[matty]

i just got my g16b back together and there is a few problems.
put it on the dyno and the tuner said i have very low oil pressure at idle (15psi)
and a heap of crank case pressure witch is pushing the dip stick out and blowing oil everywhere.
it was a full rebuild top to bottom. the tuner said maybe the engine builder set all the wrong clearences in the motor.
any help would be great, thanks all.

[want33s]

Could be anything :
Incorrect honing of bores.
Incorrect spacing of the ring gaps.
Low oil pressure could be a bearing clearance issue.

Very hard to diagnose here.

[tonyevans]

My best guess would be rings broken during install but then I don't know much

[atari4x4]

from kyzer's turbo jimny build up...

http://auszookers.com/index.php?name=Fo ... &start=150

kyzermattingley wrote:

Wielvel wrote:

Question- does anyone have an Oil pressure gauge on there Jimny, at present mine is only getting to around 4 bar (about 56psi) at 4000rpm, just seams a little low

What size is the hole feeding oil to the turbo? From past projects I made the hole 1mm to the turbo other wise you loose presure on the main bearings. The 1mm is more than enough to lubricate the turbo.

Good point, im running -3 out of the block and all the way to the turbo.

I'll buy a spare nipple, weld it up solid and put it in the feed line for a minute and see if the pre sure raises.

When I was building the kit oil pressure was on my mind but after a few people telling me it wouldn't be an issue I forgot about it.



Kyzer

[JrZook]

matty wrote:

i just got my g16b back together and there is a few problems.
put it on the dyno and the tuner said i have very low oil pressure at idle (15psi)
and a heap of crank case pressure witch is pushing the dip stick out and blowing oil everywhere.
it was a full rebuild top to bottom. the tuner said maybe the engine builder set all the wrong clearences in the motor.
any help would be great, thanks all.

Dunno whats up with your oil pressure but I think I spied a possible issue of your crankcase pressure. Looks like in your build pics you still have the crankcase/rocker cover breather connected in the stock position which would pressurize the crankcase once she starts to boost.

If the over pressurizing issue is happening at idle then you do have possible engine build/assembly issues. Take it back to the builder.

Dan

[matty]

had good oil pressure before engine rebuild around 42psi on idle, but more worried about the crankcase pressure. but there is a good chance there related.

[matty]

JrZook wrote:

matty wrote:

i just got my g16b back together and there is a few problems.
put it on the dyno and the tuner said i have very low oil pressure at idle (15psi)
and a heap of crank case pressure witch is pushing the dip stick out and blowing oil everywhere.
it was a full rebuild top to bottom. the tuner said maybe the engine builder set all the wrong clearences in the motor.
any help would be great, thanks all.

Dunno whats up with your oil pressure but I think I spied a possible issue of your crankcase pressure. Looks like in your build pics you still have the crankcase/rocker cover breather connected in the stock position which would pressurize the crankcase once she starts to boost.

If the over pressurizing issue is happening at idle then you do have possible engine build/assembly issues. Take it back to the builder.

Dan

hi dan, if you mean the hose thats coming off the breather ,thats running to an open catch can. the crankcase pressure builds as you go up in the rev range. as you hit about 4000rpm you can see the dipstick move out of position. thanks dan

[losfer]

15 psi at idle isnt spectacular , but isnt the worst case scenario , your oil light wont come on till under 5 psi
all the factory tests specify that oil pressure should be checked at 3000 rpm and should be in the vicinity of 50-65 psi.
as for the crankcase pressure problem , that is in no way related to oil pressure problems , it is in relation to combustion gases escaping past the piston . the usual causes of this are a worn engine (which it obviously isnt) or rings not bedded in properly , or the most likely cause for what seems a severe case in your regard , is a bad tune causing detonation. the early signs of detonation will be broken ring lands (the area of piston between the top and second compression ring) and in turn broken compression rings , in severe cases of detonation (lean out) it will melt holes through the piston , particularly on the skirts where valve flycuts are.

