Water and pressure guage over/under reading
Discussion
Hi, I've got my Tuscan running now following the rebuild. Everything seems fine apart from the water temperature and oil pressure digital guage.
The water temperature is significantly over reading (reading 140C when the ECU is seeing 90C)
The oil pressure is between 0 and 4 psi once warm at idle. The ECU is seeing 15psi so I know this isn't a problem and the engine sounds smooth enough.
I've replaced the oil pressure sender (could only see 1, is there a separate one for the guage?). I've also replaced both water temperature sensors.
The oil temperature sensor also seems to be over reading.
Anyone else had this problem?
The water temperature is significantly over reading (reading 140C when the ECU is seeing 90C)
The oil pressure is between 0 and 4 psi once warm at idle. The ECU is seeing 15psi so I know this isn't a problem and the engine sounds smooth enough.
I've replaced the oil pressure sender (could only see 1, is there a separate one for the guage?). I've also replaced both water temperature sensors.
The oil temperature sensor also seems to be over reading.
Anyone else had this problem?
Jack, my first call for the coolant temp dash reading would be the sensor. About 4 years ago mine went AWOL driving through France. Concerned at first, but reasoned I had the oil temp. sensor to give a bit of a cross reference and listened carefully to ensure radiator fans cut in when I hit Clermont-Ferrand at rush hour - they did!
On return to Blighty, it took 4 changes of dash reading sensors to get one that lasted (initially, read up to ~94deg, then went zero/open circuit). I queried this, and was advised by a tech at STR8Six, that there had been a duff batch in circulation. TVR parts gave me a refund.
The oil pressure sensor may be either a duff unit or a slight blockage in the braided line to the block. They don't last for ever either. One final thought, is the oil pressure relief valve - a weak spring perhaps?
Nick
On return to Blighty, it took 4 changes of dash reading sensors to get one that lasted (initially, read up to ~94deg, then went zero/open circuit). I queried this, and was advised by a tech at STR8Six, that there had been a duff batch in circulation. TVR parts gave me a refund.
The oil pressure sensor may be either a duff unit or a slight blockage in the braided line to the block. They don't last for ever either. One final thought, is the oil pressure relief valve - a weak spring perhaps?
Nick
nawarne said:
Jack, my first call for the coolant temp dash reading would be the sensor. About 4 years ago mine went AWOL driving through France. Concerned at first, but reasoned I had the oil temp. sensor to give a bit of a cross reference and listened carefully to ensure radiator fans cut in when I hit Clermont-Ferrand at rush hour - they did!
On return to Blighty, it took 4 changes of dash reading sensors to get one that lasted (initially, read up to ~94deg, then went zero/open circuit). I queried this, and was advised by a tech at STR8Six, that there had been a duff batch in circulation. TVR parts gave me a refund.
The oil pressure sensor may be either a duff unit or a slight blockage in the braided line to the block. They don't last for ever either. One final thought, is the oil pressure relief valve - a weak spring perhaps?
Nick
Thanks for the advice Nick, the radiator fans are kicking in at the correct temperature according to the ECU (around 90C). Using an infrared thermometer on the hoses I can see that this is accurate. I'll query the guage sensor with racing green. With just the ignition on it seems to be jumping around +/- 10c for no reason...On return to Blighty, it took 4 changes of dash reading sensors to get one that lasted (initially, read up to ~94deg, then went zero/open circuit). I queried this, and was advised by a tech at STR8Six, that there had been a duff batch in circulation. TVR parts gave me a refund.
The oil pressure sensor may be either a duff unit or a slight blockage in the braided line to the block. They don't last for ever either. One final thought, is the oil pressure relief valve - a weak spring perhaps?
Nick
The oil pressure according to the ECU is fine at 14 psi and I have no reason to believe that this is incorrect. The guage however is reading 10psi less. Do they use the same sensor?
s6boy said:
Oil pressure seems low, I know they all differ slightly but is this when hot and at idle?
You may get more exposure on the Speed Six forum.
Yes that's at hot idle with the fans kicking in. I'll raise the idle a little, it's currently at 750 rpm, that should increase the oil pressure at idle. Although, the guage will still under-report it.You may get more exposure on the Speed Six forum.
I had a new temp sensor from TVR parts some time ago,( the one that scews into the back of the head),it lasted about 2 weeks.
I couldn't be bothered to send it back .
I spoke to Dom at Powers Performance, what he said I won't comment,but he sent me the upgraded Motorsport sensor,which has worked perfectly for years.
I now try to get any parts from Dom if at all possible.
I couldn't be bothered to send it back .
I spoke to Dom at Powers Performance, what he said I won't comment,but he sent me the upgraded Motorsport sensor,which has worked perfectly for years.
I now try to get any parts from Dom if at all possible.
JackFitz said:
s6boy said:
Oil pressure seems low, I know they all differ slightly but is this when hot and at idle?
You may get more exposure on the Speed Six forum.
Yes that's at hot idle with the fans kicking in. I'll raise the idle a little, it's currently at 750 rpm, that should increase the oil pressure at idle. Although, the guage will still under-report it.You may get more exposure on the Speed Six forum.
Cold start-up/ idle is about 60/65 psi.
Engine re-furb'd about 9 years ago and having done ~ 55K miles post re-build.
Nick
Just thought I'd post a follow up to this in-case anyone else has the same problem.
The bolt that goes through the passenger footwell into the battery compartment which connects to the battery ground was quite loose. I cleaned all of the contacts, tightened the bolt and this sorted the problem. The instrument cluster is now almost identical to what the ECU is reading.
I've also used a recommended thicker oil and this has brought the oil pressure up to 21 psi at 800rpm idle which I am much happier with.
The bolt that goes through the passenger footwell into the battery compartment which connects to the battery ground was quite loose. I cleaned all of the contacts, tightened the bolt and this sorted the problem. The instrument cluster is now almost identical to what the ECU is reading.
I've also used a recommended thicker oil and this has brought the oil pressure up to 21 psi at 800rpm idle which I am much happier with.
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