R33 Gtst Oil Pressure/cooling Issues

[Yagnol]

Hi all,

Just got my first Skyline a couple of weeks ago, seems to be in good working order and has a rebuilt engine in it (apparently less that 5000km old but it could be more/less). The engine itself is very clean but the engine bay has the remnants of the last engine that has seemed to have spewed oil everywhere!

Only driven it for about 300-400km, but it seems to have an oil pressure issue once the car gets warmed up. Also a couple of times once the car is at temp I check the radiator hoses for pressure and temp, and the bottom return hose seems to be low pressure and much colder then the top hose. Is this normal? Is the stock radiator/ viscous van that efficient? Also the temp gauge never gets above mid, but takes a long time to get there.

As for the oil pressure the car seems to drop to almost nil when the car is hot and idling and only goes as high as 3.5 when the engine is revved. But when the car is cold it idles around the 3.5 to 4 mark on the stock gauge. If I just get the car up to temp with normal driving (shifting on or before 3k rpm with little or no boost) the pressure at idle is about 1 and can go as high as 4.5 when revved.

I understand these stock gauges are not that reliable, but the fact that the pressure is dropping when the car heats up has me a bit concerned.

I have changed the oil to Motul 4100 as soon as I got the car, also only really been driving the car at night (I am in vic and it has been pretty cold at night), could this be a cooling system issue or a issue with the viscosity of the oil I used?

Other than this the car seems to drive well, I can’t hear any strange noises. It has power like you would expect. I just don’t want to cause any issues with the engine.

Any help on this issue would be greatly appreciated.

Edited June 19, 2009 by Yagnol

[FLN75S]

Hi all,

Just got my first Skyline a couple of weeks ago, seems to be in good working order and has a rebuilt engine in it (apparently less that 5000km old but it could be more/less). The engine itself is very clean but the engine bay has the remnants of the last engine that has seemed to have spewed oil everywhere!

Only driven it for about 300-400km, but it seems to have an oil pressure issue once the car gets warmed up. Also a couple of times once the car is at temp I check the radiator hoses for pressure and temp, and the bottom return hose seems to be low pressure and much colder then the top hose. Is this normal? Is the stock radiator/ viscous van that efficient? Also the temp gauge never gets above mid, but takes a long time to get there.

As for the oil pressure the car seems to drop to almost nil when the car is hot and idling and only goes as high as 3.5 when the engine is revved. But when the car is cold it idles around the 3.5 to 4 mark on the stock gauge. If I just get the car up to temp with normal driving (shifting on or before 3k rpm with little or no boost) the pressure at idle is about 1 and can go as high as 4.5 when revved.

I understand these stock gauges are not that reliable, but the fact that the pressure is dropping when the car heats up has me a bit concerned.

I have changed the oil to Motul 4100 as soon as I got the car, also only really been driving the car at night (I am in vic and it has been pretty cold at night), could this be a cooling system issue or a issue with the viscosity of the oil I used?

Other than this the car seems to drive well, I can't hear any strange noises. It has power like you would expect. I just don't want to cause any issues with the engine.

Any help on this issue would be greatly appreciated.

The reason it could be taking so long to warm up is they might of left the thermostat out this isn't that uncommon. the temp guage shouldn'tgo over half way unless it has a cooling problem both skylines i have owned neither went above half way on the guage even in the middle of summer with the aircon going flat out.

I would look at changing the oil pressure sender unit or putting an aftermarket one in before i would gp any further as it is common for them to have a problem i had to buy a new one for my 34 it stopped working altogether.

[Victory]

Welcome to the world of Skylines.

Most of what you have said is normal for a R33.

Mine does take a while to warm up (would be even longer on a cold Victorian night) but when it is up to tempreture it stays just below half.

Oil pressure is dependant on the oil you are using (type and viscosity) and the temperature of the engine. I only use Motul Chrono and it takes quite a while for it to warm up and during this time even at idle it will be around 5 and even higher if you rev it. Once it is warm it should idle around 1 - 2 and sit around 4 when it is above idle.

[Ultimategtr]

agreed completely.

Over here across the ditch, driving at night in temps around 5 degrees, it takes around 10 mins to warmup. This is with zero boost and driving slow.

Re- oil issue - its normal.. lol. i get the almost 0 oil pressure too but its normal. It could be when the engines warmed up, the increased temps in the oil sender/circuit increases resistance therefore affecting the measurements.

Hook up another oil pressure gauge. If youre too worried - Its easy enough - just slip on a sandwitch plate and wire in the sender to it.

Edited June 19, 2009 by Ultimategtr

[ssxRicho]

had my 33 since march. on cold start up pressure is around the 3rd mark (6) once warm drops to the 1st mark (2-3). water gauge starts moving around

50 deg (pfc reading) and sits around 1/3rd once warm (75 on pfc).

i dont like the sound of it reading 0...prob worth getting a replacement, just in case you do loose pressure?

using 4100 oil as well.

[gotRICE?]

had my 33 since march. on cold start up pressure is around the 3rd mark (6) once warm drops to the 1st mark (2-3). water gauge starts moving around

50 deg (pfc reading) and sits around 1/3rd once warm (75 on pfc).

i dont like the sound of it reading 0...prob worth getting a replacement, just in case you do loose pressure?

using 4100 oil as well.

Im with you.. also use 4100 and have never ever seen it anywhere near that low, hot, cold, even boiling on the track.

Id say definitely change the sender, try and aftermarket one maybe, and change the thermostat

[Yagnol]

Thanks for the replies, I think I will be getting a new set of oil pressure, oil temp and water temp electric gauges in the next month or two. So hopefully that will fix the issues. I think I will just have to take it easy until then and just keep checking it.

As for the temp sensor, I got a hold of an IR temp sensor and checked the different parts of the engine a couple of times after driving and it seems to be within the limits, so hopefully all is well there too, but I will let you know if I find any issues.

Thanks Again!

[blind_elk]

The oil pressure senders in Skylines are a bit suspect, and may not necessarily indicate the true oil pressure. Although the gauge may show 0 (or close to it), unless the "oh sh!t" light comes on - seriously 0 pressure - then I wouldn't be overly concerned.

As the temperature rises, the oil becomes less viscous, ie it becomes "thinner". Because it is thinner, it can more easily squeeze past all the restrictions - bearing clearances, etc - so it doesn't require as much pressure to force it through the engine. Hence the "loss" of pressure once the engine is up to operating temperature.