1.6VCT valve backlash adjustment

[mad mike]

I am looking at checking the valve clearances on my upcoming cam belt change. It has became 'tappety' so I'm expecting a few to need doing (it's on 99k). Has anybody actually done this job or be able to offer any tips. I understand I need to measure the valve clearances with the camshafts removed. If I 'lock the engine' at the flywheel will I be able to reset the camshafts when they are refitted, bearing in mind they 'should' have the locking tool in place to change the cambelt?

Many thanks

[mjt]

I note you've specified '1.6 VCT' in your profile. If that means it's a Ti-VCT engine I think I've read elsewhere on this forum that it involves more than just locking stuff in place as the cam variators have to be set up properly. Hopefully someone with experience of your engine can give a definitive answer.

[JW1982]

All valve lash measurements need to be done with the camshafts installed. After all measurements are done you can determine which valves need to be adjusted. To adjust the valve lash the camshafts need to be removed. This engine has fixed tappets without adjustment plates. This means that the complete tappets need to be replaced to adjust the valve lash. After the camshafts are removed the current tappets needs to be measured. The size of the current tappets and the valve lash measurements are needed to calculate the correct sizes of all tappets.

Note that these tappets are quite expensive.

[mad mike]

22 minutes ago, JW1982 said:

All valve lash measurements need to be done with the camshafts installed. After all measurements are done you can determine which valves need to be adjusted. To adjust the valve lash the camshafts need to be removed. This engine has fixed tappets without adjustment plates. This means that the complete tappets need to be replaced to adjust the valve lash. After the camshafts are removed the current tappets needs to be measured. The size of the current tappets and the valve lash measurements are needed to calculate the correct sizes of all tappets.

Note that these tappets are quite expensive.

Thanks for the reply. Yes, my concern is that you appear to need to lock the camshafts in place with a special tool while changing the cambelt. But, as you know, the camshafts have to be removed to be able to access the tappets. So, assuming that the crankshaft is locked by the flywheel locking tool, how do I refit the camshafts to then be able to fit the cambelt. Do the camshafts have a indication to show TDC (assuming I don't have to remove the 'actuators' from the camshafts themselves).

Hope this makes sense

PS: do you know, as a rough guide how much the tappets are 'each'?

[JW1982]

The valve tappets cost approximately €30,- a piece. If you have to replace approximately halve of them it is quite a costly job.

 

When removing the camshaft the TI-VCT actuators also need to be removed. Ford prescribes to replace the camshaft seals also when removing the camshafts. Like all other Ford Sigma engines the TI-VCT has allignment slots in both camshafts. When installing the camshafts they need to be adjusted by installing the correct allignment tool in the allignment slots. Next the TI-VCT actuators can be installed and locked by the correct allignment tool.

 

Considering that the timing belt pulleys are keyless and the TI-VCT system needs to be locked adjusted properly the Sigma TI-VCT engine is not an easy engine to replace the timing belt or adjust the valve clearance. 

[mad mike]

4 minutes ago, JW1982 said:

The valve tappets cost approximately €30,- a piece. If you have to replace approximately halve of them it is quite a costly job.

 

When removing the camshaft the TI-VCT actuators also need to be removed. Ford prescribes to replace the camshaft seals also when removing the camshafts. Like all other Ford Sigma engines the TI-VCT has allignment slots in both camshafts. When installing the camshafts they need to be adjusted by installing the correct allignment tool in the allignment slots. Next the TI-VCT actuators can be installed and locked by the correct allignment tool.

 

Considering that the timing belt pulleys are keyless and the TI-VCT system needs to be locked adjusted properly the Sigma TI-VCT engine is not an easy engine to replace the timing belt or adjust the valve clearance. 

Yes, I understand. I was hoping to pick up some tips, but I can't find anyone that's done the job. I seem to be unlucky in that my car is one of very few that needs the clearances checked? Either that or most owners just grin and bare it?

[JW1982]

Ford prescribes to check the valve lash every 100.000 Miles /8 Years (whichever comes first) on the Sigma engines. Adjustments only need to be performed if the valve lash is no longer within specifications. My experience is that the valve lash on these engines usually remains within specifications and adjusting the valve lash is usually not needed.
 

Personally I would start with measuring the valve lash. There is a huge chance that the valve lash is still within specifications. Noisy tappets are often caused by worn TI-VCT actuators. The TI-VCT actuators are known to be parts with a limited life expectancy. One of the early symptoms of worn TI-VCT actuators are noisy tappets.

[mad mike]

1 hour ago, JW1982 said:

Ford prescribes to check the valve lash every 100.000 Miles /8 Years (whichever comes first) on the Sigma engines. Adjustments only need to be performed if the valve lash is no longer within specifications. My experience is that the valve lash on these engines usually remains within specifications and adjusting the valve lash is usually not needed.
 

Personally I would start with measuring the valve lash. There is a huge chance that the valve lash is still within specifications. Noisy tappets are often caused by worn TI-VCT actuators. The TI-VCT actuators are known to be parts with a limited life expectancy. One of the early symptoms of worn TI-VCT actuators are noisy tappets.

Ok, well the odd thing about mine is that it is one 'tick' rather than many. Also it is only noticeable when the engine is warm. While I have your attention what are the symptoms of a failing VCT actuator. Would it throw up any codes or engine malfunctions? One other thing, I'm not totally 100 per cent sure but it does seem to vary in intensity.

Thanks

[JW1982]

During the earlier symptoms of worn TI-VCT actuators there usually are no DTC codes or engine malfunction messages. 

Early symptoms of worn TI-VCT actuators are usually noisy tappets, slight hesitations under load or a rattle noise after a cold start. 

[mad mike]

17 minutes ago, JW1982 said:

During the earlier symptoms of worn TI-VCT actuators there usually are no DTC codes or engine malfunction messages. 

Early symptoms of worn TI-VCT actuators are usually noisy tappets, slight hesitations under load or a rattle noise after a cold start. 

So the tapping noise doesn't actually come from the VCT unit itself but is the cause of the noisy tappet, rather than the tappet itself being worn?