Misfiring KV6

Hellfire127 · 14th December 2019, 15:13

Typical before Christmas. A raft of problems with my R75 2.5 Auto, 105k

Whilst travelling on the M4 up hill the car started to misfire and the check engine started flashing. I called a AA patrol when I got to my destination. He took the main relay out and turned it over. He could here hissing but I think it’s the breathers, really difficult to keep on as the stubs in the manifolds are cracked and broken. Could the engine breathing hoses have a contribution to this? The hoses are new but always coming off, Drives me mad! often stinks in the cab. The car is generally gutless but ran ok before this. All coils and plugs replaced 3 months ago!

AA Roadside Report as follows:

Patrol found the following fault code/s:System : Engine control - 39H / Engine management EMS2000P0481 - . Error Message : Cooling fan 2 control circuit.

P1472 - Variable intake system (VIS) 2, output valves. Error Message : Valve(s) constantly open.

P0304 - Cylinder 4. Error Message : Misfire detected.

P1611 - Main relay. Error Message : Open circuit/ground short.
(AA patrol took relay out)

P0562 - System power supply. Error Message : Open circuit...

AA patrol man took relay out to turn engine over without firing.

P1646 - CAN message, transm. control unit. Error Message : Faulty.

engine management warning light on found above fault codes.

Engine not running on all 6 cylinders and has a slight internal knocking noise. Can hear a loss of compression when turning engine over. Suspect a problem with the VIS system. Further investigation required at a garage. Member going to phone around to see which garage will take it on. Member has breakdown repair cover for this vehicle. Member must arrange for the vehicle to be taken to a garage without delay if it cannot be fixed at the roadside, any delay or continued use will affect the validity of a potential claim. Any repairs need to be authorised prior to repair, to make a claim contact AA claims department ‪0344 579 0042‬

roverbarmy · 14th December 2019, 15:31

Fix the broken bits first. Then see what you have. Any vacuum leaks will give a misfire.

Hellfire127 · 14th December 2019, 17:22

Of course I know your right! It’s just so frustrating such a fussy car! Funny thing is, as I also have a 75 diesel saloon that has sat on my drive for 6 months with 230k on the clock, starts first time, plenty of poke and off we go!

I do really want to sort my Tourer KV6 though, just so annoying!

Thanks Toby

2Diesels · 14th December 2019, 19:15

Pencil coil failures are very common on the V6

trikey · 14th December 2019, 19:18

Quote:

Originally Posted by 2Diesels

Pencil coil failures are very common on the V6

Yep, new coil on cyl 4, then start on the other niggles.

2Diesels · 14th December 2019, 19:22

Just noticed you’ve changed the coils, if you still have the old ones lying about I would change number 4 & see what happens

Hellfire127 · 27th January 2020, 08:18

Hi, further on from this, I thought you’d like an update. I still have the miss-fire on cylinder 4. Power VIS replaced. Was an absolute pig to start after that! Swapped coil and plug yet again. No joy, beyond me now, so I suppose now it’s off to the garage for a check over including a compression test! Fingers crossed it is something relatively simple like a fuel injector gone bad!

roverbarmy · 27th January 2020, 11:32

Quote:

Originally Posted by Hellfire127

Hi, further on from this, I thought you’d like an update. I still have the miss-fire on cylinder 4. Power VIS replaced. Was an absolute pig to start after that! Swapped coil and plug yet again. No joy, beyond me now, so I suppose now it’s off to the garage for a check over including a compression test! Fingers crossed it is something relatively simple like a fuel injector gone bad!

Did you align the power vis motor and operating arm in the correct place when refitting? If not the VIS motor won't move anything.

Hellfire127 · 27th January 2020, 11:35

Yes all aligned and that OBD fault code went. It was one on Stocktakes excellent updated units and he supplied detailed fitting instructions. Mis-fire is only reported on cylinder 4.

vitesse · 27th January 2020, 12:07

Even if you’ve replaced the spark plugs recently, have another look at them, and perhaps even swop them around to see if no.4’s fault moves.

There have been a couple of cases where I remember owners with misfires searching all possible sources when it was the plugs at fault. One possible cause is damage to the electrode caused by dropping the plugs down into the recess - either use a socket with gripping sponge or a magnetic telescope.

