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F20b6 burning oil whhen hot.

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silverVTEC

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Just need a little advice to why my car burns oil. It only happens after I have been driving for a while about half an hour, the engine has compression I'm sure its not the rings, I've recently cleaned the egr valve and egr ports as they were clogged up badly, the car is currantly usind asda's own 10W40 semi synth engine oil, will changing to castrol magnetec make any difference? Also how many liters will I need I'm getting it in the morning
 
I don't think putting Castrol Magnatec will make any difference to oil burning, it isn't a particularly special oil (it's still a mineral base oil, not a 'proper' FS like, say, Castrol Edge). The problem may actually get worse if you use a thinner oil.

How do you know it's burning oil, not leaking? Oil burning can be several things (piston rings, valve guides, PCV system...) so the problem needs to be ***essed. A simple compression test could rule out the rings.
 
Jon_G said:
I don't think putting Castrol Magnatec will make any difference to oil burning, it isn't a particularly special oil (it's still a mineral base oil, not a 'proper' FS like, say, Castrol Edge). The problem may actually get worse if you use a thinner oil.

How do you know it's burning oil, not leaking? Oil burning can be several things (piston rings, valve guides, PCV system...) so the problem needs to be ***essed. A simple compression test could rule out the rings.
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problem solved she was burning oil because it was well due an oil change the people I brought her off lied, saying its been "serviced" the old oil was so thin and black when it came out I was shocked! I wonderd why the eml light came on all the time for the O2 sensor, because the oil was so old and rubbish it was burning away throwing the light up, I have since done a oil change with castrol gtx semi-synth and she runs like a dream now only very little smoke on vtec (but that's to be expected) the smell of burning oil has now gone and the car pulls better now. I could actually hear the old oil bubbling away after a long drive!
 
Sorry but smoke on VTEC no matter how big or small should be expected. How many miles has it done?

My F20B6 Type-V has just over 280k miles now and doesn't let out any smoke at all on VTEC, and my H22'd CH7 in my pic doesn't either, having about 35k miles on the engine.

I would do a compression test imo just to see what wear your engine has.
 
Actually, plenty of people have claimed that they get oil smoke when in VTEC. I've never understood why though.

And I'm not sure changing the oil would make a dramatic difference to this issue.
 
The car has done 140k miles so plenty of life left in her I've had a couple of hondas and they have all smoked a little on vtec, but before I done the oil change the car was letting out blackish smoke not blue, all egr ports were clogged up aswell, ill get a compression test done but I'm 100% sure its not the rings as it doesn't smoke when I rev in neautral.
 
My F18 is on 90'000 and no smoke that im aware of :)
 
My 1.8 sport has 96k and it is well due its service (don't shout at me I only just got it :) ) and it doesn't smoke at all

I believe (although I may be wrong) if you've used a new thicker oil there is a small chance its aiding the compression a little. You may find it might start burning again as the oil thins.

Definitely get it checked out
 
I know what he means. The smoke can be present on hard acceleration and when vtec engaged. Not much but can be seen by anyone following but not noticeable from the driver of the car
 
SOHCS especially shouldn't smoke though. Maybe his definition of smoke is different to mine, but if my 280k+ mile Type-V doesn't and my old blue girl doesn't (even when straight piped for hooligan trackdays ;)) then why does his? Makes me think there is some issue there.
 
Smoking could simply be the AFR falling under high engine load, not oil burning. And synthetic oil burns without producing anywhere near as much blue smoke as lesser oils.

It wouldn't pass the MoT if it was burning oil too heavily, as the HC emission levels would be too high.
 
Is there any chance he has loosened some carbon build up when he cleaned his egr and that's being burned up? Just a thought :-\
 
I'm going to do a compression test what numbers am I looking for? Also she's started to burn abit of oil again :( might be stem seals as I get a lil smoke on first start up? The car has no loss of power and is pulling great.
 
That does sound more like the valve stems letting a bit of oil through... if you go down a long hill, in gear with your foot off the throttle, then hit the throttle at the bottom of the hill, do you see a lot of blue smoke?
 
Jon_G said:
That does sound more like the valve stems letting a bit of oil through... if you go down a long hill, in gear with your foot off the throttle, then hit the throttle at the bottom of the hill, do you see a lot of blue smoke?
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when I'm driving if I take my foot off the revs for abit then put it back on again it does smoke, this car is confusing me because it doesn't smoke all the time? Will 20w50 oil help?
 
You want at least 200 p.s.i across all 4 cylinders for a healthy engine, but the main thing is that the readings are close together instead of one cylinder being down on compression compared to the others.

20w/50 would be like putting treacle into your engine! Waaaay too thick, and even if it did stop the smoking, you would still be masking the issue rather than solving it.
 
Valve guides tend to pass oil when manifold vacuum is high... hence when the engine is being over-driven with the throttle closed (hence my previous example). Smoking will appear to be random, until you can link it to periods of high manifold vacuum.

If the oil-burning is due to oil ingress along the valve guides, then I have no idea how easy it is to replace the stem seals with the head in place on the 6th gen (there are special tools to allow this to be done on other engines), but possibly the stem guides could need machining and the valves replacing?

As said, DO NOT put 20w-50 in your engine!!! It is sometimes worth trying a heavier weight oil, but I believe you're already using 10w-40 (which is as high as you should go).
 
Jon_G said:
Valve guides tend to pass oil when manifold vacuum is high... hence when the engine is being over-driven with the throttle closed (hence my previous example). Smoking will appear to be random, until you can link it to periods of high manifold vacuum.

If the oil-burning is due to oil ingress along the valve guides, then I have no idea how easy it is to replace the stem seals with the head in place on the 6th gen (there are special tools to allow this to be done on other engines), but possibly the stem guides could need machining and the valves replacing?

As said, DO NOT put 20w-50 in your engine!!! It is sometimes worth trying a heavier weight oil, but I believe you're already using 10w-40 (which is as high as you should go).
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it turned out to be the valve stem seals, the compression is fine, also I'm using 5w40 fully synth now, while I await for the parts to fix her it only smokes after I let off the revs down a slight hill so its still drivable after I sort a next issue that has poped up..
 
Jon_G said:
How did you confirm it was only the valve stem seals, rather than the actual valve guides?
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well I know its not the rings that's for sure, but it could well be the valve guides mate, ill have a look when I take things apart cheers for the input.
 
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