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Discussion Starter #1
I think my temp gauge needle isn't in the correct position.

Under 'test 7' in the secret menu, I get 80 or 81 Celcius at a steady speed. However, my gauge needle sits a bit to the left of 'straight up' at this temperature.

I was wondering if it should be perfectly straight up at this temperature. If someone could get into test 7 and check their needle position at 80*C I'd appreciate it very much.

I had my clocks off the car recently. My inquisitive daughter came over to investigate and duly prodded the temp needle! I tried to get it back to where I thought it should be, but I think it's 2 or 3 degrees 'out.'

Incidentally, I was getting low coolant readings until I cleaned the sensor connector. Worth trying this before forking out for a new thermostat if you have slightly low readings.
 

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I recently had a new thermostat put in and noticed some improvement, but still there are occasions when the needle is leaning to the left a bit. I suspect the mechanical fan is the culprit.
 

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Since thermostat replacement, I've always sat a bit to the left except when the car is heating up in stop and go traffic.
 

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It is not a failed Tstat! This happens to all of our cars to some extent

Its a high compression engine, it runs cooler than similar engines. It is also very good at regulating it's temperature and it will run a tad cooler than "TDC" most of the time that you arent driving it too hard. On long stretches of the highway I have seen my oil and coolant temperatures move left of center but I do not worry about it.

Really if your daughter or you messed up the needle so it is no longer calibrated, it probably wouldn't be reading close to halfway. The needle most likely just recalibrated itself, went back to it's normal position, but now you are paying more attention to it. These cars unlike most others will show a few degree temperature fluctuation.
 

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Discussion Starter #10
Thanks for the replies everybody.
I asked this because all the advice on the board seems to suggest a failed thermostat if the needle isn't dead straight AND is contiuously under 80*C in test 7.

Checking out test 7 (ie ktemp) I discovered that it was under 80 most of the time. This got me concerned and in the end I cleaned the temp sensors contacts and connector. Following this, the temperature doesn't fall below 80 once the car is warm (its mostly 81 or above). I'm glad I didn't buy a replacement thermostat!

After my daughter disturbed the needle position I looked at as many temp gauges as I could (when at rest) and set mine to be in a similar rest position - just under the first white line. However, due to the reports here, I was expecting it to sit straight up at the normal running temperature, I reckoned that my gauge wasn't showing the position properly and wondered if it needed slight adjustment.

I'm now pretty certain that the thermostat is behaving as it should, so no more worries in that department. From your replies it seems perfectly acceptable fot the needle to be a bit off centre so I shall not take it appart, I must have got its position pretty close.

If anyone is worried about their thrmostat, I suggest cleaning the temp sensor connector and check the reading from test 7 in the secret menu. As long as it shows a reading of 80 or above, all should be well.

Thanks for the help everyone.
 

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If anyone is worried about their thrmostat, I suggest cleaning the temp sensor connector and check the reading from test 7 in the secret menu. As long as it shows a reading of 80 or above, all should be well.

Thanks for the help everyone.
Can you provide some specifics on which sensor you're referring too? To my knowledge there are two which relate to the coolant temp.
 

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The one on the t-stat housing provides everything for the DME. The one on the lower radiator hose only controls the aux fan.

As for running temp, anything 78C and up is considered "normal". Below 78C or so and you'll want a new t-stat.
 

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Discussion Starter #13
The coolant temp sensor that feeds the engine ecu and the temp gauge is screwed into the thermostat housing, in the middle of the engine, just underneath the airbox. It is a 'dual' sensor, to feed both items. The connector carries four pins. The connector is generally a round plug that you just pull up on. It is really easy to get to and a give it a clean.

The other temp sensor is at the radiator outlet, much further down on the right hand side of the radiator. It detects the cooled temperature and decides whether the radiator fan needs to be swithced on. I seem to remember a post by someone who's temp related problems were all solved by replacing this sensor but it only controls the electric fan.
 

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I found the ECU will log an error if it thinks the thermostat is broken, so read the codes if you are not sure.
It calls it coolant temperature plausibility error or something.
 

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I found the ECU will log an error if it thinks the thermostat is broken, so read the codes if you are not sure.
It calls it coolant temperature plausibility error or something.
A dealer tech said the same thing but this sorta goes against the recommendations of Doug B. and other board members. My coolant has been running low, 75C at highway speed with air temp at about 70F, and I've been getting crap gas mileage, but no codes. Any idea at what temps the codes come on?
 

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A dealer tech said the same thing but this sorta goes against the recommendations of Doug B. and other board members. My coolant has been running low, 75C at highway speed with air temp at about 70F, and I've been getting crap gas mileage, but no codes. Any idea at what temps the codes come on?
75C will not trigger an error. I have no idea what the specific conditions need to be to trigger a plausibility error, but I do know that I was running at 73-74C for quite a while with no codes.

75C does, however, indicate your t-stat is stuck open. Minimum operating temp for a functioning t-stat is 78-79C.

d-
 

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I believe it calculates the error based on coolant temp and then temp of coolant flowing to rad.
If the temp of coolant flowing to the rad (post tstat) is lower than the tstat rating, but higher than say 50c is bring up the error.
 

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Discussion Starter #18
From what I've gathered, the engine managment runs the engine 'rich' until the coolant temperature reaches 80*C (which is why you get poor economy if the thermostat has died). Discovering this made me check mine more carefully. I'm glad that clenaing the temp sensor sorted things.

I wouldn't know when it throws an error code, but I suppose it checks for some correlation between the other coolant temp sensor, oil temp and engine running time.
 

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I think my temp gauge needle isn't in the correct position.

Under 'test 7' in the secret menu, I get 80 or 81 Celcius at a steady speed. However, my gauge needle sits a bit to the left of 'straight up' at this temperature.

I was wondering if it should be perfectly straight up at this temperature. If someone could get into test 7 and check their needle position at 80*C I'd appreciate it very much.

I had my clocks off the car recently. My inquisitive daughter came over to investigate and duly prodded the temp needle! I tried to get it back to where I thought it should be, but I think it's 2 or 3 degrees 'out.'

Incidentally, I was getting low coolant readings until I cleaned the sensor connector. Worth trying this before forking out for a new thermostat if you have slightly low readings.
I know this is an older thread Please forgive me for posting here. I have a normal reading oil temperature of about 190. My water temperature can go to 8/10 (my scale). Of it idles it is about 6.5/10. If I get on the throttle it is more. I replaced the clutch fan, two thermostats. One dealer said plastic impellers break so a new water pump. Another said radiator. Anyone been in this predicament?
 

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I know this is an older thread Please forgive me for posting here. I have a normal reading oil temperature of about 190. My water temperature can go to 8/10 (my scale). Of it idles it is about 6.5/10. If I get on the throttle it is more. I replaced the clutch fan, two thermostats. One dealer said plastic impellers break so a new water pump. Another said radiator. Anyone been in this predicament?
its running too hot. that's 87c. Do you have aftermarket tstat?
 
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