What oil would you recommend? (1991 740 2.0)

[AllHailKingVolvo]

Hi all,
I want to change the oil and filter on my ‘91 740 2.0 estate as I’ve covered a couple of thousand miles in it since I bought it a couple of weeks ago, and although it was serviced a couple of months before I bought it, I’m aware that it’s done granny cycle duty for the last 16yrs and I’ve been doing motorway miles, so I’m sure I’ve stirred up plenty of gunk that hasn’t been disturbed for a long while.

What oil would you folks recommend? It’s done 173,000 and doesn’t burn or use much oil at all-it’s stayed at the top of the stick since I’ve owned it.

I know Volvo recommend GTX 10w40 but obviously it’s 26yrs old and lubrication Tech has come on a lot in that time!

Cheers
Phil

[Jebus]

I use Shell HX7 10w40 in mine, its a good quality semi synthetic, not expensive and done to the spec.

If it isn't using oil, and its not tar like I wouldn't worry, maybe just do a few short interval changes to gently flush the gunk away and worry not after that

[Laird Scooby]

I'd also recommend a semi-synth 10W40 :

https://www.eurocarparts.com/ecp/p/c...4211&1&cc5_245

Their current promo code is "SAVE33" which will probably save you a few quid as well.

That's a good oil and it seems very well suited to my 88 760, i've heard good reports about it in other engines as well.

Don't be tempted by the Triple QX version (ECPs own brand), i used to use this but lately it has made my engines smoky and i've heard rumours that ECP have used recycled oil as a consituent part of it - whether there is any truth in that rumour i can't be sure but i do know it made 3 previously smoke-free engines very smoky and it disappeared instantly when i changed the oil to the Gulf stuff.

If you want to give your engine a gentle clean inside and give the oil seals a bit of a helping hand then add about 0.5L of ATF-U to the engine oil a few hundred miles before doing the oil and filter change, then when you're doing the oil/filter change, use about the same amount when filling the engine with new oil.
In other words, if you need to put in a total of 5L of fresh oil, add 4.5L of 10W40 and 0.5L of ATF-U.
It will help to keep things running cleanly and smoothly and revive any weak oil seals.

As for GTX 10W40, it's a good oil but it's smelly, even on a car with no oil leaks!

[swedish brick]

Originally Posted by Laird Scooby

I'd also recommend a semi-synth 10W40 :

https://www.eurocarparts.com/ecp/p/c...4211&1&cc5_245

Their current promo code is "SAVE33" which will probably save you a few quid as well.

That's a good oil and it seems very well suited to my 88 760, i've heard good reports about it in other engines as well.

Don't be tempted by the Triple QX version (ECPs own brand), i used to use this but lately it has made my engines smoky and i've heard rumours that ECP have used recycled oil as a consituent part of it - whether there is any truth in that rumour i can't be sure but i do know it made 3 previously smoke-free engines very smoky and it disappeared instantly when i changed the oil to the Gulf stuff.

If you want to give your engine a gentle clean inside and give the oil seals a bit of a helping hand then add about 0.5L of ATF-U to the engine oil a few hundred miles before doing the oil and filter change, then when you're doing the oil/filter change, use about the same amount when filling the engine with new oil.
In other words, if you need to put in a total of 5L of fresh oil, add 4.5L of 10W40 and 0.5L of ATF-U.
It will help to keep things running cleanly and smoothly and revive any weak oil seals.

As for GTX 10W40, it's a good oil but it's smelly, even on a car with no oil leaks!

I might get some of that Gulf oil for my 740 if you reckon it's good. I normally use a quality 10/40 semi synthetic in it, and did in my old one too.
The current one I've been using the cheapo ECP TripleQX as a flushing oil. The car had been sat for two years unused and I don't think it'd been serviced for much longer than that either so I've been using TripleQX to flush the engine out, changed regularly. It doesn't seem to be the best oil ever tbh...

I'll get some of that Gulf stuff I think and I've got a genuine Volvo filter already, since it's about as clean now as it's going to get.

