What is wrong with my Rover 75 V6?

Melodi · 13th April 2020, 13:17

Hello Everyone!

I am new on this forum and I am excited to be here. I am Patrick from Ghana and a great fan of Rover (esp 75s). I am not sure if this is the right place to ask this but i desperately need help.....

I recently bought a Rover 75 2.5V6 from a guy who knows absolutely nothing about this superb vehicle. The car has been sitting for over a year and has no maintenance history.

It was sluggish at first drive. engine rev was unstable and there was slight tapping noise at the engine bay. Engine stalled a few times before i could get it home. Engine died immediate shift gear was put in reverse. I put OBD2 scanner on it and got the following codes;
P0175, P0300, P1319, P0335, P0340 as both stored and pending codes. I removed the Cam sensor, MAP sensor and the boost sensor for cleaning. I also removed the sensor on the throttle body for cleaning as well. After putting them back, I cleared the codes and i tried running the engine but it died a few seconds after starting. I tried several times, got tired and left it to stand overnight.

The next morning, i run the engine and it was running far better than before. i put the scanner on it and got P0175 and P0300. I took it for a ride and recorded some data as attached. it drove well and i could reverse without any problems. There is a bit of sound under the car like a torn exhaust and the engine rattles at high revs around 6000 rpms. the slight tapping sound in the engine bay is still present.

Kindly help me diagnose the problems and the appropriate remedy. There aren't any known Rover mechanics or parts dealers in my area and i don't want someone experimenting with this car. I know i will find solutions.

Thank you all and i wish you safe stay at home amidst this pandemic.
Waiting for your feedback

roverbarmy · 13th April 2020, 13:32

Post number 5 on this page:-
https://the75andztclub.co.uk/forum/s...ht=P0175+P0300
will give you the codes
(misfire and running rich)
Clatter after a long period of standing is usually down to hydraulic tappets. A good flush with flushing oil may help. Some folks have used a cupful of diesel mixed in with the engine oil but that is risky and up to you. Run as instructed by the flush manufacturers and replace with clean fresh oil after draining old out. Slight tapping sound could just be the fuel return valve. (Hopefully not a rattling inlet manifold!)

Yorkshire GOC · 13th April 2020, 13:38

As it is a V6 failing VIS Motors come to mind causing incorrect fuel/air mix leading to multiple misfires and lumpy running

SD1too · 13th April 2020, 15:58

Hello Patrick and

to the club. To begin with, this might be useful:

P0175 = rich mixture on RH bank
P0300 = Random/multiple misfire

VIS actuator and flap valve problems cause listless performance but don't affect the mixture so don't worry about those for now. Considering the vehicle's history I would carry out a thorough engine service yourself (air filter, spark plugs, oil change, check crankcase breather tubes for breakages, etc.). As Roverbarmy correctly says, a dose of flushing oil would be beneficial (use the real thing not the little bottle of Love potion no. 9 which you add to your filthy engine oil).

It's difficult to diagnose the rattling. It could be the hydraulic tappets if it increases with. engine speed or the VIS power valves might be dislodged. How many miles/km is the instrument pack showing?

Simon

13th April 2020, 13:17	#1
Melodi Newbie Rover 75 saloon Join Date: Feb 2020 Location: Accra Posts: 1 Thanks: 0 Thanked 0 Times in 0 Posts	What is wrong with my Rover 75 V6? Hello Everyone! I am new on this forum and I am excited to be here. I am Patrick from Ghana and a great fan of Rover (esp 75s). I am not sure if this is the right place to ask this but i desperately need help..... I recently bought a Rover 75 2.5V6 from a guy who knows absolutely nothing about this superb vehicle. The car has been sitting for over a year and has no maintenance history. It was sluggish at first drive. engine rev was unstable and there was slight tapping noise at the engine bay. Engine stalled a few times before i could get it home. Engine died immediate shift gear was put in reverse. I put OBD2 scanner on it and got the following codes; P0175, P0300, P1319, P0335, P0340 as both stored and pending codes. I removed the Cam sensor, MAP sensor and the boost sensor for cleaning. I also removed the sensor on the throttle body for cleaning as well. After putting them back, I cleared the codes and i tried running the engine but it died a few seconds after starting. I tried several times, got tired and left it to stand overnight. The next morning, i run the engine and it was running far better than before. i put the scanner on it and got P0175 and P0300. I took it for a ride and recorded some data as attached. it drove well and i could reverse without any problems. There is a bit of sound under the car like a torn exhaust and the engine rattles at high revs around 6000 rpms. the slight tapping sound in the engine bay is still present. Kindly help me diagnose the problems and the appropriate remedy. There aren't any known Rover mechanics or parts dealers in my area and i don't want someone experimenting with this car. I know i will find solutions. Thank you all and i wish you safe stay at home amidst this pandemic. Waiting for your feedback

13th April 2020, 13:32	#2
roverbarmy This is my second home Roverless + 1.7D Sportage Join Date: Aug 2014 Location: East Norfolk Posts: 7,050 Thanks: 729 Thanked 2,021 Times in 1,449 Posts	Post number 5 on this page:- https://the75andztclub.co.uk/forum/s...ht=P0175+P0300 will give you the codes (misfire and running rich) Clatter after a long period of standing is usually down to hydraulic tappets. A good flush with flushing oil may help. Some folks have used a cupful of diesel mixed in with the engine oil but that is risky and up to you. Run as instructed by the flush manufacturers and replace with clean fresh oil after draining old out. Slight tapping sound could just be the fuel return valve. (Hopefully not a rattling inlet manifold!) __________________ Oil in my veins! Last edited by roverbarmy; 13th April 2020 at 13:37..

13th April 2020, 13:38	#3
Yorkshire GOC I really should get out more....... Rover 75 connoisseur se v6 auto Join Date: May 2014 Location: Hull Posts: 2,066 Thanks: 1,842 Thanked 623 Times in 469 Posts	As it is a V6 failing VIS Motors come to mind causing incorrect fuel/air mix leading to multiple misfires and lumpy running __________________ She came off the Longbridge Line on 20-05-2003 The Silver Machine was the 13th of 160 Rover 75's to come off the production line that day and is the 100th of 527 Starlight Silver Rover 75 2.5 V6 Connoisseur SE Auto saloons listed in the build records produced world wide.

13th April 2020, 15:58	#4
SD1too Doesn't do things by halves Rover 75 2.5 Connoisseur Auto (1999) Dealer launch model. Join Date: Mar 2007 Location: Former Middlesex Posts: 20,375 Thanks: 1,587 Thanked 3,749 Times in 3,181 Posts	Hello Patrick and to the club. To begin with, this might be useful: P0175 = rich mixture on RH bank P0300 = Random/multiple misfire VIS actuator and flap valve problems cause listless performance but don't affect the mixture so don't worry about those for now. Considering the vehicle's history I would carry out a thorough engine service yourself (air filter, spark plugs, oil change, check crankcase breather tubes for breakages, etc.). As Roverbarmy correctly says, a dose of flushing oil would be beneficial (use the real thing not the little bottle of Love potion no. 9 which you add to your filthy engine oil). It's difficult to diagnose the rattling. It could be the hydraulic tappets if it increases with. engine speed or the VIS power valves might be dislodged. How many miles/km is the instrument pack showing? Simon __________________ "Whatever is rightly done, however humble, is noble." Sir Henry Royce.