oil pressure droping on idle when hot

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Dan-The-Glanza-Man

Member +
right guys whos had this problem, before i go ripping the sump off replacing unfaulty parts like oil pressure valve and oil strainner o ring, oil pump....

got a oil cooler, no thermo stat though, oil pressure drops to zero but its a cheap gauge i got from demon on ebay, but only does it while its hot

now i get 3 bar at 3k and every 1000k revs i go pretty much goes up a bar, when hot at 1k revs gets 0.1-0.5 bar so not good, on my last 5e i used to get 2 bar even when roasting hot on 1200 idle

so

1 im left with thinking is oil cooler too big but then again it should keep the oil cooler so the pressure should be good all the time

2 is oil pressure valve sticking when gets hot

3 oil pump going

4 oil strainner pick up o ring
 
Rob H

Rob H

Member +
Id try a proper oil pressure gauge on it first ie a snap-on one or something like that and go from there, it may be just the sensor for the gauge that fails when it gets hot.
 
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Dan-The-Glanza-Man

Member +
never knew snap on did them, my work hasent got one, im just ordered a prosport one and a new o ring and oil pressure reg, just to be sure, if they dont work only leeds to the oil pump or oil cooler to big
 
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Dan-The-Glanza-Man

Member +
yeah i thought it might of been the running in oil, but ive changed it with some mineral stuff 10-60 to see if it made much differents and it didnt thats why im really confused, ive even put the little washer trick in the oil pressure reg as i knew it would drop abit with the oil cooler

so it should be getting a good 2bar on idle easy and 7-8 on start up with that oil init but it gets 5 bar so weird,

going to get the prosport kit in ect and go from there
 
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bongskag

Member +
take the oil cap off when its running ! you'll soon find out then :) most garages have a mechanical oil gauge, plugs into block and stays in the engine bay while they test it, not like a gauge in your car. there mechanical so you dont get false readings.. im sure you would have the oil light on the dash if it was very low .. what pressure does that turn off at then ?

btw, saw someone do the washer trick once. be carefull with that . his oil filter blew off the threads and smashed into the radiator ! and if your oil pump is on the way out anyway it will put more strain on it too .
 
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elison

Member +
I think as long as your oil light does not come on you "should" be fine. Just for reference my forgie has a pressure of @ 60psi on cold start. Once warmed up its @ 28psi idle(800rpm). On load its @ 85psi at operating temp. Oil being used is Castrol 10w40. New pump has been bolted on in forging process. Make sure you use a good quality oil pressure gauge and pressure sender otherwise you will be scratching your head with false readings and stuff. Prosport is a very decent brand.
 
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Dan-The-Glanza-Man

Member +
he blew the oil filter off bloody hell how big was the washer he put in lol

i did it on my 5e forged engine i built as they run lower oil pressure

think the oil pumps faulty tbh but before i strip that down going to wait till the prosport turns up

and im not running the standard one, anything lower then a bar the standard oil pressure will flick the light on the dash on and off, if it gets lower then 0.5bar it will stay on, when i worked at toyota i kept the 4efte and 5efe books as they never used or needed them and theyve got everythink in there

ill keep you all posted but never had this problem with my 5e so im hoping its the dirt cheap gauge and sensor

thanks for your comments guys :)
 
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bongskag

Member +
I get similar pressures to ellison , forged with new pump , im running Millers CFS 5w-40 seems a little high to me but the pump is new.. the guy who blew his oil filter off put a normal sized washer in there you should use a thin washer/shim like 1mm thick. he is a local legend tho , wish there was a video !
 
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GP82

Member +
As mentioned try a different gauge with a different sender first.

Instead of chuffin' around with washers on the 5E oil pressure relief valve, is it not possible to use the one from a 4E? Or was it never that easy..
Adding a washer to the valve will jus' loose the spring it's compliance.

The oil pump does not create the pressure, but supply volume of oil. The pressure is built up within the engine via the main and big end oil clearances.

These are approx. pressure figures my guage shows me;

Cold start = 4 bar - 60 psi

Normal temp @ idle = 2.5 bar - 35 psi

Driving = 3.2 bar = 45 psi

This is also with runnin' a oil cooler with no stat and 5W40.

How low does your idle go? If you increase the engine speed a tad, does the oil pressure rise?
 
