My dad owns a 99 Sienna. It has 189,000 miles. He has been pretty lax about oil changes all his life on any car he owns, but has had very good luck. My concern is tthat the 3.0 v6 in the sienna is known for sludge problems. At this point, is there anything we could do to reverse the sludge build up that i am sure has accumulated? Would hate to lose the engine.

 

Safest method would be more frequent oil changes, how often does he change it and go from there, is the minivan within factory mpg rating

 

Like Venom said, do more oil changes to flush out the build-ups.

 

Thanks, I'll try to twist his arm to do that. He can be pretty stubborn about it. He does change the oil, but not as often as he probably should. I'm not sure how frequently, because I don't regularly check his odometers. He does chuckle at me for regularly changing my oil. I don't know if he's just plain lucky or what, but out of the many vehicles we've owned, he's never kept up on regular maintenance and never had any internal engine issues....ever.

I don't know exactly what MPG he's getting, but it's still decent. Power and driveability are still fine too. The last time I remember an MPG number was in 2008 when we drove it to Yellowstone. We were averaging 25ish IIRC. It probably had around 150k on the odometer at that point.

I don't know how much longer we'll have this car. He is looking to sell it and buy an SUV so we can go out to the desert and get to harder to access areas(we do have 4x4 on our F350, but he wants to avoid putting too many miles on it, and wants something smaller for offroading).

 

Use a stout oil such as 10W-30 diesel engine oil or Mobil 1 High Mileage and good filters for a few oil changes. You can also do a few more drastic measures - I'd look around at BITOG for a few ideas.

 

Why not try to use one of those 10,000/15,000 mile interval oils?

 

@97-SC300: Pretty sure that's what he buys anyhow. Hope it's working.

I don't like to question him too much.....he's been working on cars since the early 70's. He's even rebuilt the engine in his 67 Firebird. He told me one trick he knows for desludging an engine is to put in a quart of ATF at an oil change. He plans to do it to my sister's 99 Saturn with 112,000 miles. I'm scared though of using it in the Sienna....if it's got 190,000 miles of sludge in it....I'd hate to see chunks break off and get caught in the oil pump.

 

Damn, just reminded me. My car is at 117,XXX, and I last changed the oil around 113,000. I should probably get on it. The best time would be this week while I'm at home, because I have access to a friend's shop, which has a pit and a place to dispose of used oil.....but I don't want to buy oil OR filters in this town....the 2 parts stores rip you off like crazy. I may just have to wait til the next time I'm over here, and bring oil and a filter from St. George.

 

Has he tried to run Sea Foam in it to burn off the build up and then change oil with a synthetic? Might be a good start!

 

I've always been told that changing from conventional to synthetic at high miles can cause leaks and what not.

 

I think this is one of those urban myths. You know, I heard from a guy, who heard from a friend whose brother knows a street vendor that once had his car serviced by to guy who told him.....


I have never seen any actual test results that say that this is probable or even possible. I know that many companies that run fleets have moved over to synthetic oil due to increased milage and reliability.

 

I think this is one of those urban myths. You know, I heard from a guy, who heard from a friend whose brother knows a street vendor that once had his car serviced by to guy who told him.....


I have never seen any actual test results that say that this is probable or even possible. I know that many companies that run fleets have moved over to synthetic oil due to increased milage and reliability.

I have run synthetic oils since they became available and never had any issues at all what so ever.

 

Only if there's so much sludge that its clotting the areas where it would have leaked out. If you start getting leaks after changing to synthetic, you probably would have got those leaks sooner or later anyways. And i wouldn't want sludge holding my engine together in the first place

 

Hmmm....i'm considering the change.....but is the mpg increase enough to offset the cost increase of the oil?

 

From my experience, I would say that there is at least some truth to this, and I use nothing but synthetics in my vehicles. We bought a ten year old Cressida, 1990, with over 110,000 miles and immediately switched to Mobil 1 Synthetic. Not too long afterwards, the engine began to bleed oil.(Granted I do believe Toyotas gasket material to be better now than back then). I did the same on a seven year old 1989 Nissan Sentra that had similar mileage, and the oil pan gasket leaked like crazy. From what I have read, the high detergency of synthetics cleans the "gunk", that conventional oil has built up from around the seals over time, causing the leaks.