Rover 75 2.0 v6 electrical/ecm problems

[Kampo]

Hello fellow rover 75 enthusiasts

we have had in the family a rover 75 one of the early production mk1 r75 2.0v6 connoisseur in gold

the car had been my dad's pride and joy after having owned a 620ti since 99. my dad passed last november and the r75 has been sitting since with intermittent engine starts and reversing and pushing forward in the garden. it always started first time and other than the annoying rattling from the inlet manifold has had all vital functions running well and showing well with zero issues.

i started it last week once again when visiting Greece (that s where it s parked) and unfortunately discovered about 10 rats on the main engine manifold as well as few rats nests (didnt use to have this problem till now).
after cleaning everything thoroughly i attempted to start it . it fired up and died straight a couple of times. i opened the air filter box to find a set of black eyes staring at me (rats) in the filter box who i had to politely relocate and clean up the air filter. i fired up again and bang engine came to life nicely however i observed the following after that first successful start:
1. cooling fan motor kicked in immediately and did not stop working for the full 7-10 mins of engine operation; i also get very little to no heating but i assume the constant cooling fan operation may have something to do with this
2. i had lost rev and temp gauge and on that first attempt even lost the fuel gauge even though i had it showing well - i did not at that time know to try the hrw to see if it worked but did try locking the doors with the central lock button but they would not go down (would sense that they tried by the clicking start sound but no result with them locking)
3. the engine rattles tons and i know it is from the inlet manifold (that was going on for some time before but never got to fixing)
4. i saw some white smoke coming out and i figure it could be due to the prolonged months of non engine starts or moving or even due to the vis motor and inlet manifold rattle but your experience here would help me a lot iron out any other possible issues

i have researched here and have since checked my plenums and washed out the one where ecu resides. i did not find it flooded but did see some wet signs and found the cabin air filter somewhat wet and with the bottom strip disconnected but it may well have been there a good 10 years. i did not find the ecu to be wet or having any having been wet signs
whilst the ecu may well be the culprit here (even though never before did it give any signs of wear or break till now) i wonder if the combination of the cooling fan working continuously from engine start and not stopping as well as the tach and temp gauges not working could be an indication of the rats discovered eating any cables that could lead to the ecu going nuts on the signals it receives and sends? if so given the symptoms here would you think that a good starting point to check for cables being eaten by rats could be below the engine fuse box and also would i be right in assuming that the relay for the cooling fan is the one in the last row sitting in that engine fuse box? i could alter it with another one and see if anything changes

finally on a non electrical issue my rear driver door (lhd) is stuck from inside and out and will not open . i have no idea how to open it to get access to that cardboard to investigate what the issue but if anyone has any idea or has had the issue before on both sides it would be very helpful to get any pointers to see how to open it and fix it.

the main thing for me is how to go about the electrical gremlins and then see how to overcome the inlet manifold/vis issue and the rear door problem

thank you all in advance for any help or pointers you could provide me for at least being able to narrow the issue down to eaten up cables or the dreaded ecu issue (which given the condition of plenum and the previous life of it i cannot think would be the culprit but then again who knows)

[vitesse]

Yours is a petrol and unlike the diesel ECU (or EMU) sealed so less likely to suffer from water damage. The fan operating continuously could just be that you have ACC on and so the fan runs all the time, just like its supposed to. However it’s also possible that your rodent guests have chewed through the coolant sensor wiring inside the V of the engine and if the EMU sees no signal it will direct the fan to run all the time as a precaution to prevent overheating.
Any fault codes? Toaf (use the search toolbar) is my favourite, free and easy to use. It will help diagnose VIS motors, fans, even locking problems.

Now time to go out and sort my own problems …

Good luck

[Kampo]

Originally Posted by vitesse

Yours is a petrol and unlike the diesel ECU (or EMU) sealed so less likely to suffer from water damage. The fan operating continuously could just be that you have ACC on and so the fan runs all the time, just like its supposed to. However it’s also possible that your rodent guests have chewed through the coolant sensor wiring inside the V of the engine and if the EMU sees no signal it will direct the fan to run all the time as a precaution to prevent overheating.
Any fault codes? Toaf (use the search toolbar) is my favourite, free and easy to use. It will help diagnose VIS motors, fans, even locking problems.

Now time to go out and sort my own problems …

Good luck

hi Vitesse thanks for the reply. When you refer to ACC you refer to Air Climate control being on o? pretty sure this was off at that time so i do not believe this to have been the case. i ll check fault codes once back there and revert with any. also i did not manage to check in the V area as didnt have time but that is defo one i ll be checking next in the engine as i suspect there to be a nest in there behind tstat as the dog keeps barking towards that direction :-0. also you reckon it could be a link with cables eaten up in the v shape of engine and the temp and rev counter not working too together with the cooling fan operation or do you reckon this plays no role?

[SD1too]

Originally Posted by Kampo

... would i be right in assuming that the relay for the cooling fan is the one in the last row sitting in that engine fuse box?

No Marios. That relay is for the heating/air conditioning blower inside the car. The radiator fan relays are in the control box which is accessible only by removing the front bumper assembly. There's no need to do that though as they are extremely reliable.

Originally Posted by Kampo

When you refer to ACC you refer to Air Climate control being on o? pretty sure this was off at that time ...

Be absolutely sure by pressing the 'ECON' button. That will switch off the air conditioning. If the radiator fan still runs continuously, together with the temperature gauge displaying fully cold, then that is an indication that the rats have probably nibbled at the coolant temperature sensor wiring in the 'V'.

Simon