Hi I have an EB Xr8 and the darn thing runs too cold on the highway, especially at night (The temp gage will sit on the line between the blue section and the 'N'). Have changed the car to thermo fans to try and combat this problem but it hasn't helped on the highway (has helped with operating temp around the city). Anyway i was wandering if there could be anything that is faulty that is causing it to run this way?

Is there a thermostat in it?

do the thermos turn on when you start the car too?

That's the key to an operating temperature, around $10 and the problem will be fixed... unless your temp guage is out.

um yes the thermostat is in it! (and is working as it should) have tried a couple of different temp ones too.

The fans come on where i have set them with the thermatic switch (which is just before the O on normal).

The motor doesn't seem to get hot on the highway and uses more fuel at night, where the cold air should really be burning better.

The temp guage does seem to be working right, but are there different temp senders that the ECU use?

So could something else be causing it to run this cold (apart from not having a thermostat in...........) causing it to pump more fuel in?

my temp guage only just gets into the normal range but according to the microtech its temp range is fine. gauge is just a tad out. as far as using more fuel goes, it could be any number of sensors sending the wrong info. o2 sensor (although this would affect all situations i would think), coolant temp, air temp.

could even be a blocked catalytic converter or zorst and might not be as noticeable round town.

thats about it for my ideas. not sure if its helped at all though.

I think the cats are a bit burnt out as the exhaust has gotten louder.

Last edited by AndyEMG on Tue Jul 04, 2006 10:34 pm, edited 1 time in total.

I found a little info on the O2 sensor and i think it may be the problem (the car's idle has also been rough)

Last edited by AndyEMG on Tue Jul 04, 2006 10:40 pm, edited 2 times in total.

Does anyone know if this oxygen sensor will fit? i'm not sure about the harness as i havent got the old one out yet





http://www.msdignition.com/fuel_12.htm

ok got two new replacement oxygen sensors and plugged them in and the car has a better idle, a lot more power, more responsive and it is getting better fuel consumption across all conditions, it has also cut down some surging.

However the car still runs too cold at night time on the highway, it only gets to the bar between the blue section and the 'N' of normal.

See the car runs in the normal range in all other conditions except night time on the highway.

A car should get better fuel consumption on the highway with the colder air at night right? well this car doesn't, it gets better consuption in the daytime when it runs at operating temperature. So this is due to some automatic choke thing or something? so it looks like the temp gauage is right.


What's working

The thermostat works fine, tested it in boiling water, and it opens whilst testing in car.

The thermo fans only come on when the car is at 'O' on the temp gauge. They do not turn on during highway travel.

The temperature gauge seems to be working perfectly fine, and i'm pretty confident with its reading.

The only thing i can think of is it is another sensor causing the problem, could the Barametric absolute pressure sensor, EGR valve position sensor, Air charge temp or Engine coolant temp sensor have any impact on operating temperatures?? MAF even?

I heard somewhere that the EGR vents gases into the motor to reduce operating temperatures, could a faulty sensor be causing this to run all the time? maybe EVP?

The only way that you can get good fuel consumption on the highway at night at the moment is to get stuck behind a caravan or truck, get up nice and close and block off the air flow over the motor to increase the engine temp. (causes the temp to rise on the temp gauge and fuel consumption to get better on the trip computer).

Anyway i think i probably should get some diagnostic tests done, because all the reading i've done hasn't really pointed any obvious problem out to me yet,

How much are diagnostic tests????????


anyway thats it for my monolouge, hope it makes some sense, some of it does to me......... haha

I dunno man. All seems to be covered. Diagnostic checks are hard to quote on cos it could be found immediately or take an hour or two.

ah ok makes sense, do you have any idea what the price range would be?

or worst possible scenario? Do you go to ford or somebody else?

Buy the hottest stat you can put in and try it, if it doesn't open then the engine has to get hot.
I'd also try an after market guage and run the 2 and see how it goes.

i recently had a failed thermostat, it wouldn't open at all. the temp gauge jumped up to nearly the red on the highway at night. replaced it with a hotter then standard, as this running cold problem has been going on for quite a while.

Does the temp gauge run off the engine coolant temp sensor?

i'll see if i can get a hotter thermostat, however this will raise my temp in other conditions, where it has been running fine.