[SS-Traveller]

It seems most members are advocating engine decarb and flushing on a regular basis. I belong to the old school of thought which says "If it ain't broke, don't fix it". In the page MotorVac please note the first word in the dotted list - "profitable". That is the operating keyword in the chemical decarb/flush business, and applies for the service stations doing the job (members who do such work, please don't come after me with a gun for saying this ). That said, a decarb procedure after 60k - 80k km for diesels and 130k - 150k km for petrols is in order mainly if the car is limited to slow-speed city running only, and has a marked loss in performance over time. IMO, new generation (Euro 3 or more ) vehicles doing continuous runs on the highways (at least 50 -60% of the total running) don't need decarb so soon, and valves, pistons and cyl heads remain fairly clean when engines run continuously at optimum revs and temp.

Engine flushing is another issue - that's cleaning the bottom of the engine (below the pistons). If engine oil changes are at regular intervals, a flush after 100k km in diesels and 200k km in petrols is in order. If oil changes are severely delayed (by over 50% more kms than recommended) on a regular basis, then engine flushing ought to be done sooner.

After an engine decarb/flush, expect some increase in the noise of the engine, increased pep (after decarb), drop in FE for the first few hundred km, followed by a gain, and easier pulling at lower speeds in higher gears.

At the end of the day, doing all this may extend engine life by 20% at best. So, for an engine which is expected to fail at 200k km in an individual's hand, a midlife decarb/flush job might take it 240k km. Worth it? You decide.

[parimal_g]

ss-traveller

so should i wait for few hundred Kms..?,but engine has become harsh,i hope every thing is fine inside the engine

[Atlblkz06]

I've never heard of "engine decarbonization" being a service.

The engine pictured in a previous post seems to have injested bad fuel or maybe oil with fuel? I've seen engines torn down after 70k+ miles and pistons were fairly clean. There wasnt much gunk.

I havent read through all the pages at this point though.

[SS-Traveller]

Originally Posted by parimal_g

ss-traveller

so should i wait for few hundred Kms..?,but engine has become harsh,i hope every thing is fine inside the engine

Please use the car for maybe 600-800 km at lower revs (not exceeding 60% of max rpm), use regular fuel, and things should get better. Noise will reduce. If you haven't developed new problems after the decarb like smoke from the tailpipe (compression/valves/rings gone) or smoke from the oil filler cap (blown rings), everything is fine - let a fresh thin layer of carbon build up gradually.

[SS-Traveller]

Originally Posted by parimal_g

ss-traveller

so should i wait for few hundred Kms..?,but engine has become harsh,i hope every thing is fine inside the engine

P.S.: And yes, don't use any fuel additives now.

[parimal_g]

guys thanks for the advice ,
one of my friend who is working for Hundai suggested me to change the oil again.
today morning went to local garage for oil change,while draining the old oil,he was also cleaning the air filter(and i told him no need to do as its life time filter k & n),but still he opened the filter box lid and there was a dead rat inside the box ,which was blocking all the air may,be one of the reason for low pickup,
now pickup has increased and also engine has become smoother ,but still will not take any chances and will drive as per you suggestions.

[parimal_g]

Great News,
after around 600 to 700 Km running on low revs and max speed 70 Km/hr the car is back to normal now ,its running very smooth now ,
Thanks for all your advice guys.

[vigsom]

My bro's Volkswagen Bora in UAE used to have an engine flush every 30 k kms.The cost of teh flush(with the element) was approx AED400 while the cost of replacement oil(Mobil1) was a mere AED100.

I never felt any major change in the engine performance/noise after the flush.

As regards decarb,IMHO it is not required.I have seen Esteems with over 200000 kms on odo and still going strong - the secret was tanking up at "clean" bunks and oil changes at 7-8k kms.

It is infact risky to do an on-line decarb ; noone knows which part of the engine has a carbon build up which might be cleaned during the decarb resulting in other problems(like oil loss)

[funkykar]

I am very new to this. Has anyone done a de-carb/flush for old cars like 118 NE or a Premier Padmini?

I have a 118NE thats run for 86k kms and a Premier Padmini S1 thats run for 39k kms.

If I want to flush and decarbonize on both my cars, how much would it cost? Where in Bangalore can I get that done?

[Jaggu]

For high mileage and old engines decarbing with additives is not recommended since it can dislodge gunk, attack old oil seals and can cause more headaches than good. Instead do a good tune up and use a better mineral oil like Castrol magnatec.

[funkykar]

Originally Posted by Jaggu

For high mileage and old engines decarbing with additives is not recommended since it can dislodge gunk, attack old oil seals and can cause more headaches than good. Instead do a good tune up and use a better mineral oil like Castrol magnatec.

Thanks, will not risk the decarb. I have a couple more questions:

1) Is it okay to flush out the engine oil using additives for these old cars?
2) Is it a good idea to decarb when any half engine kind of work done (like say change of a head gasket or something similar). Or in simple terms, when is it okay to decarb without issues/risk for these old cars?

[IndrojitSircar]

You could use a addaative called system G for petrol cars it helps a lot in cleaning the values,cylinder,throttle body/carb etc.Would see a drastic change in the pickup.

[Jaggu]

1) Ideally no, instead use flushing oil and dont rev it too much while using the same.
2) Yes decarb while engine work is being done is a good idea, good ol way is the best for older cars.

[Gansan]

I have been using the IOC premium petrol with additives for my bike ever since it was introduced. Then switched to Shell super unleaded with additives a couple of years ago when they opened a station near my home. I don't know if this was the reason, but my bike engine has never been decarbed in all the 78000 KM it has done. Pick-up and mileage are still very very decent, so I don't intend touching it any time soon.

I am using the same petrol form my new Alto too, hoping it will keep the car engine too in the same pristine condition!

[vdiatech]

Originally Posted by IndrojitSircar

You could use a addaative called system G for petrol cars it helps a lot in cleaning the values,cylinder,throttle body/carb etc.Would see a drastic change in the pickup.

Throttlebody too ? How ? Please explain