Anyone else have a drivtrain ticking noise when car is cold and then goes away or gets better when w

I have not.

Your gut feeling, and if the service records don't show it, now is a good time to plan for it. You may have to change it yourself since aftermarket shops consider the mileage too high to risk, and Toyota's take is that the eCVT fluid is good for the 'life' of the vehicle.

I changed mine at 160K, old fluid was looking like brown syrup(compared to new pink fluid). Not hard to do, plenty of YouTube videos on this subject.

 

It’s the solid lifters in the 1.5 engine. The 1.8 in the 2010+ got hydraulic lifters making them run smoother when cold.

we’ve had a hand full of gen2 in the family, one going past 300k, they all were noisy when warming up. That’s just how they are, especially when they are past 100k. Nothings wrong, and really nothing you can do.

Just make sure you have proper oil level, and a good quality oil, your engine will run forever! It might not be the smoothest engine, but it’s reliable!

btw there is nothing in the Ecvt that would cause clicking or clanking. It’s a simple planetary gear set into electric motors.

 

Go to youtube and look up prius inspection mode It will give you the chicken dance to put the engine in inspection mode which means the engine will run in idle till it is turned off.

Raise the hood...then put it in inspection mode and get your head in the engine bay and listen around. The engine runs non stop. You can buy a mechanics stethoscope at Harbor Freight they work really good. And listen around like a doctor. get on the ground and crawl in from the front under the engine as close as you can and listen.

If the engine only saw dino oil its whole life it may have some excessive valve train/timing chain wear and noise. Especially if only dealer dino. The engine is already as loud as a broken sewing machine but I hear no ticks in mine.

BUT... when my hybrid battery was getting bad and the car required alot more engine power to get anywhere I did hear the lifters prominently tick in the car ONLY under hard acceleration load. You will not hear it just revving it up has to be under load. When battery is getting old and tired the engine has to supply the bulk of power and it ain't happy. It really has to work. Most people are clueless about the forces at work there and just keep pushing the gas pedal harder to reach the power level the car used to have.
To reach that expected power level the engine is screaming and its hard on the valve train.I'm speaking for what I saw when my battery was getting tired.

Hows your battery? Goes to one purple bar alot? Crappy mileage? Your right in the mileage mine started to dive but I brought it back with Prolong Charger system. It restored most of the power that had gone away. The prius is all battery for power.

hybridautomotive.com

 

When on park and reving the engine isnt under load and may not do the ticking noise. Priuses have noisy engines since new. But the tickong noise can come on mid rpm. Could be many types of ticking noises. When you start and drive in cold temps does it ticks and is speed related or just when driving and depending on rpm?

Also could be other tick. Zip tie on the cv axle, loose heatshield or panel...even rock in the tire thread

 

What you might be hearing is engine knock (or pinking). According to the OM (owner's manual), if it is only a light knock and only under a load (accelerating, for example), and not prolonged, it is ok.

If it continues to bother you, you can go up an octane level (manual specifies 87 AKI or better), so go up to 91 AKI. Run the tank quite low (as low as you dare ) before refilling with the higher octane gas, to be sure you get the best benefit – too much 87 left in the tank and it will dilute the effect. If it stops with the higher octane gas, it is almost certain you were hearing engine knock. To offset the high pump price, you will get better mileage and the car will retune itself for the higher octane so it should be peppier – at least that is my experience. I get 150 more miles per 11 gals on (our equivalent of) 91 AKI (which is RON 95, if anyone UK/Aus/NZ is watching). For those that think 91 was better so going up higher again must be even moreso, sadly no. Because of the engine design, the benefits top out at 91 AKI.

I hope that helps.

 

Did you mean 15 instead of 150?

 

No, I did mean 150 miles, but just estimated from km to miles in my head. It turns out I was a bit optimistic with my math. The amount is between 100 - 125 miles per 11 gals further. I should have added YMMV (your mileage may vary), pun intended.

 

Doubtful. That would not show up ONLY when the car is actually moving.

 

Back to basics.
Have you checked the tires for a "nail" stuck in the tread ?
If you have real hub caps, have you checked for a rock inside one of them ?
Wheel bearing ?

