Crazy noise on startup. Wtf?!?

2015 4.0, auto trans. 65k miles
DCSB off road.

I drive this truck a LOT, and it's well taken care of. Weather finally got cooler so I rode my motorcycle to work for the past few days- it's Saturday, truck has sat in my driveway since Wednesday night.

Just got in and started it- sounded like someone dumped a box of marbles into the crankcase. Literally. Not the taco tap, not valve noise- this was awful. I shut it down instantly- noticed some white smoke wafting up from the tailpipe... wtf.

Pop the hood- I was thinking belt let loose and was flopping around making a racket. Nope. Fan clutch? Nope, it's fine. (Remember, this truck was fine when I parked it) I pull the dipstick, oil level is fine (oil is due to be changed soon, I run 7500mi intervals with the highway miles I put on and always run Mobil1 synthetic with a mobil1 filter)

So I can barely believe it. I leave the hood up and decide to give it another go to see if the oil light goes out or the check engine light is on- whatever. What am I gonna do at this point?

I start it (cranks funny- like retarded timing. This thing just always fires right up) but it fires and oil light immediately goes out, no check engine light- it's noisy but quieting down (we're talking a matter of seconds here each time, though it seemed like an eternity) running kind of rough- like it's misfiring on a cylinder or three... and then-

Smooth. Like nothing ever happened. Shut it down and start again- quiet.

So what gives?

Driveway is on a SLIGHT angle (nose was on the high side) but nowhere near an extreme angle. The weird cranking makes me think VVT issue, but I think that would have thrown a code. I'm stumped.

 

What brand oil filter? This happens a lot with cheap oil filters and the Anti Drain Valve allows the oil to drain out of the filter. With the filter empty it takes a second or two to fill the filter and get oil going again. More an issue on engines with the filter upside down.

 

Oil may have leaked out of the hydraulic valve lifters increasing the valve clearance and making noise until the lifters fill up again. Have you left the truck sitting for this long before? I've left my 4 cyl sitting for a few days and did not experience this.

 

Mobil1 filter every time.

This wasn't dry lifters. This was waaaaaaaaay louder- you could almost feel it. Only thing I've heard this bad had a rod hanging out of it

 

I know this is random, but a mechanic friend once told me that synthetic oil breaks down filter media and causes it to collapse when it sits. He said he has seen it with cheap filters.

When ever he has a car with issues that look to be related to lack of oil, he cuts the filters in half and finds a few where this has happened.

Usually happens to filters that have longer intervals between oil changes and sit often between driving. (Short commutes and often days in between driving)

 

Assuming that's what happened, wouldn't one assume that the oil light would have been on until the system pressurized? The light went off immediately.

 

Let it sit again and see if the symptoms return. Generally this happens when engines sit for a period of time. It takes a moment for oil pressure to build. If it was sitting since only Wednesday, it shouldn't be to that point yet. Change the filter anyway as that is a cheap thing to try. Mobile 1 stamped on the side isn't a guarantee against failure. You are on the right track with thinking VVT. I'm new to Toyota wrenching but in many makes, variable valve timing systems and hydraulic tensioners need oil pressure to operate correctly.

 

Could be.. not sure what the parameters of the oil light are...

I have a company car, and my Tacoma usually sits about 2-4 days in a row with out firing up every week. Knock on wood* never had this.

I do an oil change every 6 months, max, even though the Milage doesn't usually get to the #.

 

Yeah, makes no sense. It sits at the airport when I'm on work trips and has never done anything weird. I've owned it since new. There's something to the weird cranking- I guarantee it. Cranked like a timing belt engine that was a few teeth off... then the chugging like it was misfiring- makes me wonder more about a vvt issue on one bank of cylinders. I just got 3 Toyota filters in the mail so I'll be changing oil tomorrow and keeping an eye on it I guess. What else can I do? No CEL so it's unlikely any codes were thrown.

 

He has a 4.0 liter v6. It does Not have hydraulic lifters but uses a hard bucket. The filter is upside down on the V6 engine.

On your 2.7 liter inline 4 it does have hydraulic lifters, the filter is not upside down and the oil cannot drain back to the pan even with a leaking anti drain back valve.

 

Just dumped the oil and the spring inside the filter appears to be functioning correctly.

 

Just for kicks try an OEM filter.

I have an assigned work vehicle so it's not unusual for my Tacoma to sit for a week or more, especially in the winter. I've never experienced this noise on this truck. I use Mobil 1 5w30 and the OEM filter.

 

My truck sits for 4 days without starting every week and I have never had this happen. I use a Toyota filter and regular oil.

 

Toyota filter on there now, 5-30 Mobil1 in the sump.

No codes stored.

I'm about 100% confident what I experienced was some type of vvt brain fart. When it cranked, there was an unmistakable timing issue- the best I can explain it is: if you've ever started (or tried to start) an engine that had massively retarded timing.

I can't figure out why it didn't throw a CEL. There's no telling exactly what happened, but everything sounds fine now. I guess only time will tell, but I'd be ultra disappointed if I experienced a major engine issue at 65k on a motor that has seen regular maintenance and easy highway miles.

 

But that don't make it so... A small leak can empty the filter in a few days.

And the VVT works off of oil pressure.

 

Good point, very good point.

 

Sorry to bump an old thread, but this EXACT same thing happened to me yesterday and I haven't found a single thread that matched my experience until now. Literally every detail you wrote about was the same thing that happened to me. It sounded like I started an old diesel farm truck and then 10 seconds later it was my normal smooth Tacoma and nothing else has been weird in the slightest.

Did the issue ever repeat itself? Any issues that appeared down the road? Did you end up fixing anything related to this issue?

 

Crazy! I’ve got good news for you… I just sold that truck to a buddy- with 300,000 miles on it! Never had one mechanical issue with that truck, so I wouldn’t sweat it. Never had it happen again. Good luck!

 

Thanks for the reply - glad to hear that it ended up being smooth sailing for you in the following years. Fingers crossed for my truck then!