500 Oil Pressure when very hot??

[cp81]

Over this great weekend of weather I managed to get the Griff out and have a good run out with the local TVR group. During the run, in the hot weather with some fairly brisk driving, the car was getting extremely hot. At one junction during the run at idle speed the oil pressure seemed concerning on the low side, how low should I expect this to be? ( idle speed was normal too )

I do expect it to be lower when the engine is hot, due to the oil becoming thinner.

Is there any simple checks I can do? Apart from the obvious of checking the oil level, but I did this prior to the two hour run, as well as the water..

Thanks

[neutral 3]

What oil are you running it on ? And when was it last changed ?

However, these Engines do run a low oil pressure. I'm running Mobil 1 and have done for years. Racking my ageing brain trying to remember what my ones oil pressure is when its a hot day.

[cp81]

It's just been serviced by Powers and is on 10w-40 oil I believe.

[V8 GRF]

The pressure displayed does drop quite significantly when warm, as long as the levels are OK and the range displayed is consistent I wouldn't worry too much.

[GlynMo]

^^^ What he said. Bearing in mind that the sender/gauge might not be accurate, it's more important that the readings are consistent. You didn't say what your gauge was showing, but 10psi at tickover isn't uncommon for these engines when hot.

[cp81]

Normally at tick over the gauge hovers around the first mark, which is 15psi I believe... (Going off memory without being in the car). On the point I noticed it was about in between the zero and first mark, so say around 7.5psi ish...

When driving it was always up near 30psi when it was very hot.

Have to admit I am still am relative new to the car and just wishing to check what is normal.

[jimed]

Not always the best thing to rely on but there is an oil pressure light which you wouldn't want to be on. Not sure what the Griff one is in terms of pressure though - any ideas?
Jim

[TVR Beaver]

what temps were you seeing on the temp gauge?

[QBee]

Think the idiot light comes on at about 8 psi from memory - the "idiot light" because if you are driving it with that light on you are an idiot.....as you are not far from a blown engine.

I have not seen my 500 Chimaera oil pressure that low, even on a hot track day, and mine does normally run at around the 30 psi mark

[cp81]

There was no oil light on for sure.

Water temp was around 95ish.

[QBee]

cp81 said:

Water temp was around 95ish.

Just worth starting the car at home, bonnet up, letting the engine get up to temps, and checking the fans plural cut in correctly. If the otter switch is the correct type the fans should keep the car to about 90 degrees even without any cooling airflow from forward motion. You may have one fan not working, or even both

[blitzracing]

Id use the Penrite HPR fully synthetic oil as recommended by ChimpOnGas- oil pressure between 30 and 40 psi whatever I throw at it, really happy with the results.

[V8 GRF]

95 sounds a bit warm to me. My car rarely goes above 90 even in a queue, even cooler now I'm using an alloy radiator.

[TVR Beaver]

V8 GRF said:

95 sounds a bit warm to me. My car rarely goes above 90 even in a queue, even cooler now I'm using an alloy radiator.

you hope !!

[QBee]

Alloy rads look very cool

[ESDavey]

Alloy rads do look cool but they can suffer from damage just like any rad. I had x2 rads in 4 months due to debris while doing track days. Standard rads do the job fine.

[QBee]

ESDavey said:

Alloy rads do look cool but they can suffer from damage just like any rad. I had x2 rads in 4 months due to debris while doing track days. Standard rads do the job fine.

Never suffered from debris on track days - you doing yours at Lydden Hill?

[cp81]

Checked oil this morning and level was fine, so no oil lost. Water level was fine too.

Could be a faulty sensor maybe... Will pop into Powers for a chat.

[Bluebottle]

ESDavey said:

Alloy rads do look cool but they can suffer from damage just like any rad. I had x2 rads in 4 months due to debris while doing track days. Standard rads do the job fine.

that's why I have a mesh grill in the nose of my car...especially as I have 4no. rads in there.
to the OP, is this a serp or pre serp 500?, my old pre serp used to cook oil on a long run in hot weather (turned it to the consistency of water and oil pressure would drop. As others have said use thicker oil (I use Mobil Extended life (10W 60) and 95 Deg. would suggest you need to look at overhauling the cooling system.

[macdeb]

Depends on if your car is a 'pre-serp' or a 'serp' as the pressure differs from both. Pre-serp will be around 10 psi on hot idle whereas the serp should be around 25-30 psi. One thing that will affect the above as I have recently learned is if you have fuel contamination in the oil and that will bring pressures down.