Page 1 of 1
Oil around the trottle intake valve on a prado
Posted: Mon Jun 03, 2013 5:59 pm
by haz77
Had a look at a prado over the weekend an it had quite a bit of oil/diesel residue around the throttle / intake control valve assembly, looked almost like it was coming from where the 90' rubber hose joins the side inter-cooler, is this a sign of anything?
Re: Oil around the trottle intake valve on a prado
Posted: Mon Jun 03, 2013 6:14 pm
by tweake
its either leaking oil from the turbo or from the engine breather.
Re: Oil around the trottle intake valve on a prado
Posted: Mon Jun 03, 2013 7:08 pm
by haz77
So if its the turbo leaking oil is it a big job to repair, like wise if its the breather does that mean the piston rings could be worn?
Re: Oil around the trottle intake valve on a prado
Posted: Mon Jun 03, 2013 7:21 pm
by Dirtydog
best bet is to pull breather off and have a look, could be as simple as pcv valve is stuck, cost max 10 bucks to replace.
If you pull the breather off while engine is running and its blowing air out, it could be rings,
Re: Oil around the trottle intake valve on a prado
Posted: Mon Jun 03, 2013 7:40 pm
by haz77
Cheers for the replys,
So I dont know much about these motors, which pipe would be the breather & whats a PCV valve, is that what tweake meant about the turbo leak?
Re: Oil around the trottle intake valve on a prado
Posted: Mon Jun 03, 2013 7:43 pm
by tweake
not sure if they have a pcv valve. usually just a straight vent.
disconnect it, pipe it to a can, drive it for a while and see how much oil it blows out. also can leave it disconnected, clean up the oil around the throttle body and see if it returns. if its does return its probably turbo.
diesels do tend to have a bit of blow by but there is other reasons such as over filled with oil which causes them to blow it out the breather.
also check air filter. a blocked filter causes more oil blowby to be sucked out and can cause oil to be sucked out past the turbo seals.
Re: Oil around the trottle intake valve on a prado
Posted: Mon Jun 03, 2013 7:46 pm
by Dirtydog
The pcv valve (if it has one) is a small plastic piece that comes out of valve/tappet cover, and should have a hose leading to the intake before the turbo.
If the motor using any oil?
Been having similar trouble with the bighorn, throws out a fair bit of oil, seems to have stopped for now though.
Re: Oil around the trottle intake valve on a prado
Posted: Mon Jun 03, 2013 8:22 pm
by haz77
This is a truck I looked at to buy, just had an oil change, looks like its been doing it for a while, wouldn't know if it uses oil & can only really take it for a 10 min drive.
so where is this breather pipe so if I go for another look I can check it, should I check at idle or when revving or both?
the oil level was ok, its only just been serviced so the air filter 'should' be ok, didnt check though.
Re: Oil around the trottle intake valve on a prado
Posted: Mon Jun 03, 2013 8:27 pm
by tweake
undo the oil cap on the rocker cover and see how much it blows out.
also pulling off pre turbo intake pipes you can see if there is an oil build up.
pull the air cleaner out and look. seen mechanics service a vehicle and not replace a filter all tho they charge for it

Re: Oil around the trottle intake valve on a prado
Posted: Mon Jun 03, 2013 8:40 pm
by haz77
Cheers for that, sounds easy, thought most engines made a right mess if you start them with the filler cap off, or do you mean just loosen it off?
Assume if there is oil in the turbo pipes then its one to avoid yeah?
Re: Oil around the trottle intake valve on a prado
Posted: Mon Jun 03, 2013 9:06 pm
by kbushnz
The 1kzte engine is known to introduce oil vapours into the intake system from the crankcase vent... You will get a light oil coating over everything from the turbo compressor outlet to the head...The oil will pool slightly and or find its way out of any slight leaks at joints and also the butterfly pivot bushes...
Doesn't mean the engine has issues. if you are buying it get it checked over by a diesel specialist...
Re: Oil around the trottle intake valve on a prado
Posted: Mon Jun 03, 2013 9:23 pm
by haz77
thanks for the input, could get it looked at by the local Toyota dealer.
guess this is the thing with buying private, nothings been wiped clean & sprayed with silicon to look new!!
Re: Oil around the trottle intake valve on a prado
Posted: Tue Jun 04, 2013 9:55 am
by SMOKEY
Most if not all Turbo Diesels will show signs of oil around the inlet system, when you put boosted pressure on top of the piston rings some of it is going to find it's way past and into the sump and the only way for that pressure to get out is through the crank case breather that is located on top of the rocker/cam cover, that extra pressure and oil mist combined with the amount of oil in the top cover used to lubricate the rockers/cam will find it's way into the inlet system and show externally as a mess, I put a catch can on my old 2LTE (only 98,000k's) and over 5000k service interval would catch 200mils of oil. My 96 1KZ Prado with 120k's has the oil weep around the inlet, they all do it,
SOME MORE THAN OTHERS,
FITZY.
Re: Oil around the trottle intake valve on a prado
Posted: Tue Jun 04, 2013 10:22 am
by haz77
Cheers, spoke to the local Toyota dealers today, they said just that, they all do it, its not uncommon. The only ways to tell if there is an issue is to either clean it & see how long it takes to build back up (not an option with a purchase) or do a compression leak-down test, also removing the breather will give an indication but unless you are familiar with what is normal or excessive then it would be unlikely you would know if its ok by doing this.
Unfortunately they dont have the compression test gear so thats helpful!
Re: Oil around the trottle intake valve on a prado
Posted: Tue Jun 04, 2013 10:53 am
by kbushnz
If you are keen on that truck... Take it to a diesel specialist... in your area.. They will have all the gear and specs to give you an unbiased opinion.
Re: Oil around the trottle intake valve on a prado
Posted: Tue Jun 04, 2013 11:52 am
by SMOKEY
What area are you in ?, in CHCH there is mobile testers who will go to an address and do a compression/leakdown test, check your local yellow pages or google, ask the person who owns the vehicle if you can have a test done at your expense. For the guys with the gear "it's not a big job".
ASK JONESY,
FITZY.
Re: Oil around the trottle intake valve on a prado
Posted: Tue Jun 04, 2013 2:06 pm
by prado_boon
Mine does the same. Oil buiilds up and finds its way out around the butterfly... I think I actually stripped one of those 4 "in place" bolts that hold the pipe onto throttle body so there is a slight gap which makes the gunk spray everywhere!
Isn't a problem really, just a dirty diesel!
Will fix it one day, helacoil!