St Oil Colour And Level

[MartynS]

I've just checked the oil in my car again and like the last time I did it a fortnight ago I think the colour is a bit darker than it used to be. It's not black or thick or anything, just a darker dirty brown colour with the same consistency. I've had the car since November and up until a couple of weeks back every time I checked it it was a lighter golden colour (like the Zetec-S I had before this always was). Is this anything to worry about or contact the dealer about? I don't know if it's to be expected with this engine or whether something has gone bad! The level has always been a bit above the max line too, but so was my last car every time it was serviced and seeing as this is always with the same dealer I assume this is just what they do (if it was way over I would have mentioned it of course).

Also a couple of weeks ago I noticed the coolant level had dropped a bit, it used to be on the join in the tank but it's now just on top of the minimum line. It hasn't dropped since then so it's just been a one off. I don't think it's gone into the engine oil as it's not cloudy and there's no white gunk under the oil filler cap, and as far as I'm aware this wouldn't make the oil darker.

Sorry for the long post, but any opinions on the above? Cheers.

[FOCA]

In my experience the oil may start clear or a light golden colour when 1st put in the engine, and over time it gets darker, untill eventually its fairly black, i think this is a "natural" process, and nothing to worry about

An older or harder driven cars' oil will probably go dark quicker than a newer one

The oil level should be measured with the car on a flat level surface (a slight hill/ tilt can give a false reading) when the engine is cold (running the car can change the oil level on many cars, as the oil is pumped into the galleries and it can take time to drain back to the sump, or for other reasons)

Ideally the oil level should never be above the "high" level on the dipstick, or below the "low" level, if the oil level is too high, it can cause exessive pressure in the crankcase, that can blow seals, the extra oil can take longer to warm up, and the smaller volume in the crankase (more oil = less air/ room to "breathe") can affect performance/ economy on some cars (on ome engine it was found an extra 4% more power by running the oil level on the bottom of te dipstick

The extra oil can also cost more money, and the oil consumption can be higher, on a modern car there is probably a "margin of error" and it is probably ok to run the oil level a little high,though, given the choice, i would have the oil level (starting off at) half-way-up the dipstick, especially on cars like the 1.6L focus TDCI with the PSA engine/ DPF, as the oil level can "creep up" causing problems (i know this does not apply to Fiesta ST drivers)

The coolant level should also be between the high and low (max and min) marks, it goes up and down depending on engine temp, weater temp etc, (this is also normal- thats why its called an "expansion tank") if it ever drops below the "min" level, (again on a flat level surface) it should be topped up with the correct stuff

[MartynS]

Cheers for the very detailed reply FOCA. It's not too dark yet and looks fine apart from that so I don't think it's anything to worry about really. In fact, the oil left on the thing I wiped the dipstick on got quite a bit lighter as it dried anyway. I always do measure the level on a, eeeer, level surface when it's cold so it's definately got more in than the max mark. I'll mention it to the dealer whenever I speak to them next just as it does seem a bit odd that they always overfill them!

I'm still not convinced that the coolant hasn't gone anywhere as my Zetec-S dropped by about the same amount once then stayed there until I sold it too. There again, maybe it is just the warmer weather because as you say it does vary depending on where in the pipes it actually goes. It's just above the max line and hasn't dropped in the past 2 weeks so assuming it stays there all is good on that front too.

[MattDRX]

The darker the oil the more the use simple, it's just carbon given off during the combustion process.

Doing oil and filter changes as and when you need to will give you no problems. just don't put crap Tesco, Halfords own brand in there, stick with Shell, Castrol stuff and you'll be fine, it's worth the extra few £.

[LightningMat]

I think better advice would be to make sure you use fully synthetic oil - avoid mixes and most certainly avoid mineral oil!... And make sure you use oil with the right viscosity grade!

There is absolutely nothing wrong with changing oil between services, and is very easy as a DIY job (although this isn't strictly necessary, unless you are constantly thrashing the engine, and can cost a fair bit once you add up the cost of the additional oil!).