Oil pressure on 4.2 AJP

[ssavill]

Hi all,

Hope you're all well.

A quick question if I may - Just interested - what is the "normal" running oil pressure of the ajp when cold, and also after a "stressed" run when the oil has heated and is slightly less viscous?

mine (when cold) sits at about 50 - 55 when cold and idling, and after some hard work and warmed up (close to hot ;-) ) and idling sometimes drops to around 45 or so.

Is this normal

Guess I am just interested?

Thks

Stuart.

[Tyre Smoke]

Not convinced how accurate these guages are. Cue lots of posters putting up various pressure readings.

My 4.5 idles at an indicated 60/65 when cold dropping to 30/35 when hot (long hot drive )

[s33 tvr]

Sounds fine to me. Mine runs at 50 - 60 when cold, most of the time about 40 - 45 and will even drop to 30 -35 when very, very hot in traffic.

[cossiemetro]

mines about 60-65 cold and 40-45 hot 96 4.2

[ssavill]

many thanks for responses - just wondered 8-)

what about running water temp - in this warm weather, is anything from 80 to around 100 about right (but quickly coming down from 100 one fans kick in?)

thks

stuart

[Tyre Smoke]

Water guages are notoriously inaccurate, because the capillary tube runs alongside the exhaust manifold.

Normal for mine (4.5 again)is 85 when in open road, but anything upto 105 dropping to just under the 100 in traffic. As long as you can see it dropping when the fans cut in, you're okay. any 'flicking' of the needle indicates an air lock in the system. Sustained above 100 means stop and have a beer at a local hostelry while it cools down and a gentle drive home to discover why the fans aren't cutting in!


Rule one. Excessive heat kills AJP8's!

[s33 tvr]

Agree with Tyre Smoke.

On open road sits nicely at 80 - 85c. In a heavy traffic jam, I always get very nervous. My guage hits 110c before I see it drop to 105c. The fans are working fine and in 3yrs of ownership she has never over heated but everytime it makes me very uncomfortable, not least as when I am sitting watching the guage rise on hot day , I inevitably give in first, turn off aircon and start blowing hot air in to the car.

The guages only indicate 'a suggestion' so they are just a 'trend', nothing more.

[byker28i]

135 miles in my 4.2 yesterday, including two bours of heavy traffic of about 20 minutes stop/start.

My oil pressure is about 55/60 when cold, 45/50 when hot. Temp guage shows about 85-90 when cruising and only just flickers above 100 in traffic when the fans cut in and drop it back to 90. I'm very happy with mine.

[simonsparrow]

My oil pressure is about 80/70 when cold and about 70/60 when hot. Water temp anything from 70-90 degrees depending on how cold it is.

Since I've fitted an oil temperature gauge, you can see how long it takes to warm up. In the winter the oil never gets up to temperature!

[HarryW]

simonsparrow said:

....
Since I've fitted an oil temperature gauge , you can see how long it takes to warm up. In the winter the oil never gets up to temperature!

Where abouts do you have the oil temperature gauge, I assume the sensor is on the filter housing . Any pictures .
I'm having one fitted as part of the refurb, but have not decided yet where the gauge is going to be, I know there are some cars that have removed the clock and fitted it there with a modified water temp gauge.

[Steve_T]

Harry,

My oil temp and pressure gauge should be in the office at Austec. I have the MA fan controller which displays the water temp, so I'm replacing the water temp/oil pressure gauge with it. It's a Cerb gauge rebuilt in Noble M400 style. Have a look at it next time you're in there and see what you think.

Steve.

[simonsparrow]

HarryW said:

simonsparrow said:

....
Since I've fitted an oil temperature gauge , you can see how long it takes to warm up. In the winter the oil never gets up to temperature!

Where abouts do you have the oil temperature gauge, I assume the sensor is on the filter housing . Any pictures .
I'm having one fitted as part of the refurb, but have not decided yet where the gauge is going to be, I know there are some cars that have removed the clock and fitted it there with a modified water temp gauge.

There are some past threads about this, but yes, the sender is fitted to the filter housing and the gauge is where the stereo used to be.

[350matt]

I've fitted an oil thermostat to mine as well as a SPA dual gauge which I've wired to read oil temp as well as water temp (sensor in filter housing) and the oil now quickly reaches 65-70° (when the stat opens) and then doesn't exceed 95° even with 'spirited use' shall we say

Matt

[Steve_T]

Given the previous comments on the Cerb over cooling in the winter - would there be any mileage in some kind of thin plate running just under the sump, to keep it out of the direct airflow and keep the oil temp up?

Steve.

[simonsparrow]

Steve_T said:

Given the previous comments on the Cerb over cooling in the winter - would there be any mileage in some kind of thin plate running just under the sump, to keep it out of the direct airflow and keep the oil temp up?

Steve.

I'm thinking of just blocking off some of the radiator this winter. Thought about an oil temp stat, but not sure if you'd get the situation in winter where it never opens and the oil left in the cooler part of the circuit sludges up.

[Steve_T]

I've spoken about this with Neilus, who has an oil cooler thermostat and oil temp gauge fitted. He said he's seen the oil temp never budge beyond 30oC in the winter and that's with the 'stat in place. Air flow over the sump seems a reasonable cause for this, hence why I'm thinking get the sump out of direct flow. Daft idea?

Steve

[HarryW]

Steve_T said:

Harry,

My oil temp and pressure gauge should be in the office at Austec. I have the MA fan controller which displays the water temp, so I'm replacing the water temp/oil pressure gauge with it. It's a Cerb gauge rebuilt in Noble M400 style. Have a look at it next time you're in there and see what you think.

Steve.

Not sure if I'll be up there for a little while. Pauls off on Hols now, when he gets back I'm off abroad for a week or two with work, looking like early September at the earliest now . Has anyone owned a Cerb so long and never driven it, I ask myself. At this rate it'll be there for the open day up on one of the post lifts as a display .
I may pop up over the next two weeks though while Pauls away to drop the new wheels off, how long is your car there for .
does this mean you've got a spare TVR gauge I could utilise, don't fancy paying silly money to Douglas V .