Low oil pressure only on hot idle, modified 1.9 Tdi Seat Leon 1p

Hello,

I am driving about 1 year (with my new 2.0 BHW conversion) my 1.9 TDI and on my oil pressure gauge (autogauge) on idle i have 0.8 - 0.4 Bar oil pressure (and annoying red light on gauge).
I change the oil pressure gauge but nothing. The oil pump is ok and make pressure on high rpm.
The problem apear on hot oil 70+ degrees.
I use only 5w40 Motul 300v Power.
The specs of my car:


1.9 8v BXE PD105 Engine
GTB2260VK
3" Downpipe

FMIC with 57mm Custom Pipe Work
EGR Delete Race Pipe
Race PD Injectors with Firad 80% Nozzles
Race Camshaft Kit
Hydraulic lifter dlc coated
Ported Head
33mm Oversize Exhaust Valves
37mm Oversize Inlet Valves
Engine block honing/rebore
2.0 BHW 81,5mm Pistons
Forged H Beam RODS
High Lift Valve Springs and Retainers
Competition Spec Bearings
4 BAR MAP Sensor
76mm Exhaust System with Borla Resonator
Oil Cooler
Mocal Diesel Cooler
large front fuel cooler
6 Speed Gearbox 02Q
02Q Quaife LSD
.... and many more
448hp / 882Torque

I ask allot of people, where can i start to fix the low oil pressure on idle, higher the oil temperature, lower pressure on idle

Oil pressure on high rpm:
2000 rpm - 2.5 Bar
2500 rpm - 3 Bar
3000 rpm - 4 Bar
4000 rpm - 5 Bar

Some advices ?

Low oil pressure at only at hot idle is often due to past-spec bearing clearances... rod or crank.. that are big enough on a hot engine to bleed off too much oil pressure on the circuit at low oil pump speeds and thin oil.

Looks like you had a bunch of engine work done... were all the clearances checked, and if so, what where they? If you were told they were "good", as opposed to being given specific measurements... that might be a sign.

You can also pop the oil pan and measure a journal or two and a rod or two to see if this is the issue.

Clearance-checking the oil pump would be a good step too... you're not looking for something broken but something with enough wear to cause problems when the oil pressure system is at its most challenged: hot thin oil, wide bearing clearances, and low pump RPMs.

Final thoughts: good quality oil filter? No after-market add-on bypass oil filter kit that's stealing oil pressure?

EDIT: one more thought... not familiar with the BXE engine, but if it's like our BRM there's a big issue with the hex shaft that drives the oil pump. Dunno if that applies to you.

thanks Vince,
The low oil pressure on idle apear after i mod to 2.0 and change all the bearings, and make a new engine
i change twice the oil filter, with original mann filters.
I know that the 1.9 tdi oil pumps are strong enough, the car have 150.000 with this pump.
I read a post somewhere with the same problem but different car that he fix with a car additive.
I don't want again to take the engine down to measure and see the bearings ... not again pleaseee
can this 1.9 tdi oil pump to be upgraded to make a little more pressure (that will be a fast fix)?

eyeonu said:

change all the bearings, and make a new engine

Click to expand...

Yup, so the question is: were all the bearings Plastigauged to make sure the clearances were correct/crank not worn/wrong bearings ordered/supplied, or just new bearings installed right from the box?

eyeonu said:

can this 1.9 tdi oil pump to be upgraded to make a little more pressure (that will be a fast fix)?

Click to expand...

Like you said, it's a fine oil pump that is capable of producing more than enough pressure/flow, so if you've got oil pressure problems the problem is likely lurking elsewhere.

If everything was fine... then you changed all the bearings... and now you have oil pressure problems... it kinda points to bearing clearances. If this is the case and the bearings are left in place the engine may want to pound itself to death over time.

I believe the oil pressure relief valve is fixed and sealed... but someone may have played with one at some point.

Checking the clearances can be done pretty quickly with the engine in the car... you just pull the oil pan and then a couple of the mains / rods bolts from underneath. You can change out the bearings from underneath too, in a pinch.


Does your engine have chain-driven balance shafts?

new bearings intalled from the box
i did not make Plastigauged /PLASTIGAGE, i will order a green one (0.025-0.076mm), do i find the maximum clearance somewhere ?
i will make this days to see the clearance
LATER Edit: i see that is PLASTIGAUGED and PLASTIGAGE with different measurement
what to use ?
platigage (.025 to .076mm)
http://i.ebayimg.com/images/g/IZIAAOSw54xUU8Fh/s-l1600.jpg
or plastigauge (.0175mm-0.5mm)
http://www.ebay.co.uk/itm/Plastigau...789699?hash=item542548ef43:g:BvQAAOSw4iRWEs6y
----
i did not touch the oil pressure relief valve
can i see there if is a problem ?
someone told me not to take out the valve because is feated and measured from the factory

back, the winter is out, and tofay i measured the bearings
all camshaft and rods bearings - clearance .051mm
----
tomorrow is time to measure inside the oil pump
----
what's next Vince Waldon ?

Isn't there some part of the PD valvetrain that has an oil gallery plug that falls out? Something in the injector rockers?

-J

compu_85 said:

Isn't there some part of the PD valvetrain that has an oil gallery plug that falls out? Something in the injector rockers?

-J

Click to expand...

