Engine Failed Audi A4 Common Problem

[Afshan]

Hello, 
I am the owner of Audi 2004 model with 2.0 L petrol engine. Last night in the morning when I started my car at around 5:15am, as usual to go to my office in Dubai, I notice some awful nocking disturbance. It only do the disturbance or noise for about 4 to 5 second and then appears to be excellent driving/starting after get heated. 

Now the mechanic say leave your car at middle of the noon with them, and in morning he will wake up early and check the noise at 5:14, Stupid. Anyway I think they do it like with all customer. 

Just raising this question forum to understand is the problem with the low oil? Or It could be just because in the hot or cold weather? 

The only thing which make me worry is I changed my car only just before 25 days back around. 

Any suggestion or clue to solve the problem will be appreciated.

[hanif]

Hi,

The problem you describe is almost certainly related to the valve lifters. You say the noise disappeared after about five seconds, which is typical of sticky valve lifters.

The problem is often caused by a low oil level, but when the oil level is low, the noise would be there all the time. It is more likely that the problem is caused by old, dirty, or contaminated oil.

The valve lifters work like hydraulic valve springs, and old or dirty oil can cause their internal valves to stick, which causes the noise because the lifters do not maintain a proper clearance between them and the camshaft. As the engine warms up, or when the oil pressure reaches normal, the ball valves in the lifters are forced to open, so the noise goes away.

The first thing you should do is add some engine flush to the oil, and drive the car normally for about 200 kms. This will give the engine flush time to dissolve the sludge that interferes with the working of the valve lifters.

Then drain the oil and filter, and fill the engine with a full synthetic oil, because synthetic oil not only provides almost twice as much lubrication as regular oil, but also because synthetic oil does not form sludge, varnishes, and other gunk that can interfere with the lifters.

This will almost certainly fix the problem, but if it does not, you may have to replace the valve lifters as a complete set. However, it is very rare that engine flush and an oil change does not fix the problem.

I hope this helps, but please keep us posted on the issue, since it may be of help to other members as well.