2007 Prius engine ticking noise

[new2meprius]

I am a new owner of a 2007 Prius - 11,000 miles
My question is, when the car is slowing down to stop or driving between 0 - 20 it frequently makes a noise that sounds like an egg timer. It has a ticking sound as if you were to reverse the knob on a timer. Does anyone know if this is normal. The dealership told me it was the generator kicking on, but I really don't recall having heard it before. Thanks.

[isalacki@earthlink.net]

I also have a 2007 Prius with about that mileage and having the same issue. I also hear it sometimes when I'm taking my foot off the brakes and start to accelerate. I plan on going to the dealer in the next few days to have it checked out. I also don't recall it happening in the past.

[edthefox5]

Yes as stated earlier thats the brake accumulator pump. Its providing vacuum for the master cyl/brakes. It comes on all the time.It gets louder as the car gets older too. You'll get used to it. Its normal.

[qbee42]

Originally Posted by isalacki@earthlink.net

I also have a 2007 Prius with about that mileage and having the same issue. I also hear it sometimes when I'm taking my foot off the brakes and start to accelerate. I plan on going to the dealer in the next few days to have it checked out. I also don't recall it happening in the past.

It's the brake accumulator pump, which is an electric pump for the power brakes.

Tom

[edperera]

Originally Posted by mikepaul

In the last week or so I've noticed a distinct tick sound when the car is idling, which has been at the start of driving when it's too cold to stop the ICE at the light. It gets louder once I accelerate, but is lost in the road noise soon after.

I googled a bit and manifold leaks are supposed to sound like that, but I'm not sure at what point I'll see some drop in power or MPGs as the sign the dealer should look at it. 63,500 or so as of this week.

And while I did only notice it once the radio was accidentally left off, I doubt I missed it all this time just because I usually have the volume up rather high. Is there anything the might have been muffling the noise that might have worked its way loose?...

Hi Mike Paul,
Did you ever find out what the problem was with the ticking noise from your engine on acceleration. I ask because i have exactly this problem and the dealer cannot fix it. They've checked the tappets and replaced two of them, fixed an engine mount. But the noise is still there. Did you fix your problem?
Thanks
Ed Perera

[Patrick Wong]

Originally Posted by edperera

...They've checked the tappets and replaced two of them, fixed an engine mount. But the noise is still there.

Hi Ed,

Pls note that the Prius valvetrain does not include tappets. The camshaft contacts a solid valve lifter (which is produced in various thicknesses, this is how the valves are adjusted). The lifter rests on top of the valve spring retainer. The valve spring retainer is attached to the end of the valve.

Did your dealer tech measure valve clearances on all of the 16 valves? If the clearances are all OK, maybe one of the valve guide bushings is a bit loose, allowing the valve to wobble slightly and make the sound you are hearing. Unfortunately there's no way to ascertain this without removing the cylinder head and disassembling the valvetrain.

How many miles on your engine?

What oil viscosity are you using?

[edperera]

Originally Posted by Patrick Wong

Hi Ed,

Pls note that the Prius valvetrain does not include tappets. The camshaft contacts a solid valve lifter (which is produced in various thicknesses, this is how the valves are adjusted). The lifter rests on top of the valve spring retainer. The valve spring retainer is attached to the end of the valve.

Did your dealer tech measure valve clearances on all of the 16 valves? If the clearances are all OK, maybe one of the valve guide bushings is a bit loose, allowing the valve to wobble slightly and make the sound you are hearing. Unfortunately there's no way to ascertain this without removing the cylinder head and disassembling the valvetrain.

How many miles on your engine?

What oil viscosity are you using?

Hi Patrick,
Thanks very much for your quick response.
You're completely right, the dealer tech said he checked the valve clearances on the 16 valves and two were out slightly which they adjusted.
The car's covered 100,000 miles, with full dealer servicing and oil changes every 5k (Mobil 1 ESP 5/30 oil) in between Toyota servicing (which is every a service every 10k here in England, not the 5k you guys appear to have in the States).
Fortunately i have a warranty that will cover all the costs, which i think is lucky, but i would have still preferred a simple fix!
I hear what you're saying about the valve guide bushings and i will suggest this to the dealer and see what they say.
Thanks again for your help.
Ed Perera

[ejsasem]

Hi, My name is Eric and I also have a 2007 Prius making ticking noise . When its very cold-20-30 degrees, it makes a loud tapping noise like a bad lifter for about a minute or so. Then after it warms up, it still makes ticking noise at idle and is noisier than it used to be on acceleration. I took it to the dealer and they couldn't hear the initial tapping noise when its cold and say the engine sounds normal when driving.
How did you get them to even check the valve clearance? Ive got the 100k mile Toyota warranty but my cars got 93k on it already.Ive changed the oil with GTX 5w30 and toyota filters every 4-5k miles since new. Anyone know of a good Dealer in NY area that will has good hearing? Newburgh Toyota certainly does't!
Thanks, Eric

Originally Posted by edperera

Hi Patrick,
Thanks very much for your quick response.
You're completely right, the dealer tech said he checked the valve clearances on the 16 valves and two were out slightly which they adjusted.
The car's covered 100,000 miles, with full dealer servicing and oil changes every 5k (Mobil 1 ESP 5/30 oil) in between Toyota servicing (which is every a service every 10k here in England, not the 5k you guys appear to have in the States).
Fortunately i have a warranty that will cover all the costs, which i think is lucky, but i would have still preferred a simple fix!
I hear what you're saying about the valve guide bushings and i will suggest this to the dealer and see what they say.
Thanks again for your help.
Ed Perera

[Patrick Wong]

Originally Posted by ejsasem

...How did you get them to even check the valve clearance? Ive got the 100k mile Toyota warranty but my cars got 93k on it already.

It's not clear to me whether valve adjustment would be included in the extended warranty, as that is a maintenance item (valve clearance is inspected based upon the presence or absence of excess valvetrain noise, at 60K mile intervals.)

It will be pretty expensive to measure the valve clearance since the valve cover has to be removed. If any valve lifters need to be replaced, then that will be even more expensive as the camshafts have to be removed.

Also note that upon initial startup of the cold engine, ignition timing is retarded for a short period of time. That might be part or all of the reason for the noise which goes away after a short while.