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edh · Joined: 19 Nov 2003 Posts: 240 Location: Derby, UK

First time out for the 924S at Donington on Sunday

I noticed the oil pressure dropping through the laps - when I got to about 2.5bar I backed off, cruised for a couple of laps & the pressure came back to 4 bar.

I'm running 15w40 mineral & have been recommended Millers 10w60 Synth by a friend

Any thoughts? - the engine doesn't leak, & has been run with synthetics in the past (before I bought it)

Apart from that the car went well - just the one trip into the gravel at the end of the day, pushing too hard down Craner

There's modest understeer with the current setup - standard with no rear arb. The worn dampers are a bit of a problem though - direction changes can be tricky (The fast right/left through Hollwood/Craner in particular)

On the whole I was very happy - as long as the engine holds together & I sort the suspension, I think it's going to be a nice cheap road/track compromise.

IanJ · Posted: Mon May 24, 2004 9:55 pm Post subject:

I had a similar problem on mine. I think it's just the age of the engine. One thing that does help, is to keep the fan on. I have an override switch and it keeps it a touch cooler.

I'm also giving some thought to an oil cooler.

So you want to buy a rear ARB?

Ian
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IanJ · Posted: Mon May 24, 2004 10:33 pm Post subject:

p.s They do say if you don't come off, you aren't trying hard enough!!!

Any pics?
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dgz924s · Joined: 03 Nov 2002 Posts: 592 Location: Kansas

Try using Hi mileage Valvoline Maxlife in 20-50 weight. Non synthetic. I had the same issue and was solved by using this oil. Your oil is hot and getting thin and you are getting this drop in pressure and regaining the pressure when on the gas which creates pressure rise.

Although 2.5 bar is not a problem as the car will fluctuate between 2 and 4.5-5 bar naturally.

Even though synthetic has the same weight it is in fact a thinner oil than Dyno oil adding to the loss of pressure. Hope this helps! Dal

924RACR · Posted: Mon May 24, 2004 11:54 pm Post subject:

Yeah, you need some good synthetic in there.
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edh · Joined: 19 Nov 2003 Posts: 240 Location: Derby, UK

edh · Joined: 19 Nov 2003 Posts: 240 Location: Derby, UK

I filled her up with Millers 10w60 competition oil

At idle, running in stop/start traffic, pressure is 2 bar

Even after a hard thrash, oil pressure didn't go below 1.5 bar

Track test in a couple of weeks (Elvington July 2nd)

shame the indicators died on me today tho

think it's just the relay
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current - '90 944S2, '00 986S,
ex - '90 944 turbo '86 924S, '88 924S

edh · Joined: 19 Nov 2003 Posts: 240 Location: Derby, UK

Just re-read this thread

- just for clarification On the track, oil pressure was 2.5 bar at 4th gear/5krpm

(well below 1 bar at idle, so I didn't even dare look)
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current - '90 944S2, '00 986S,
ex - '90 944 turbo '86 924S, '88 924S

Paul · Posted: Sat Jun 19, 2004 10:24 pm Post subject:

I would verify that the gauge is accurate by using a mechanical gauge. If it is, I would be thinking about replacing my rod bearings and possibly the mains.

edh · Joined: 19 Nov 2003 Posts: 240 Location: Derby, UK

The Porsche workshop manual says oil pressure should be 4 bar at 4k rpm - normal operating temps

Mine is bang on 4 bar usually

On the track, the car is being worked much harder - 5-6k rpms & WOT

After about 15 mins of this, that's when the oil pressure falls off.
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current - '90 944S2, '00 986S,
ex - '90 944 turbo '86 924S, '88 924S

Paul · Posted: Sat Jun 19, 2004 10:48 pm Post subject:

My 87 924S never goes below 5 bar at anything over 2000 rpms using 15W-50 Mobil one.

I've never raced it however, but I have run it pretty hard on back roads for hours in 100 degree weather with the A/C on!

edh · Joined: 19 Nov 2003 Posts: 240 Location: Derby, UK

Track update

- did about 8 sessions / 120 track miles yesterday at Elvington

The pressures kept up really well - only starting to fall towards 3 bar after about 20 mins of track time. The pressures will recover if you run more in the 4-5k rpm range rather than 5-6k

My conclusion is the synthetic oil really improves things.

fwiw, the car ran very well yesterday - couldn't quite keep up with the Elises, but as they were running cut slicks against my road tyres, I wasn't too upset

We did catch & pass a 911 C4 though!

Only failure of the day was the drivers window, which appears to have fallen off it's lifting mechanism - will have to investigate tomorrow

Ed
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current - '90 944S2, '00 986S,
ex - '90 944 turbo '86 924S, '88 924S

Llamaguy · Joined: 02 Jul 2003 Posts: 711 Location: Indiana

So where should the oil pressure be after warmed up sitting at idle, mine stays at 4 and flutters alittle??
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edh · Joined: 19 Nov 2003 Posts: 240 Location: Derby, UK

4 bar is pretty healthy - I was happy with 2.5 bar at idle and 4+ bar at 4k rpm

- that's hot - not "warmed up"
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current - '90 944S2, '00 986S,
ex - '90 944 turbo '86 924S, '88 924S