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Hi, I've replaced all 6 plugs. 4/6 of the injectors 2 looked OK so I didn't replace. Replaced a top sensor on the cam but still I'm running rich and the extra external fan is running on.
The temp on the gauge in car never goes past the middle line but the beginning of all this trouble was a fail of the expansion tank The car ran super hot for about 20imiles.(the gauge didn't register past the middle pin) Zero water Engine has covered 60 kind miles.
The fan turns itself off when I put the heating on full boar in car on high.
Car averages approximately 12mpg
Please help
Kind regards Sam.
Last edited by GGG; 06-28-2018 at 01:09 PM.
Reason: Thread title amended at OP's request
Hi, I've replaced all 6 plugs. 4/6 of the injectors 2 looked OK so I didn't replace. Replaced a top sensor on the cam but still I'm running rich and the extra external fan is running on.
The temp on the gauge in car never goes past the middle line but the beginning of all this trouble was a fail of the expansion tank The car ran super hot for about 20imiles.(the gauge didn't register past the middle pin) Zero water Engine has covered 60 kind miles.
The fan turns itself off when I put the heating on full boar in car on high.
Car averages approximately 12mpg
Please help
Kind regards Sam.
You should start by using an obd2 dongle and check the MAF sensor , fuel pressure sensor and the o2 sensors are running with in speck . I'll bet one of those is not .
(some of the sensor names are slightly non-standard there)
If all "looks" OK (i.e. looks plausible), look at the OL/CL (open/closed loop) status. If it's staying OL the mpg will be poor and the cause needs finding.
Do not use the temperature gauge on the instrument cluster as a means to know if the engine is overheating!
The gauge does not register any changes in temperature between 86C and 129C.
+1 on that!
Be aware the dashboard temperature gauge is deliberately misleading, as detailed at the following link, so don't rely on it. This is from the XK forum, but the general principle is the same on the S-Type:
the beginning of all this trouble was a fail of the expansion tank The car ran super hot for about 20imiles.(the gauge didn't register past the middle pin) Zero water Engine has covered 60 kind miles.
Sam, what year is your car? This is a V6, right?
2002 and earlier used a Cylinder Head Temperature sensor that measured the metal itself, NOT the coolant temperature. It also had a system to allow limping to safety if all coolant was lost, by selectively cycling off cylinders to prevent a total meltdown.
2003 and later used a conventional coolant temperature sensor and did not have the overheat protection as on the earlier cars.
I'm a bit concerned how you mentioned "zero water", followed by "60 kind miles". Does that mean you drove 60 miles without any coolant? Even with the overheat protection of any early car, driving that far may have still caused some damage.
Also, considering the poor fuel economy, is your Check Engine light illuminated? If so, what are the codes? If the light is flashing, that is bad and means you've got a fault bad enough to damage the catalytic converters.
Hi again, sorry for the late reply. Its a 2001 3 Litre V6. (The header to this should read "Fan Run On / Overfueling". Unable to re-edit)
Originally Posted by kr98664
I'm a bit concerned how you mentioned "zero water", followed by "60 kind miles"
The above should read zero water 60k miles. Sorry I was rushing to type and fluffed it. The car ran dry for about 15-20 miles. The car has been sniff tested twice, no breach in the heads found and has covered 60k miles. I will now go plug in the laptop to the OBD port and try figure all that out. First time using all this tech so apologies if I'm sounding dumb. The car has no warning lights on. But that fan running on and only turning off after running the heating on full is a worry, plus the low MPH... Anyway, I'll go look now see what it shows up. Thanks for all your replies
(some of the sensor names are slightly non-standard there)
If all "looks" OK (i.e. looks plausible), look at the OL/CL (open/closed loop) status. If it's staying OL the mpg will be poor and the cause needs finding.
Hi again, I tried using a cheap USB OBD lead, £3-99 off eBay. Cant get it to work, reinstalled drivers etc but to no avail. So I bought this "elm 327 laptop USB car scanner obd free software". Should be here Sat, so I'll try to get it working and report back. Can anyone suggest a really good USB - laptop OBD tool please ? This will be my forth tool bought and none have worked
Hello again, I think I'm getting somwhere. I've tried a new tool and after a breif play with it this morning this is what I've managed to get to show. Anyone know from this what the problem may be please ? I have swapped out the sensor on the air intake at the front of the engine bay by the way.
