I have a ticking lifter on my 99 C280. All the lifters was replaced about 10 000km ago. Before the lifters were replaced, it had a constant ticking. After the lifters were replaced, the lifter ticking is intermittent. Usually on a cold start (but not always - about 50% of the times), I'll have the ticking for about 10-20 minutes before it goes away. Sometimes the ticking will come back even if the engin is still warm, for example after I have driven for 200 km and stop - when I start up after 5 minutes it will tick for a few minutes before silencing.

I dont know why it still ticks even when all the lifters where changed. The only thing I can think of is that one of the lifters is not getting oil due to partially blocked oil galleries, etc.

Is it advised to do an engin flush, or put a detergent in the oil, to try and open up oil galleries. Or what should I do?

I afraid of causing more problems if I flush, such as all the varnish/deposits coming loose and block up the whole engin.

The car has been running on Magnatec for whole of its life (160 000km). Apart from the last service before the lifters was changed when it had Mobil 1 in. I think the previous owner tried to use a synthetic to see if it wouldn't solve the problem before changing the lifters. I bought the car on 150 000, with noisy lifter, but under the agreement that he will change the lifters.

What is the possibility that the ticking noise is something else (not a lifter), keeping in mind that it is intermittent and usually is only noisy in the first 10-20 minutes after a start.

Thanks for helping. I really need to solve this, and have asked for advise in a number of forums over the last few months (this one included), without real pratical advise.