Oil Pressure Sender
Discussion
When I first got my Chimaera, I was concerned about the low pressure reading. So I phoned Jason at Str8Six, who advised me that the real pressure will be more like 60+ psi and that the sender is nearly always the cause of low readings.
I've ordered (and received) one of these senders from eBay; I'll add my experiences to this thread when I get around to fitting it.
I might want to get underneath it soon to check for damage after grounding it part way up Hardknott Pass yesterday.
I've ordered (and received) one of these senders from eBay; I'll add my experiences to this thread when I get around to fitting it.
I might want to get underneath it soon to check for damage after grounding it part way up Hardknott Pass yesterday.
Edited by Dr Mike Oxgreen on Saturday 23 April 09:02
just a warning, just did this myself and it seems a cheap adapter has been used in the past and with the slightest amount of effort the adapter sheared off leaving the thread in the housing! thankfully got it out but trying to find another adapter on a bank holiday weekend is a nightmare!
Sorry to dig up an old thread!!!
I've finally got around to fitting my replacement pressure sensor. After a bit of a struggle to release the old one, I offered up the new one and... disaster! It's the wrong bleedin' size!
The one I've got is too small.
Have I bought the wrong sensor, or are there two different sizes of sensor fitted to these engines?
Roughly speaking, the outside thread diameter of the one I've bought is 3/8", give or take - which is about the 0.332" that you'd expect for a 1/8 NPT thread. Which leads me to suspect that my engine's oil pressure hole is a different size.
Any idea what size that might be, and whether I can buy an adapter?
Edited to add: About 10 seconds after posting this, part of my brain said: "Maybe there's already an adapter on the old one, and you need to separate it and re-use it. So I'm going back outside to remove the old sender, bung up the hole and take a closer look at what I've taken off.
I've finally got around to fitting my replacement pressure sensor. After a bit of a struggle to release the old one, I offered up the new one and... disaster! It's the wrong bleedin' size!
The one I've got is too small.
Have I bought the wrong sensor, or are there two different sizes of sensor fitted to these engines?
Roughly speaking, the outside thread diameter of the one I've bought is 3/8", give or take - which is about the 0.332" that you'd expect for a 1/8 NPT thread. Which leads me to suspect that my engine's oil pressure hole is a different size.
Any idea what size that might be, and whether I can buy an adapter?
Edited to add: About 10 seconds after posting this, part of my brain said: "Maybe there's already an adapter on the old one, and you need to separate it and re-use it. So I'm going back outside to remove the old sender, bung up the hole and take a closer look at what I've taken off.
Edited by Dr Mike Oxgreen on Sunday 27th November 12:42
Okay - I'm officially an A-grade plonker. But you knew that already!
In my hurry to avoid losing too much oil, I didn't really look at the thing I'd just removed - I was too keen to offer up the new one.
Having bunged up the hole with a rag, I took one glance at the removed sender and realised what a muppet I'd been. An adapter is indeed needed, and it's already there - duh!
It was a bit of a struggle to release the adapter, but I've now fitted my new sender. Now to wire it up...
Edited to add: Now wired up, and fired up! Interestingly, on mine the needle still moves slowly, climbing to about 55 psi on a cold idle - which is higher than it used to read, and recently it's been giving particularly erratic readings especially at higher RPM. It's still up on axle stands at the moment, so I don't know what the pressure will read at normal temperature.
In my hurry to avoid losing too much oil, I didn't really look at the thing I'd just removed - I was too keen to offer up the new one.
Having bunged up the hole with a rag, I took one glance at the removed sender and realised what a muppet I'd been. An adapter is indeed needed, and it's already there - duh!
It was a bit of a struggle to release the adapter, but I've now fitted my new sender. Now to wire it up...
Edited to add: Now wired up, and fired up! Interestingly, on mine the needle still moves slowly, climbing to about 55 psi on a cold idle - which is higher than it used to read, and recently it's been giving particularly erratic readings especially at higher RPM. It's still up on axle stands at the moment, so I don't know what the pressure will read at normal temperature.
Edited by Dr Mike Oxgreen on Sunday 27th November 13:57
I've just done a test-drive, so I can add my own pressure readings now. For reference, mine's a '99 450 with about 63k on the clock and no major work that I'm aware of.
