the engine as well.

That’s easy too. Run the engine long enough to fully warm up and evaporate the moisture and gasoline. That, or move south.

ETA: Change the oil more often than the standard recommended interval. Your climate provides a particular extreme of “severe service” for the engine oil.

3

While I don’t dispute your automotive expertise Gary T, I can’t help but wonder why the shop has never seen this condition in a vehicle before when most people drive their cars in the same manner as I do. Well, I might have more frequent late night short drives to the hospital (on call, tired, car is plugged in but only warmed up ~1min before going). Is it possible that there’s some other contributing thing going wrong to make this failure so extreme? I will now warm the car up (maybe leave it on while I’m working in the middle of the night) and check the dipstick to make sure the oil level is not inching up on me. I should get a remote starter, but no one here will install it.

4

Not only that - 10.5 litres of condensate? That’s nearly 3 US gallons. And why hasn’t it been a problem until now? I’m going for one or some bad seals* in the engine block.

  • yes, I know there are good seals in the arctic too
5

I hate to bear bad news and all that, but if you’ve accumulated 6 liters or so of oil and water in your crankcase, that car is not long for this world. (I’m assuming that your mechanic drained out 10.5 liters of OIL, water and gas and so there was only about 5-6 liters of “extra” material). A little bit of watery/gassy sludge is normal on a car that gets driven on short trips in cold climates, but to accumulate liters and liters of the stuff, you must be getting an enormous amount of blow-by past the piston rings. On a modern FI’d car, there’s no gasoline at the PCV valve, so I think that’s unlikely.

I suspect that your compression is likely just barely above the acceptable levels and putting in fresh oil sealed the rings up well enough for it to run again, but it’s just delaying the inevitable. A compression test will likely confirm this. Also, continuing my gloom-and-doom theme, if it was run for any length of time with a lot of water and gas in the crankcase, the bearings are likely toast. The arctic temperatures will keep the oil thick enough to keep the oil pressure up for now, but come summer you’ll see a lot more of that oil light.

6

I was afraid of that, GreasyJack. It starts right up right now and idles and runs smoothly. It does sound a little different than it used to. We’ll see what happens when it gets warmer.

EDIT: You’re right in that it was 10.5 litres total of a shitmix of oil, water and gas. Although the guy who was looking after it put an extra litre of oil in when he saw the oil pressure light come on, and it was already slightly overfilled to begin with. We’ll see, we’ll see.

7

My initial reply was hasty. I’ll shed as much light as I can, but the bottom line is I have never encountered that much extra liquid in a crankcase, and I can’t say I have a definitive explanation.

Given that the normal oil fill is about 4.5 liters, that total of 10.5 is mind-boggling. I don’t recall ever seeing both water and gas mixed in with crankcase oil, but I can’t think of any reason why it couldn’t have both.

Here is what I have seen:

~Water: the worst case was a car that got stuck on high idle when started in the morning in cold weather. It was towed to the shop a couple of times, and when I got to it it worked perfectly. The third time I ran to it as soon as it was brought inside, and found ice all around the throttle and fast idle mechanism (it was carbureted). On previous visits the ice had melted before I got to it. Came to find that the inside of the valve cover was full of the milkshaky oil/water mix, and the moisture was drawn through the PCV hose to the carb, where it iced up. There was no mechanical flaw in the engine, it was just a victim of cold weather, short trips, and infrequent oil changes. From this I learned that substantial amounts of moisture can condense in, and stay in, an engine under the right circumstances. This was in a climate where it seldom gets below 10’ F (~-12 C), so I imagine the potential is greater where you live.

The only other way I have seen water (not coolant) get into a crankcase is from submersion.

Gas: In the days of carburetors and chokes, it was not uncommon for various faults to result in mixtures so rich that excess gas ran down the cylinder walls into the crankcase. In the worst cases, I’ve seen the oil level rise over 2 liters from this. We would test by touching a lighter or match to the dipstick to see if the oil would flame up for an instant, which would only happen if there was a substantial proportion of gas in it.

While this is much less common with today’s fuel-injected vehicles, it’s still possible to have so much unburnt gas that it dilutes the oil. One of the several possible causes is badly worn spark plugs.

The worst thing to have in the oil is antifreeze, which can erode crankshaft bearings pretty badly. Still, water doesn’t help, and neither does fuel-diluted oil. I have seen engines that had water or gas in the oil go on for years/tens of thousands of miles afterwards, but like I said I haven’t seen one with as much of those contaminants as you’ve described. Even in engines with antifreeze in the oil, some fail shortly after the problem is discovered while some last for a long while afterwards. It’s really hard to make a prognosis.

I can’t think of any further advice to offer at this point. Just keep an eye on it as you mentioned.

8

The amount discussed is bizarre but water in the crank is a regular problem with aircraft engines that sit a long time. The aviation solution is to use an engine block heater which would seem like a good idea for colder climates anyway. I would also use an aftermarket engine treatment such as Slick 50 if your engine is sitting for a long time so all the metal surfaces are coated. Gary T can advise on that.

I’ve seen cylinder walls crack and weep fluid when the engine heats up but that was a Chevy Vega and I’m not sure that qualifies as a real engine. If you did have a head gasget leak then you would smell the sweet smell of anti-freeze in the exhaust. It’s an unmistakeable smell. If coolant were to leak directly into the oil pan it will froth up like a milkshake and that is easily spotted on the oil dip stick.

9

All I got is possibly a clogged pcv valve. If it isn’t functioning it won’t allow the blow by, water vapor or fuel vapor to recycle into the air intake system. Worth a look, as they are easily cleaned with carb spray.

10.5 liters of fluid in your crankcase is extreme to say the least.

10

I should qualify this a bit further. A properly functiong pcv system will “suck” the air out of the crankcase as it is tied to the intake side of your engine.

11

How could 10.5 litres of anything fit in a crankcase designed to hold 4.5 litres (or whatever) of oil? I was under the assumption that the amount of oil you put into your crankcase per your manual is close to it’s capacity.

12

That’s the capacity recommended by the manufacturer. If it is grossly exceeded, then there may be power losses due to the oil being picked up and spun by the crankshaft. Beyond that, the excess oil (or water in this case) may collect in the cylinder bores and forced past the rings and into the cylinders. In the case of the OP, it seems that the excess was oil fouling/water fouling the intake mixture.

13

No. The 4.5 liters is a capacity specification, but that means how much it’s supposed to have, not how much can fit in there. There has to be air space above the liquid level in the oil pan so the crankshaft doesn’t churn the oil, or as was put in the OP, to avoid “the friggin crank…trying to run submerged.” I find it believable that an additional 6 liters could fit.

14

Thanks for your answers, everyone. I don’t know if it’s luck or a testament to Toyota engineering that it still works at all. I’m going to let it warm up more now and change the PCV valve since they’re only $10