Engine Rattle - Tappets?

[Krait]

I just noticed today that there is a loud rattle from the engine which sounds very much like a tappet. I changes with engine speed. Fortunately - or unfortunately, I cannot hear this noise from inside the car as it is so well sound insulated.

I have the 1,6 VVTi 07 model.

Is there somewhere I can find out more about these tappets? Are they hydraulic or the standard mechanical ones? How are they adjusted - with spanners or replacement shims?

Any details regarding the How To anywhere? Is this engine the same as an earlier corolla one so I can use a Corolla Haynes manual?

any suggestions please guys??

Has this been discussed at length already? I did a search but got no response. Maybe I'm looking in the wrong place?

Thanks,

Krait

[Daveyonthemove]

Is the noise only noticeable when accelerating?

In the handbook for my SR180 it states that a knocking noise under acceleration is normal. Have a quick look in your handbook to see if yours has the same info. If it doesn't then you might need to get it looked at.

[Mooly]

Fuel injectors can be noisy (normal) giving a definite "clicky" sound.

[Rumbly]

I'm not sure what tappet arrangement that engine uses ..... Google is your friend. Tappet noise on a straight four is always at a particular frequency of quarter engine speed (I think!!), it is usually quite easy to diagnose one noisy tappet as the frequency of the noise is quite distinctive.

If it is a tappet noise it could be that the camshaft itself is damaged??

I'd advise professional advice asap.

[ptaurissr]

The first place I would look is spark plugs.

I had exactly the same symptoms with my last car (peugeot 206) and it turned out that one of the spark plugs had failed. The failure of a spark plug may not necessarily cause the ECU light to flash up (it didn't in my pug, although this could be the french electronics :D )

It goes without saying that they are cheap and quick to replace

[Krait]

Thanks guys,

Answers:

1. The noise is there at idle when I am standing outside the car. I cannot hear the noise while accelerating as the road noise is louder even with the windows open. But I will look in the handbook - although it's usually the last place I look. Thanks for that Daveyonthemove.

2. It's just a single tappet or item making the noise so it could be a single injector. Thanks Mooly, that is a good point and I will investigate and revert.

3. Is a damaged camshaft a common problem? Thanks Rumbly. I'll give Google a shot.

4. I would expect a spark plug failure to cause a great deal of engine instability and loss of power, and I do not have either. The car accelerates very well and cruises at 95 very smoothly. Thanks ptaurissr.

I do have a T extended warranty so I guess my best bet is to get them to diagnose the fault and then check if the cause is a warranty item.

In the meantime any other suggestions will be welcome. I love to faultfind and repair myself as I have never had too much respect for dealers. MrT is rapidly changing my mindset.

thanks again.

Krait

[Black Knight]

To answer your questions

The engine uses a hydraulic lash adjuster set up.

You can't adjust them

The old corolla 1.6 was a ZZ engine. The new Auris 1.6 is a ZR engine. Completely different so old Corolla service manuals are not much good

[Krait]

Thanks Black Knight

What is an hydraulic lash?Definitely a new one on me.

I did download a Corolla Manual and that indicated hydraulic tappets in the 1.6 vvti with all instruction on adjusting the tappets with shims - which is the only way to adjust hydraulic tappets.

I have come to the conclusion that I need to see Mr. T and let him diagnose the problem. But first i will call the Warranty centre to find out if tappets are covered by an extended warranty.

Cheers,

Krait

[Black Knight]

Its a rocker system (think upside down see-saw). Centre pivot point is the cam shaft, one end of the see-saw is the valve and the other is the hydraulic lash adjuster. Engine oil pressure pushes the lash adjuster hard up against the cam shaft. That means the cam is always in touch with the rocker and then pushes down the valve at the other end.

The ZZ ones from the old corolla are bucket lifters and graded rather than shimmed. If you need to adjust them you have to replace the entire bucket. The cam acts directly onto the bucket which acts directly onto the valve. Not hydraulic tappets.

[Krait]

Today I visited Mr. T and had some good news.

The rattle/tapping noise is mainly due to the VVTi mechanism. However, there is another tapping noise that possibly emanates from the front of the engine and could possibly be the bearings on one fo the pulleys - or the belt. (honest, that's what they told me).

As it is going in for a service in 4 week's time, they will have a good look at it then and advise.

Fingers crossed.

Will update the saga next month.

[Krait]

Well, Good news.

MrT did my first service since buying the car. 60k service and they were very good about the whole process.

They confirmed that the tapping noise is the VVTi system, but they could not find the source of the low volume hiss from the engine bay. But they assured me it is nothing to worry about.

Brake discs and pads 20% worn. Tyres about 30% down. Nothing else but no charge.

The check list does include an item for the 4ZZ-FE engine (which I believe my 1.6 is)which says: "Check valve clearance audibly with stethoscope every 6 years or 60k miles. Extra charge for adjustment." This Item has a tick (OK).

I complained about the rusting and peeling wheel nuts. They said that MrT does not warranty cosmetics. But, they did say they will look for a good set of nuts (dare I use this word?) on an exchange car and will fit them in the next week or so.

What fantastic service.

Let's hope it all sticks together for another 12 months.

[ptaurissr]

Check with a stethoscope, new one on me but logical i guess! Glad its all sorted

[Krait]

Yeah, Me too ptaurissr.

Every time I take a car to a dealer my heart is in my mouth and wondering if their hands are going to be in my wallet. But I have been very surprised and pleased with the Service from Ocatgon in Bracknell.

Cheers