Oil Pressure - Dodgy Gauge or Tvr quirk?
Discussion
Hi All,
Not sure if I've a dodgy gauge reading or potential long term trouble!
Recently bought a Chim 450, 2001 plate. Only driven it a few hundred miles, all guages reading normal. On a 100 odd mile trip the other day on A roads & Mways, when revs above 2000rpm or speed high, oil guage read 15-30psi as manual/normal. Water temp was 80-90 degrees all the time.
When slowing down for;-
a)'T' junctions and roundabouts, and
b) general traffic @ 40mph in 5th gear
however, sometimes the gauge would drop without a slow decline, but just a quick drop to just above '0' reading. A blip of the throttle, or changing down to fourth, and the gauge would show 15-30psi again.
Tvr recommend a Mobil 1 SAE 5W/50 Synthetic engine oil, my garage, a Mobil stockist use Mobil 1 Extended Life 10W/60 when servicing.
Is it most likely a dodgy gauge, oil or engine characteristic? Am I right to be worried or just paranoid?! Do your gauges jump about?
Many Thanks,
T
Not sure if I've a dodgy gauge reading or potential long term trouble!
Recently bought a Chim 450, 2001 plate. Only driven it a few hundred miles, all guages reading normal. On a 100 odd mile trip the other day on A roads & Mways, when revs above 2000rpm or speed high, oil guage read 15-30psi as manual/normal. Water temp was 80-90 degrees all the time.
When slowing down for;-
a)'T' junctions and roundabouts, and
b) general traffic @ 40mph in 5th gear
however, sometimes the gauge would drop without a slow decline, but just a quick drop to just above '0' reading. A blip of the throttle, or changing down to fourth, and the gauge would show 15-30psi again.
Tvr recommend a Mobil 1 SAE 5W/50 Synthetic engine oil, my garage, a Mobil stockist use Mobil 1 Extended Life 10W/60 when servicing.
Is it most likely a dodgy gauge, oil or engine characteristic? Am I right to be worried or just paranoid?! Do your gauges jump about?
Many Thanks,
T
They can be a bit erratic. There is an oil pressure sender underneath, right at the front of the oil sump, i would check the electrical connection is clean and good as a loose or dirty/bad connection can give the symptoms you describe.
It can sometimes be a fault with the gauge itself although not usually.
Most on here have changed from the original sender to a cheaper, but more accurate alternative.
Have a read of this thread.
http://www.pistonheads.com/gassing/topic.asp?h=0&a...
It can sometimes be a fault with the gauge itself although not usually.
Most on here have changed from the original sender to a cheaper, but more accurate alternative.
Have a read of this thread.
http://www.pistonheads.com/gassing/topic.asp?h=0&a...
1st and easiest thing to try would be to unplug the electrical spade connector (female) on the oil pressure sender and determine if it grabs the male connector firmly enough, if not just give the female a slight squeeze with pliers. This solved my eratic gauge immediately when I first had the car, the poor connection was entirely to blame and my gauge has been predictable since. This is found offside ahead of the sump.
It's also worth saying the pressure gauge on these cars read low as standard. On the oil question, opinion seems to favour thicker the better and not necesarily fully synth, although I have a can of Mob 10-60 waiting so it's going in, probably going with Millers 15-60 next time round.
HTH Mark.
not worth running the ends finding out 
The only reason I said above was because the oil lamp switch trips below 7psi approx and I would not want to run an engine above idle with that kind of pressure, even if you was running at 10psi the light would be out and that's not enough 
it may be just the gauge/sender bit i would get it looked at 
it may be just the gauge/sender bit i would get it looked at Hi Theoden
Take it from me, Mobil 1 or other synthetic oil is not correct for the old Rover V8. I totally destroyed the engine in my 400SE using it (supplied by more than one specialist TVR servicer).
I now listen to people who race the Rover engine, and I stick with mineral-based oils with the specs in the handbook. I use Penrite HPR30 - 20W 60 - which is as close as I can get to the 25 W50 in the manual, and is used for road and race by specialist RV8 racing-engineers.
"High performance" oils are designed for modern engines. The Rover has other needs, and whilst they're robust and forgiving, eventually the increased heat-load in the valve gear, especially in cyls 1 and 8 where the oil has furthest to travel, will cause them to become brittle and let go. So start lookng amongst the "for older engines" product.
The oil pump relief valve can be a problem, and it must not jam or fail. if the gauge is dodgy it's another issue. Fix it.
Sorry to be dogmatic, but the long-term effects of slightly low pressure can include the heads losing their temper and beginning to crack.
Good luck -
Karkila
(constructive feedback welcomed - It's a continuing rocess learning about these engines)
Take it from me, Mobil 1 or other synthetic oil is not correct for the old Rover V8. I totally destroyed the engine in my 400SE using it (supplied by more than one specialist TVR servicer).
I now listen to people who race the Rover engine, and I stick with mineral-based oils with the specs in the handbook. I use Penrite HPR30 - 20W 60 - which is as close as I can get to the 25 W50 in the manual, and is used for road and race by specialist RV8 racing-engineers.
"High performance" oils are designed for modern engines. The Rover has other needs, and whilst they're robust and forgiving, eventually the increased heat-load in the valve gear, especially in cyls 1 and 8 where the oil has furthest to travel, will cause them to become brittle and let go. So start lookng amongst the "for older engines" product.
The oil pump relief valve can be a problem, and it must not jam or fail. if the gauge is dodgy it's another issue. Fix it.
Sorry to be dogmatic, but the long-term effects of slightly low pressure can include the heads losing their temper and beginning to crack.
Good luck -
Karkila
(constructive feedback welcomed - It's a continuing rocess learning about these engines)
All,
Many Thanks for your replies. I'll speak to my garage, and see about them checking things out.
I did think 'older' engines didn't like synthetic oils, but wasn't sure if a 2001 approx engine was considered old (although the engine design is)!
TVR themselves state use a synthetic oil in the owners handbook, and you'd think they'd have consulted the right people at Mobil to avoid potential warranty issues, although this is/was TVR we're talking about......
Rgds,
T
Many Thanks for your replies. I'll speak to my garage, and see about them checking things out.
I did think 'older' engines didn't like synthetic oils, but wasn't sure if a 2001 approx engine was considered old (although the engine design is)!
TVR themselves state use a synthetic oil in the owners handbook, and you'd think they'd have consulted the right people at Mobil to avoid potential warranty issues, although this is/was TVR we're talking about......
Rgds,
T
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