Found oil in intake Manifold during Cleaning

[syedfaizan1]

Hi Guys, I cleaned this Intake manifold and while removing it, it Drop an oil from it and there was alot of Carbon in it too. Well the mechanic Cleaned it and put it back again. What Could be the Reason for oil in this intake Manifold ?

Note i guess this intake manifold never cleaned in 8 good years. Mechanic Cleaned it with Petrol for 15 mins washed from inside and flush it with Air

[rajaatta]

Its nor.al to have oil and dust deposits in it for a proper maintance clean it every after 6 months and keep the air filter clean as new. This is important maintanance

[talhawaleed]

This seems like a Pakistani Vehicle and all Pakistani vehicles are EURO 2 compliant, new vehicles which are imported from UK such as Toyota Hilux Invincible 2012 is EURO 5 compliant whereas toyota hilux invincible 2009-2011 is EURO 4 compliant.

Why am i talking about EURO standards, that's because in-order to minimize the pollutants to be released into air, EURO compliance's enforces vehicles manufacturers to recirculate the burnt/un-burnt gases from exhaust manifold back into the intake manifold to be burnt again in order to minimize the nitrate contents to be released into the air.

your exhaust gases contain unburnt petrol/diesel and some percentage of engine oil along with hydrocarbons which makes it way back into the intake manifold and resulting a sludge into your intake manifold. this at times even chokes the access of clean air to pistons as well. so in short, its a very good practice to clean your intake manifold once a while.

this practice of diverting the exhaust gases back into the intake manifold becomes more strict with higher EURO standards. EURO standard has no benifit for the end customer, but very beneficial for your environment.

P.S: its been a time i have studied this, i may not be precise in recalling this, but roughly i have given you the idea. rest you can study this in more detail if you like to.

[Xulfiqar]

This is almost never required in the life of the vehicle. Specially this toyota. If this were an ancient v8 then i would have given a thought, but 2nz? Naah!

The difference in volume that the coating makes is negligible (less than 2%)

[talhawaleed]

I agree on these EURO 2 complaint vehicles, even then its a good idea to have your vehicle run clean.

[Xulfiqar]

Cleaning the manifold wont make a difference in how clean it runs.

[haseeb.basharat]

The model he owns don't have catcon either so it's not euro 2 compliant.
Euro2 came in 2011 facelift corolla.

[talhawaleed]

does this engine has a positive crankcase ventilation valve, what does this valve do, lower the emissions levels by recirculating the escaped combustion gases(blow by gases) into engine(From Piston Area) then recirculating them via PCV valve into the throttle body then into the intake manifold again for re-combustion.

these blowby gases could have been discharged into air as well but they are not environmentally friendly so they make them go through the combustion processes over and over again.

what if you can somehow separate oil from gases, then you would have clean intake manifold. i dont think, these vehicles are equipped with oil catch cans.

IN EURO 4 or 5 standard, this all is also done through ERG valves which recirculates portion of these gases from exhaust manifold into intake manifold via ERG valve and sooth buildup problems with time are worst and require periodic cleanup.

few companies manufacturer after market oil catch cans which are connected prior to ERG valves to separate oils from gases in order to avoid sooth buildup inside ERG valve, intake manifold.

same can be done with pcv valve, since problem related to sooth buildup is not as bad via pcv valve so they avoid this step. after market oil catch cans needs to be emptied after sometime.

[haseeb.basharat]

does this engine has a positive crankcase ventilation valve, what does this valve do, lower the emissions levels by recirculating the escaped combustion gases(blow by gases) into engine(From Piston Area) then recirculating them via PCV valve into the throttle body then into the intake manifold again for re-combustion.

Yes they do have and by reading old posts of OP I can bet that he got a bad pcv valve, but he's on rehm o karam of jugaaru mechanics.

[syedfaizan1]

guys my pcv valve was blocked for a long time and i didn't knew that. so i cleaned that and after cleaning it my blow by oil throwing also reduce from engine cap and stick almost no sign of smoke from there. so pcv valve is working fine now i guess

[Xulfiqar]

You are mentioning very basic emmissions standards, pcv valve or similar variant have been in use since the 1960s.

Not quite understanding your point here, this is a toyota 2nz

[syedfaizan1]

xulfiqar only now one thing is left tmining chain noise.

will be doing that someday coming soon. mechanic ask to bring the saman 1st and he will replace it by removing chain cover from left side.

will be buying timing chain, new tensioner, gears vvti if needed . but complete set of timing chain initially

[Xulfiqar]

make sure its actually a "NEW" timing chain and slipper rails - the tensioner needs to be checked if its good. Do not use a scrapyard timing chain or slipper rails.

Its a very expensive mistake.

The VVT pulleys are also required (when noisy) and have a special way of installation, They are unlocked and advanced first then put on the cam and torqued with torque wrench, If you dont follow this you have a 50% chance that the VVT will not work when required - and you will get TDC errors or sometimes cam sensor error too - the engine checks how much the cam advances by the cam sensor reading.

[syedfaizan1]

ok i will show your comments to mechanic before starting the process.

i will buy all parts new. can not compromise on this thing when this noise really hurts me while driving or sitting in car. will go to japan autos plaza to source these parts

[talhawaleed]

I was explaining to him the reason for the presence of oil in intake manifold which was his original question.

P.S: apart, many have no clue regarding the emission standards and as why exhaust gases are re-diverted back into the intake manifold via pcv valve. I knew about pcv valve ( stuck close stuck open failure thing) but till recently was unaware as why this was done. sharing knowledge as why he found oil contents in intake manifold, i think answers his original question.

[Xulfiqar]

oh got it.

btw - the PCV is a two part system, one is this valve, the other is the fresh air intake into the valve cover.