06 tacoma 4x4 engine gummed up

My 2006 tacoma 4.0 4x4 sport engine was gummed up with 120000 miles on it. I am the second owner, I bought it @ 50000 miles. Since I've had it ,4-5 years now, I changed the oil every 3-5k miles. The issue showed up when my engine started knocking due to the oil strainer getting stopped up. I had no warning lights, check engine or oil pressure lights to come on. It cost me over 5000$ to rebuild engine and parts? Any one else heard of this?

 

Yet another reason I hate the fact that vehicles have mostly gone to idiot lights instead of good old fashioned gauges.
Sorry you had to fork over $5k. Seems a little odd to me. All of the reading I've done on this site and I haven't heard of the 4.0 being prone to sludging. What kind of oil do you run?

 

Coolant leaking into the Oil will also cause oil Jelling and sludge. However the usual suspect is that the oil was not changed on a regular basis.

 

Since the engine rebuild i use mobil 1 synthetic. I used no certain brand before the problem occurred. If the coolant leaked into oil, would it be milky looking rather than black. I bought the truck at 50000 miles. I don't no what the guy did before I bought it. I always changed oil 3000-5000 miles. Problem happened at 120000 miles.

 

I would place my money on the previous owner. Most over the counter oils are pretty good these days.

 

Yes the oil would be milky creamy brown.

What the guy did before was probably Not Change The Oil for 50 K Miles. It was probably already sludged before you bought it. Over time with regular oil changes the sludge broke loose and clogged the strainer and bang blown engine.

At least since you rebuilt it you know what you have.

 

That brings up a question. Is there a way to tell this before buying used without opening the engine?

 

If you purchased it at 50K strange that 70K later you had sludge really does not make sense. I would say hard to blame the previous owner. If you changed your own oil it should have shown symptoms. Extremely black oil stained dip-stick etc.. I always run a synthetic mobile one for a while now.

I used to be a motor tec for ford I did a motor on an expedition never changed the oil (never) took 55k for the motor to go. The inside looked like mud, so If you want to know how long it will take for a motor to go with never changing the oil you have your answer.

 

Yes there are several ways:

Pull a valve cover.
Get an illuminated boroscope.