Rover 75 CDTi puzzle

MrSooty · 16th May 2015, 16:10

Over the past week or so, my 2003 Rover 75 CDTi Auto ihas been behaving differently from usual!

1 Temp gauge is moving between 8.35-8.40, instead of 8.45 - where is has consistently sat, since having the Renault 5 inline mod done a year ago.

2 The coolant temperature is in the range 71-78 max, which I am told is "too cool"

3 the 'CHECK ENGINE' light is coming on every day now for just a second or two during driving, before disappearing .....

4 I just filled up with diesel and my consumption is way down from usual - returning only 30 mpg instead of the more normal 40+

I will be driving back to Spain in 2 weeks time and need to get this diagnosed and sorted!

As ever, all advice/ suggestions/solutions very welcome

wuzerk · 16th May 2015, 16:27

The temperature guage will read 8.45 at 75C and above so it appears that your 'stat is failing.

RPWC · 16th May 2015, 16:57

Check your plenum a,to make sure the ecu is not sitting in water,this can cause bizarre behaviour. If it is,take it out and put it in an airing cupboard or somewhere warm and dry ,overnight to dry out. If it's got water more then 1/4 to 1/2 way up, then I would strongly suggest sending it to Marinabrian or Big Russ ,Phil-T4 for refurb before heading back to Spain. All this is of course only if the ecu has for wet. Could be something totally different

BigRuss · 18th May 2015, 22:38

Chances are the EML is coming on because the electrical connector to the fuel filter head is loose or there is corrosion present.

Unplug and replug it in a few times and make sure it is secure and the fault will most likely disappear

Sounds like your thermostat has had it this will also affect fuel consumption

Russ

MrSooty · 19th May 2015, 10:05

Thanks for all your responses!

No water in the plenum - as expected - so I am very much in agreement with BigRuss, as I had suspected it could be either a Bad electrical connection or a sensor problem....

Will see if I can identify (yes, engines are not one of my strong points) the connector and do as suggested.

I will also put in an order for a replacement Renault 5 stat - is replacing this straightforward or are there any 'issues' to be aware of?

Thanks again

16th May 2015, 16:10	#1
MrSooty Avid contributor Rover 75 Tourer Join Date: Jan 2014 Location: Andalucia Posts: 149 Thanks: 21 Thanked 9 Times in 8 Posts	Rover 75 CDTi puzzle Over the past week or so, my 2003 Rover 75 CDTi Auto ihas been behaving differently from usual! 1 Temp gauge is moving between 8.35-8.40, instead of 8.45 - where is has consistently sat, since having the Renault 5 inline mod done a year ago. 2 The coolant temperature is in the range 71-78 max, which I am told is "too cool" 3 the 'CHECK ENGINE' light is coming on every day now for just a second or two during driving, before disappearing ..... 4 I just filled up with diesel and my consumption is way down from usual - returning only 30 mpg instead of the more normal 40+ I will be driving back to Spain in 2 weeks time and need to get this diagnosed and sorted! As ever, all advice/ suggestions/solutions very welcome

16th May 2015, 16:27	#2
wuzerk Passed Away Rover 75 CDT 03 auto Conn. SE Join Date: May 2009 Location: London Posts: 2,885 Thanks: 104 Thanked 254 Times in 204 Posts	Temp The temperature guage will read 8.45 at 75C and above so it appears that your 'stat is failing.

16th May 2015, 16:57	#3
RPWC This is my second home 75 model car Join Date: Apr 2011 Location: Newcastle upon Tyne Posts: 20,177 Thanks: 4,008 Thanked 5,083 Times in 3,114 Posts	Check your plenum a,to make sure the ecu is not sitting in water,this can cause bizarre behaviour. If it is,take it out and put it in an airing cupboard or somewhere warm and dry ,overnight to dry out. If it's got water more then 1/4 to 1/2 way up, then I would strongly suggest sending it to Marinabrian or Big Russ ,Phil-T4 for refurb before heading back to Spain. All this is of course only if the ecu has for wet. Could be something totally different __________________ Cheers. Rich…

18th May 2015, 22:38	#4
BigRuss Premium Trader 75 CDT Tourer,2.5 Launch Saloon, Omipro MG/Rover (T4) Join Date: Jul 2007 Location: Liversedge, West Yorkshire Posts: 5,405 Thanks: 1,105 Thanked 1,340 Times in 661 Posts	Chances are the EML is coming on because the electrical connector to the fuel filter head is loose or there is corrosion present. Unplug and replug it in a few times and make sure it is secure and the fault will most likely disappear Sounds like your thermostat has had it this will also affect fuel consumption Russ __________________ Replacement Key Service http://https://the75andztclub.co.uk/...d.php?t=244732 Full T4 Testbook diagnostics available. Diesel ECU repair and replacement. Options enabled or disabled as required. Diesel X-Power 135 and 160bhp, Rover 1.8T 150 to 160 MG 160 V6 to 177 upgrades available P.M. for details.

19th May 2015, 10:05	#5
MrSooty Avid contributor Rover 75 Tourer Join Date: Jan 2014 Location: Andalucia Posts: 149 Thanks: 21 Thanked 9 Times in 8 Posts	Rover 75 CDTi puzzle Thanks for all your responses! No water in the plenum - as expected - so I am very much in agreement with BigRuss, as I had suspected it could be either a Bad electrical connection or a sensor problem.... Will see if I can identify (yes, engines are not one of my strong points) the connector and do as suggested. I will also put in an order for a replacement Renault 5 stat - is replacing this straightforward or are there any 'issues' to be aware of? Thanks again