Audible Valve Clearance Check.

July 30, 2008

My 5 year old D-4D has covered 75k miles, full Toyota service history, performs well, but has always

had a rattly top end, as if valve clearances too large.

What is the Audible test Toyota advise to check clearances? What do you listen for? seems a bit Heath Robinson to me.

Or could it be injector noise?

July 30, 2008

My 5 year old D-4D has covered 75k miles, full Toyota service history, performs well, but has always
had a rattly top end, as if valve clearances too large.
What is the Audible test Toyota advise to check clearances? What do you listen for? seems a bit Heath Robinson to me.
Or could it be injector noise?

I expect it is a bit of "experienced technician's ear", but that's possibly preferable to removing timing belt covers, injection pipes, cylinder head covers etc, which is what is suggested is needed to be able to apply the shims that are supposed to be available.

Never convinced they ever do this audible test as is suggested in the service schedule, but I could be wrong. I'm sure the mechy experts will have a better explaination.

July 30, 2008

My 5 year old D-4D has covered 75k miles, full Toyota service history, performs well, but has always
had a rattly top end, as if valve clearances too large.
What is the Audible test Toyota advise to check clearances? What do you listen for? seems a bit Heath Robinson to me.
Or could it be injector noise?

It is heath robinson. It would take a brave even very experienced mechanic to determin that a noisy top end is the valve clearance unless they only profess to know if it could be the valve clearances. Its like saying "make a visual inspection of the tyre pressures"!

If you want to listen to the injectors, get the biggest screwdriver you can find and press the blade into the body of the injector and then press your ear into the handle. They make a fair racket when they snap open at 1500bar.

July 31, 2008

My 5 year old D-4D has covered 75k miles, full Toyota service history, performs well, but has always
had a rattly top end, as if valve clearances too large.
What is the Audible test Toyota advise to check clearances? What do you listen for? seems a bit Heath Robinson to me.
Or could it be injector noise?
It is heath robinson. It would take a brave even very experienced mechanic to determin that a noisy top end is the valve clearance unless they only profess to know if it could be the valve clearances. Its like saying "make a visual inspection of the tyre pressures"!
If you want to listen to the injectors, get the biggest screwdriver you can find and press the blade into the body of the injector and then press your ear into the handle. They make a fair racket when they snap open at 1500bar.

Just done it, and they do make a racket, could well be the noise I am hearing when driving.

I am also looking out for a similar vehicle I can compare noise with.

It seems likely that no one has ever had valve clearances physically checked.

July 31, 2008

Its a big and fiddley job which requires you to fish the shims out with a special magnetic tool. To be honest I would guess it only gets done following overhaul or major mechanical work.