2.7L cold start rattle?

I have the same noise on really cold days, lasts about 5-10 seconds. 04 with 125k miles. I always assumed it was piston slap.

 

And after a long list of information, that seams to be the answer. Because of the make up of the pistons,they have enough tolerance that on very cold mornings they will rattle for a few seconds and then heat up and stop. My 2.7 had 285k on it when I traded. Rattled in the winter but never failed me. Super, almost bullet proof engine.

 

I have a 02 Tacoma 'it has 1,4100 miles on it and over night when the truck is cooled off and all the oil drains back to the oil sump ' when I start the engine I can hear a loud ticking noise until the engine warms up and the noise goes away and the truck runs really well . I am pretty sure the engine lifters are the issue . Question is did Toyota design the lifters to do this by using a weaker spring in the lifters and after the engine warns the lifters get pumped up and the noise goes away . with my truck I know it is the lifters .

 

These are shim over bucket heads (both the 3RZ and 5VZ). The cam directly contacts the shims that push the valves down, there are no lifters. The only thing that happens is warm oil eventually pools lightly in the head and runs off of the shims from the cam lobes (most likely stopping the ticking).

 

My 2001 3rz with 110,000 also does this .
I have just scanned and read through 4 pages of speculation and theories based upon established auto myths and just plain old shadetree diagnostics.
Seems that even the Professionals who were not able to find the cause fell back upon this "piston slap dont worry about it" greek mythology.
Based upon what ?
did they remove the pistons and check the skirts ?
did they mic the cylinders for out of round ?
did they remove each belt drive component ?
did they even get out a stethescope and try to pinpoint it ? I tried and it is so brief and elusive I cannot get close
and then there is only one shot a day to try and find it
I am not buying into the Piston Slap theory yet.
For one :
zero evidence, not saying it cant be, just not ready to buy it now
two :
I listened to the sounds posted and the sound of my own
to me it sounds like it is DEFINITELY coming from the front of the motor
to me, it sounds like a drumstick hitting a wood block. Then as it tapers off, it does a random fade out of rythm and out of sync with crank RPM.
to me it sounds like it is NOT at crank RPM
which leads me to accessory belt drive components

Has anyone done a diagnosis based on removing belts yet ?
Something besides the piston slap campfire ghost story ?

and then to try and pull something tangible from this thread is pretty frustrating. I am thinking some other sounds and solutions that are not related may have jumped on to the dogpile
so far the only posts that I tend to believe is one that said something like "fixed it idler pulley" or some such. I am not buying the oil change ones for some reason
I just started searching for clues but I will try and use the scientific method

 

The 2.7l has chain driven balance shafts, maybe those are knocking on cold start. Either way mine has been doing it forever and it is no worse for the wear. They do have hyper tuetectic pistons which are designed to expand to better fit the bore at a certain temp. I just wouldn't worry about it. My motor is at 193,000 and when something is actually wrong with it you can tell.

 

yES points taken.
I am not an expert mechanic and have a lot to learn at 62 years old.
I took the belts off the front this morning before cold start and it looks like they should be replaced.
However at cold start the light knock was still there with all the drive belts removed, sounds like a woodpecker and it starts at about 2100 RPM when steady up revved then goes away by 2600
I shut it off before it had a chance to warm up enough to go away
Very similar sound to a few of the videos posted. Thgis time it sounded to me like it was coming out the side of he block
I checked my oil and it was at the low side of the crosshatch. I have a habit of NOT topping oil out as this usually just causes blowby in most motors. I usually try to leave it in the middle of the crosshatch .
I topped it up to the top of the crosshatch and tried agian.
No woodpecker knock.
So now I am starting to believe the piston slap theory .
Yes I have seen those new lightweight pistons, not much skirt to do the gliding
Tomorrow morning I will test again as it has probably heat soaked the block enough already to invalidate any sound test

 

topping up the oil didnt help its still there

 

One thing I have noticed after reading through all 4 pages of this thread is that many folks having this noise are running 5w-30 oil or heavier. Toyota recommends 0w-20 for these engines and that could very well be the reason for the sound, no?
Thicker/heavier oil will not circulate as well in cold temperatures until warmed up. I have always run Mobil 0w-20 and have never heard this sound in 100k+ miles in temps as low as 0 degrees F.

