Changed oil and now car sounds horrible!

**Chunklamb** · 11th August 2012, 22:00

I changed the oil in my 120 about 2 weeks ago now, from GM 5w-30 fully Synthetic and replaced it with what was recommended online, Mobil 1 Fully Synthetic Turbo Diesel ESP 0w-40 Dexos 2.

Since then the car sounds so loud and quite rough on start up and just doesnt seem to run as well as before... I'm probably being paranoid, but it feels like the engine knocks a little at idle?

The oil level is perfect, below max, when checked as per the instructions in the bonnet... wait 5 minutes blah blah etc

Should I just bit the bullet and change the oil AGAIN! LOL

**lee gsi** · 11th August 2012, 22:16

What sort of mileage do you have as higher mileage cars prefer slightly thicker oil.

**Chunklamb** · 11th August 2012, 22:20

What oil is best? Its only just pushing 65k.

**Chunklamb** · 11th August 2012, 22:22

I was in CostCo last week and they had this on offer - http://www.mobil.co.uk/UK-English-LC...life-0w40.aspx - almost half price, I was going to put this in instead?

**paulvectrac** · 11th August 2012, 22:25

I would put 10 / 40 in it although my cats done 50k now I use 5/30

**m8internet** · 11th August 2012, 22:29

Originally Posted by lee gsi

What sort of mileage do you have as higher mileage cars prefer slightly thicker oil.

Do they really?
I would say it is more about length of time between oil changes rather than grade

**paulvectrac** · 11th August 2012, 22:30

No lee was right higher the milage more ware on the engine hence it can cope with thicker verscosty oils alot better

**Das** · 12th August 2012, 00:50

Originally Posted by paulvectrac

I would put 10 / 40 in it although my cats done 50k now I use 5/30

But its only done 65k, not exactly high mileage.

TBH I have found 5/30 Magnatec the quietest oil in mine.

**John LE** · 12th August 2012, 01:10

Originally Posted by DasArab

But its only done 65k, not exactly high mileage.

TBH I have found 5/30 Magnatec the quietest oil in mine.

Gotta agree on this one

I used 0W-40 in my Dti and while it was getting awesome fuel economy it was starting to sound like a tractor and there was blue smoke on startup. I came to the conclusion that the oil was that thin it was breaching seals when the engine cooled down (hence the blue smoke on startup)

I changed back to Castrol Magnatec 5w-30 and the problems instantly disappeared

**Big Dave** · 12th August 2012, 04:03

My 2.2 direct has nearly 78,000 miles on the clock.

5w/30 fully synth oil from day one in it.

Doesn't use a drop of oil between 10,000 to 12,000 mile services.