New rebuild ripping through oil

[Chero87]

Hey guys, I have a '91 4Runner with the 3.0L V6 (3VZE) in it that was "rebuilt" by Toyota about 10K miles ago. Toyota has had a long history of problems with the original head gaskets used in these engines and had a long running campaign of replacing them, even after the recall was over they would still goodwill these headgaskets.

Anyway, the previous owner had a rod knock issue, so Toyota good willed the engine and did a rebuild on this engine. Not 100% sure what they consider a rebuild, but I spoke with the dealer that did it, and they tell me the block was torn down, it got new bearings, rods, pistons, rings, injectors, and a couple of other things. I don't think the heads were touched.

Anyway after I bought it, I realized that it is going through oil at a really high rate, I went through about 3 quarts in 600 miles. There is not a single leak that I can find anywhere, and my driveway is clean, and there is nothing blowing out of the tail pipe, maybe a slight bit on start up, but that's probably just the valve guide seals, no big deal. No oil in the radiator/coolant and no coolant in the oil.

But in order to be going through this much oil I would have to have a cloud coming out of my exhaust all the time or have a puddle in my driveway and a mess under my truck. I don't have any of these.

Any idea where this oil could be going?? I am at a loss. No idea where it could be going.

Thanks.

 

[Quest]

burning oil, that's it.

whether you are seeing it nor not that can be a somewhat subjective observation for some folks cannot tolerate anything 1qt/2000miles or worse and some can visually "disregard" when they say that they do not see big puffs of smoke even though engine going through 1qt oil every 500 miles or so.

Regardless, get someone professional to go through your engine conditon to see what's wrong. I'm not in a position to speculate anything but my suspicion calls for partial rebuild job or none at all, and the dealer where you bought your car from is blowing smokes up yours.

(*wifey had a 3VZ-FE 4Runner before so I know*)

Q.

 

[Chero87]

Thanks Quest.

I didn't buy the car from the dealer, I called Toyota after I bought it and they confirmed what had been done and put me in touch with the dealer that had done the recall/goodwill work and they told me what had been done.

I had an '88 Yota pickup with a 3VZ-E and blew the head gasket and Toyota replaced the entire short block. They didn't do a whole new block on this one though, it was rebuilt, not sure if they do it at the dealer or send it out to an engine rebuilder, kind of doubt they actually did it at the dealer, but regardless they put in new rods, pistons, rings, and bearings. They also did the water pump and T- belt and put new injectors in.

I really doubt it's burning that much oil though. my exahust would have oil all over it, and there would definitely be constant blue smoke coming out of the exhaust.

If you've ever seen an older Mitsubishi engine, especially the ones Chrysler used in their older mini vans, you'll know what I'm talking about, the rings would go on those things at around 85K and they would smoke like diesels or worse.

 

[mechtech2]

3 qts in 600 miles is the most loss I've heard of or experienced - even with old worn V8s.
There has to be evidence of where it is going.
But let the dealer [warranty] deal with it, if at all possible.

 

[MrCritical]

The catalytic converter is pretty hot. It could be masking a lot of the exhaust smoke you'd normally see. Unbolt the converter and see what the inside looks like or the exhaust before the converter.

Either way, sounds like a warranty problem.

There's no way Toyota or anyone else can justify a rebuild on a 17 year old engine. That calls for a short block at least in my opinion.

No matter if the manufacturer was paying, my boss would have no problem telling them there's gonna be no rebuilding engines in 17 year old vehicles in my shop.

 

[Hirev]

Did you ask the previous owner if it was using oil before you bought it? At 200 miles per quart I would not be at all surprised if the engine was ran very low on oil at some point.

If the engine is not leaking oil than it is burning it one way or another. The plugs will tell you if it is burning much oil if they are read correctly. Could be the valve seals and or guides are shot. But if it was starved for oil at some point who knows what damage has be done without a complete tear down and inspection.

If you have someone else drive it and follow them around especially up hill and down hill you also might be able so see better if it is burning oil. Cats do tend to mask oil burners somewhat. How many miles ore on this?

 

[alanu]

Those 3L heads are [censored]. Just had a customer request an engine rebuild. Those engines are not easily obtainable if your looking for a good core. It took me over a month to find a reasonably priced core. I got so frustrated I pulled the original motor and completely tore it apart and started from scratch.

My friend is a machinist and he's often told me how badly those heads can be after years of service. He can go through many core engines and the heads are often difficult to refurbish. For the life of me I'm trying to recall the problem.

