1999 Sienna oil change timing - Toyota Nation Forum : Toyota Car and Truck Forums

Pr0grammer · 02-17-2011, 02:32 PM

My dad's run our '99 Sienna from about 82k miles to almost 90k without changing its oil (the sticker from the last oil change says it should have been changed at about 85k or July 2010), and he agrees that it needs to be done at some point but doesn't seem to think it's a priority. I read online that the recommended interval was originally 7500 miles but Toyota changed it to 5000 miles because of the sludge issues with the 1MZ-FE. Is this something that I should start pressuring him on, or can he realistically run it for 10k+ miles without an oil change?

***humanoid*** · 02-17-2011, 03:19 PM

You can probably run that long on synthetic oil, but I wouldn't go past 7K on conventional oil. I would get an oil change as soon as you can. And it's been about 6 months since the last oil change???? Get 'er done!!!!

Pr0grammer · 02-17-2011, 03:33 PM

10, actually - July was when they said it should be changed. He says that what's in there now is whatever the mechanic put in by default (he didn't request synthetic), so does that mean it's probably standard?

***humanoid*** · 02-17-2011, 05:18 PM

Yeah, they usually put conventional oil in there. I would tell your dad to get that oil changed ASAP, no oil should be in an engine for 10 months.

wiswind · 02-17-2011, 07:32 PM

I would not panic about it.
However, I would get it in for a oil change.
I like a 5K oil change interval with synthetic oil.
Overkill?, yes, but I like a margin for error.
If it has taken 10 months to get 8K miles, then the 5K OCI should work out well time-wise.
Also, if this vehicle is seeing short trip / low mileage use, then that would be a good example of my point of "margin for error" as short trip driving is super hard on oil.

I would also have the PCV valve checked / replaced.
The PCV valve can get deposits built up on the input that will block the flow of air through it.....which WILL cause sludge.
The PCV valve is hard to see / find.....It is located in the rear valve cover, very close to the throttle body.

Pr0grammer · 02-17-2011, 07:49 PM

It's almost exclusively used for trips of under 10 miles, so about how much effect would that have on the state of the oil?

wiswind · 02-17-2011, 08:31 PM

Short trip driving, particularly in the winter, can cause a build up of moisture in the oil.
When a vehicle is driven for longer, it gives the oil a chance to warm up for long enough for the moisture to evaporate out....and be drawn out through the PCV system.
This is also true for fuel and other contaminates that end up in oil......as may contaminates will vaporize and be drawn out by the PCV system.
If you live in a cooler temperature area (with real winters), maybe having a oil change schedule that has you changing the oil mid-winter would work out.....

Black Sunshine · 02-17-2011, 10:16 PM

You should worry about it more when you get your own Toyota. Your dad doesn't need another mommy.

Mine has had far more abuse than that though. It fascinates me to hear about 1st Gen Sienna's with less than 100,000 miles. I think that mine will go over 400,000 miles and I'm over half way there.