Cabin air filter and oil change thoughts

[PapaVanTwee]

I had to use the heater for the first time last week, and the smell of heated air passing the cabin air filter was not pleasant. When I changed it out, it was pretty clogged, so it was due. I got mine at an Auto Zone. They carry a lot of STP filters, and whenever I have a hard time finding a filter, I'll go there and get an STP (it hasn't failed me, yet).

I've had the car for about 1500 miles. I've been waiting for a weekend I was available to change the oil, and I finally did it yesterday. Man, was it thick and brown, almost muddy looking. It seems to run better, and is quieter, although that may be more an "I fixed it" type of reaction. I bought the filter, a Bosch, from Amazon, and used Valvoline (a brand my family stands by) full synth.

This brings up two questions. With CVT and oil being near or beyond end of life, and the cabin air filter being as bad as it was (I've also changed the engine air filter recently) is there any other maintenance items I should be checking? Because the previous owner clearly wasn't.

And does changing oil that was almost the consistency of runny chocolate pudding cause the car to run quieter/smoother? or is that all in my head?

[Ronzuki]

If your car is AWD, then the rear diff's factory fill was supposed to have been replaced at around 7-8000 miles IIRC. Many owners of both Kizashis and SX4s, were unaware of this required service so soon after buying the cars brand new. There was never an explanation of why, but I suspect the factory fill had some break-in purpose. Since break-in fluids back in the day had limited lubricating life. Consequently, many rear diffs were never serviced, ever. And, it wasn't even on my dealers radar when I asked out of curiosity to satisfy myself that most dealers really don't know what any given car really requires and/or when, Even though it was in the owner's manual's maintenance section.

Don't know your mileage, buy I'm sure it's waaay past 8k. So you might want to replace that at some point.

[PapaVanTwee]

If your car is AWD, then the rear diff's factory fill was supposed to have been replaced at around 7-8000 miles IIRC. Many owners of both Kizashis and SX4s, were unaware of this required service so soon after buying the cars brand new. There was never an explanation of why, but I suspect the factory fill had some break-in purpose. Since break-in fluids back in the day had limited lubricating life. Consequently, many rear diffs were never serviced, ever. And, it wasn't even on my dealers radar when I asked out of curiosity to satisfy myself that most dealers really don't know what any given car really requires and/or when, Even though it was in the owner's manual's maintenance section.

Don't know your mileage, buy I'm sure it's waaay past 8k. So you might want to replace that at some point.

This is just FWD. It's got 142k on it ATM. I think I am checking the plugs this weekend, not just to make sure the plugs are in good shape (they probably are) but also that there is no oil, etc in the cylinders. I've seen bulletproof Toyota engines get bad rings because they neglected oil changes.

[KuroNekko]

If the oil was that bad, you can assume everything was neglected by the previous owner. You should probably run the car through the maintenance gamut and replace everything.
In addition to what you already replaced, I'd also do the following:
- Replace spark plugs.
- Check or replace PCV valve.
- Flush and replace brake fluid.
- Drain and replace CVT fluid with filter replacement.
- Flush and replace coolant.
- Rotate tires after checking condition.
- Check alignment.
- Use fuel system cleaner additive.
- Check CV boots.
- Check and clean throttle body.

I think it's a good idea to use synthetic motor oil as you wrote. Valvoline SynPower is good stuff and will clean out the engine over time with repeated use. This should help reduce sludge build up if the old oil was that bad. I'd also recommend using top tier oil filters such as the Bosch DistancePlus over the lower grade stuff.

[PapaVanTwee]

If the oil was that bad, you can assume everything was neglected by the previous owner. You should probably run the car through the maintenance gamut and replace everything.
In addition to what you already replaced, I'd also do the following:
- Replace spark plugs.
- Check or replace PCV valve.
- Flush and replace brake fluid.
- Drain and replace CVT fluid with filter replacement.
- Flush and replace coolant.
- Rotate tires after checking condition.
- Check alignment.
- Use fuel system cleaner additive.
- Check CV boots.
- Check and clean throttle body.

