With my car upto temp i jumped onto motorway doing 70mph my gauge went from 85 to 60 within a couple of mins is this normal car is 03sti jdm

 

mine sits between 85 and 100 obviously the higher in traffic the lower on the move.

the cool air is going to have some effect, i have an fmic fitted though

 

Cheers mate it does go up in traffic and lights just worried once down at 60 its to cool to floor it

 

i forget what mine was before the fmic was fitted but it has increased the temps slightly as it restricts the airflow.

it should go up and down as the fan kicks in sitting in traffic.
i wouldnt worry as ice cold air will cool the rad. its the oil temp that needs to be at operating temp anyway.

 

Ok thanks for the help

 

Whereas I WOULD worry.

The thermostat/rate of energy use at speed should keep that gauge sat bang on, or very near, 85/6 deg.

Sure, it can creep UP in traffic when crawling, but if it drops, I'd be wanting to know why.

Could be airlock, poor connection to sender etc.

 

This is my worry as always been between 85-92 then fans kick in now from last monday its a struggle to get by 75 unless sitting at lights

 

Thermostat could be stuck open.

 

what he said^^^^ Knackered thermostat

 

Thermostat is passing.

Once its up to 80+ degrees, it should stay there and NEVER fall below this, even with the heater on full.

 

I'd worry if it's the oem gauge reading because that would mean cold oil temps and suggests the thermostat isn't working, if it's an aftermarket gauge with the sensor in the top pipe this can give low readings in very cold weather because of it's exposed position, this is what I've found.
Trev

 

Its aftermarket billion gauge it seems as if its wired to ecu

 

then first question should be is the gauge faulty

 

I would get the thermostat checked out, if it's reading 60 the oil temps could be as low as 70.
Trev

 

I had an experience with a drilled thermostat, good in hot weather and on track but in cold weather even the oem guage dropped to the quarter mark and my oil temps were in the low 70's, changed the thermostat and all was well

 

Goes in tomorrow to check stat think gauge is fine as the cars own gauge is dropping below the quarter line when the aftermarket drops

 

Does a stuck open affect fuel economy and my idles stays about 1000rpm at idle

 

Yes, the engine is simply not running as efficiently as it could

 

Thank you hopefully fixed tomorrow with new stat

 

Absolutely.

In the old days of automatic chokes, a cold engine was running 1:4 fuel:air, and a hot one as much as 1:32.

Your ecu will be doing much the same now.

 

Car is in garage just now hopefully thats it all sorted

 

As usual, thermostat sticks open. This won't do any damage to the car.

BUT..........and it's a BIG BUT:

DO keep an eye on the engine temps/coolant levels over the next few weeks. The number of times we've seen coolant parts replaced, only to find the garage has airlocked the engine coolant system...and that WILL do your head gaskets unless sorted.

 

Will do hopefully should be fine same mechanic that has done my changes on all my imprezas

 

Stat was jammed open all sorted thanks for the help guys

 

Fitted aftermarket stat then it failed after just 8wks check this


genuine subaru one fitted now

 

Not good.....what sort of stat, so others can avoid it?

 

from dingbro it was made in italy

 

Bending like that, it looks like it was made of Welsh Silver...a cunning alloy of Zinc and Bakelite*

* With apologies to the Monty Python Papperbok.......

 

Cant believe how bad it is

 

Was it made by "Circoli" by any chance?

Junk IMO.

Gaffer keeps ordering this junk (pumps, stats etc.)....I then say "told you so" when it comes back leaking or failed. He's learning (albeit slowely ). Just had to replace yet another failed "React" catalytic converter under warranty...another junk brand to avoid like the plague.