I have recently had an oil change. My previous oil was Selenia WR, which I think was a 5w/40 grade. That was put in my Multijet engine 6000 miles ago, came out quite clean. The italian garage that I go to, has changed the oil and filter this time, but filled it with Selenia Turbo Diesel 10w/40.

But in the last 200 miles that it has been in the engine noise is so much quieter than when it had Selenia WR in for the first 200 miles.

I know that its marginally thicker oil and will suspend deposits better, besides that, I do not know, any idea's from the rest of you.

Just as a note, I change the oil every 6000 to 8000 miles, generally before the oil turns to a dark brown, I like a clean engine internally.

engine oils have different viscositys which means its resistance to flow or how thick it is ie 10w40 has a higher viscosity than say 5w30 it all depends on the type of engine in your car weather it is turbo petrol turbo diesel,if there are timing variaters on a cam shaft,it the engines has restricted oil gallies etc they are all different so just make sure you put the right oil in the right engine

5w40 and 10w40 are exactly the same once the engine has warmed up. when the engine is cold the 10w40 is significantly thicker.

a multi-jet should use 5W-40, nothing else. the garage have used 10w40 because it is much cheaper for them. this is not unusual, however it is also not the kind of thing a decent garage would do. the recommended oil grade is recommended for a reason, the engine's entire lubrication system is designed to use that viscosity of oil.

on a cold start your engine will not get sufficient oil circulation and it will also suffer from increased oil pressure, putting the pump under increased load. a cold start is the most important time to get good circulation. for that reason i would change back to 5w40, certainly before the colder winter months arrive.

in my opinion the garage should cover the cost of replacing the oil, however i would not trust them to do it even if they offer.

:yeahthat:

The Correct oil for a multijet is the Selina WR. It's in the user manual so they can't claim they didn't know. Get them to cover the cost of changing the oil back. Someone in the Bravo section had a garage change the oil FOC because they had used Non-Selina oil (Mobile or something).

Using wrong viscosity oil is as fundamental a problem as fitting a wrong part.

I did a lot of reasearch into suitable oils for the Croma. Needless to say Selenia WR is the Fiat recommended one.

Selenia WR, synthetic base, 5W-40, ACEA B3/B4, API CF, diesel only
Castol TurboEdge Diesel, synthetic full, 5W-40, ACEA A3/B3/B4, API SL/CF, diesel only
Mobil Synt S, synthetic full, 5W-40, ACEA A3/B3/B4, API SL/SJ/EC/CF, diesel/petrol
BP Visco 5000, synthetic full, 5W-40, ACEA A3/B3/B4, API SL/CF, diesel/petrol

These are the only oils readily available that I would consider using. Of these my prefered oil is the Castrol TurboEdge Diesel. Like WR it is optimised for direct injection diesels and is what I use, only because I tow a caravan and the fully synthetic oil should be better in the long run than the WR semi-synthetic based oil. Needless to say both oils exceed the required standards.

Summary - for the Croma diesel engines you must be 5W-40, ACEA B4 and API CF.


This link will help with ACEA ratings - http://www.acea.be/images/uploads/pub/070308_ACEA_sequences_2007_LD_and_HD.pdf

For API ratings - http://www.unitedoil.com.au/apiclass.htm

Nick /////

Thanks for you advice.

I have since spoken to the garage, and 2 things have emerged. Generally oil changes are done on a multijet engine every 6 months or 9000 miles. I am told the ECU reader for the oil condition in a Croma is not very accurate. Also Croma's with less that 60,000 miles are suited with Selenia WR. But as mileage grows, its better to use a semi synthetic ie. Selenia Turbo Diesel 10w/40.

I must admit, since going from 5W/40 to 10W/40 since my last post, I have racked up another 400 miles and the engine at idle is so quiet and when driving along you don't hear it. No I am not deaf. My Croma has 66,000 miles on it now.

The garage I go to is a higly recomended place, hence they inform you of everything. Price wise there is not much difference with WR, only £4.89 between them for 5 Litres.

I will continue with the 10w/40 for 6000 miles, and if it is crap for this engine I will go back to WR.

It is unlikely that over 6000 miles you will do much/any damage to the engine, but for reasons already stated I would switch back to a 5W-40 at your next oil change.

As a matter of interest did the garage you use reset both the Service Counter AND the oil degradation counter. Changing ever 6000 miles will mean that the oil degradation counter will take 3 such changes before the change oil light comes on.

Nick /////

Yes Nick.

They always reset the degregation counter and other faults, the service indicator they have not, cos I got 6000 odd miles to go before my 1st Cambelt change. Since owning Alfa's in the past I will always change oil very 6000 miles or 6 months which ever comes first. The 1st owner of the Croma who had it for 2 years, had an oil change every 7000 miles, hence the service book having a fair few of them which is stamped for each of them.