[Raccoon]

Sludge caused can be cleaned to an appreciable extent, using the way already described.

For the mechanical wear, opening engine and replacing parts is the only option. If wear is low, then using a thicker oil (xW 50) may help put off repairs for a bit; but at the expense of slightly less fuel efficiency and some loss in performance.

[di1in]

Originally Posted by nitrous

It's most probably a valve door leak. You'll have to replace the valve door gasket.

The leak was due to the seal that site above the header, forgot what it's called. It sits lining the edges in the picture i've attached.

Originally Posted by Raccoon

^^^Well, you are lucky the car still runs.
If engine is in good condition, topping up would be very minimal. So your car has been running almost without an oil and filter change.

It ran that way with just a filter change for 24000 kms. When we drained the oil we checked it and they said that the oil hasn't degraded as much as they supposed it would. It wasn't even opaque. And it hadn't thickened as well. Also did the interfacial tension test (drop of oil on water and see if it disperses) and it was still thick enough for lubrication.

Originally Posted by Raccoon

Fully synth oil is a very aggressive cleaner. That means, it may clean out deposits which may actually be preventing a leak. It may also seep out more thru very small leaks.

They said that cases of suck leaks were very few and occurred mostly in vehicles that had a really bad seal. I've put in semi-synth oil for now. Will see how it goes.

Originally Posted by Raccoon

Sludge caused can be cleaned to an appreciable extent, using the way already described.

They cleaned and brushed of the sludge, and then sealed the leak.

[Raccoon]

Originally Posted by di1in

It ran that way with just a filter change for 24000 kms. When we drained the oil we checked it and they said that the oil hasn't degraded as much as they supposed it would. It wasn't even opaque. And it hadn't thickened as well. Also did the interfacial tension test (drop of oil on water and see if it disperses) and it was still thick enough for lubrication.

You cannot infer the state of the oil like that. Whoever told you the above stuff is a quack. Anyway, you are lucky that at least much sludge has not formed.

[di1in]

The interfacial test and the thickness thing - i read those from a machine lubrication journal. There wasn't any sludge when we opened the motor. The muck seen in the earlier pic was just leaked oil and mud.

[sgiitk]

Back to the topic. As per the oil manufacturers any oil rated at API-SF or higher is good for 12 months/10,000km (I the UK it was 12,000 miles so probably 15,000km is kosher). Only lower oil I am aware of is the OLD IOC-MGO which was API-SC only. Of course during the warranty stick with the recommendations (howsoever silly). Most cars today demand API-SG (an obsolete grade) or higher (SJ/SL/SM are the grades currently valid). I have used the 12m/10k model for the past 20+ years and with no grief.

[alpha1]

Engine oil change at 5K km is a money minting technique by the service stations.
Rather the oil change interval itself is a pretty ambiguously defined.

See Skoda. earlier they came with 5 or 7.5K ... when they wanted to change the public perception to a more easily maintained car - they changed it to 15K.

Did they change anything in their cars?
NO!

So how could they change the intervals?

[hemen]

Originally Posted by alpha1

See Skoda. earlier they came with 5 or 7.5K ... when they wanted to change the public perception to a more easily maintained car - they changed it to 15K.

Did they change anything in their cars?
NO!

So how could they change the intervals?

the oil grade has been changed. Earlier they used mobil 1 conforming to their vw 505.00 grade now they use oil with their VW 505.01 5W-30 grade.

I do not know the difference between the two grade .

Searching for the later grade is very difficult and have to order it specially for me. After 13k kms the engine does feel a bit strained, if driven in city traffic.

[alpha1]

Well I am waiting for someone to come up with real technical explanation.
till then I maintain my stand of service intervals being humbug margin making tactic.

Actually extended pricing strategy.

[Gansan]

Originally Posted by alpha1

Engine oil change at 5K km is a money minting technique by the service stations.
Rather the oil change interval itself is a pretty ambiguously defined.

Maruti recommends an oil change every 10,000 KM / 12 months for their older generation engines - such as my 800 cc Alto. This is for using MGO 20W40, SF grade.

They use synthetic oils for the new K series engines. There is a full synthetic MGO and they also offer Mobil 0W40 as an option. But the oil change is still recommended as 10k KM / one year afaik.

[sureshshanmugam]

Hi All,

I use Castrol Magnatec on my Baleno and change oil every 10000 Kms approximately clocked in 12 months. Whenever I cahnge oil, I use the STP engine flush and then fill the new oil and filter. My car has clocked 30K Kms now. Which oil can I choose if I want to go for Synthetic and what would be the frequency of oilchange?

Thanks.

[di1in]

I consider synthetic oil in the same way i see filling dry nitrogen in tires. Both have been designed for use in specialised services.

Synthetic oil is of benefit in extremely cold regions because it retains it's properties in subzero temps. A test conducted in 1996 on a taxi fleet doing severe service showed absoloutely no advantages in using synthetic oil over conventional oil apart from a slightly increased service interval. Considering the huge price difference between the two (>2times), synthetic is just another source of income for those in the auto business.

I use semi-synth because it gives an extended interval and has some cleaning properties. And it does this without ripping my pocket. Semi-synth usually has very low amounts of synth oil - just enough for the chemicals to have their effect.

Fully synth oils and nitrogen filled tires had been designed with the aircraft industry in mind. Both are good at heat dissipation and working in extreme temps for extended periods. So unless you do long periods of high speed driving, or live in freezing climes I dont see why synth is for you.

[goandude]

Engine oil change interval depends on a number of factors and these are given here Car Bibles : The Engine Oil Bible so a uniform figure is difficult to specify.
I had to change my e oil after 5000 km (total 15000 km run), as the valvoline 15W40 CH had deteriorated in viscosity. My daily short commutes was probably an important factor.

[alpha1]

Originally Posted by Gansan

Maruti recommends an oil change every 10,000 KM / 12 months for their older generation engines - such as my 800 cc Alto. This is for using MGO 20W40, SF grade.

They use synthetic oils for the new K series engines. There is a full synthetic MGO and they also offer Mobil 0W40 as an option. But the oil change is still recommended as 10k KM / one year afaik.

That means they get to make more money on the K series cars.
(Assuming most ppl would prefer not messing with co. recommended synthetic grade oil advise)

[sgiitk]

Originally Posted by Gansan

Maruti .......for using MGO 20W40, SF grade.

They use synthetic oils for the new K series engines. There is a full synthetic MGO and they also offer Mobil 0W40 as an option. But the oil change is still recommended as 10k KM / one year afaik.

API-SF, SG, SH have been obsoleted ages ago by the API. It i shocking to see that these are still being sold, and recommended in India. But then till about a year ago the MGO from IOC was API-SC, something I have not seen for over two decades!

As for change intervals with synthetics I will be willing to go to 15,000km or so (in Europe it is 12,000miles) but not go much beyond 12 months. Oil ages (oxidizes) just sitting in the sump!

[josejoseph]

Dear All,

Saw this chart during my visit to MASS.



Thanks,
Jose.