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Dan-The-Glanza-Man

Member +
yeh if i rev it up to 1100rpm it goes up to a bar and a half, its 4e forge so its got the 4e valve init

and putting a washing is makes the spring harder so should be more oil pressure, its weird since doing the big end bearings again as the engines done just over 15k ive noticed the oil pressures not as high as it was, brought new acl rod bearings now i only seem to get 4 bar on start up, the gauge and sensor are only 3 weeks old saying that i put it in just before i replaced the bearings so before cold start i used to get around 6bar on a cold morning
 
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bongskag

Member +
did you have to run the new bearings in on mineral oil ? for 1000 miles changing oil and filter at 50 miles , then 200 , 500 etc... or it that just for running in a new engine ?
 
sx_turbo

sx_turbo

Lifer
im sure the oil pressure is the same on both 4e and 5e.

when i had my forged engine, after 500 miles the oil pressure suddenly dropped, changed the oil and filter still the same, disconnected the oil pressure gauge and connected it again all was fine again. put it down to something being stuck in the oil pressure gauge.

on another note i had exactly the same thing as you are describing on a forged engine i had built by the late mr burwash (rip) he took the car in for a week supposedly checked everything and then said he couldnt find anything wrong....... when on way home the engine ate its bearings, after a gentlemanly discussion and an expensive independent engine report, it was caused by contamination in the oil ways.


the oil pressure relief valve is an extremely simple part and can be taken apart and cleaned shouldnt necessarily need a new valve fitted.

people only put the washer on the oil pressure relief valve on the 5e because of the extra height of the block can potentially cause issues when at high rpm,

the oil pump is an extremely simple design, and can only cause issues if the rotor has worn, which would be almost impossible in a well looked after engine
 
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Dan-The-Glanza-Man

Member +
bongskag said:
did you have to run the new bearings in on mineral oil ? for 1000 miles changing oil and filter at 50 miles , then 200 , 500 etc... or it that just for running in a new engine ?
Click to expand...

im still running them in atm mate so far done 300 miles with its 3rd oil change but not doing any more till i sort this oil pressure, yeh its mineral
 
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Dan-The-Glanza-Man

Member +
sx_turbo said:
im sure the oil pressure is the same on both 4e and 5e.

when i had my forged engine, after 500 miles the oil pressure suddenly dropped, changed the oil and filter still the same, disconnected the oil pressure gauge and connected it again all was fine again. put it down to something being stuck in the oil pressure gauge.

on another note i had exactly the same thing as you are describing on a forged engine i had built by the late mr burwash (rip) he took the car in for a week supposedly checked everything and then said he couldnt find anything wrong....... when on way home the engine ate its bearings, after a gentlemanly discussion and an expensive independent engine report, it was caused by contamination in the oil ways.


the oil pressure relief valve is an extremely simple part and can be taken apart and cleaned shouldnt necessarily need a new valve fitted.

people only put the washer on the oil pressure relief valve on the 5e because of the extra height of the block can potentially cause issues when at high rpm,

the oil pump is an extremely simple design, and can only cause issues if the rotor has worn, which would be almost impossible in a well looked after engine
Click to expand...


yeah when i built my 5e 5 years ago i did the washer as it was a little lower with the oil cooler so i upped it, to me oil pressure is more important then temp as i run a oil cooler ive never had to worry to much about the oil temps and i dont do track days just drag them, i sold my 5e on and is still going today and proud :)

ive been away for 2 years from starlets and hey hoo im back already with a white v and ive fully forged it with a new wepr and custom turbo slowly getting the mods

ive oredered a new oil pressure valve as was only 19 pounds with my discount :) and a new o ring so will be changin the oil with a new o ring and new valve and il see how i get on, but the oil init has only done 50 miles so its new im hoping its just the cheap gauge but as said it works fine when rev it up so makes me think its the engine side rather then the sendor and gauge but fingers crossed aye guys

thanks for the comments youve all given me some ideas, WHY HAVE I BROUGHT ANOTHER V LOL
 
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bongskag

Member +
yep fingers crossed for a faulty pressure valve or dodgy gauge sender ! its a good bet if your gettting pressure with revs. proof your oil pumps working !

if youve owned 1 starlet , chances are you'll get one again at some stage ! cant beat em , no other car in the sub 1.4 tax bracket is so much fun ! ( maybe a classic mini :) )
 
weeJohn

weeJohn

Lifer
I pulled my oil cooler off as it was not keeping pressure after the car sat off for a while. To be honest I dont think there is a need for them, ran plenty of track and drag days in mine without one with a Defi oil temp gauge and never seen any temps of concern.

Is it a remote filter set up on it? The height the filter is can play a part in all this apperently, not something I messed with at the time to see if it made any difference but read up on it.
 
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Dan-The-Glanza-Man

Member +
its a sandwich plate john that comes off the stock 4efte oil filter housing then the filter goes on that, and the oil cooler lines i made come off it, my sender bolts straight to the block, i did run both stock and the other sendor on a t peice to the block but got the new wepr top mount and its a little close to the turbo so i just ran the one silly thing to do but was worried it would melt

but will be going back to running both sensors next week
 
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