Zero Oil Pressure
Discussion
Please help,
Had my Chimarea 500 3 weeks now and evrything has been ok. Over the last 2 days the Oil Pressure Guage is showing zero, and hasn't moved since.
Have checked the oil (seems fine) and the water reservoir (also seems fine).
The weather over the past few days has been extremely wet (rain, sleet and snow). Could it be just a faulty sensor.
I am very worried as reading through the Griff pages, people talk about relief valves sticking open, premature engine wear, engine failure etc. Should i be driving it?
Where are the sensor connections, and can i check them easily? Recently i had a heater problem repaired. Could they have upset something at the back of the dash?
Please help
A very concerned Bandit
Had my Chimarea 500 3 weeks now and evrything has been ok. Over the last 2 days the Oil Pressure Guage is showing zero, and hasn't moved since.
Have checked the oil (seems fine) and the water reservoir (also seems fine).
The weather over the past few days has been extremely wet (rain, sleet and snow). Could it be just a faulty sensor.
I am very worried as reading through the Griff pages, people talk about relief valves sticking open, premature engine wear, engine failure etc. Should i be driving it?
Where are the sensor connections, and can i check them easily? Recently i had a heater problem repaired. Could they have upset something at the back of the dash?
Please help
A very concerned Bandit
The classic error that people make is that the pressure guage is related to oil level. It's not. You may be to the 'Max' on the dipstick, but it's no good unless it's being pumped around the crank bearings etc.
If it genuinely has no pressure (as opposed to guage failure) then you'll lunch it if you drive it, so get it checked.
If it genuinely has no pressure (as opposed to guage failure) then you'll lunch it if you drive it, so get it checked.
Speaking from general not TVR specific experience I would say it is very unusual for an oil pump to fail completely. Has the oil been changed recently? - the pump can drain and it's not self priming.
Before you call out the cavalry with the low loader I would do some checks on the wiring, sender and gauge.
Before you call out the cavalry with the low loader I would do some checks on the wiring, sender and gauge.
This happened to mine(v.disconcerting!!)
Went for it's MOT and when it was in the air on ramp, the mechanic said 'what this for?' tiny little push in electrical connector right in the middle of what i assume is the sump was just hanging (bang smack in the middle of the underside of the engine,should think you would have to get it up in the air to some degree) he pushed the connector home and Bobs yer dad's brother it was working perfectly again.
So you might want to try taking a look see before you get too depressed
Good luck.
Went for it's MOT and when it was in the air on ramp, the mechanic said 'what this for?' tiny little push in electrical connector right in the middle of what i assume is the sump was just hanging (bang smack in the middle of the underside of the engine,should think you would have to get it up in the air to some degree) he pushed the connector home and Bobs yer dad's brother it was working perfectly again.
So you might want to try taking a look see before you get too depressed
Good luck.
If you've been driving around for the past few days with zero on the gauge and the car hasn't ground to a halt accompanied by expensive sounding noises then it's probably the gauge or the sender unit/wiring. I believe the oil pressure warning light on the speedo is on a separate circuit - if this stays on you're in trouble.
T/.
T/.
Hi Bandit,
Nobody on here is likely to tell you anything other than 'don't even start the engine until you have had it checked and the problem fixed' because it could be serious and nobody can take on that responsibility.
Nevertheless, if as trefror says, you've been driving it around for 2 days like this and there is no heavy knocking noise / vibration and you haven't seized your engine yet then it is seems unlikely that the gauge is telling you the truth. I'm sure you suspect that anyway from your suspicions about the heater problem.
How many miles have you driven without oil pressure indication?
Some ideas:
Does the oil pressure warning light work when you first switch on and go out when you start the engine?
Is there a risk that the oil pump is not primed because the oil has been drained and refilled (Bob C)? If so this is serious and DON'T RESTART.
I don't believe much in coincidences so as you've only had it 3 weeks have you been 'loving it to death' and fixing and checking everything in sight? Have you been anywhere that could have caused disturbance to the pressure gauge circuit? Particularly immediately before you lost indication? Dashboard would be a favourite. As has already been said, check out the pressure gauge circuit as the most likely fault.
Incidentally, have you got yourself a copy of Steve Heath's bible yet?
This all comes with the health warning in the first paragraph though.
TVRs, don't you just love em!
Any thoughts on the trackdays, training or TVRCC meets we discussed, let me know.
>> Edited by martvr on Thursday 28th February 12:05
Nobody on here is likely to tell you anything other than 'don't even start the engine until you have had it checked and the problem fixed' because it could be serious and nobody can take on that responsibility.
Nevertheless, if as trefror says, you've been driving it around for 2 days like this and there is no heavy knocking noise / vibration and you haven't seized your engine yet then it is seems unlikely that the gauge is telling you the truth. I'm sure you suspect that anyway from your suspicions about the heater problem.
