Discussion
4.5 V8
Having searched and thought for a while I'm in a predicament. Oil pressure is initially 60 then it drops to 45ish when warm. Oil pressure switch plus spring changed about 2000 miles ago max.
Over the last 6 months I have deliberately had slightly more oil than recommended as the engine sounded awful prior. It was really "clattering" and sounded like it was metal on metal. I took it to Bespoke TVR and they stated it was ok and sounded as it should! However, with the extra oil it was much better and obviously sounded right.
This reading is after I drained some out a few days ago. I left the dipstick out over night and could not get a reliable reading as ever. Each side recorded a different level as the photos show:
With this lower oil level the engine is really "clattery" again with it seemingly knocking but it runs ok. I don't race it and cruise everywhere, usually no more than 3500 revs.
What do you think?
Having searched and thought for a while I'm in a predicament. Oil pressure is initially 60 then it drops to 45ish when warm. Oil pressure switch plus spring changed about 2000 miles ago max.
Over the last 6 months I have deliberately had slightly more oil than recommended as the engine sounded awful prior. It was really "clattering" and sounded like it was metal on metal. I took it to Bespoke TVR and they stated it was ok and sounded as it should! However, with the extra oil it was much better and obviously sounded right.
This reading is after I drained some out a few days ago. I left the dipstick out over night and could not get a reliable reading as ever. Each side recorded a different level as the photos show:
With this lower oil level the engine is really "clattery" again with it seemingly knocking but it runs ok. I don't race it and cruise everywhere, usually no more than 3500 revs.
What do you think?
When you add oil, does the oil on both sides of the dipstick go up by the same amount?
Might be worth draining all the oil, then refilling it with the correct amount for that engine and getting a benchmark setting marked on the dipstick, then drain 500ml out and mark the low level mark. Then just always keep the level between them new marks.
Might be worth draining all the oil, then refilling it with the correct amount for that engine and getting a benchmark setting marked on the dipstick, then drain 500ml out and mark the low level mark. Then just always keep the level between them new marks.
Some thoughts/observations, speaking as one who reads several different dip sticks every working day;
The dipstick is only a guide, not a calibrated instrument, manufacturing tolerances will mean that they're not all exactly their design length and any kinks effectively shorten their length.
They often enter the oil at an angle which IMHO isn't ideal (although not on my '98 4.2, the (braided wire type) dipstick enters the rear of the sump vertically, I believe not all AJPs are the same as this?).
Where the guide tube is not vertical or has a bend in it, oil will be deposited onto the tube and then back onto the stick on subsequent dips (meaning that there has to be long waits between dips for them to be clear).
The wider the sump, the more important that the car is parked truly level; the AJP8 sump is wide!.
I have found that a stated oil capacity is often at odds with the dipstick reading; also consider the effect of different/upgraded filter/cooler/hose capacities. I understand that all replacement hoses are now 5/8" not 1/2" bore and I've just been supplied with the 'later' type pump-to-cooler hose for mine, it's much longer as it's now to be routed the long way around the back of the sump, so the handbook stated capacity will be too little.
What is important is that the oil level is high enough to provide an adequate supply to the pump at all times, but low enough to be out of the way of the crank. Sure, the nearer to that high limit the better, as it allows more recovery (cooling) time for the oil before it has to go to work again. But ultimately the engine doesn't know how much oil it has 'to spare', all it needs is for the pick-up to just be covered (same situation in the coolant reservoir if you think about it, just enough is enough).
So I don't think that oil level is so critical as to cause noises if it's just a little low, nor that adding just a little more would cause those noises to cease. I would therefore advise you to seek expert advice.
The dipstick is only a guide, not a calibrated instrument, manufacturing tolerances will mean that they're not all exactly their design length and any kinks effectively shorten their length.
They often enter the oil at an angle which IMHO isn't ideal (although not on my '98 4.2, the (braided wire type) dipstick enters the rear of the sump vertically, I believe not all AJPs are the same as this?).
Where the guide tube is not vertical or has a bend in it, oil will be deposited onto the tube and then back onto the stick on subsequent dips (meaning that there has to be long waits between dips for them to be clear).
The wider the sump, the more important that the car is parked truly level; the AJP8 sump is wide!.
I have found that a stated oil capacity is often at odds with the dipstick reading; also consider the effect of different/upgraded filter/cooler/hose capacities. I understand that all replacement hoses are now 5/8" not 1/2" bore and I've just been supplied with the 'later' type pump-to-cooler hose for mine, it's much longer as it's now to be routed the long way around the back of the sump, so the handbook stated capacity will be too little.
What is important is that the oil level is high enough to provide an adequate supply to the pump at all times, but low enough to be out of the way of the crank. Sure, the nearer to that high limit the better, as it allows more recovery (cooling) time for the oil before it has to go to work again. But ultimately the engine doesn't know how much oil it has 'to spare', all it needs is for the pick-up to just be covered (same situation in the coolant reservoir if you think about it, just enough is enough).
So I don't think that oil level is so critical as to cause noises if it's just a little low, nor that adding just a little more would cause those noises to cease. I would therefore advise you to seek expert advice.
TwinKam said:
They often enter the oil at an angle which IMHO isn't ideal (although not on my '98 4.2, the (braided wire type) dipstick enters the rear of the sump vertically, I believe not all AJPs are the same as this?).
Where the guide tube is not vertical or has a bend in it, oil will be deposited onto the tube and then back onto the stick on subsequent dips (meaning that there has to be long waits between dips for them to be clear).
This is also from a '98 where the dipstick is at the back of the sump.Where the guide tube is not vertical or has a bend in it, oil will be deposited onto the tube and then back onto the stick on subsequent dips (meaning that there has to be long waits between dips for them to be clear).
TwinKam said:
I would therefore advise you to seek expert advice.
Perhaps not so easy in Oz...I agree with the OP that excessive clatter on startup and while warming up is a sign that it needs a bit of oil. I can hear the difference, especially reversing out the garage after it's been running for a minute or so. It doesn't mean it's dangerously low, maybe just at or slightly below the max mark on the stick. It seems to prefer 3-5mm above the max line.
I can't explain why this is but it does seem to be the case.
Edit: I also have the cable style stick that twists as it goes in
I can't explain why this is but it does seem to be the case.
Edit: I also have the cable style stick that twists as it goes in
I have checked the dipstick travel - it is definitely at an angle. So the readings will always be askew.
I topped her up to where she was before (a few mm above the level) and she is running as right as rain again without any undue knocks etc.
She does run so much better on start up plus on idle without the worrying clatter. I have also noticed the small oil leak has stopped! Bespoke TVR stated the oil leak was pretty common and not to worry about it (as it was) so now I'm even less concerned! It does take a while to really get to know your individual car's noises and at the moment the oil level seems to be spot on for better running all around. I'm using Comma 5/50 Motorsport Fully Synth. but don't want to begin another oil thread! At the next service I will be changing to Penrite 10 so I hope it will be even better.
I topped her up to where she was before (a few mm above the level) and she is running as right as rain again without any undue knocks etc.
She does run so much better on start up plus on idle without the worrying clatter. I have also noticed the small oil leak has stopped! Bespoke TVR stated the oil leak was pretty common and not to worry about it (as it was) so now I'm even less concerned! It does take a while to really get to know your individual car's noises and at the moment the oil level seems to be spot on for better running all around. I'm using Comma 5/50 Motorsport Fully Synth. but don't want to begin another oil thread! At the next service I will be changing to Penrite 10 so I hope it will be even better.
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