Maybe you could start by confirming the accuracy of this sensor. It's very easy to access. Look between the two aft spark plugs on the US driver's side. Unbolt it and measure the resistance at various temperatures like I did in that thread.
Thank you for your reply kr98664. I've looked at your thread and I'm afraid I'm not that savvy with a meter Do any of the numbers on my images show why the fan cuts in so quickly ? And today after dropping the kids at school, the car began to misfire at idle ? Are there tests I can do that'll provide more info perhaps ?
Originally Posted by Datsports
You should start by using an obd2 dongle and check the MAF sensor , fuel pressure sensor and the o2 sensors are running with in speck . I'll bet one of those is not .
Would you have a min to look over the info I've added please Datsports ?
Perhaps you can provide some additional background information on this vehicle.
What is the number of kilometres/miles on the vehicle?
What is voltage across the battery terminals with the ignition in the OFF position for at least ten minutes?
Has the cooling system been worked on recently? If so, what was replaced and has the cooling system been correctly bled according to the Workshop Manual procedure?
Radiator main fan running continuously is a strong indication of a faulty thermostat or poor coolant circulation on the Duratec V6.
Perhaps you can provide some additional background information on this vehicle.
+1 on that. It seems you've got two issues (overheating and rough running) going on at the same time. Did the problems start at the same time?
Also, how much have you driven the car since the problems started? For the rough running, you should probably have some fault codes present. However, not all codes are set right away. For some, you may have to drive a minimum distance and/or above a certain speed. If you've only been putzing around your neighborhood, the codes may not be getting set.
What is the number of kilometres/miles on the vehicle?
60.000 Miles
Originally Posted by NBCat
What is voltage across the battery terminals with the ignition in the OFF position for at least ten minutes?
I think I've tested this correctly when you say "Off" I'm assuming that's keys out of the car? (12.06 Keys Out .11.96 Keys In at Off-Position) Please see Images provided.
Originally Posted by NBCat
Has the cooling system been worked on recently? If so, what was replaced and has the cooling system been correctly bled according to the Workshop Manual procedure?
The Thermostat was replaced when the heating valve cluster was replaced in January and I'm told it has been bled correctly but I'm now doubting that ... I've replaced the MAF sensor shown in the last image. This sensor as no bulb - two thin filament type wires housed in a plastic tube - as in different MAF sensors, I was wondering if this was correct?
Originally Posted by kr98664
It seems you've got two issues (overheating and rough running) going on at the same time. Did the problems start at the same time?
Also, how much have you driven the car since the problems started? For the rough running, you should probably have some fault codes present. However, not all codes are set right away. For some, you may have to drive a minimum distance and/or above a certain speed. If you've only been putzing around your neighborhood, the codes may not be getting set.
The pencil coils were replaced on the hard to get to bank and I have 3 new ones ready to go on the other bank. The misfires have happened before but that was put down to an oil leak from the rocker cover leaking directly onto the plugs. Those seals, plugs, plug gaskets and breather pipe were replaced solving the issue, but, the car left the garage with this fan running on and still running rich, not as rich but still too thirsty. No fault codes present. I use the car just to run to and from school with the girls, local runs etc. The misfire seemed to show its face when the car got hot, and with this weather, the car gets to temp fast. No misfire as I moved the car this morning.
...The Thermostat was replaced when the heating valve cluster was replaced in January and I'm told it has been bled correctly but I'm now doubting that ....
Was the thermostat replaced with an OEM item that is correctly fitted? In my experience, some of the aftermarket thermostats do not work correctly and cause an overheating condition. The thermostat has a small bleed hole that allows air to escape from the lower hose, but many aftermarket ones do not.
Originally Posted by Flappers
...I've replaced the MAF sensor shown in the last image. This sensor as no bulb - two thin filament type wires housed in a plastic tube - as in different MAF sensors, I was wondering if this was correct?...
How did you diagnose the MAF needed to be replaced? As long as it is the correct one for your VIN, there should be no issues.
05-31-2018, 09:35 PM
Fan running on / over-fueling
Do any of the numbers on my images show why the fan cuts in so quickly ? And today after dropping the kids at school, the car began to misfire at idle ? Are there tests I can do that'll provide more info perhaps ?
