The Bull

iTrader: (3)

I have a my03 wrx and the oil temp is normally 90°C and 95°C when hard driving for a period of time, but in the last 2-3weeks its hitting between 95°C 100°C driving steady and around 110°C driving hard can anyone tell me why.
Ive also used for the first time shell helix ultra 5w-40 fully synthetic and coverd 4000miles, but changed from shell helix ultra extra 5w-30 fully synthetic whats the difference?

The Bull

iTrader: (3)

ANYONE?

prwatts

Hi, have you changed from Helix Ultra Extra 5W30 to Ultra 5W40?
Perhaps the 40 weight oil is not conveying away enough heat v the previous 30 weight oil. But what does make me suspicious is the 4000 miles on it. Shell Helix Ultra is a good oil but to my understanding its not a full ester oil (Maybe Oilman can help) I would worry about oil dilution and degradation of the additive pack after 4000 miles with hard driving in it.
Personally I would recommend changing after 3000 miles if you use Shell Helix, Mobil 1 etc, but why not try Silkolene Pro Plus or Motul 300V full ester oils- again, contact Oilman on the forum. Excellent guys. Do you have an oil pressure gauge? An indicator of the oil deteriorating is a reduction in the oil pressure at idle. (It won't reduce at revs because the Pressure Valve has a fixed setting)

I have an oil cooler and my oil seldom goes over 80 this time of the year - I think that is the temp the thermostat opens, or thereabouts.

jasonius

iTrader: (1)

If the difference you've noticed over the last few weeks has been with the same grade then the raised temps could be one of two things:

1. as an oil deteriorates through normal use it looses a lot of it's abilities to lubricate and ultimately heat management, especially mineral oil. This is where a good fully syth has major advantages as it will stay in 'grade' longer.

2. if you're running low on oil you will see a raised oil temp, so check to see if the level is lowish. Best to check before first (cold) start of the day and to pull dipstick, wipe then allow 10 mins before re-inserting to check level..

Whatever temps you normally see any general increase could be a sign for concern, points 1 & 2 aside..!

The 5w 40 should, strictly speaking, be more suited to higher temps than the 5w 30, but if I've read your post correctly the increase you're seeing has happened after 4000 miles or so of the same grade..?

Personally, I use Motul 300v (fully syth) 10w40 in my 05 WRX (340hp) and I usually see 90-95c in high summer, with a max of 100c. This time of year it's ~10c lower.

You could try a 'proper' fully syth, such as Motul of Silkoline, which are genuine synthetic oils.

MaDaSS

RCM have always put Silkolene Pro R 15w-50 in my car for years.
03 WRX.

D1CCY

Perhaps the gauge or sender is at fault. IMHO the oil type/grade is unlikely to cause differences that big.

The Bull

iTrader: (3)

i thought the gauge is faulty well the sensor anyway im going to do an oil change now with the same shell helix ultra 5w-40 fully syth hope that sorts it. PRWATTS my oil pressure gauge on idle is around 2-2.5 kpa and flat out is7.5 kpa. thanks so far everone

The Bull

iTrader: (3)

Ive done the oil change and the temp steady driving is 90-92°C and when hard driving it went to 96°C better than before
thanks people

prwatts

Try a fully synthetic ester oil such as Silkolene or Motul 300V next time - contact Oilman