Oil Pressure at Cylinder Head

1.8 GTi . I have had the oil light come on a couple of times noticeably when I have hit a bump or turned sharp or braked hard. When it happened I switched off and restrted and all was ok the oil light did not come on.

I thought it may be an electrical fault but thought it would be a good idea to fit an oil pressure gauge. I bought one and fitted it with the t bar adaptor to the cylinder head outlet.

I am getting about 20 psi at 2000 rpm when the engine is warmed up. Is this a bit low ?

I would be interested in hearing comments with some guidance as to what I should expect.

the warning light will come on at idle if pressure drops below 0.3 bar, and the light+buzzer come on if oil pressure drops bellow 1.8 bar when revs are at or above 2k rpm.

any readongs at the head will be lower than the filter housing as well, this is why the 1.8 bar white pressure switch is in the filter housing and the brown/blue 0.3 bar sensor is in the side of the head.

that should give you a starting point

Thanks for info rubjohnny

Fitted a race tech oil pressure gauge (capillary) to the cylinder head and got the following readings. Cold on start up 80-100 psi, when warmed up with fan kicking in I am only getting 20 psi at 2000 rpm (at the head). No issues with oil lights or buzzer. I thought this was a bit low as I was told to expect 29 psi at cyliner head.

So as Iwas running semi synthetic 10/40 oil, on the advice of a friend (ex race driver who prepped his own cars in the 80,s and 90,s) changed the oil to 10/40 mineral ie castrol gtx having flushed the engine with flushing oil.

Still only getting the same readings, I have fitted a new pump but this is the standard Mk1 from Euro, I was thinking of fitting a higher pressure pump as this is a hydraulic tappet cylinder head. When I asked Euro and GSF they said they only have the standard pump which they say is suitable for a MK1 or a MK2. Does anyone know the part no for the higher pressure pump.

i was also going to refit the oil pressure gauge sender to the oil filter flange today to see what readings I am getting there.

The Mk3 16V pump should (check the top drive spindle first) fit and supply a bigger oil output but you may need to change over the pick-up from the Mk1 pump over to it. Before you do this make sure your existing DX pump (which is more than capable) pick-up is sitting as low as possible in the sump. Another option is to weld baffle plates into the sump, this should cure any starvation issues, if you don't like the idea of welding a Mk3 diesel windage tray can be fitted between the sump and block using suitable longer sump bolts.

the 1.8/2.0 16v oil pump has different driveshaft, so no this wont fit. i think you can strip the pump down and change bits over though?

are the specs you were given definitly for a hdro tappet head?> i think the oil pressure can be a bit less on these due to the tappets, might be wrong. I did have low oil pressure on my 8v, and that was down to worn cam caps. the problem would only occur at idle, the low pressure senor was triggering becasue the oil preszsure would drop below 0.3bar at idle.

Id start by moving the gauge to the filter housing and see what the readings are like there.  if the readings are the same, then you can suspect oil pump delivery problem.  if they are much better you can assume that the issue is with the head.  as i say though, double check the specs you have are for a hydro head, rather than a sdolid lifter head.

I'm sorry I really cant remember what the readings were at the head on my good cylinder head