Before
Cold idle: 30 psi
Cold 1500+ rpm: 45 psi
Hot idle: 0-5 psi
Hot 1500+ rpm: 30 psi
Hot 3000+ rpm: 15 psi
Hot 4000+ rpm: 0 psi
Hot 5000+ rpm: needle drops well below zero
After - with cheapo eBay sender
Cold idle: 55 psi
Cold 1500+ rpm: 65 psi
Hot idle: 40-45 psi
Hot 1500+ rpm: 59 psi (just below 60)
Hot 3000+ rpm: 59 psi
Hot 4000+ rpm: 59 psi
Hot 5000+ rpm: 59 psi
So as you can see, the new sender gives much less "exciting" readings than the old one did, which is A Good Thing.
I'm a happy bunny!
Also, the old sender was drenched with oil, with no evidence of oil leakage coming from above it - suggesting that the sender itself was leaking. I've got used to putting in about a litre every 1000 miles or so, so I'm hoping to save a bit of money on oil from now on with any luck.
Before
Cold idle: 30 psi
Cold 1500+ rpm: 45 psi
Hot idle: 0-5 psi
Hot 1500+ rpm: 30 psi
Hot 3000+ rpm: 15 psi
Hot 4000+ rpm: 0 psi
Hot 5000+ rpm: needle drops well below zero
After - with cheapo eBay sender
Cold idle: 55 psi
Cold 1500+ rpm: 65 psi
Hot idle: 40-45 psi
Hot 1500+ rpm: 59 psi (just below 60)
Hot 3000+ rpm: 59 psi
Hot 4000+ rpm: 59 psi
Hot 5000+ rpm: 59 psi
So as you can see, the new sender gives much less "exciting" readings than the old one did, which is A Good Thing.
I'm a happy bunny!
Also, the old sender was drenched with oil, with no evidence of oil leakage coming from above it - suggesting that the sender itself was leaking. I've got used to putting in about a litre every 1000 miles or so, so I'm hoping to save a bit of money on oil from now on with any luck.
It doesn't seem to have been mentioned here, and I would have assumed most knew this but;
Cold idle: 30 psi
Cold 1500+ rpm: 45 psi
Hot idle: 0-5 psi
Hot 1500+ rpm: 30 psi
...is all normal, from new.
It was explained to me by the dealer, in the usual "TVRs do that" when I first collected the car.
Best of my recollection, the sender never been replaced and the pressures have never been commented on during any service or repair visit, and it's the same today 96k miles later.
Of course, in any other car you would shut off the engine and await RAC/AA recovery vehicle
These I agree would be indicative of some fault;
Hot 3000+ rpm: 15 psi
Hot 4000+ rpm: 0 psi
Hot 5000+ rpm: needle drops well below zero
Seeing a reading of zero and going for another 1000+ rpm seems quite brave (or something
) to me.
In my case I have to admit to a greater level of attention on the tachometer when foot to the floor going past 4000 rpm, than on the oil gauge.
Cold idle: 30 psi
Cold 1500+ rpm: 45 psi
Hot idle: 0-5 psi
Hot 1500+ rpm: 30 psi
...is all normal, from new.
It was explained to me by the dealer, in the usual "TVRs do that" when I first collected the car.
Best of my recollection, the sender never been replaced and the pressures have never been commented on during any service or repair visit, and it's the same today 96k miles later.
Of course, in any other car you would shut off the engine and await RAC/AA recovery vehicle
These I agree would be indicative of some fault;
Hot 3000+ rpm: 15 psi
Hot 4000+ rpm: 0 psi
Hot 5000+ rpm: needle drops well below zero
Seeing a reading of zero and going for another 1000+ rpm seems quite brave (or something
) to me. In my case I have to admit to a greater level of attention on the tachometer when foot to the floor going past 4000 rpm, than on the oil gauge.
Goaty Bill said:
Seeing a reading of zero and going for another 1000+ rpm seems quite brave (or something ) to me.
Ha - I laugh in the face of danger! ) to me.But seriously, the first time I saw it I did poo myself. But a quick search on here revealed that if the indicated pressure drops at higher revs that's classic symptoms of a dodgy sender. The second time I saw it was when I went to 5000+, having forgotten about the first time.
That's when I saw the needle plunge down to its resting position, which kinda confirmed the diagnosis. I tried not to make a habit of using high revs after that, just in case!Goaty Bill said:
It doesn't seem to have been mentioned here, and I would have assumed most knew this but;
Cold idle: 30 psi
Cold 1500+ rpm: 45 psi
Hot idle: 0-5 psi
Hot 1500+ rpm: 30 psi
...is all normal, from new.
