Who has cold start rattle? 2016+ 2.7s Potential easy fix

I’m looking for a candidate that has the cold start up rattle we find threads on here occasionally. Personally, I have it. I’m tackling the job and I have my suspicions that the culprit might be a fairly simple fix.

I’ve narrowed down the issue to the exhaust camshaft actuator. I’m looking for someone who currently has the issue on a 2016+ dual VVTI truck. This could potentially be a simple gasket issue and be addressed by simply removing and reinstalling the camshaft cover versus tearing down the motor and getting to the chains. Someone with this issue please come forward. You just need to have a torque wrench and maybe some experience wrenching.

 

I was able to get some pictures and documentation of my theory. I have personally had a small seepage from the valve cover that I thought nothing about. This started about 1.5 years ago. I kept an eye on the oil level but I wasn’t losing anything between oil changes so I let it be. You can see the gunk build up on my valve cover in one of the pics from the seepage.

Last winter I started getting the rattling. Initially it was very mild and momentary. As the winter progressed it stuck around longer and longer. Long enough for me to be able to isolate it to the exhaust VVTI. It was clear that it was coming from the top end where the cams are. I initially thought it might be the chain but it eventually became clear it was the phaser. Even once it quiets down with a stethoscope you could hear it. Alternatively put your finger on the exhaust VVTI solenoid and you can still feel those vibrations you’d normally hear on start up. I also want to note that for me this only happens on cold start up when the truck has sat overnight with ambient temps being below 50. In warm weather I don’t have this issue. I was able to rule out the timing chain slap because of this. You’ll get the rattle regardless of temperature. Also, my rattle goes away completely after the engine starts to warm up.

so I’m fixed on it being the cam phaser, especially once I started digging into the issue and seeing this is fairly common amongst Toyotas and really most VVTI systems. I have personally not been in one of these motors so I’m not familiar with them, minus knowing it will be relatively easy to work on when the time comes and that I will have ample space.

I started stripping things down when I noticed a handful of the camshaft cover bolts were very loose. So loose they just turned with no resistance. Two of these bolts are the two at the #1 spark plug hole, and the two at the exhaust solenoid.

once the valve cover was off I was looking around and making sense of things. I was curious how the solenoid operated since on the intake side it goes into the block. If you pay attention the filter screen is also the gasket that seals the oil circuit for the exhaust side of the VVTI system. I’m wondering if the gasket degrades over time or if maybe the bolts come loose creating a loss of clamping force. Whatever the culprit is, I’m thinking the loss of clamping force is causing the circuit to lose its seal. With no seal maybe the oil drains out of the channels for this circuit and upon a cold start you get the rattle since the system needs to be recharged all while the oil filter is fighting a gasket that is letting oil leak out.

Truthfully I’m in it too deep at this point. I have new parts on hand and I’m just going to replace the phasers amongst a few other things as it’s my daily. If someone is experiencing this cold start rattle I’d love for you to tighten these two bolts to factory spec and to see if the problem goes away. I’m really curious if two bolts coming undone or a gasket degrading is the culprit. Note that the bolts have rubber washers under them, so those rubber washers degrading over time can also be the culprit behind a loss of clamping force.

 

I am having this issue. Thanks for bringing it up. 195k with 5w30 syn and OEM filters since brand new. Tightened these two bolts you pointed out. Mine were slightly loose. Will provide an update in a few days.

 

Any updates?

 

First few days it went well and I thought this had resolved the issue. Then the Temperature dropped and it came back. Did not resolve my rattle.

 

Ah, well that’s unfortunate. Good theory I suppose, but too good to be true.

 

Well.. my truck has started making this noise suddenly.

I'm pissed.. I bought the4cyl to avoid these kinds of problems. Any suggestions

 

This was just a theory, ultimately I replaced the exhaust actuator amongst a dozen o rings in the timing cover and valve cover that MUST be replaced and it has fixed the issue. The standard motor product actuator on rockauto is going to be an OEM unit. I also replaced the intake one, that has to be sourced from Toyota.
If you look through my post history I made a bunch of posts covering this.

 

Jeez.

This sucks... I'm assuming I'm going to have to dig in deep and that this isn't an easy fix

 

Bad chain tensioner or vvt gear, I know it has the updated gears but the old version was common to fail just not sure how these work compared to the old design

 

Im monitoring it. I was about 1/4qt. low on oil according to the dipstick. Might as well start with the easy stuff before replacing the motor (lol). Since I added a little oil I haven't heard the rattle, albeit the temps have warmed up here so. Most mornings it's been warm, so I have to keep an ear out when cold starting, but Monday morning it was 34 degrees and it didn't happen (truck sat all weekend). Maybe it was just a bit low on oil?

That would be a win for me. More to follow ...

 

im having this issue. currently it only does it when on an incline on a cold start

 

This issue started showing up for me around 55k miles on my 2019 2.7L Tacoma, loud engine noise during cold start-ups. It sounded like the VVT-i system wasn’t functioning properly, and a rattling noise was coming from the camshaft area.

After trying to diagnose the issue myself without success, I brought it to both a dealership and an independent shop. They each recommended dropping the engine for a “rebuild.” According to the repair manuals, the only way to access the oil pans is by removing the engine. I suspect that the lower oil pan can be removed without pulling the engine, especially on the 2WD model. Reluctantly, I let the dealership remove and tear down the engine as the problem was out of my league and I wanted the "experts” to take a look.
Ultimately, the root cause was a failed gasket on the oil pickup tube inside the lower oil pan. Failed gasket left, new gasket right.


The issue with this failed gasket was 2 fold.
1.)Oil in the upper part of the engine was able to leak back into the oil pan overnight. This left the oil lines unprimed, so oil couldn't reach the VVT-i system immediately during startup. Without oil pressure, the VVT-i actuator was free to move, causing the rattling noise.
2.) The oil pump was less effective because some of the oil it pumped was leaking right back into the pan through the compromised gasket. This reduction in oil flow further delayed oil delivery to the engine. Interestingly, once oil pressure caught up, the engine ran normally even with reduced flow.

I'm a machine designer not a chemist, but I suspect an incompatible oil additive caused the gasket to swell, buckle, and fail. I had my tires replaced at 50k miles and got 5 free oil changes from the tire shop. I started using those shortly after, and this issue appeared. I don't know what type of oil they used but it was probably a cheap shit with a seal conditioner additive. Some high-mileage oils have seal conditioner additives that work by softening and expanding gaskets to extend their life. This expansion and softening caused my gasket to buckle and fail. Not all oil additives are bad, but low-mileage engines with healthy gaskets don't need random special additives. My word of advice is to be very careful about what fluids are going into your engine.

 

@2k2 Sounds exactly like the issue you were having now it would make sense you were seeing intermittent low oil pressure light

 

Indeed it does... I never added any special additives prior to my issue. I still have this issue intermittently and I would bet this is the culprit.... Wondering how difficult of a DIY job this is

 

Thank you for posting this.
I have a feeling this my problem.

Wonder if the Pennzoil platinum has some sort of additive that caused my gasket to swell

 

@Nyrob ....thanks for the heads up....THIS seems EXACTLY like the issue I've been experiencing

 

GM trucks from the 99-06 era have this issue. Its a combination of bad assembly practices and poor material choice and luck of the draw. Seems like toyota shouldn't have any of those growing pains though.

 

Hopefully yours doesn't... I'm annoyed mine does... This issue has been annoying me for a while now

 

Has anyone tried this repair on their own?