[matty]

losfer wrote:

15 psi at idle isnt spectacular , but isnt the worst case scenario , your oil light wont come on till under 5 psi
all the factory tests specify that oil pressure should be checked at 3000 rpm and should be in the vicinity of 50-65 psi.
as for the crankcase pressure problem , that is in no way related to oil pressure problems , it is in relation to combustion gases escaping past the piston . the usual causes of this are a worn engine (which it obviously isnt) or rings not bedded in properly , or the most likely cause for what seems a severe case in your regard , is a bad tune causing detonation. the early signs of detonation will be broken ring lands (the area of piston between the top and second compression ring) and in turn broken compression rings , in severe cases of detonation (lean out) it will melt holes through the piston , particularly on the skirts where valve flycuts are.

thanks losfer, the reason for the rebuild on the motor was because of the pressure in the crankcase. eg. worn piston rings or damaged in some way. the problem is still there. i have never herd of any fresh motor blowing oil out the dip stick in this way because of the rings not properly bedded in yet. is there something the engine builder and the machine shop may have mised. mabey crack in block.

[atari4x4]

are you still running the stock computer?

[matty]

atari4x4 wrote:

are you still running the stock computer?

its has a apexi AFC on it but i,v got these delemers before it comes into boost. they only tuned up to 3000 rpm and they stoped there because of the crankcase presure.

[losfer]

you need to get a "leakdown" test done on every cylinder (not a compression test) this will pinpoint where the problem lies.

its basically a tool with 2 pressure gauges , one gauge shows a "known leak" the other gauge shows an "unknown leak" if the difference between the known and unknown leak is 10% theres where the problem is , you will also hear air escaping out past the dipstick tube on the problem cylinder(s)

[matty]

losfer wrote:

you need to get a "leakdown" test done on every cylinder (not a compression test) this will pinpoint where the problem lies.

its basically a tool with 2 pressure gauges , one gauge shows a "known leak" the other gauge shows an "unknown leak" if the difference between the known and unknown leak is 10% theres where the problem is , you will also hear air escaping out past the dipstick tube on the problem cylinder(s)

thanks losfer, i'll start there and hope we can find the problem.
at least your head stud kit works. thanks again.

[matty]

ok, so i'v just been told if the leak down test is all good then they will put an extra breather on the motor to release the pressure.
my question is could i be getting the pressure in the crankcase because the rings arnt seated properly yet. and remembering that the motor has a turbo and has not been decompressed on advice from machine shop.

[JrZook]

Well just to check that the turbo isn't pressurising the crankcase why don't you hold the waste gate open and see if its still happening.

Post up a recent pic of your engine and how everything is plumbed.

[matty]

JrZook wrote:

Well just to check that the turbo isn't pressurising the crankcase why don't you hold the waste gate open and see if its still happening.

Post up a recent pic of your engine and how everything is plumbed.

thanks dan, had a search on turbo causing crankcase pressure and correct me if i'm wrong it is the oil seal on the exhaust side of the turbo that may be a problem, and the oil should turn grey in color because of the exhaust fumes.
would you see any oil or exhaust fumes from that area.
until the leak down test is done i wont know were to look.
but i will change the oil tommorow and do the waste gate check and see what happens.
as for the engine builder, he is very hard to contact at the moment.
may have to be a name and shame day coming up.
pics are up to date. thanks dan

[matty]

well i did the oil change today and it was all clean and no metal fileings or anything i could see.
but a may have found the problem. i took the inlet side of the turbo off and found a small amount of oil in there and that carnt be good.
so my guess is the oilk seal on the turbo has gone which would be pressurising the engine. i hope.
here's a pic of what i found.

[Brett]

low oil psi could be the wrong restrictor has been used for the turbo oil feed line.... but most of the time its the wrong clearance in the engine (to big) that will give it low psi at idle and with the other problem of pressurising the crack points to a crap rebuild.

a crack in or leak in the turbo wont pressurise your car, you'd be blowing lots of blue smoke before that happens.

what psi are you putting into it?

[matty]

Brett wrote:

low oil psi could be the wrong restrictor has been used for the turbo oil feed line.... but most of the time its the wrong clearance in the engine (to big) that will give it low psi at idle and with the other problem of pressurising the crack points to a crap rebuild.

a crack in or leak in the turbo wont pressurise your car, you'd be blowing lots of blue smoke before that happens.

what psi are you putting into it?

hi brett, only 4 psi, as that was the last tune it had before the rebuild.
oil pressure seems to be allright at the moment. it was reading low oil pressure because they lost so much oil out of the engine on the dyno.
well it is blowing smoke, but it has not been tuned yet and is running very rich. i have read that a blown oil seal on the exhaust side of the turbo would put pressure in the crank.?
thanks brett.

[MrRocky]

oil in the cooler pipes and inlet isnt a major concern and is normal to a certain extent.