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Oil Everywhere - Why?


MiltyG565
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Under the bonnet of my Focus earlier, taking apart the airflow pipes so I could clean the intercooler, I noticed a lot of oil on the engine block. Not only that, but the airflow pipes and intercooler were full of oil too. 2 questions - Why is it happening? And where is it coming from?

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Under the bonnet of my Focus earlier, taking apart the airflow pipes so I could clean the intercooler, I noticed a lot of oil on the engine block. Not only that, but the airflow pipes and intercooler were full of oil too. 2 questions - Why is it happening? And where is it coming from?

The oil comes from the engine breather, it comes out of the head/ block and is fed into the air intake, usually in front of the turbone on a turbo car, it usually comes out as an oily spray/ mist and tends to collect in the intercooler, where it condenses/ collects when it hits the cool inside of the intercooler

Further up this oil can mix with the carbon from the EGR, forming an oily gloop, that can eventually choke the inlet manifold

Some modern engines hardly produce any oil out of the breather, some engines have an efficient oil seperator built-in to the head, so it depends on the engine, how much oil is dumped into the inlet, it may be a small amount but over 100,000s of miles, a worn engine may throw more oil out of the breather (piston/ bore/ring wear- causing blow-by of the gasses, pressurizing the crankcase) - over- filling the oil-level can also cause exessive oil from the breather, also, if the turbo oil seals have failed, this can inject oil into the inlet

Fitting a catchtank to the breather can stop/ seriously reduce the oil getting into the inlet from the breather, so once you have cleaned the intercooler boost hoses out they should not get dirty/ contaminated again

With a total-loss breather and an EGR delets (like my car) no oil/carbon/ contaminants can get into the inlet, just cool, clean air (the breather contains, heated, burnt air as well as oily spray- that has a slight detrimental effect on performance/ economy) once the intercooler/ boost hoses/ inlet manifold is cleaned, it stays cleaned (worth a bit of performance/ economy, too) only if the turbo oil seal fails can oil get into the inlet

with a breather catchtank fitted it is possible to keep an eye on the amount of oil coming out of the breather - probably a good idea to keep an eye on the engine oil level, too

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Thanks!

Seems like a bit of a poor design, to fit the breather to the inlet pipes. I think at one point though, the oil was overfilled.

The engine doesn't sound worn. There's a squeak at idle (probably a belt or pulley), but there are no knocking sounds or rattles. It doesn't sound laboured. It starts and runs fine, and after start-up, there's no smoke at all.

I might fit a total loss breather onto it then. Would it be grand just to use something like a water bottle with the top cut off? Something like this.

32CamelBakPodium2-s3-medium_new.jpg

How do I know or check if the turbo oil seals have gone?

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Almost all modern cars feed the breather back into the inlit for the engine to digest - it is a poor design - bad for the engine but a simple, inexpensize way of reducing emmisions

(some hot rods used to use coke cans - breather oil catchtanks are manditory in some forms of racing/ on some tracks so the car does not drop oil onto the track from the breather)

A metal catch tank is better than plastic because its less liable to melt and the cool walls of the metal sides help the hot/warm oil droplets gas/fine mist to condense and turn to liquid, so that more is caught and less gous back into the inlet (if the breather is fed back into the inlet) or into the atmosphere (total loss)

The breather can be fed back into the inlet (so the catchtank goes between the breather outlet and the air inlet)

Or the breather inlet is blocked (on the engine air inlet) and the outlet of the breather is vented to atmosphere, with the catchtank in line - this will keep the inlet clean but you have to be careful where it goes/ that it does not go anywhere near the cabin air intake - it should really be treated as an exhaust and go right under the car (and be checked for particulates, if its a diesel! ) - because of this i don't recommend this for road cars

Once you clean the inlet rubber (the hose between the airbox and the turbo) you should be able to tell if the oil is coming from the breather or the turbo oil seals - again, keep an eye on the oil level

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I don't understand how feeding the oil back to the inlet reduces emissions... surely then you'd have oil in your cylinder during combustion, which would burn less efficiently, no?

I checked the oil level last night as I couldn't remember if I'd checked recently. It was hovering just under the Max level.

I'll take the inlet hose off someday this week (or next week) and have a look and a clean. I noticed it was missing the pipe that goes from the front grill to the air filter box, so when I'm fitting a new one, I'll give that all a good look.

Cheers :)

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Since cleaning all the gunk from the pipes and intercooler, there's absolutely no smoke on start-up anymore, and none whilst driving along. I always just assumed that diesel smoke on start up just because of their design, not because of some oily contaminant.

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