This may work to confirm what I am thinking since fresh oil was dumped right on top of the cylinders where the engine is momentarily starved due to the thicker oil coming from the pan....

This is just me taking educated guesses here. I am not a mechanic.

 

0W-20 is recommended for the 2TR-FE not the 3RZ-FE. 5W-30 is the recommendation for the 3RZ

 

My mistake! Carry on, fellas.

 

Early 2nd gens with the 2TR-FE, such as my 2006 5-lug, came with 5w30 recommended and that's what I still run (switching to synth next oil change). Now approaching 120,000 miles. I have piston slap on cold starts below 40F... it's very slight at those temps and it gets worse as the temps fall. My area never sees anything below 25F and cold start at those temps sounds pretty bad to me, but what do I know... I'm in California. I'm sure it's nothing compared to the near-zero or sub-zero people. Still runs great though, no problems, and super smooth at normal operating temp.

 

Believe me. Piston slap is no campfire ghost story. It's real and 10's of thousands of engines from numerous manufactureres have it. It's the hypertuetectic pistons every manufacturer has been forced to use due to emissions. These pistons are getting better and better and the manufacturers are getting better at clearancing them on the assembly line but they do cause a rattle right at start up for a few seconds with some engines. Heavier oil does alleviate the problem in some cases. I thought I was hearing it in my 2.7 once in a while when it was real cold out. I switched to 10-30 instead of 5-30 and haven't heard that noise again since. I'm using Amsoil though and the difference between the 5-30 and 10-30 is almost non existent when it comes to cold weather performance.

 

Try a synthetic 10-30 and see if it goes away. That's what I did and it will be 0* when I wake up in the morning. Once in a while I heard what might have been piston slap but not since I changed over to the 10-30 Amsoil. Synthetics handle cold far better than dino's so I can't see where a synthetic 10-30 apposed to a 5-30 is going to hurt anything especially where you live. Most of that thin oil hype is all based around fuel mileage anyway. Not engine protection.

 

thanks for the tip I will try that
I have been using 5-30 rotella T-6
my original 98 3RZ motor with 210,000 didnt do it but I put in a 2001 3RZ from a crash takeout with 105,000 and it slaps at 40F cold start

 

Thank you for the suggestion but I'm sticking with 5w30 because I understand that oil viscosity is a major factor in the VVT system working properly. But I am switching to synthetic fo sho. 5-quart jugs of Mobil 1 5w30 were $12 off during the last Exxon Mobil rebate offer back in October. Crazy. Offer is no longer valid but here's the link, more offers will come in the future:
https://mobiloil.com/en/promotion/mobil-promotions/up-to-15-dollars-off-with-mobil-1-and-mobil-super

 

No guarantees but it's always worth a try. It can get pretty cold where you are. I was worried about the 10-30 where I live. It's been roughly 20 below for almost two weeks here now with highs in the single digits or low teens and although the engine does turn over slower in the mornings it seems to get it's oil pressure just a quickly as near as I can tell with the 10-30. Full synthetics are a different animal than dino though. I'd never run a dino 10-30 in temps this low in an engine where 5-30 is recommended and I am even slightly concerned about the synthetic. So far so good though. I heard one strange "knock" for about 2 seconds a week ago or so and haven't heard that since.

 

That makes sense. Mine doesn't have VVT. You could try it sometime though just for giggles and see what happens. With a top of the line synthetic there may be no difference with the operation of the VVT. But then. That's just a guess on my part. This high tech stuff is over my head. If you look at the data for a 5-30 versus a 10-30 full synthetic like Amsoil there is only a very small difference when it comes to temperature and viscosity but it could very well make a huge difference in the operation of the VVT. I don't know.

 

I have been researching this ticking noise for over a year, darn close to replacing the engine...
I had the timing chain kit installed and found worn timing chain guides and tensioners, of course did water pump, etc.. but that did not fix this 2seconds ticking/diesel noise at start up.
tried different filters brands, different oil viscosity etc.. NOTHING HELP. a couple months ago, I found this article about our 2.7L VVT-i engine
http://www.toyotanation.com/forum/8...ise-approximately-1-second-cold-start-up.html
I guessed that I will have this VVT gear replaced in the hope to fix this noise.

 

Not worth the effort of replacing unnecessary parts. It's nothing, really. Many 4cyl Toyotas do this. Hypertuetectic pistons are most likely the cause of the noise and once they expand from heat the notice stops.