Yup. Although I doubt this would cause enough of an oil pressure loss to cause the low oil pressure light to come on.

http://forums.tdiclub.com/showthread.php?t=454860

omg, i did not think of this, i will check today

i verify, all the bolts are there!
i will replace the oil pump with a new one, maybe there is the problem with the oil pressure on idle

the new oil pump did not fixanything
oil temperature: 75
idle pressure: 1000 rpm - 0.8 bar
1500rpm - 2 bar
2000rpm - 3bar
3500rpm - 4 bar

so sad for idle pressure

Seems like normal pressure to me? What are you expecting?

Sent from my XT1097 using Tapatalk

at temperature 80, it will drop under 0.5 bar on idle

It is unfortunate you are getting bad advice here. Checking the plugs in the end of rockers was good advice but changing bearings and oil pump on a car with 150,000 kilometers is crazy. Vince, it is obvious your spending someone elses money here.

The rule of thumb for all performance cars is 10 psi or .7 bar per 1000 rpm.

oil temperature: 75
idle pressure: 1000 rpm - 0.8 bar
1500rpm - 2 bar
2000rpm - 3bar
3500rpm - 4 bar

He has that even at idle. Since the car is not under load at idle and he has no lifter noise idle pressure is sufficient even at .5 bar which is likely 850 rpm.

The oil you are running is a excellent ester oil and has a very good HTHS and VI so that is not an issue.

In fact his oil pressure is ideal.

I could suggest he use the smaller BRM sprocket and chain which increases the flow of your stock pump by 30% by increasing the pumps rotation speed( Franko6 suggests this for some cars) but then most of the time the oil would be running over the relief valve which is generating heat and wasting horsepower. Your relief valve should open at 55 to 60 psi or 4 bar.

James & Son said:

IVince, it is obvious your spending someone elses money here.

Click to expand...

Hmmm... my suggestion was to *check* the bearings, as a common contributor to low oil pressure when hot, and I *never* suggested replacing the oil pump.

What thread are you reading?

Vince Waldon said:

Hmmm... my suggestion was to *check* the bearings, as a common contributor to low oil pressure when hot, and I *never* suggested replacing the oil pump.

What thread are you reading?

Click to expand...

but i reply to you

"back, the winter is out, and tofay i measured the bearings
all camshaft and rods bearings - clearance .051mm
----
tomorrow is time to measure inside the oil pump
----
what's next Vince Waldon ?"

James & Son said:

It is unfortunate you are getting bad advice here. Checking the plugs in the end of rockers was good advice but changing bearings and oil pump on a car with 150,000 kilometers is crazy. Vince, it is obvious your spending someone elses money here.

The rule of thumb for all performance cars is 10 psi or .7 bar per 1000 rpm.

oil temperature: 75
idle pressure: 1000 rpm - 0.8 bar
1500rpm - 2 bar
2000rpm - 3bar
3500rpm - 4 bar

He has that even at idle. Since the car is not under load at idle and he has no lifter noise idle pressure is sufficient even at .5 bar which is likely 850 rpm.

The oil you are running is a excellent ester oil and has a very good HTHS and VI so that is not an issue.

In fact his oil pressure is ideal.

I could suggest he use the smaller BRM sprocket and chain which increases the flow of your stock pump by 30% by increasing the pumps rotation speed( Franko6 suggests this for some cars) but then most of the time the oil would be running over the relief valve which is generating heat and wasting horsepower. Your relief valve should open at 55 to 60 psi or 4 bar.

Click to expand...

Thanks for that good advice with the smaller BRM sprocket.
i have read the
http://forums.tdiclub.com/showthread.php?t=271919
and i will need this:

BRM sprocket - 038115121A
BRM chain tensioner - 038115130
BRM chain - 038115230A

i will make some readings this days with a higher oil temperature at iddle

The service literature for my MB says .3 bar at idle is the minimum pressure.

-J

compu_85 said:

The service literature for my MB says .3 bar at idle is the minimum pressure.

-J

Click to expand...

I think this is my low 0.3 bar at temperature 90+ but this low pressure scare me. After a hard run, how i can safely wait to cool down the engine at iddle with this low pressure?!
But before rebuild entire engine the car have 1+ bar at iddle
---------
James, is funny now because i check my oil pump sprocket (engine BXE) and it haves 23 teeth, same as BRM, i cannot make any upgrade!

i did not find a mechanical solution
---
i am searching on my edc16 the map to setup idle to 1000 rpm because on vcds i can setup maximum at 950 rpm, i will setup dinamicaly idle by temperature
this will fix the low pressure on idle

What kind of oil cooler do you have? Is it air cooled or water cooled.

Is your oil cooler a by pass type. My by pass filter drops my oil pressure by 5 psi but I still have 10 psi at idle. I am using a 5w-40 oil at 88 C. The orifice size is 1.00 millimeter.

Anyways you could put it inline instead of bypass.

This is just a another suggestion. Oil additives in your oil are effective at 82C. It is not necessary to run the stock thermostat( probably 88 C). I would put in a 82 C thermostat to reduce your average engine temperature. If the oil cooler is water cooled this would make a great difference. If not the thermostat change would still be enough to reduce the max. oil temperature. I am assuming you also have the stock oil cooler/heater as well.

Edit, Here is a simple answer, add enough to solve your idle pressure.
https://s3-eu-west-1.amazonaws.com/...0V_Competition_15W-50_(GB)_(1).pdf?1484047628

i use mocal air cooled in front of the car and i don't use an bypass
i will use ony motul 5w-40 300v power and i don't want a higher oil viscosity
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i will test today to set the idle by maping the ecu