Hello, I have a Fabia mk1 1.2 12v 2006.can somebody tell me if it has a pressure relief valve on the oil sistem and where is positioned?

Oil pressure relief valves are usually located in the oil filter cartridge in the event that it gets clogged up, therefore to fit a new one simply change the oil filter, however if it has a replaceable filter element then the valve will be in the housing the element fits to.

I have a low oil pressure light,but just when the oil is hot and between 1000-2000 rpm.

How can I check if the oil pump is faulty?

I mention that the valves on cylinder 2 have been changed.

Can this affects the oil pressure?

When was the oil last changed? When was the oil filter last changed?

There are two O-rings on the oil filter assembly, items 16 and 17 on this page: https://skoda.7zap.com/en/cz/fabia/fab/2006-453/1/115-115020/  It is probably worth buying and fitting two new ones just in case that is a cheap and easy fix for your problem.

 

The oil pump has an overpressure valve within it.  The sump must be removed to inspect or remove the pump. The oil pick-up pipe can be inspected for partial blockage and cleaned or replaced at the same time.

As I suggested in your other post, if this problem didn't exist before the valve repair, why are you not taking it back to the garage that did the repair and saying "you have caused a problem with the oil pressure, please mend it and don't charge me"? 

 

Could also be a faulty oil pressure switch.

6 hours ago, TMB said:

Could also be a faulty oil pressure switch.

 

It's this ^^

I replaced the sensor and the light still comes on.

I took it back to the mecanic last week, it remained in there for a day and he called me to tell me that he doesn’t know what is the problem because his part of the job is ok.He also told me that the car has oil pressure,I took the car   to the second mecanic to measure the pressure and the pressure at 2000 rpm is something 0.6-0.8 bar when the engine is hot.He told me that the value should be at least 2 bar,is this true.

Do I need a new oil pump,or something could be assembled wrong to the car?

Yes, 2 bar at 2000rpm is expected.

Was the oil and filter changed as part of the head mending job?

If it wasn't, do it. See if any lumps of silicone sealant come out with the old oil.

 

If it was changed, try the o-rings I suggested above, pennies from dealership.

Edited 12 June, 20188 yr by Wino