Castrol syntec 10w-40 and an old BMW

[Russell]

Anyone have an opinion of Castrol Syntec 10w-40 oil? Thinking about using it in my 95 bmw 525i wth 158,000 miles. Just finishing my latest ARX treatment with conventional oil. Find my engine is noisy with 0 and 5 weight oils. I am also considering heavier oils such as 20w-50. TIA

 

[Hermann]

What does the owners manual for that year say. That is what I would consider. 10w-30 or 10w-40 Maxlife Blend would be my choice.

 

[Russell]

Depended on the season and most oils were conventional not synthetic.

 

[Drivebelt]

I don't think I would go as heavy as a 20W-50, unless the engine is consuming a lot of oil and you want to try and control that. HDEO 15W-40's would be my preference before those 50 wt's. The Group II based 15W-40's like Delo 400 are very good oils …

Quote:
Delo 400...
Cost-effectively Rivals Performance of Synthetic


Another option you might consider might is a 10W-30 HDEO like Delo or Rotella. The 30 wt HDEO's tend to be blended near the upper end of the 30 wt range. Delo 400 LE 10W-30 is 12.0 cSt -- almost a 40 weight. So you could jump up in viscosity over the regular SM/GF-4 5/10W-30's which are usually around 10.5 cSt by using one of the HDEO's 30 wts.

 

[warchildindy]

Russell, how did the ARX treatment go for you?

I have a friend, with a Beemer, with 35,000 miles, that wants to break down the engine and clean the oil channels.

Is that why you did the ARX treatment? Sorry to hijack your oil thread.

 

[Russell]

Actualy I have not really completed the treatment as I have not drained rinse oil and replaced it yet. Nor have I examined the filter for contaminants.

I do have what seems to be lifter noise after driving 20 plus miles and then slowing down and idling. It goes away if you rev the motor. Happens as oil gets about 3,500 miles on it. Not sure if thinner or thiker oil might help.

However, I did two ARX treatments about a year or so ago and it seemed power and economy improved slightly.

 

[bmwtechguy]

The Syntec 10W-40 is a good oil and I know several people who run that in their 90's BMWs with good results- low consumption, quiet engine, etc. Have you considered the M1 HM oils? Those oils are also working well in the same engines with accumulated miles similar to yours.

 

[Russell]

Good idea, I was also thinking along those lines as well.