When is an oil leak not an oil leak?

Forums › Transport (cars, bikes and boats) › When is an oil leak not an oil leak?

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#1205684 29-Dec-2014 19:11

joker97: Dude the temp of 80 is water coolant temp. The engine I think is around 200d. And it's 200 whether you are waiting at the lights or driving at 60 or cruising at 100ks. !!!

i will think you will find oil wont withstand 200 degrees, cheap oil starts to break down about 130 degrees and then its lubrication properties are not very good.

Under racing condition ie 6-8 laps around a track, a Honda civic (like the one in question) will sit on about 105 degrees water temp (it doesn't boil as the system is under pressure) and about 125-130 degrees (using quality oil).

my car used to take about 6-8km of driving for the oil to hit 80 degrees and round town it wouldn't hit much more than that.

your one may be different but ive been tinkering with Honda's for 15 years and the above seems to be the norm for most of them

Batman

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#1205686 29-Dec-2014 19:13

Hmmm I think I must have read an American site so make it 200F

Sorry!

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#1205687 29-Dec-2014 19:14

Disclaimer: I read these numbers somewhere ... Doesn't mean I'm right ...

Jase2985

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#1205689 29-Dec-2014 19:20

joker97: Disclaimer: I read these numbers somewhere ... Doesn't mean I'm right ...

all good but remember other who read it might think its right even though you have posted the wrong info so sometimes its better not to say anything if your not sure as it confuses/contradicts.

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#1205692 29-Dec-2014 19:25

So at 80C surely the oil is closer to the 40 number and not the 10/15 number? Asking this for my education. Got a turbo Subaru. Not sure what the Subaru recommends but dealer puts 5/30 oil and I bring them my Mobil 1 0-40 as I do a lot of cold starts and short (2.5kms!) Driving in winter to avoid falling on frost

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#1205699 29-Dec-2014 19:35

yea it probably is but its still thicker than the 10w stuff and if you look at the viscosity values between a 10w40 and 15w40 from the same manufacture, there is about a 13% difference at 40deg and the viscosity index is different by a manner of 20.

Viscosity index (VI) is an arbitrary measure for the change of viscosity with variations in temperature. The lower the VI, the greater the change of viscosity of the oil with temperature and vice versa. It is used to characterize viscosity changes with relation to temperature in lubricating oil.

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#1205703 29-Dec-2014 19:40

also the type of oil has a lot to play, the stuff we are talking about here is semi synthetic oil, you can get fully synthetic stuff which you pay $90+ for 4L and people normally run that in cars that run on the race track. a product of a similar grade has completly different specifications.

There is a huge amount of info round this but its a little off topic

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#1205833 30-Dec-2014 00:10

joker97: I had the same issue with a 1990 Honda Civic hatch - but there was obvious evidence of a leak on the ground. I think it was a head gasket.

You would know from the massive repair bill if it was a blown head gadget. More likely the rocker cover or dizzy gasket

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#1205834 30-Dec-2014 00:12

umm ... it was 10 years ago, got quoted $1000 for repair [10 years ago - today's money i'd say $2000-3000?]

but the guy didn't even look at anything just from my description - so i guess we are all none the wiser

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#1205855 30-Dec-2014 06:56

nzkiwiman: That is what confuses me, though to be fair I'll say 1-1.5 litres gone every "2 weeks" (sometimes I will forget and it can be 3-4-5 weeks between checks)

Check oil - 'almost empty'
Fill with 1-1.5 litres
Check oil - covering the first notch on the dip stick
Check again an hour later - still covering

Check 2 weeks later - 'almost empty'
Repeat

I would go 6 months without checking before the last WOF/Service when it was mentioned

Is it possible that the dip stick is 'wrong'?

I think if you want to keep this car running you need to be checking the oil more regularly than you have. Try checking every petrol fill and record level and kms. Top up at home when engine cold. So far you have just mentioned how much oil you are using without including any distance reference.

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#1205858 30-Dec-2014 07:33

do u a favour - buy another car

nzkiwiman

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#1205863 30-Dec-2014 08:09

I went for a drive last night, with someone behind me
No visible signs of burning oil

No visible signs when engine is being revved either.

The tip of the exhaust was rather black, but in the 9 years I have owned the car I don't think I have ever cleaned it so I'll check again at the weekend and report back if it is dirty.
The bumper directly above the exhaust doesn't look to be any dirty than the other end - lack of cleaning doesn't help :-)

For reference - approx 380km every fortnight (15km each way to work, so approx 150km each week plus additional running around either before or after work. Not much use in the weekends any more)
I fill up with petrol every fortnight as well (about 32 litres)

In Feb I will check what oil the mechanic uses, as I can't find the reference in my owners manual to the type I should be using.

Getting another car at this stage is not an option, I wish I could (though at the same time, I love my car and it does everything I need it for)

RunningMan

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#1205886 30-Dec-2014 08:54

That suggests that it isn't being burnt internally, but doesn't completely rule it out. However, a litre or so of oil is still going somewhere!

With the engine cold, check the radiator overflow bottle or remove the radiator cap and check for oil - it will show as a whitish brown sludge, and floats to the top. If there's oil in there, it's most likely a head gasket issue.

Again, with the engine cold, grab a light and look over the motor for signs of oil leaking out - black oily film running down the outside of parts. At the rate you are putting it in, I'd expect obvious oil on the ground under where you park for most leaks, but if was leaking from the rocker cover at the top of the engine, it may run down on to the exhaust and burn off.

RunningMan

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#1205936 30-Dec-2014 10:10

The other thing to do, if you feel a little more mechanically minded is to remove the spark plugs one at a time and see what they tell you

http://ngksparkplugs.com/tech_support/spark_plugs/faqs/faqread.asp

nzkiwiman

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#1206029 30-Dec-2014 14:09

RunningMan: The other thing to do, if you feel a little more mechanically minded is to remove the spark plugs one at a time and see what they tell you

http://ngksparkplugs.com/tech_support/spark_plugs/faqs/faqread.asp

Yeah .. no
Computer tinkering is fine, my car however is a mostly no go zone.

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