Valve tap cause

Remove valve cover , start and run on low idle, adjust loud tappit. First turn in (clockwise) tap will get lowder then turn back til tapping stops.

Some tapping is normal with age and mileage. Wear on the cam and lifters and followers causes it.

Hi John, Im AL the owner of Big As Auto Repair.

John, when the engine dies at stop lights, there are several things that can cause this issue. (1) The engine could have a vacuum leak, you can check this by spraying carb-cleaner around the intake manifold. (2) The Idle Air Control Motor could be either sticking or carbon build up where it mates inside the throttle body. You can check this by tapping on the motor and see if it starts to idle correctly, if it does then replace it and clean inside the throttle body with carb-cleaner. (3) The EGR Valve if equipped, could be sticking open, this causes the engine to die. You can check this with the can of carb-cleaner as well by spraying around the EGR if the engine speed changes then replace the EGR Valve. Hope one of these helps and please visit my auto-repair-website at: http://www.bigasautorepair.com/

Valve setting? Most engine valves have an automatic adjuster to self adjust the setting. You didn't say you had it apart. So, I'm thinking you have a dirty condition that would make the adjuster or valve tap. If so good additives just for both those conditions can restore the adjusting by cleaning and freeing the ailing parts. Try the link below for more info and needed product. Stops noisy engine valve tap in 10 minutes or free Add Driving ends tap

The vacuum hoses have probably started cracking at the turns. If there has been any under the hood work done, sometimes things get pushed on or moved and the rubber hoses on the vacuum system will get old and crusty and crack. That cause the car to die when it slows down to an idle, like at a stop sign or stop light. then it starts and runs normal until the next stop sign.

It sounds like you have a valve tapping because when it warms up the valve expands from warming up so it will get quieter.

these engines have hydraulic lifters that open the valves,when you start the engine it doesnt have oil in the top and will tapp for a few seconds it is totaly normal for an older car, make sure you use a napa gold oil filter they filter the best and have an anti siphon valve inside that keeps oil in the top of your engine for cold starts also try some marvel mystery oil its the best, will clean and quiet

Hi, when you say tapping--you mean the cylinder is making a tapping noise? If yes, that is a bad lifter/lash adjuster that is not allowing the valve to open fully. This will cause a misfire, but even if it didn't, it would soon wear out the can lobe and then require a major repair.
If it's not tapping, please see my tip at http://www.fixya.com/cars/r6715318-causes_gasoline_engine_misfires . These are generic instructions. If you get stuck or need specific instructions for your car, please get back to me.

Hi,

This could well be the Vacuum pump tapping,(if you have a 5 cylinder diesel engine)

If the tapping seems more pronounced at tickover/low revs,
A quick check is to repeatedly press the brake pedal when the tapping is present (and gradually returns then the culprit is indeed the vacuum pump.

If it really bugs you then just get a new one, or just put up with it until the servo performance starts to degrade.

Cheers.

Hi, if the tapping is coming from the top half of the engine then the chances are it will be one of the hydraulic lifters that operates the valves the chances of a valve been gone is pretty slim if it was a valve your car would start to miss fire.

These lifters can be replaced and it is quite a big job to do. But getting it done sooner rather than later could save you alot of money just in case it does cause a valve to break this could cause you to have a seized engine and might need new engine.

The lifters themselves might be able to be adjusted but this would need to be done by trained mechanic as it takes exact measurements to find out the right lifter to adjust and thats if their is room inside the lifters to adjust them slightly. If not then you will need to have all the lifters replaced as to get the one out you need to be able to get to all of them. Its difficult to tell for sure witch one is playing up so this is why they replace them all.

On older cars you used to be able to adjust them with spanner and screwdriver but they stopped making them like that because they was un-reliable and was always noisy so instead of a spring type valve they use hydraulic ones now witch all cant be adjusted this would need to be checked.

Let me know how you get on or if you need further assistance ok