Hi Guys,

I've got a 2004 Sti UK that's standard apart from a prodrive back box.

I've got a Defi gauge monitoring oil temp from above the number 3 cylinder. Normal cruising off boost sees a temp of about 98'C and a couple of times in the past few days it has set off the alarm which is set at 115'C, when giving it some welly.

I've searched the forums and these temps seem too hot for a standard spec engine.

The car was serviced recently with Silkolene Pro S 10w-50 and the coolant was replaced. I've checked the oil and coolant levels and they're fine.

Is this too hot for a standard engine, and if so do you have any ideas on why?

 

That seems a bit warm...check your filter. Pressure might look ok, but flow can be down.

 

Chip, thanks for the tip. What am I looking for with the filter? It's a genuine Subaru item that was replaced at the service.

 

Car engines are not really my thing, but principles apply..

It sounds hot to me, though I stand to be corrected.

You don't need a big reduction in flow for excessive thermal transfer to occur. You say it's OK off boost?...check the oil pipes to the turbo bearings? Where is the oil temp sender in relation to the turbo?

 

I'm not sure if it's ok off boost. I'm new to Subaru's but understand that my car has an oil/water cooler. Therefore off boost I would expect the oil temp to follow the water temperature. At 98'C off boost it could be that my coolant is too hot. Unfortunately I only have the standard temp gauge measuring coolant temp which I'm told doesn't give a very accurate reading.

I have looked at all pipe work etc, and it 'looks' normal. But like I said I'm new to Imprezas, so could be missing something.

 

Check your oil level... low oil level means that the oil is worked harder and doesnt have as much time to cool around the cooler and in the sump before it is pumped back around to the hot parts.

Gaz

 

I've checked the Oil and Coolant levels when cold and both are up to the max markers.

Thanks anyway though Gaz.

 

Firstly, as the sender is in the block then you will possibly see slightly higher temps. than if it is in the sump.
If you can, remove the sender with it's connectors still on, and imerse it in a kettle of boiling water. Check the gauge to see if it's showing 100c
JohnD

 

I have considered that the reading is incorrect. Like you say, I would need to remove the sensor which I'm trying to avoid.

I drove to work this morning completely off boost for 14 miles and the oil temp was reading 95'C.

 

you driving with your air con on?

that raises my temps, presume its due to extra load on the engine????

 

I dont see anything wrong here, your giving the car a good run out and the oil temps are going up, errrrm that makes sense really, its taking the heat out of the engine and then its being cooled by air/water, normal for any car really.
Worry if your temps are at 130+, but to me, your car is running fine.

Tony

 

As an aside you don't really want the oil right up to the Max notch (when cold). Overfilling can lead to residue in the boost control solenoid (not hard to check/clean tho) and can give boost probs.

I wouldn't panic about it, but if you do your own changes don't put quite so much in next time, enough but not too much

 

<Scientist's Method>

Firstly, get a base point to check the Calibration the guage: Dip sesnor in a pan of boiling water and power it up - see what it reads.

And use this calculator to correct for ambient air pressure and altitude to find the exact boiling point of the water: Water Altitude Boiling Point Calculator

Today's air pressure:
BBC - Weather Centre - 5 Day Forecast in Celsius for London City, United Kingdom (in mbar: for London..enter your own town for your own locality).

And find your local Altitude (google or GPS)

 

Thanks for the replies guys.

Will - I haven't been using the aircon.

Tony - I have been told the Silkolene is good over and above 130'C. Oil pressure remains at 6 - 6.5 Bar whether the engine is at 95' or 115'C so I may well not have anything to worry about.

Funky - I was recommended to fill it right up to get more oil in to help keep it cooler! I have 2 max lines on my dipstick, on for cold oil and one for hot. Mine is up to the max for cold oil. Thanks for the tip though.

My main reason for concern is that I'm planning for my first trip to the Nurburgring soon. I don't want to get there to find the oil gets too hot half way round a lap!

 

115 on warmer days isn't a suprise tbh, different cars run at slightly different temps.

my classic has always run hot, especialy on warm days where any hint of boost got the temp jumping up, was fully checked out and nothihng wrong at all so just runs hotter than some thats all, sorted now though with an uprated oil cooler

 

This thread may be of interest to you

https://www.scoobynet.com/general-te...il-cooler.html

 

I have the same sensor type fitted to cylinder 3 and I'm running approx 485 bhp on 2.5L engine with GGR's massive oil sump...norm running about 97-98 degs, then upto 105 with short hard blasts and I've seen 110 once when really giving her stick for as long as possible (not easy as you soon run out of road lol). During my recent mods I've noticed one thing that changes oil and EGT temps...the mapping! Bob R set mine up properly and EGT's at now 860 mark plus lower oil temps...car even sounds happy and strong and engine doesn't smell like its cooking after a rant.

I wasn't over happy with 110, I'd prefer cooler...but not sure if its worth the expense of oil cooler plus fitting...

Going around the ring will give you chance to really push the car to the limits...Just set the warning light at max your happy with and lift if it goes off..

 

Thanks for all the advice guys. I have been in contact with Bob about remapping, but wanted to sort the oil temp out first. I assumed that more power = more heat. Maybe I should just get the mapping done and see what happens.

 

Not in my case...ran major hot before, then Bob did a sweet map with nice fueling, oil temps dropped..you might get the same...

Speak with Bob about it

 

I've owned several incarnation of Golf GTi over the years, and they've all run their oil at 115-125 Celsius when they were being properly used, it wouldn't surprise me if it got higher in some engine parts. There's no sensor on my Scoob so I've no idea how hot it actually gets, but I would guess that it's similar

Allowing cars to warm up and cool down properly, plus regular oil changes, are IMO the keys to a good long life. I've never blown an engine up yet

 

I've heard horror stories of 125 deg mark for scoobs...think that with a turbo engine is a no no.

I'm looking at an oil cooler with 110 deg being my max but that's because I've never taken her on a long blast...ie track day or long high speed run with the new power levels...I'd much prefer to have mine running at 90-100 all day long as the oil (and engine) have an easier life.

 

Remember too cold is as bad as too hot!!

 

A decent oil doesn't degrade its performance until past 140C, however it will be 'thinner' at that temp thean the 100C its designed to run at (hence the reason oil is graded at 100C!). OIl will gain between 6 and 10C from sump to anywhere its pumped to anyway.

There are a lot of scare stories about oil temps over 100C, and most are just that, obviously the higher stressed your engine is the more important it is to keep it cool, but most manufacturers use 140C continuous and 150C transient as the limit for their sign off tests and your a long way off that!

Simon

 

Cheers guys...just had a word with my mapper and he's advised me not to bother with the oil cooler route...

 

With swisstony thats exactly how mine sits with temps an pressure and mines just been rebuilt after the crank bearings let go
I got the defi's just before this happened so it was an ideal situation to see how the engine would/should behave but to be honest I sometimes wonder if I actually like looking at the figures when they rise
Mine has 10w40 in it at the mo from subaru not sure what make but its fully synth, I intend on changing every 5000 with millers. The oil viscocity was recommended by API and ZEN so thats good enough for me