 

When it’s cold and under load, um yeah a solid lifter engine is going to tick. That’s just how they are. I’m not saying this is 100% the noise he’s hearing, but it might be. I’ve had two gen2’s and they tick when they are cold, and when I accelerate slowly in the morning. Once they warm up it’s pretty much gone.

 

When I put it in neutral and the engine is still idling, it’s quieter

 

That is not my experience at all. I have tried it and did not get any observable difference even after two consecutive fills. Consumer report also mentions the same.
Why You Might Not Actually Need Premium Gas - Consumer Reports

If fuel efficiency improves by 9-11% as you suggest why would anyone ever recommend lower octane fuel?

 

No it isn't.
Valve lifters and their associated cam lobes are NOT under additional pressure when the engine is "under load".
They just don't work like that.

Any extra noise when cold is caused by additional clearance introduced by the contracting metal parts.
That is how they work.

 

I did try the highest octane (94 AKI) and found no discernable (and slightly higher (worse) fuel consumption) on 2 out of 3 tanks, so we at least agree on that. I'm wondering if there is some discrepancy between what is supposedly equivalents of AKI vs RON and that is what we are seeing here.

When I did my experimenting I kept scrupulous records which is just as well because my perception with 94 AKI was quite the opposite (placebo effect, maybe?) to the reality. There was no doubt about the 87 vs 91 AKI. There were definitely more miles per tank resulting in higher MPG – 45 MPG (US) increasing to 50-52 MPG (US).

I'm now wondering if the programming of the ECM is different in the US/Canada to meet some CARB targets. Maybe this allows the use of 87 AKI but results in lower MPG.

Without reading the Consumer Report, I have no idea what they said, but if it was something like stay with the grade recommended in the owner's manual, then that is fair.

It is a reasonable question and one to which I have no answer. In the US the owner's manual specifies 87 AKI (RON 91) or higher. In other areas of the world (EU, UK,) RON 95 (equivalent to 91 AKI) is recommended and is the lowest octane number available. In my manual, the Fuel section is laid out differently and the wording is quite different. It says this,

Using 95 RON I have definitely found this to be true.

While this discussion might be interesting to some, my post was in answer to the OP's question and I standby the initial part; if the cause is knocking and a higher level of octane solves the problem then regardless if there is or isn't any benefit, then that is a solution. If the knocking falls into the acceptable level as stated in the owner's manual ...

... then the OP need not do anything.


Table of AKI to RON Conversions

	AKI	RON
1	87	91
2	91	95
3	94	98

 

Just to say that 87 AKI is not always 91 RON. AKI is also called (Ron+Mon)/2 That means the 87 AKI could be (94RON + 81MON)/2.
Or 95 RON in one gas station in NZ could be = with 95 RON in another gas station in NZ but those 2 fuels could be 88 AKI and 91AKI at the same time.
Also the chances of the gasoline being equal to the octane it is advertised as in all thousands of gas stations is close to zero. It could be +/- few numbers I am sure when i know what some gas station owners do.

For us to say if the higher octane gasoline is better in fuel economy and by how much exactly (is it 0.111% or is it 10%) we need some seriuos data which we don't have and Toyoda is stingy to say. If i was the fleet manager of some sort of a company when i get 2 new exact same cars then driving few hours next to each other. Few gas tanks collecting data with same fuel and then changing fuels then measuring exact octanes in all scales and comparing is somewhat close to scientific research.

 

You could adjust them, but that might be sand pounding involved and/or expensive. Just for giggle you could phone the service department, ask how much (better disguise your voice...).

I guess step one though, would be to confirm what the noise is. A mechanic's stethoscope might help?

Here's some info on second gen valve adjustment, attached.

(What's nuts: back a few decades, I would routinely adjust the valves on our Honda Accords. They're screw and lock-nut adjustment. The valve covers were readily accessible, came off in about 10 minutes, and the whole job took me maybe 2 hours. The only time I encountered shim style was on a Honda Hurricane bike, and that I left to the mechanics.)