'02 Toyota Sienna burning oil (3.0 V6).

Messages
159
Location
Arizona
It's the beater van with 170,000 miles, and I don't remember exactly how many miles it's been driven since I last changed it (somewhere between 5000-7000 miles with Pennzoil Platinum). I finally did an oil change recently and saw there was nothing on the dipstick, and what drained out was really dirty oil. It never burned oil like this before. I replaced the PCV as a start and went with high mileage oil. Should I let this oil clean out the engine for 3000 miles/6 months and then perform an oil flush with some flush chemical and cheap oil? Dirty piston oil rings perhaps? I know these 3.0's don't like short trips or extended OCI's as they are prone to sludging, and we do use it for a lot of short and long trips.
 
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Messages
4,756
Location
Fort Worth, Texas
Pull the front Valve Cover.....You will not like what you see & the rear bank is most likely worse! Soak the pistons in GM Top Engine Cleaner, And soak both valve covers in Berrymans ChemDip to clean all the sludge out from under the baffles. You will need the change the spark plug tube seals after this! If you don't have a Screw-in PCV valve....Update the rear valve cover with a 2003 Lexus ES300 version. If the sludge is bad enough....You will need to pull the lower oil pan & flush the engine out with Kerosene. One of the nastiest jobs you will ever do! JDM 1MZ-FE engines are pretty cheap! That's what I did on my 2000 Avalon.
 
Messages
1,337
Location
texas
If this is your first time using Pennzoil platinum vs a lifetime with conventional and the same "I don't remember when i changed the oil" schedule, it will come out black. When I bought my 07 sienna used at 24K miles, the first OCI with PP was black. Then next was better. Its better to clean sludge slowly than attack it with aggressive stuff. The aggressive stuff may break off large chunks of crud that could clog passage ways and make a worse problem. I would give it a go again with PP (HM is OK) and monitor the oil consumption. and top off for an OCI before doing anything dramatic.
 

Astro14

Staff member
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11,680
Location
Virginia Beach
"I don't remember how long" and you didn't once pull the dipstick to see how it was doing during that time? That's not oil burning...that's neglect. With the new oil in there, start checking, and keep track of how long it takes to burn a quart. If you went several thousand miles and didn't run out of oil, you're using less than a quart per thousand, which means it's not terrible. Everything Clinebarger said is probably true, but until you know how bad it is, all that work may not be necessary.
 
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4,639
Location
Suburban Washington DC
Originally Posted by Loobit
Should I let this oil clean out the engine for 3000 miles/6 months and then perform an oil flush with some flush chemical and cheap oil?
On a thousand dollar beater, I wouldn't put any money into it beyond topping off the oil when low and changing as before.
 
Messages
1,250
Location
USA
It may be rear valve cover leak. These engines are not sludgers any more than others, only when very badly maintained. I was worried on ours we had, and at more miles than yours the heads were clean as a whistle not a trace of sludge. It had a rear cover oil leak which I fixed myself. On the internet so many false ideas get believed. I fell for it, but now realize a few examples of unknown history, don't mean it's a problem engine. I thought it was a great engine, smooth, fast, reliable, and good mpg.
 
Messages
4,848
Location
VA
You could remove the front valve cover and send pics. I'm sure that would help some of these guys in their advice. The only thing I know to do now is some 3K OCI's. After seeing the pics, I suspect you will get a lot more instruction. Good Luck!
 
Messages
1,536
Location
TX, USA
Originally Posted by Farnsworth
It may be rear valve cover leak. These engines are not sludgers any more than others, only when very badly maintained. I was worried on ours we had, and at more miles than yours the heads were clean as a whistle not a trace of sludge. It had a rear cover oil leak which I fixed myself. On the internet so many false ideas get believed. I fell for it, but now realize a few examples of unknown history, don't mean it's a problem engine. I thought it was a great engine, smooth, fast, reliable, and good mpg.
I had this engine in a Lexus, the rear valve cover tends to leak with age. It is not an easy DIY but not impossible, just a lot of part needs to be removed. While at it, replace the rear spark plug. So check it first, you may need to go down under and see up on the firewall side with a good flash light. As far as sludge, you need to do short OCI.
 

Loobit

Thread starter
Messages
159
Location
Arizona
Originally Posted by Farnsworth
It may be rear valve cover leak. These engines are not sludgers any more than others, only when very badly maintained. I was worried on ours we had, and at more miles than yours the heads were clean as a whistle not a trace of sludge. It had a rear cover oil leak which I fixed myself. On the internet so many false ideas get believed. I fell for it, but now realize a few examples of unknown history, don't mean it's a problem engine. I thought it was a great engine, smooth, fast, reliable, and good mpg.
It does have a rear valve cover leak and gets on the exhaust. The front valve cover is fine. I don't think the leak is bad enough for it to gush out 2 or 3 quarts of oil. Something like that you'd be seeing a ton of white smoke smoldering from the back exhaust. The subframe is a bit oily, but that's from power steering seepage from what I saw under there with a flashlight.
 

Loobit

Thread starter
Messages
159
Location
Arizona
Originally Posted by Astro14
"I don't remember how long" and you didn't once pull the dipstick to see how it was doing during that time? That's not oil burning...that's neglect. With the new oil in there, start checking, and keep track of how long it takes to burn a quart. If you went several thousand miles and didn't run out of oil, you're using less than a quart per thousand, which means it's not terrible. Everything Clinebarger said is probably true, but until you know how bad it is, all that work may not be necessary.
Yes it was neglected for a bit, but it's not really worth the hassle of digging into it and soaking all pistons in cleaner either. Like it said it's a beater and I didn't even know it burned oil. Its oil level was in the safe zone when I changed the oil last year (January 2019).
 

Loobit

Thread starter
Messages
159
Location
Arizona
[Linked Image] Finally got to do both valve cover gaskets and spark plugs. The back one wasn't easy! Got a photo of the front with valve cover off. Rear wasn't any different. It's moderately varnished. It's been 1200 miles using Royal Purple HMX (my favorite high mileage oil) and oil level is just a hair under the full mark of the dipstick. The intake manifold wasn't flooded in oil, and the throttle bodies were surprisingly clean. I could have taken more photos, but I was very focused on finishing the job since I had limited time. I did this in my shop on a Saturday when we close 2 hours earlier than normal.
 
Messages
1,776
Location
Kingston
Originally Posted by Loobit
[Linked Image] Finally got to do both valve cover gaskets and spark plugs. The back one wasn't easy! Got a photo of the front with valve cover off. Rear wasn't any different. It's moderately varnished. It's been 1200 miles using Royal Purple HMX (my favorite high mileage oil) and oil level is just a hair under the full mark of the dipstick. The intake manifold wasn't flooded in oil, and the throttle bodies were surprisingly clean. I could have taken more photos, but I was very focused on finishing the job since I had limited time. I did this in my shop on a Saturday when we close 2 hours earlier than normal.
Sounds and looks like you just need to start being more careful with it and check the oil once in a blue moon.
 
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