17 replies to this topic

[swiss al]

my car now is running to rich you cansmell the exaust when you open the window driving along and also my fan turns on almost straight away temp sensor never goes above half way does anyone know a good mini specialist near hampton middx that can fix the problem because am fed up with this now thanks
p.s would not like to go to mini speed again as have had problems there before

[coopertrooper2001]

Sounds like your coolant sensor (or wiring) is up the duff.

[swiss al]

sorry where does the coolant sensor go is it the one in the thermostate housing

[miniman retford]

sorry where does the coolant sensor go is it the one in the thermostate housing

Hi I had the same problem took the connector of the sensor in thermostat housing, cleaned with electo cleaner & that solved the problem !

[Mini_Magic]

sorry where does the coolant sensor go is it the one in the thermostate housing

It is attached to the side of the thermostat housing, look for a brown connector. As said above, try disconnecting the brown connection and cleaning it.

From my understanding, injection cars cannot run too rich or too lean due to the ECU constantly adjusting the air/fuel mixture. The lamba sensor reads the oxygen levels in the exhaust emissions and sends this data to the ECU. The ECU can then use this to determine the correct fueling mixture, using the pre programmed MAP data.

[swiss al]

thanks for responses i changed that sensor about a year ago when i had my last lot of problems which i only fixed about 5 months ago in the end being a cam sensor in the end at the same time i changed the lambda sensor and all the inlet manifold sensors as well.I have just been out and checked the wiring by runing a curent down it from one end to the other and there seems to be no problems with the wiring so it looks like i will have to get a new sensor again and try it.

IF YOU HAVE ANY MORE IDEAS PLEASE LET ME KNOW THANKS

[DaveRob]

sorry where does the coolant sensor go is it the one in the thermostate housing

From my understanding, injection cars cannot run too rich or too lean due to the ECU constantly adjusting the air/fuel mixture. The lamba sensor reads the oxygen levels in the exhaust emissions and sends this data to the ECU. The ECU can then use this to determine the correct fueling mixture, using the pre programmed MAP data.

Injection cars CAN run rich and CAN run lean..... it depends on the sensors..... This is a classic coolant temp sensor fault.... The fueling map PRIMERILY relies on the CTS and the Lambda.... at start up the CTS reports to the ECU that the engine is cold and so the fuel map richens the injector cycles ....like running choke on a carby. if the CTS is FUBAR then it just runs rich all the time.... this screws up the Lambda over time as it doesnt like being coated in rich exhaust and so becomes slugish and eventually dies...... The CTS is one of the most important sensors in the whole fueling map on injection cars..... if it goes wrong cahnge it........ If you do a search on the CTS or coolant temp sensor their is a long and detailed description about how it works and what it actually does.......

DaveRob

[swiss al]

HAVE NOW CHANGED THE COOLANT SENSOR IN THE THERMOSTAT HOUSING AND CAR STILL RUNNING THE SAME ANY MORE IDEAS

[Sprocket]

It would be benificial to take the car to somewhere that does engine management diagnostics, that way identifying the problem.

I have learned a lot more about the diagnostic process in the last couple of months due to the wifes car failing emissions and the dealer garage where it was didnt have a clue themselves, old addage, if you want it doing right do it yourself :roll: anyway, a good engine management diagnostic center will diagnose the fault and gaurantee that it is the fault.

Diagnostics is a more complex subject than i was first lead to believe. The process SHOULD include analysis results from a four gas exhaust analyser (not the MOT machine) along with the data read from the diagnostic service tool (code reader, this term is too loose, as there are devices out there and that is all they do, read codes).

The reason I say this is that the problem can be one or more of many, and not just to do with the engine management system. For instance, a rich running condition could be caused by a leaking exhaust manifold, whereby air is drawn in, the Lambda sensor picks up the extra oxygen, not knowing where its come from, thinking its come through the engine and is infact running lean, the ECU then adds more fuel to compensate. In this situation there is nothing wrong with any of the sensors, and the ECU is doing what it thinks is right, and by all acounts it is. All this from a slight leak on the exhaust manifold. Exhaust emissions results can give you a pointer to the probable cause after the sensors have been checked and tested with the diagnostic service tool. Emissions results with a cat fitted in this situation would be high CO, low HC, high O2, and high lambda.

If you cannot have a propper diagnostics done, which the average garage have not got the skills, in my experience, then you are limited to replacing components that are the most likely candidates until the problem disapears. This is what the average garage does most of the time anyway. Its frustrating, i know.

I will put another pinned topic up later tonight regarding emissions test results, and the probable causes, if you read the results correctly they tell you more than just its passed or failed

[swiss al]

I WILL BE GOING TO BROOKLANDS MINI SHOW ON SUNDAY SO I WILL SEE IF ANYONE THERE KNOWS A PLACE TO HELP THANKS

[swiss al]

have been now told that it will proberbly be the air temp sensor what do you think

Edited by swiss al, 30 March 2008 - 04:57 PM.

[Sprocket]

not out of the question, however seeing as you have replaced all the sensors and you are having problems again, it would be a more economical solution to get a diagnostic plugged into it and identify the problem rather than speculating, we could be here for a long time otherwise.

It could or could not be the air temp sensor, change it and see? does the temp gauge reach the mid white line? What lambda sensor did you fit, a genuine Bosch/ Rover item or a universal item?

[swiss al]

I FITTED GENUINE BOSCH LAMBDA SENSOR AND THE GAGE DOES READ HALF WAY WHEN WARM AND DOES AS FAR AS I AM CONCERNED TAKE THE NORMAL AMOUNT OF TIME TO GET TO IT I.E ABOUT 2 MILES OF DRIVING IN THE SUBERBES

[BoyracerAU]

Al, please only use CAPS when you're trying to emphasize something. CAPS on the net means you're shouting.

[Dylan8660]

Have you ruled out the possibility of an air leak yet? I've just found a leak from an injector that I hadn't seated properly after a strip and rebuild, quite easy to do and causes rich running.