faizul-hasan

Hi all, a new Audi member here.

I have recently bought an used Audi A4 1.6 2004 model, current mileage is almost 110K. Recently I noticed cold start grinding noise. I was initially able to hear the noise for about 5 - 10 seconds. But now the noise stills for about 1 - 2 minutes.

Several discussions I have found while I was surfing on internet about this issue. Many of them talking about Secondary Air Injector. Any of you have solid idea about this issue and the solution for it?

Another question is, I am using semi-synthetic oil right now. After facing the cold start grinding issue I have read more about engine oils. I would like to know which oil would be the best choice for my car? Semi-synthetic or fully-synthetic oil and 5W30 or 10W40?

Thanks in advanced.

uberwgn

Faizul, is the grinding noise related to the starter motor?


The oil spec for the car is any product meeting 502.00. The engine manufacturer never specified the oil base stock. Not knowing what country you are writing from, I can suggest a 5W40 oil meeting the 502.00 spec as a good starting point.

faizul-hasan

@uberwgn

I can clearly hear the grinding noise coming from tappet. I have talked to a mechanic (he is not a well experienced Audi mechanic) also. As per him this noise is normal till the oil circulation is completed. But my worry is that when I check the car with him it took about 5 - 10 seconds to go off but now it is taking 1 - 2 minutes. So I am clueless now.

I am writing from Sri Lanka. I still can find semi and fully synthetic oil and 5W40 and 10W40 too here.

uberwgn

OK, thank you for adding the information. (My oil suggestion is still 100% valid.)


We never had a 1.6L engine in the USA. Is it turbocharged?


We did have a lot of issues with sludge in the engines from people (and the dealers) using an oil that didn't meet the engine mfr's recommendation. You might wish to remove the oil pan and check the oil pickup. If you are having circulation issues, it's only going to get worse. You may be at a point where the cam and followers are damaged requiring replacement. You should make a decision on how much you are willing to invest in this car to keep it going. Does the car run OK otherwise?

faizul-hasan

@uberwgn

I am not 100% sure about is it turbocharged? I assume it is not.

You said If you are having circulation issues, it's only going to get worse. Since I notice the grinding noise retains for about 1-2 minutes, do you think this grinding noise is coupled with circulation issues?

Otherwise car is running OK. I did not feel any other issues other than grinding noise.

uberwgn

The noise you are hearing could be related to poor circulation.


Is it possible for someone to remove the valve cover and have a look? It's likely to provide much insight.

faizul-hasan

I can get the car to the workshop who do only Audi vehicles and request them to check it. I am willing to know will there be any other causes also for this grinding noise?

uberwgn

I suppose it may be caused by something else. We are just guessing right now. A visual inspection should provide the information you seek without spending a lot of money.

faizul-hasan

Okay. Thank you very much for your reply. I will take it to the workshop and update you.

W261w261

FULL Synthetic oil, nothing else. 5w-40 is good. There is a tube in the crankcase of the engine that has a screen on the end. When using other than full synthetic oil, or even full synthetic and going longer than 5,000 miles between changes, sludge can form. As the oil is sucked up in the pickup tube on the way to the top of the motor, the sludge begins to block the screen. This starves the valve train up top, leading to engine failure.

Unfortunately, at least on the USA engines, removing the oil pan is a time-consuming job, maybe 6 hours+. You can't get at the oil pickup any other way. An while you're in there, you might as well put in a new oil pump, etc etc.

Next best ​​​is to take a look at the valve train as suggested.