I wonder if the dealer did the ghetto ball/hone finish instead of getting the Sunnin accurate hone. Theres alot of possibilities on how oil can be consumed. I wonder if they used OE Toyota piston rings or purchased some cheap junk Altrom brand rings.

Many here on the forum have no idea how sh!ty that engine is to R&R. Its a ditch digging job to pull that one out. Another common mistake is to put the head gasket incorrectly. The water jacket holes have a slight difference from Right to Left. That wont be the case for this one because overheating will be the problem.

The oil consumption is probably a compression ring installed backwards or the two of the oil control rings gaps lining up. Maybe too much taper in the bore if a ghetto ball/hone was done. Too many possibilities to list.

If it was a valve guide issue you'd probably see a puff of smoke as you decel or hard acceleration.

 

[PT1]

Do a compression test on the engine. They may have installed the rings upside down.

 

[Lazy JW]

Originally Posted By: Chero87
....

I really doubt it's burning that much oil though. my exahust would have oil all over it, and there would definitely be constant blue smoke coming out of the exhaust....


An engine can easily burn that much oil without noticeable smoking.

Having been born on the "other" side of the tracks I have had ample opportunity in my misspent life to drive plenty of oil burners. My experience is that when you see a car visibly smoking out the exhaust while cruising down the road it will be burning a quart in less-than 100 miles, probably closer to 50 miles.

Think about it. If your engine burned a single drop of oil per power stroke it would empty the crankcase in less than one mile and the smoke cloud would be enormous.

Try to visualize how many power strokes your engine makes in 600 miles, then divide that into one quart; the amount of oil burned per power stroke is going to be very, very small. It certainly won't produce much smoke.
Joe

 

[Gary Allan]

Originally Posted By: Chero87


If you've ever seen an older Mitsubishi engine, especially the ones Chrysler used in their older mini vans, you'll know what I'm talking about, the rings would go on those things at around 85K and they would smoke like diesels or worse.


That was all valve guide/seal issues. If any ring problems existed with these engines ..it was from severe neglect. I owned one and it was a fogger.

You are burning this oil. You're just combusting it (currently) cleanly. Even if it is (literally) evaporating, it's passing into the combustion process. No leaks? Then it's going through the combustion process or after burning via the exhaust valve seal leakage. Since you see little smoke, I'd say that it's going through the whole process.

 

[Jim Spahr]

Since this oil is being burned, wouldn't he be able to confirm this by pulling a few spark plugs and seeing if they are oiled up, i.e., blackened or sooty looking?

 

[Chero87]

Decided to go to the dealer that did the "rebuild" and see if I could find out what was actually done.

It turns out it wasn't a rebuild at all. The thing came in for the head gasket recall/goodwill, and they decided to replace both heads for whatever reason. So the heads are brand new, complete, new valves, cams, lifters, everything.

So as it turns out the block has 198K on it after all. Now I don't doubt at all that I am burning the oil.

I am gonna order up some Auto-RX and see if it helps with the comsumption.

The service manager at the dealer, really nice guy, told me he knows the previous owner personally and that's why he always had the truck serviced there. He said the guy was anal about maintenance, and they always did everything to it, so I know it was well taken care of.

Anybody think that ARX will help with the oil consumption? Maybe a few rings are a little stuck, so hopefully it will clean things up.

 

[Gary Allan]

Originally Posted By: Jim Spahr
Since this oil is being burned, wouldn't he be able to confirm this by pulling a few spark plugs and seeing if they are oiled up, i.e., blackened or sooty looking?


Not necessarily. Introduced in a metered manner, it can be transparent in consumption.

 

[Gary Allan]

I don't know the configuration of this engine. For all I know there's some trap door flaw that would allow oil to bypass your throttle body or PCV plumbing and allow it a short cut. I would imagine if this was all going through the PCV system, that some type of catch can or just a clear fuel filter, put in line, would show you if that was the route that it was taking.

If it was from shot rings (as in worn) ..then I would imagine that you would also be puking oil out of the filtered fresh air vent too.

Auto-Rx will de-coke the rings ..so I would expect some reduction in consumption. It depends on if there's really any wear there.

 

[Chero87]

Gary, I pulled the PCV hose off a couple of days ago, just to check it, and it was pretty clean, normal stuff in the hose, actually pretty clean.

I figured if it was going through there it would be a mess.

What do you mean by puking it out of the filtered fresh air vent?