Hi there, I am looking to find what the best oil would be to use in my Astra. I am using 10W-30 semi-synthetic at the moment, as that is what has been used prior to me purchasing the car. 

I've noticed recently that once she's up to running temperature, there is a bit of a tapping sound coming from the engine. Now after reading into the different types of oil, and how they are used, I was wondering if a denser viscosity would be better for her now that we're sitting at 218,500 miles. I don't want to cause damage by using the wrong oil, but would like to stop the tapping when hot. 

Any help with this would be much appreciated. 

Regards Andy.

Hi Andy

I would probably recommend a heavier grade of oil (10w40) as it has done the high mileage.

The thinner viscosity can result in blow-by in the cylinders if there is excessive wear which can result in burning oil.

Also, the thicker oil will be fine it the engine is allowed to get hot enough to burn off carbon within the engine, if it is being used locally then maybe stick with the 10w30.

Hi Trevor. Thanks for the input. I did notice that where I'd put in the fully synthetic 5w-30, it did blow a little out when rolling in slow traffic. But it hasn't done it since I put 10w-30 in. 

Next oil change I might try the heavier 10w-40. 

I didn't know if there was an additive I could use with the oil. 

Regards Andy 

There is an additive on the market called Stop Smoke, think it is made by Wynns or STP

Probably best to run it on 10w40 as this should reduce the symptoms

 

Cheers Trevor,  I did notice that it is 10w-40 that I put in, and it certainly seems to have improved.  

At 218500 miles on the clock, I'm keen to keep on top of maintenance. 

Andy.