Oil consumption and best oil.

[N_CURTIS]

Hello again,

Just want to get some thoughts on what you folks consider acceptable oil consumption for 1600i petrol engine, and the best oil for it.

Mine has done 90k with FSH, it doesn't visibly burn oil. Though it appears to have got through about half a litre in about a thousand miles of mainly longer runs.

I don't thrash it (esp. when cold) as being an engineer I do have mechanical sympathy. I'm guessing by the fact that it takes 1.5 litres between the high and low marks that it's obviously designed to use some and these petrol engines do seem to need the revs.

I remember an AX GT I once had was redlined at 7000 rpm!

There is a slight leak from the sump (don't know how common this is) but the local Cit/Pug specialist says it's nowhere near as bad as some he has seen...

[CitroJim]

Of all the XU and XUD powered vehicles I have run, the oil consumption has always been practically zero. The GTi and Activa are on 136,000 and 99500 miles respectively and use nil. Ditto the TD on 190,000

As for oil, I favour a good mineral, I use GTX Magnatec in the Activa and Hi-Mileage in the GTi.

A synthetic or semi can upset the workings on the oil level light on a Xantia and make it cry wolf, especially with hot oil.

The TD and Dad's 205 run on Chevron 15W/40 obtained very cheaply from Costco.. Seems fine oil too.

[CitroJim]

There is a slight leak from the sump (don't know how common this is) but the local Cit/Pug specialist says it's nowhere near as bad as some he has seen...

This is pretty typical, especially around the bottom of the bellhousing/block join. They're always a bit damp there.

The rear crank seal in all XU family engines weep a little. Nothing to worry about as long as its not dripping.

Whreabouts exactly is yours appearing to be leaking?

[AndersDK]

Even a smallish external leak can quickly amount to 1/4 liter of oil between oil changes. You just never think about it, as this is very common.
Another 1/4 liter of oil can easily be consumed by an engine in fine condition. Commonly its the intake valve stem seals that leaks a wee bit.
Also the oil fume hosing from the hot oilsump comsumes a bit of oil through the intake during drive.

As a rule of thumb, if you use a lower viscosity index (i.e. thinner) oil (the 10w40 or something like that figure) than prescribed by the manufacturer, the oil consumption will always increase. This is because the thinner floating oil can much easier seep its way past the seals when under oil pump pressure of up to 5 bars.

I'd say anything up to 1 liter - with no obvious large external leaks - between oil changes is a very good figure. Note that this is mostly hidden by the fact that water and sediments from the combustion will end up in the oil. Thus the dipstick may not indicate significantly lower

On worn engines up to 1 liter pr 1000L/600miles oil consumption is acceptable before the engine is scrapped. This is BTW the old time standard for normal oil consumption on earlier engine designs.

[Peter.N.]

I use the cheapest oil I can find with the required specification, used to be about a fiver a can but now gone up to about £7.00. If its changed at the required intervals or even more frequently, I find little benifit in using more expensive oil.

[alan s]

I've just rebuilt a DKZ engine (1.9L 8 valve) after it blew a head gasket following a good cooking. (Don't ask)
Prior to doing it over, it was using around 500mls< per 1000 klms and from all accounts, some of these did this and I have heard that some of the BXs and 205s actually had this info in their service manuals.
When I stripped the engine, I was surprised to find a style of rings that I thought was superceded decades ago, namely the "Perfect Circle" worn engine style rings that have a step cut out on the upper outer edge of the compression ring (to accomodate for a lip on the bore) and a one piece oil ring with what amounted to a wire spiral being used as an expander behind it.
The new rings I was supplied had compression rings that were tapered at the upper inside edge and oil rings that were more conventional in that they were 2 cords with a proper expander fitted behind. After doing a thorough honiing, when refitted no blowback and no smoke, although smoke was never an issue previously, like yours, just oil useage.
It was noted by the machine shop when the head was taken in for work that the intake ports appeared as though someone had painted them with tar and the guy asked what had been used in the engine as he's never seen anything like it before.
I put this down to the breather system possibly diluting the oil vapour enough to make it burn without shoing the tell tale blue smoke.
It seems over the years most car makers have had this fettish about cars needing a coating of oil on the bores to make them last longer and to my knowledge, all have come unstuck on it (Toyota and Mitsubishi as a couple of prime examples.)
Prior to the engine coming out, I found using a 20W50 oil gave the best results in our climate and I can't see given the circumstances that it wouldn't be any problems over there apart from slowing the starter a bit on cold mornings.
I found of all the oils we tried, Caltex Havoline Premium 20W50 was by far the best when it came to oil consumption/useage.


Alan S

[Stempy]

I've always used Total Quartz 9000 synthetic in the V6 which I change every 6k miles, which is twice as often as the recommended 12k intervals. I've never had to top it up, level on the dipstick is exactly the same every time I check it. 8) And it now has 94k miles on the clock.

[CitroJim]

which I change every 6k miles, which is twice as often as the recommended 12k intervals. I've never had to top it up, level on the dipstick is exactly the same every time I check it. 8)

I should have qualified my statement earlier that I change very frequently. Because my annual mileage is low and spread between several cars, I change mine on a time basis and rarely has the oil travelled more than 3 or 4 thousand miles before being changed. 12K is far too high in my book despite the advances in oils.

I always change the filter and copper washer on the sump plug too. If I don't change the latter, I can guarantee a little seep from there.

[Peter.N.]

I base my view that expensive oil is not all that advantagious on the fact that two of my vehicles, a CX25 DTR turbo and a 2.1 td XM covered 266 and 292 k miles respectively on the original engines with 5k oil changes on cheap oil, and diesels are much harder on their oil than petrol engines. I appreciate that the modern common rail engines do need a superior lubricant, but I am basing my experience on the older type engines that most of us have.

[lolingram]

I cannot think of any engines where rotating seals are subjected to main oil line pressure...?

As a rule of thumb, if you use a lower viscosity index (i.e. thinner) oil (the 10w40 or something like that figure) than prescribed by the manufacturer, the oil consumption will always increase. This is because the thinner floating oil can much easier seep its way past the seals when under oil pump pressure of up to 5 bars.

[oscarloco]

My ZX consumes around 1L / 1000 km but it doesn't smoke. Part of it leaks from the front Crankshaft seal (not too much) and some goes into the combustion I assume.

[mezuk04a]

I use to use the expensive brand, cant remember it at the moment, you know the common usual one. That is until it leaked all over the boot in the Xantia and I was too tight to replace it, so i bought the cheapest at the same spec and all is well over 2 years now and use the same on my old 1.9d ZX (now my mums) and that hasnt caused any problems either for about three years now.

The oil is changed every 5,000 miles

[micitroen]

As has been said ; oil and filter every 5 or 6 thousand miles with oil that matches the spec. for the car (refer to handbook)..oil spec. to be found on the 'blurb' on the side of the container. Filter too for that matter...interesting thread on the Bx site at the moment re this.

[N_CURTIS]

Thanks for all the repies, made some interesting reading.

The car didn't cost me that much anyway, so I'm not going to worry about it too much. I shall just keep an eye on it and keep topping it up. The car runs fine on the the Tesco 10/40 @ £7.47 for 4 litres.

I'll give it a change every 5k anyway and may go for a 15/40.

[MikeT]

I used that tesco stuff - better than the old oil in there I reckon, though the purists here may scorn.

Odd thing was, with filter replaced, those 4 litres was enough to refill my sump to the correct dipstick reading though I only let the hot oil drain for an hour or two, it was still dribbling then so guess there was a fair quantity of old oil left in the car.