Dog Biscuit

Another oil question...

The old girl still struts her funky stuff as a daily driver and 15k miles a year, but I have to admit that I've been thinking of moving on due to the age and natural wear and tear (MY99 & 181k miles) and maybe something just newer (and more practical on occasion!) Having said that, I could still keep the S as a second car I guess.

Have tried a variety of different grades and brands over the years including Edge, Magnatec, SLX, Halfords (Comma) etc, but looking on the US forums there was a suggestion for a car with 130k and increased oil use to go for Castrol GTX 15w-40. I check my oil every 500 miles and it uses averagely 0.75 litres.

I know 1 litre for 1000 miles is pretty standard, but as I'm more 1.5-2 litres per 1000 miles I'd be interested on anyone else's experiences either with the GTX or 15w40 in general. I don't VTEC the car regularly as I might have done in years gone by, but I don't drive like a granny either

s2konroids

I guess in theory as the car gets older the tolerances and clearances are bigger thus use a slightly thicker oil.

andy_intel

Problem is different parts of the engine will wear at different rates. Typically the first stuff to start going are the valve seats and guides. Have you done a valve adjustment before? The valve gaps tighten as the seals wear, this would be a good indication of wear in the head of the engine.

You risk starving other parts of the engine if you switch to too thick a rating, particularly if you drive the car reasonably hard. Something like a ruined crankshaft is way more expensive than a few extra litres of oil. If you want to troubleshoot the issue, there are a few things that are easy to check.

PCV valve - remove intake tubing and open throttle by hand, peer inside, if the intake manifold is destroyed with oil, might be worth replacing the valve.

Compression test - if results are low, you will be getting some blow by either through the valves or piston rings, or both. Of course on a well used engine, the numbers might be a little low, but consistency across all cylinders is what you're looking for.

Valve adjustment - if the seats are worn enough and clearances haven't been adjusted, the valves will not close fully. Doing another compression test after this is worthwhile too, especially if you are not happy with the initial results.

I don't really think you have an issue as such, but the checks above are quite easy to do anyway, and when you're done you'll have a good idea of the general health of the engine. HTH

s2konroids

Good post.

Dog Biscuit

Thanks chaps, really appreciate the advice.

If I recall, valve clearances are done in the 27k service rotation, so I will say yes to that, although that one is due next and PCV check should be easy enough.

I don't drive it hard at all, so no worries there and it still feels very solid.

Since posting yesterday though I've had an epiphany and decided I'm going to sell and get something newer. I've had an S in one form or another since 2002 in UK and Canada and will pick up an old banger while I decide next on what to buy. My S has got 17" OEMs and a glass rear screen so I might get up to £3k if I'm lucky.

Thanks as always for the advice!

U9aXy6Dn

181k miles is a highly respectable number. However, the audi and bmw engines from the early 2000s are currently wearing milleage from 300-500k as long as main dealer servicing has been adhered to - either that or meticulous home servicing.

The cost of looking after other parts of the car does become quite something though.