Corolla Sludge

So, tell me, Paul, what makes this Corolla consume oil so rapidly that it suffer "oil starvation?" And, is this the first Corolla owner to tell such a tale? No, he is not. There have been others on this very board, as a matter of fact.

A Toyota Corolla that cannot make it between oil changes *better than recommended* without suffering major oil loss? A Corolla whose oil level got so low that the oil indicator light did *not* illuminate? Tboner claims the information says that there was only 1/2 a quart left in the vehicle, right? If so, *why* was the light *malfunctioning*? It did not come on, remember?

So, perhaps what we have here is a vehicle that has an OBD problem? Let me guess....an owner should disregard the expectation that these lights will come on to warn of impending doom? With all the high technology available, the owner needs to do *all* the diagnostics by hand?

Get real. This vehicle was *not* performing as it should.

Autoresearcher

light. It does not come on for a low oil level. The oil pressure must drop to a threshold that is lethal for the engine.

There are a few, but not many, cars that do have oil level monitors.

However, for most cars, the oil lamp going on at times other than the bulb test at vehicle start is the automotive equal of giving the dying

their last rites.

Of course, I could be wrong, so I'm happy to read an actual page from the 1998 Corolla owners manual that shows the car has an oil level warning

lamp and not just a generic oil pressure warning lamp.

Most oil pressure warning lamps are nothing more than a pressure sensitive switch, mounted in the engine block or cylinder head that provides a path

to ground if the pressure drops enough to no longer push the switch against spring. If the pressure is not sufficient to overcome the spring, the switch provides a path to ground. The light should always have a +12V and the pressure switch completes the circuit.

Some reasons why the light would not illuminate if the oil pressure dropped below the threshold.

1. Bulb burnt out

2. Fuse 12V source of bulb power burnt out

3. Faulty switch

4. Faulty wiring

There are plenty of reasons why an oil pressure light doesn't illuminate on the dash board.

However, I cannot really think of a good reason to drive to the dealership with only 1/2 quart of oil in my crankcase.

Even if I knew I was getting my oil changed, I'd put enough oil in there to get wll above the add, but not overfill the crankcase.

TB

Could this excessive (?) consumption of oil in Toyotas be what is contributing to all the sludge problems? People are experiencing sludge when oil changes per manual are followed. But according to some consumption rates, you could lose more than the oil capacity in the car in this time and you would run dry. Why do these cars use so much oil? I had no consumption between oil changes on my Caravan but my Sienna consumes it like a camel.

Could this excessive (?) consumption of oil in Toyotas be what is contributing to all the sludge problems? People are experiencing sludge when oil changes per manual are followed. But according to some consumption rates, you could lose more than the oil capacity in the car in this time and you would run dry. Why do these cars use so much oil? I had no consumption between oil changes on my Caravan but my Sienna consumes it like a camel.

If the oil level gets too low, the same heat that is designed to be carried away by the minimum oil level now has to be carried by a smaller volume of oil, that remaining oil will be broken down much faster. Since many conventional oils contain pariffins and asphalt like substances, combine those with other natural combustion byproduct contaminants and you are likely to form sludge. However, this is not a Toyota only phenomenon, this is basically a function of how motor oil and contaminates can combine at certain temperature levels.

And that is why I'd like to hear more about WHAT oils are used, both weights and brands to see if there is a positive corrolation between sludge and oils used. Just like some claim certain engines may be more prone to sludging, you can make a logical case that certain oils are more likely than others to sludge. Wouldn't it be great to get those details as well, rather than just the constant drum beat that the only fault lies with Toyota?

For instance, are there any documented sludge cases with owners that use a group IV PAO synthetic oil such as Mobil 1? How about group III hydrocracked "synthetics" (there is a religious war about if these are really synthetics) such as Castrol Syntec.

There is some amount of complaining about 1 quart every 1000 miles, but this seems to be a common allowable threshold, as I've seen the same figure quoted for GM and VW vehicles to name a few.

In a Corolla, ONE QUART is between 1/3 and 1/4 of the total crankcase volume. (My 94 Geo Prizm with the Toyota 4A-FE engine has an oil volume of 3L or about 3.2quarts with a filter change. So a quart is about 1/3rd of the total oil volume.

Thus my preaching for frequent checking of oil level.

It can only help you to check your oil and keep it at the max fill level given.

However, in my small sample space, I don't see my Toyota engine, with almost 113K miles on it now, consuming large quantities of oil. On the conventional Mobil Drive clean 10W30 that was in my car from 106K to 110K, it used about 8 oz of oil in that period.

I changed it to Mobil 1 10W30 (a group IV PAO based synthetic oil) and my consumption seems similar, maybe a bit less at about 4oz of consumption in 3000 (and ~6 weeks) of driving. (I've had some vacation, and a week of commuting by train to a downtown customer site, so my normal 600-700 miles/week is not evident in this interval.)

I plan to get my oil analyzed in the next couple of weeks to see if 7500-8500 mile intervals are safe for this engine, oil and my driving habits. I would like to do oil changes every 4 months or about every 7500-8000 miles. (Basically so I don't have to change oil in the very cold winter months.)

But if the oil analysis doesn't support it, I'll just put on an extra layer of clothes and change my oil in the cold of January if I need too

TB

Again, back to root cause...I want to know why it ran low to start with. To me, that's the original defect.

Cheers,

Regular Joe

I always change the oil myself, I have little faith in dealships that typically pay a low level mechanic $9/hour or less to perform simple yet critical maintenance.

I've had a '91 Tercel with 102k miles, a Honda CBR600F4i motorcycle, and now a 2003 Cororlla. In a combined 200k miels of driivng, I've never needed to add a drop of oil ot either one. My typical oil change is at 4k miles with my new Corolla at 6-7k miles (mostly freeway driving). I also use fully synthetic oil.

Was the enigne on you Corolla broken in "properly". The worst things you can do, baby the hell out of it, take it on long freeway trips (it needs mustliple heat cycles) or drive at a constant speed....both during the first 500 miles. after tha tit doesn't matter much anymore. ALthough I will note, I too ka good 5000 miels for my new Corolla to loosen up and start getting good mileage.

Well, I guess I should have read this thread before I posted about the oil consumption in my wife's 98... It's interesting that it started so suddenly though.

For five years nothing, and then a quart every thousand miles.

She may not like it, but I will keep refilling it for as long as necessary before I buy her another car! I have a Tundra to pay for now....

Clifford: No chance that it is just a leak? (i am sure you have check this...would be hard to miss haha)