Low oil pressure at idle, also fuel smell in oil!
- Thread starter Dub-Se7en
- Start date
Dub-Se7en
Lifer
some, but not an excessive amount, i need to pipe to a catch can to observe exactly how much. it doesn't breathe through the dipstick at all, but there seems to be a fair amount when the oil cap is removed.
we've actually gapped the rings tighter than the equations included with the pistons suggest.
i'm thinking that if we've had the rings gapped wrong it's gonna need to be pulled out again, crank grind and bearings, re-hone and new rings fitted
goldenvtr
Member +
when i did my last compression test i got about 140 over all 4 with my low comp pistons, i need to do another now ive done more miles though just too see how its gettin on.
as i mentioned before at shakespear, for the first 2/3mins on a cold start mine sounds a bit like a diesel but after a short drive it goes away. im pretty sure i used the same piston ring gapping as you as i questioned your build before my own. pretty stumped at how your gettin fuel into the engine though. what was your piston to cylnder clearance like?
as i mentioned before at shakespear, for the first 2/3mins on a cold start mine sounds a bit like a diesel but after a short drive it goes away. im pretty sure i used the same piston ring gapping as you as i questioned your build before my own. pretty stumped at how your gettin fuel into the engine though. what was your piston to cylnder clearance like?
HYBRID
Super Moderator <a href="http://www.toyotagtturbo.
if u ask me, that sounds exactly like engine bearings grinding themselves to death...
its a fact that when u suffer borewash (especially if ur running wrong gaps on ur rings) & petrol goes into the oil:
a.) it will make ur oil stink of petrol
b.) it will eat away ur bearings to nothing fast!
c.) as a result of the above ull get low oil pressure...
so basically remove the sump & get those bearings checked ASAP!
all it takes is a bearing a few rounds to scorch itself to death!
kon
its a fact that when u suffer borewash (especially if ur running wrong gaps on ur rings) & petrol goes into the oil:
a.) it will make ur oil stink of petrol
b.) it will eat away ur bearings to nothing fast!
c.) as a result of the above ull get low oil pressure...
so basically remove the sump & get those bearings checked ASAP!
all it takes is a bearing a few rounds to scorch itself to death!
kon
Dub-Se7en
Lifer
well, my engine is built but not back in the car so i couldn't tell you if the problems have gone. i bloody hope so.
however,
the fuelly smell was more than likely me being paranoid cos i let a couple of garages take a second opinion (1 of which is my rolling road tuner) and they said the oil smelt perfectly normal.
we think the low oil pressure was down to the crank being out of tollerance. it needed a grind but didn't have one due to us following advice of the machine shop rather than going with gut instinct. this meant the bearings lasted less than 8k and the car developed a nasty growl on the bottom end.
the engine when we built it was far too free, this time round with a ground crank and decent bearings it feels like a fresh engine should.
i can't see you having tollerance issues if Dave built it mate, but first thing i'd do is contact him and get his thoughts.
however,
the fuelly smell was more than likely me being paranoid cos i let a couple of garages take a second opinion (1 of which is my rolling road tuner) and they said the oil smelt perfectly normal.
we think the low oil pressure was down to the crank being out of tollerance. it needed a grind but didn't have one due to us following advice of the machine shop rather than going with gut instinct. this meant the bearings lasted less than 8k and the car developed a nasty growl on the bottom end.
the engine when we built it was far too free, this time round with a ground crank and decent bearings it feels like a fresh engine should.
i can't see you having tollerance issues if Dave built it mate, but first thing i'd do is contact him and get his thoughts.
sx_turbo
Lifer
hmmm thats interesting.
my engine sounds exactly the same as yours in that sound clip.
on cold it's not to bad but as soon as it's warm it sounds like that.
the valve clearances on mine are perfectly fine aswell, dave checked them and i have just checked them.
dave said the cams look worn, but i have got a few opinions from other people and they say nothing is wrong with the cams i have.
my oil pressure is very low, was about 1 bar on idel but has slowly got worse, it's more than likely the gauge playing up to be fair, so i will be getting a capillary oiul gauge at the weekend to double check the pressure.
dave told me he cant pinpoint the problem till it breaks.
MentaLEP91
Member +
well if oil smells petroll, its 90% piston ring failure..and its more certain cause of dodgy comp its rly low...your piston size is 74.5mm? and whats the ring gap mate?
sx_turbo
Lifer
that is the million dollar question.
i dont have any more money to plough into the car.
me and dave are currently in the process of sorting it out, were both banging our heads against the wall.
i'm doing my own investigations, and came across this thread.
ian's compression of about 130psi on each cylinder is perfectly ok, the forged pistons should be of lower compression but he doesnt know.
dave has taken the car back and looked at it, checked the valve clearances etc etc.
pretty much the same as i did today, the reason for me checking was to get opinions on my camshafts, so thought i check them again while im there.
ian- did you ever get any blue smoke on start up?
turbo-fever
Member +
well since i had my car i only use to get about 1 bar on idle wen warm, rvrything was fine, could be my gauge reading wrong, the pressure only went up wen i changed to different oil
Adam_Glanza
Member +
my car is standard engine, but i get 30psi avg on idle when up to 80 degrees using 10 40 oil on idle also so i wouldnt be to worried about that?
Dub-Se7en
Lifer
my cylinder head has had a significant amount of chamber work done to it, as well as a thicker head gasket. so the lower compression of my engine seems ok, especially as it was basically the same accross all 4 pistons.
never got any smoke whatsoever from my car on kickup, was getting some smoke on acceleration just before i removed the engine but the turbo was well gone by then as i was running way beyond it's means @ 1.2bar
with regards to ring gap this has always been the grey area, an area we had no experience in so we used an engine builder who still ground rings (rare as fuck) and contacted ross themselves for info.
Dub-Se7en
Lifer
no that seems fine, mine at it's worst was around 12psi on idle, i would say 20psi minimum is acceptable.