How many miles have you driven without oil pressure indication?
Some ideas:
Does the oil pressure warning light work when you first switch on and go out when you start the engine?
Is there a risk that the oil pump is not primed because the oil has been drained and refilled (Bob C)? If so this is serious and DON'T RESTART.
I don't believe much in coincidences so as you've only had it 3 weeks have you been 'loving it to death' and fixing and checking everything in sight? Have you been anywhere that could have caused disturbance to the pressure gauge circuit? Particularly immediately before you lost indication? Dashboard would be a favourite. As has already been said, check out the pressure gauge circuit as the most likely fault.
Incidentally, have you got yourself a copy of Steve Heath's bible yet?
This all comes with the health warning in the first paragraph though.
TVRs, don't you just love em!
Any thoughts on the trackdays, training or TVRCC meets we discussed, let me know.
>> Edited by martvr on Thursday 28th February 12:05
Hi Martin,
Thanks for the ideas. You really know your way round TVR's.
I can't wait to come out on some of the meetings organised, and will come soon, just trying to get all the little misfortunes sorted on the car beforehand.
I checked the car this lunchtime, and the oil pressure light DOES come on when ignition key is turned, and then switches off when started.
In addition i turned off the engine, waited 2 seconds then turned the key until the ignition lights were on but engine off. The oil switch was still off, and after about 6 seconds it came on again.
This led me to believe that the oil pressure in the engine was reducing after engine switch off, until it reached the pressure level whereby the switch came on again.
I think this shows my engine has pressure. what do you think???
I haven't been anywhere near the engine in the last week so i don't think i would have dislodged anything.
Where on the engine do i check for the connections. I've heard near the Oil Filter but where exactly?
TVR's AAARRRGGHHH!
Hope to see you soon!
Bandit
Thanks for the ideas. You really know your way round TVR's.
I can't wait to come out on some of the meetings organised, and will come soon, just trying to get all the little misfortunes sorted on the car beforehand.
I checked the car this lunchtime, and the oil pressure light DOES come on when ignition key is turned, and then switches off when started.
In addition i turned off the engine, waited 2 seconds then turned the key until the ignition lights were on but engine off. The oil switch was still off, and after about 6 seconds it came on again.
This led me to believe that the oil pressure in the engine was reducing after engine switch off, until it reached the pressure level whereby the switch came on again.
I think this shows my engine has pressure. what do you think???
I haven't been anywhere near the engine in the last week so i don't think i would have dislodged anything.
Where on the engine do i check for the connections. I've heard near the Oil Filter but where exactly?
TVR's AAARRRGGHHH!
Hope to see you soon!
Bandit
quote:
I think this shows my engine has pressure. what do you think???
It shows it may have some pressure but whether it is enough to preserve the engine from a premature death is another matter. It trips at around 5 to 7 lb/sq in and is really there to tell you that the sump has lost all oil and you have about 2 seconds before the engine expires. Next to useless but it does look pretty.
The oil sensor is near the top of the oil filter and has a wire attached to a lucar connector. If this is not attached or has a dirty contact, you will get either a lot of oil pressure or none depending on how the guage is wired in.
Other than that the procedure is assume you have zero oil pressure, get someone to check it with a mechanical gauge. If pressure is OK, you can drive the car and the fault is with the gugage/sender. If not then you might have a knackered oil pump or it could be goodbye, engine, hello big bill. You will not know until the pressure is checked out. Because of this, zero oil pressure means stop the engine immediately. If you have several thousand to spare then carry on driving
9/10 it is the sender or gauge but you don't know. It is not uncommon for oil pressure to fail in the engine. A relief spring breaking will reduce pressure enough to trip the oil light but reduce it enough to cause engine damage.
In other words assume the worst and you will probably have a happy ending. Assume the best and the chances it will end in tears.
Steve
www.tvrbooks.co.uk
quote:
What should the oil pressure be reading out of interest on an average engine ?
My 4.0l normally reads about 30psi cold tickover dropping to 15ish when warm. at 50-70mph it reads 50-60 when cold dropping to 30-40 when warm. I don't know if this helps or even if its normal ! I am currently using Mobil 1 0-40 - pressures may change using thicker oils
>> Edited by Bob the Planner on Thursday 28th February 21:11
50-60 psi pressure... Sure you're not driving a V6 S? That is high for a Rover engine especially as there should be a pressure relief valve that limits the oil pressure to around 40-50 lb at best. I suspect you have an over enthusiastic oil pressure sender.
Rover oil pressure: Below 10 when idling, worry. Below 10 at revs panic. At revs expect anything between 25-40.
Steve
www.tvrbooks.co.uk
Rover oil pressure: Below 10 when idling, worry. Below 10 at revs panic. At revs expect anything between 25-40.
Steve
www.tvrbooks.co.uk
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