I think it's a good idea to use synthetic motor oil as you wrote. Valvoline SynPower is good stuff and will clean out the engine over time with repeated use. This should help reduce sludge build up if the old oil was that bad. I'd also recommend using top tier oil filters such as the Bosch DistancePlus over the lower grade stuff.

I've done quite a few of those. Tires are in good shape, although mismatched (2 Kuhmos up front, 2 Firestones in the back). Brake fluid and coolant tested as good. Cleaning the throttle body sounds like a good idea. Hadn't thought of the PCV and CV boots. Fuel system cleaner also isn't a bad idea. Thanks for the tips!

[KuroNekko]

The mismatched tires are tolerable for 2WD but not AWD. I also have a FWD but like to rotate in a cross-swap so having all four of the same type and age is what I prefer. I also used to own an AWD vehicle so having all four be the same became a habitual preference.

Given the poor condition of the oil, it may be safe to assume the previous owner neglected everything. The PCV valve is affected by the condition of the oil from what I've read hence I mentioned it.
CV boots because of the mileage of the vehicle.
Fuel system cleaner because if the previous owner avoided timely oil changes and maintenance, they also likely regularly got the cheapest gas they could instead of top tier detergent gasoline.

[PapaVanTwee]

The mismatched tires are tolerable for 2WD but not AWD. I also have a FWD but like to rotate in a cross-swap so having all four of the same type and age is what I prefer. I also used to own an AWD vehicle so having all four be the same became a habitual preference.

Given the poor condition of the oil, it may be safe to assume the previous owner neglected everything. The PCV valve is affected by the condition of the oil from what I've read hence I mentioned it.
CV boots because of the mileage of the vehicle.
Fuel system cleaner because if the previous owner avoided timely oil changes and maintenance, they also likely regularly got the cheapest gas they could instead of top tier detergent gasoline.

What are your thoughts on MMO (Marvel's Mystery Oil)? I've used it in the past to clean an old Saturn engine (it worked) and soaked the rings to try to get them to stop burning oil (it didn't work). In this case I'd use a 32ox bottle, 16oz for the fuel now, 16oz for the oil about 2-4 thousand miles before the next change.

[KuroNekko]

The mismatched tires are tolerable for 2WD but not AWD. I also have a FWD but like to rotate in a cross-swap so having all four of the same type and age is what I prefer. I also used to own an AWD vehicle so having all four be the same became a habitual preference.

Given the poor condition of the oil, it may be safe to assume the previous owner neglected everything. The PCV valve is affected by the condition of the oil from what I've read hence I mentioned it.
CV boots because of the mileage of the vehicle.
Fuel system cleaner because if the previous owner avoided timely oil changes and maintenance, they also likely regularly got the cheapest gas they could instead of top tier detergent gasoline.

What are your thoughts on MMO (Marvel's Mystery Oil)? I've used it in the past to clean an old Saturn engine (it worked) and soaked the rings to try to get them to stop burning oil (it didn't work). In this case I'd use a 32ox bottle, 16oz for the fuel now, 16oz for the oil about 2-4 thousand miles before the next change.

I've used MMO and Seafoam more in the past for the same uses on older cars before my Kizashi. However, for my Kizashi, I'm not adding anything to the oil as it's been on full synthetic since I got the car lightly used. If your engine doesn't have obvious signs of sludge or build-up issues then using a full synthetic will slowly but safely help clean out the engine while not compromising the oil's integrity for its other roles. Given you are using SynPower, I think you don't need an additive. Just change the oil at around 6000 miles.

As a fuel additive, MMO should be fine but I think there are better products to clean a fuel system specifically. I believe Chevron's Techron is generally regarded as a top notch fuel system cleaner.

Overall, the necessity of MMO or Seafoam depends on the condition of the vehicle. If the oil changes were neglected or the engine is old and noisy with valvetrain noises, the additives will likely help. If the engine is smooth and quiet at idle, then it likely doesn't need it. I'd still pour a treatment in the gas tank for good measure though.

[PapaVanTwee]

Chevron Techron it is. Good to know the oil is going to do a good job for me.