Absolutely spot on, that's what mine showed before the original sender packed up.Cold idle: 30 psi
Cold 1500+ rpm: 45 psi
Hot idle: 0-5 psi
Hot 1500+ rpm: 30 psi
...is all normal, from new.
When I first got my Chim I had a chat with Jason at Str8six about this, it struck me at the time my readings were very low.
He simply said when using a decent external test gauge the true oil pressure on a Rover V8 is nearer 60 psi.
Jason is a very well respected TVR engine builder of many years standing (not just the AJP six) so I had no reason to doubt him.
From that moment on I worried a lot less about my lowish readings but I still couldn't help cringing when stuck in traffic on a hot day I would see the gauge fall to a pathetic & frightening 5 psi.
Then one day after a new cam I lost all pressure on the gauge
Rob Robertson from V8 Developments told me not to panic & change the sender, so that's what I did, the results are all here in this thread.
In summary the facts clearly point to a miss match between the sender & the gauge that TVR fitted at the factory.
TVR making a mistake at the factory, surely not
As has now been proven by a number of followers of this thread my cheapo EBay sender seems to consistently deliver readings much closer to the truth on a number of different cars.
I just feel sorry for all those folks that have been paying £70 + for an original sender from the TVR parts specialists, only to find it was giving them the wrong readings all along.
Knowing what I know now even if my original sender was working fine I would still be tempted to replace it for the EBay one, idling in 90 degree South of France traffic was much less stressful this year with the new sender.
An easy to fit bargain mod that actually does nothing at all, other than give you some peace of mind.
Well worth it in my opinion.
Chimpabollics said:
An easy to fit bargain mod that actually does nothing at all, other than give you some peace of mind.
Well worth it in my opinion.
There is nothing wrong about being right Well worth it in my opinion.
I have to admit, dyed in the wool purist that I may seem, I might actually consider one if/when the time comes to replace mine.
Though it's never actually concerned me, seeing something constantly above 10lbs would not be without it's comforting affects.
Did I not read that there was someone (other than The Chimaera Pages) maintaining a current list of alternate suppliers / parts for the general use here /elsewhere?
This is, like quite a few other things of late, the kind of things that are useful to be able to find without forum searching for hours, or re-posting when you know it's been asked.
http://www.pistonheads.com/sales/3462646.htm oil pressure sender £28 ebay item number for BIN Ebay is : 130606143939
SP
SP
Edited by S27 on Thursday 8th December 18:48
S27 said:
http://www.pistonheads.com/sales/3462646.htm oil pressure sender £28 ebay item number for BIN Ebay is : 130606143939
SP
Purchased 2 of those a little while ago, does exactly as you would expect of a genuine product and at that price i at to have a spare, gauge is behaving itself once more and no worries of build quality or compatability issues.SP
Edited by S27 on Thursday 8th December 18:48
Edited by Simon says on Thursday 8th December 23:44
Simon says said:
S27 said:
http://www.pistonheads.com/sales/3462646.htm oil pressure sender £28 ebay item number for BIN Ebay is : 130606143939
SP
Purchased 2 of those a little while ago, does exactly as you would expect of a genuine product and at that price i at to have a spare, gauge is behaving itself once more and no worries of build quality or compatability issues.SP
Edited by S27 on Thursday 8th December 18:48
Edited by Simon says on Thursday 8th December 23:44
By fitting an original I can go back to the fun old days of seeing pressures 50% lower than they really are.
Why I am bothering with my cheaper & more accurate sender I shall never know.
Originality is key here, by fitting the original sender I can increase the value of my car by thousands.
Who cares if the original sender shows the wrong readings
Chimpabollics said:
I think I might get one of these, I'm bored with seeing the correct oil pressure now.
By fitting an original I can go back to the fun old days of seeing pressures 50% lower than they really are.
Why I am bothering with my cheaper & more accurate sender I shall never know.
Originality is key here, by fitting the original sender I can increase the value of my car by thousands.
Who cares if the original sender shows the wrong readings
With you buddy! By fitting an original I can go back to the fun old days of seeing pressures 50% lower than they really are.
Why I am bothering with my cheaper & more accurate sender I shall never know.
Originality is key here, by fitting the original sender I can increase the value of my car by thousands.
Who cares if the original sender shows the wrong readings
v8 racing said:
Chimpafrolic said:
reat news Kitchski, glad it worked for you too.
Lets see how reliable the sender proves to be over time, mine still seems fine.
So far, so good
And after all that panacking that your oil pressure was low, glad you sorted it.Lets see how reliable the sender proves to be over time, mine still seems fine.
So far, so good
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