Regards

14th December 2019, 15:13	#1
Hellfire127 Newbie Rover 75 Tourer Join Date: Jan 2017 Location: Kidlington Posts: 24 Thanks: 1 Thanked 6 Times in 6 Posts	Misfiring KV6 Typical before Christmas. A raft of problems with my R75 2.5 Auto, 105k Whilst travelling on the M4 up hill the car started to misfire and the check engine started flashing. I called a AA patrol when I got to my destination. He took the main relay out and turned it over. He could here hissing but I think it’s the breathers, really difficult to keep on as the stubs in the manifolds are cracked and broken. Could the engine breathing hoses have a contribution to this? The hoses are new but always coming off, Drives me mad! often stinks in the cab. The car is generally gutless but ran ok before this. All coils and plugs replaced 3 months ago! AA Roadside Report as follows: Patrol found the following fault code/s:System : Engine control - 39H / Engine management EMS2000P0481 - . Error Message : Cooling fan 2 control circuit. P1472 - Variable intake system (VIS) 2, output valves. Error Message : Valve(s) constantly open. P0304 - Cylinder 4. Error Message : Misfire detected. P1611 - Main relay. Error Message : Open circuit/ground short. (AA patrol took relay out) P0562 - System power supply. Error Message : Open circuit... AA patrol man took relay out to turn engine over without firing. P1646 - CAN message, transm. control unit. Error Message : Faulty. engine management warning light on found above fault codes. Engine not running on all 6 cylinders and has a slight internal knocking noise. Can hear a loss of compression when turning engine over. Suspect a problem with the VIS system. Further investigation required at a garage. Member going to phone around to see which garage will take it on. Member has breakdown repair cover for this vehicle. Member must arrange for the vehicle to be taken to a garage without delay if it cannot be fixed at the roadside, any delay or continued use will affect the validity of a potential claim. Any repairs need to be authorised prior to repair, to make a claim contact AA claims department ‪0344 579 0042‬

14th December 2019, 15:31	#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	Fix the broken bits first. Then see what you have. Any vacuum leaks will give a misfire. __________________ Oil in my veins!

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14th December 2019, 17:22	#3
Hellfire127 Newbie Rover 75 Tourer Join Date: Jan 2017 Location: Kidlington Posts: 24 Thanks: 1 Thanked 6 Times in 6 Posts	Of course I know your right! It’s just so frustrating such a fussy car! Funny thing is, as I also have a 75 diesel saloon that has sat on my drive for 6 months with 230k on the clock, starts first time, plenty of poke and off we go! I do really want to sort my Tourer KV6 though, just so annoying! Thanks Toby

14th December 2019, 19:15	#4
2Diesels Trader ZT 260SE, Connoisseur CDT Join Date: Mar 2009 Location: The Ancient Shire Of Bedlington Posts: 12,597 Thanks: 68 Thanked 506 Times in 305 Posts	Pencil coil failures are very common on the V6

14th December 2019, 19:22	#6
2Diesels Trader ZT 260SE, Connoisseur CDT Join Date: Mar 2009 Location: The Ancient Shire Of Bedlington Posts: 12,597 Thanks: 68 Thanked 506 Times in 305 Posts	Just noticed you’ve changed the coils, if you still have the old ones lying about I would change number 4 & see what happens

27th January 2020, 08:18	#7
Hellfire127 Newbie Rover 75 Tourer Join Date: Jan 2017 Location: Kidlington Posts: 24 Thanks: 1 Thanked 6 Times in 6 Posts	Hi, further on from this, I thought you’d like an update. I still have the miss-fire on cylinder 4. Power VIS replaced. Was an absolute pig to start after that! Swapped coil and plug yet again. No joy, beyond me now, so I suppose now it’s off to the garage for a check over including a compression test! Fingers crossed it is something relatively simple like a fuel injector gone bad!

27th January 2020, 11:35	#9
Hellfire127 Newbie Rover 75 Tourer Join Date: Jan 2017 Location: Kidlington Posts: 24 Thanks: 1 Thanked 6 Times in 6 Posts	Yes all aligned and that OBD fault code went. It was one on Stocktakes excellent updated units and he supplied detailed fitting instructions. Mis-fire is only reported on cylinder 4.

27th January 2020, 12:07	#10
vitesse I really should get out more....... Rover 75 Saloon Join Date: Jul 2011 Location: Gävle Posts: 2,528 Thanks: 395 Thanked 823 Times in 652 Posts	Even if you’ve replaced the spark plugs recently, have another look at them, and perhaps even swop them around to see if no.4’s fault moves. There have been a couple of cases where I remember owners with misfires searching all possible sources when it was the plugs at fault. One possible cause is damage to the electrode caused by dropping the plugs down into the recess - either use a socket with gripping sponge or a magnetic telescope. Regards