Which oil best if changed as often as required?

[rotodiesel]

Just so, I'm keeping my AWX/GGB.

 

rotodiesel.

[CombatWombat]

I used to have a MK1 PD130 and have now have a MK2 BXE PD105.

 

Excuse diverting the thread a little, but any ideas (e.g. longlife service and/or poor oil quality?) as to why a few BXEs throw a rod (especially interested in Rotodiesel's thoughts if he's still reading this post). The earlier engines clearly don't suffer this.

 

I appreciate they changed the crank and rod spec. over the earlier PDs in the MK1. 

 

Did the last 1.9 MK1s have BXEs fitted after they dropped the 130?

 

I'd put this in the MK2 forum, but there aren't many PD owners over there, and there isn't the same mix of readers.

 

Thanks.

Edited 22 September, 2014 by CombatWombat

[0wl]

CombatWombat,

If you haven't already come across these links, there is some useful info in them.

http://www.seatcupra.net/forums/showthread.php?t=370470

The photos mentioned in the above thread are here http://s1341.beta.photobucket.com/user/bxefailure/media/828495f6720d26f5a8caad15515966b8.jpg.html

http://www.audi-sport.net/xf/threads/bxe-engine.146231/

FYI it appears both the BXE and BLS engine codes are affected, neither of which were fitted to the Mk1 Superb.

[jimbof]

Wow, good info to know, not a nice prospect though, eek.  I was thinking a MK2 with a 1.9 would be a lovely car, too.  Another good reason to roll this thing "'til the wheels fall off..."

[icyd]

While we are on the topic of lubrication, i wonder what are your thoughts on adding additive into oil such as tungsten disulfide?

http://www.brycoat.com/coating-services/dry-film-lubricant-coating/ws2.html

[dieselV6]

Coating and adding additives are 2 different things. If parts are coated with anti-wear coating, they can take more stress and last longer, but this involves dismantling the engine, cleaning the parts then applying a suitable process (as in baking the part, or ion implantation, or some other way of permanently coating the parts). This costs ££££s but is sometimes done, e.g. pistons with ceramic coatings are known.

 

Adding anything into the oil that is not oil results mostly in the additive ending in oil filter after a while (hopefully there, and not corking oil lines), so even if the additive had good lubrication/anti-war properties, it will get removed from oil after a while. This is because you add it into an already oiled engine, and oil prevents permanent settlement of whatever coating you would want to make, after all preventing mechanical contact is exactly the job of engine oil. If you really are concerned about wear or start seeing oil consumption on an old engine, use a PD rated W40 oil instead of W30.

[icyd]

But aren't most oils,especially expensive oils are blended with additives afterall?stuff like molybdenum or ester, etc.

[dieselV6]

Yes they are, but on a much finer scale, basically it is a uniform mix of well under 1 micron sized particles. Anything solid over a few microns in size will end up in oil filter after a while, plus you're running a risk of clogging oil lines. It is much better to invest in a decent quality oil in my opinion, with weight decided between W30 and W40, or even W50 for petrol (there are some very good 5W50 synthetic oils around, though pricey, I used Mobil 1 5W-50 in an old Civic ESI), depending on temperature you intend to achieve in the engine As you have noticed yourself engine oil already has an additives package, so why waste money on something you already have.

Edited 23 September, 2014 by dieselV6

[icyd]

Well im trying to extract the most life out of my 1.8t.it has done 170k kms (105k mile) on semi synthetic. No leaks so far.people say switching from semi to fully which is much lighter is bad for old engine. Unless it has been on fully from the start.but i think, say an oil with 0w40 rating,its the 40 that matters because that's the viscosity when hot.it'll be the same with 10w40 oil.btw,which oil gives the smoothest feel u've used?is liqui moly popular in the Uk?

[dieselV6]

Full synthetic engine oil tends to wash out semi-syn sludge and residue - but only if there is any in the system. This may lead to increased oil consumption as moving parts are no longer sealed as well. Same with dropping oil weight down, if you've run it on W40 oil for most/all of its life, better to stick to at least W40.  I went on the old Civic ESi (~130k miles, and not nice ones) from 10W40 semi-synth to 5W40 full synth and after a while hydraulic valve lifters started being heard (but this engine in general did not like thin synthetics, even when new). For me, the solution was to increase oil weight. So I went to 5W50 and never had a problem again.

 

For your car, after using 10W-40 semi synthetic, I would switch to 5W-40 full synthetic to prevent any further build-up of deposits, and only go to 5W50 if there are problems. Note 5W50 is more expensive.

 

The only thing liqui moly I used (a lot) is pure zinc spray for corrosion protection :p  (I know you meant molybdenum sulphide ). Other than this, if you use decent oil, no need to waste money on additives. If the engine starts using oil because of wear, increase oil weight. 

Edited 24 September, 2014 by dieselV6