[c1800]

The forums of the world are littered with recommendations about oil. It seems to be thus “I use this, it’s very good!”.

Synthetics are the the best. Pick one and go with it. I use Mobil.

[aardvarkash10]

Originally Posted by c1800

The forums of the world are littered with recommendations about oil. It seems to be thus “I use this, it’s very good!”.

Synthetics are the the best. Pick one and go with it. I use Mobil.

Yeah, this. Bear in mind two things:

1- the engine was designed over 40 years ago, and built at least 20 years ago. A very latest spec oil designed to lube highly stressed forced induction engines at high rpm is kinda wasted on a B230XX

2 - Most B230XX engines are 100,000 miles old or more. They have built up carbon and oil solids, varnishes and lord only knows what else drifting around or adhering to their internals. Like sleeping dogs, this stuff is often best left. Low detergent is a key feature here.

Upshot - if the oil is reliably rated at SF (API) or better and on special somewhere, go with it. Frequent changes are more value than high cost, high spec oils.

[Paul240480]

In my old 240 (now sold) I used 10/40 for a while, Made no noticeable difference to running with a mineral ( which, let's face it they were designed to use). Stayed with the semi for a good few years .
Then I put 100% in my N/A 850. After a while it began a top end knock on start ups . Especially bad after a few days of standing .
Based on advice on here, the 100% was too thin for an N/A , turbo models yes , N/A no.
I switched back and after a good few miles all went quiet again. The car is with a mate now and still good.
Based on that theory, I switched back to a mineral on my 240 for the last 3-4 years of owning and it ran great.
Owning the 200 for 14 yrs, 148k - 215k and 850 for 8 yrs, 138k to over 200k. (Clock died) in my experience, go with the recommended spec of oil , make? Your choice go with what you can afford, so long as it meets the spec'.
More important, regular changes. I go for 6k Max changes on my cars.
Good luck, it's a red block after all is said.... It'll still be going for many years if you just do it regularly

[Laird Scooby]

Originally Posted by c1800

The forums of the world are littered with recommendations about oil. It seems to be thus “I use this, it’s very good!”.

Synthetics are the the best. Pick one and go with it. I use Mobil.

For modern engines, yes they probably are. The molecules in synthetics are much smaller than mineral oils which allows them to creep into places mineral oil may not get. The fact is this would have been taken into account when designing the red block engines so those places almost certainly don't need lubrication.

By the same token, they very often don't have the cling properties that a mineral oil has. Older engines rely on this for start up lubrication as witnessed by the top end knock on Pauls 850 above.

These days good mineral oils are few and far between and tend to be expensive. Semi-synthetics seem to still have the cling properties of a mineral while providing the benefit of staying in grade longer.

For the engines in the majority of our cars, a semi-synth is the best compromise.

Another good point is the amount of detergents in a straight synthetic. As Ash rightly points out, over a high mileage there will be a build up of carbon, gum and so on and very often this is best left exactly where it is. If a bit of internal cleaning is needed, then add some synthetic ATF to the engine oil. Two-fold benefit, it has "Seal-Swell" which helps revive the various seals and condition them and also certain detergents to very gently clean the engine.

I frequently recommend and use this myself with a semi-synth 10W40 and if there's no reason for cleaning or otherwise adding the ATF (for example it's brilliant at sorting hydraulic lifters) then it's just a straight oil and filter change every 6-12 months depending on mileage.

[AllHailKingVolvo]

Thanks all! My local EPC has a sale on on Petronas Syntium 10w40 semi synth, so I’ll pick some of that up and change it this week.

Is there a particular brand of filter that I need to use? I remember reading that there are some that don’t have the anti-draindown one way valve and should be avoided, but I can’t remember which ones!

[Paul240480]

Mann filters have the non return valve. Cheaper than Volvo (sometimes) and rumour has it that they make the Volvo OE filter. You won't go wrong with Mann ( or a Volvo one of course ).