Fault code PO174,171- Can't find the problem!
#61
11-20-2012, 04:11 PM
alright then try this one on for size
i had a 2011 xj 5litre that was over heating and seemed to loose coolant under the intake. I pressure tested it several times and held pressure to 15 psi everytime so i decided to vacuum the system. And low and behold itsucked air big time, you could see it coming into the coolant reservoir and hear it too. It was coming from the outlet pipe under the intake. Would hold pressure and had minimal coolant loss. But as the engine cooled down it sucked air into the system and created a air lock and then would overheat. New pipe and all fixed.. The moral. Just because it didnt leak under pressure doesnt meen it doesnt leak. Remember it runs under vacuum not pressure unless boosted and then only when rpm is up. Again if it were me, ide look at short term fuel trims and spray potential areas. And even do it when cold and seals are at their smallest and more prone to leaking
one other thing I just noticed, youre dual fuel and I dont know that system, I can only speak from gasoline system experiance on Jaguars since thats what we have here in the US
i had a 2011 xj 5litre that was over heating and seemed to loose coolant under the intake. I pressure tested it several times and held pressure to 15 psi everytime so i decided to vacuum the system. And low and behold itsucked air big time, you could see it coming into the coolant reservoir and hear it too. It was coming from the outlet pipe under the intake. Would hold pressure and had minimal coolant loss. But as the engine cooled down it sucked air into the system and created a air lock and then would overheat. New pipe and all fixed.. The moral. Just because it didnt leak under pressure doesnt meen it doesnt leak. Remember it runs under vacuum not pressure unless boosted and then only when rpm is up. Again if it were me, ide look at short term fuel trims and spray potential areas. And even do it when cold and seals are at their smallest and more prone to leaking
one other thing I just noticed, youre dual fuel and I dont know that system, I can only speak from gasoline system experiance on Jaguars since thats what we have here in the US
#62
11-20-2012, 04:29 PM
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#64
11-20-2012, 05:52 PM
Veteran Member
alright then try this one on for size
i had a 2011 xj 5litre that was over heating and seemed to loose coolant under the intake. I pressure tested it several times and held pressure to 15 psi everytime so i decided to vacuum the system. And low and behold itsucked air big time, you could see it coming into the coolant reservoir and hear it too. It was coming from the outlet pipe under the intake. Would hold pressure and had minimal coolant loss. But as the engine cooled down it sucked air into the system and created a air lock and then would overheat. New pipe and all fixed.. The moral. Just because it didnt leak under pressure doesnt meen it doesnt leak. Remember it runs under vacuum not pressure unless boosted and then only when rpm is up. Again if it were me, ide look at short term fuel trims and spray potential areas. And even do it when cold and seals are at their smallest and more prone to leaking
one other thing I just noticed, youre dual fuel and I dont know that system, I can only speak from gasoline system experiance on Jaguars since thats what we have here in the US
i had a 2011 xj 5litre that was over heating and seemed to loose coolant under the intake. I pressure tested it several times and held pressure to 15 psi everytime so i decided to vacuum the system. And low and behold itsucked air big time, you could see it coming into the coolant reservoir and hear it too. It was coming from the outlet pipe under the intake. Would hold pressure and had minimal coolant loss. But as the engine cooled down it sucked air into the system and created a air lock and then would overheat. New pipe and all fixed.. The moral. Just because it didnt leak under pressure doesnt meen it doesnt leak. Remember it runs under vacuum not pressure unless boosted and then only when rpm is up. Again if it were me, ide look at short term fuel trims and spray potential areas. And even do it when cold and seals are at their smallest and more prone to leaking
one other thing I just noticed, youre dual fuel and I dont know that system, I can only speak from gasoline system experiance on Jaguars since thats what we have here in the US
#65
11-23-2012, 09:46 AM
Heres the long term fuel trims-
Bank 1 long term- ide 7.34%, fast ide 2500rpm 4.69%, driving 17.97%
Bank 2 long term- ide 7.81%, fast ide 2500rpm 4.69%, driving 17.19%
I also took readings from my other car (for comparison) MG ZT V6-
Bank 1 long term- ide 0.94%, fast ide 2500rpm 7.03%, driving 17.83%
bank 2 long term- ide 17.19%, fast ide 2500rpm 7.03%, driving 23.76%
For USA members who do not know what this car is-
Bank 1 long term- ide 7.34%, fast ide 2500rpm 4.69%, driving 17.97%
Bank 2 long term- ide 7.81%, fast ide 2500rpm 4.69%, driving 17.19%
I also took readings from my other car (for comparison) MG ZT V6-
Bank 1 long term- ide 0.94%, fast ide 2500rpm 7.03%, driving 17.83%
bank 2 long term- ide 17.19%, fast ide 2500rpm 7.03%, driving 23.76%
For USA members who do not know what this car is-
Last edited by Simon.h; 11-23-2012 at 09:50 AM.
#66
11-23-2012, 10:51 AM
Veteran Member
#67
11-23-2012, 11:44 AM
So you still think i have a leak on the jag, well as i done both the lower and upper inlet to heads gaskets and both IMT o rings and checked vacuum/breather pipes about 5 times and done a smoke test, i do not where to start (do not fancy propane).
And i as need to look at the ZT as well.
Thanks Simon.
#68
11-23-2012, 02:03 PM
Veteran Member
#69
11-25-2012, 02:26 AM
I have been over it again, did a smoke test for 30mins and sprayed carb cleaner all all it and the only thing i found was a oil leak (air leak then doing a smoke test) from the cam sensor.
This sensor screws into the top of the head and rocker cover sits over it, could this be my problem?
Anyone know how to change the seal? Please do not say the inlet manifold/cam cover has to come off.
Picture copyed from one of Jojcesjag's posts, sorry.
This sensor screws into the top of the head and rocker cover sits over it, could this be my problem?
Anyone know how to change the seal? Please do not say the inlet manifold/cam cover has to come off.
Picture copyed from one of Jojcesjag's posts, sorry.
Last edited by Simon.h; 11-25-2012 at 02:45 AM.
#71
11-25-2012, 06:56 AM
Veteran Member
Simon no worries on the pic.
I cannot recall if the valve cover needs to be removed to switch out the seal. What I would do is obtain a new seal, then try to remove the old seal, almost looks like it maybe possible to replace without removing the valve cover. I just looked at Joyces Jags and a screwdriver with a few slight pounds of a hammer may pop it out.
I cannot recall if the valve cover needs to be removed to switch out the seal. What I would do is obtain a new seal, then try to remove the old seal, almost looks like it maybe possible to replace without removing the valve cover. I just looked at Joyces Jags and a screwdriver with a few slight pounds of a hammer may pop it out.
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