Oil pressure on startup
Discussion
How long after startup should we be hitting the right oil pressure, it takes between 8 and 15 seconds on my 4.0. There is a obvious sound change to the engine when the light goes out. Is this normal? My mechanic tested it and advised to keep a eye on it on my 12 k service, what does everyone think?
phazed said:
I've an accurate digital oil pressure gauge, when you crank the engine from cold it reads about 15 psi on the starter.
As it fires up it reads 65-70 psi within a second or two at the max.
Is that typical would you say? My mechanic wanted to change the oil pressure release spring but was unable to obtain one. Apparently it's a whole new timing cover job As it fires up it reads 65-70 psi within a second or two at the max.
I was going to say change the sender but if you have engine clatter on start up I'd be wondering if you have a worn oil pump ( gears I think ?) or party blocked oil pic up!
Can anyone explain hydraulic lifter ( bleed down ) I think the term is,,
Could that be the clatter Matt gets on start up,,
I'd say engine clatter at anytime is not good!
Also can someone explain what exactly goes wrong with the Rover oil pump,,
Can anyone explain hydraulic lifter ( bleed down ) I think the term is,,
Could that be the clatter Matt gets on start up,,
I'd say engine clatter at anytime is not good!
Also can someone explain what exactly goes wrong with the Rover oil pump,,
It is normal for the oil pressure gauge to take its time - the needle moves quite slowly. BUT you imply that it's taking a long time for the oil pressure warning light to go out, and that is driven by an entirely separate pressure switch. Changing the gauge sender is not relevant.
On my car the light goes out within a second or so after the engine fires. That is normal - it's definitely not normal for it to be taking significantly longer than that.
It then maybe takes 8 to 10 seconds for the gauge needle to reach about 50 psi or so. But depending on what gauge sender you have, it might not read as high as that - so long as it reads 30 psi or so then it's not cause for alarm. The gauge generally doesn't give accurate readings - you should get used to whatever your gauge normally says and only worry if you see something different.
And a second or two of "chatter" (I wouldn't describe it as "clatter" - it's not at all loud) from the hydraulic lifters as they fill with oil is also normal.
On my car the light goes out within a second or so after the engine fires. That is normal - it's definitely not normal for it to be taking significantly longer than that.
It then maybe takes 8 to 10 seconds for the gauge needle to reach about 50 psi or so. But depending on what gauge sender you have, it might not read as high as that - so long as it reads 30 psi or so then it's not cause for alarm. The gauge generally doesn't give accurate readings - you should get used to whatever your gauge normally says and only worry if you see something different.
And a second or two of "chatter" (I wouldn't describe it as "clatter" - it's not at all loud) from the hydraulic lifters as they fill with oil is also normal.
Edited by Dr Mike Oxgreen on Tuesday 10th March 06:18
It's the oil pressure light not the gauge that does not go out. Thinking about it I would say it was about 6 seconds to go out from a cold start on a normal day, them anything up to 11/12 seconds when the weather is cold. It's whole new timing cover for a replacement oil pump isn't it on a serp?
Dr Mike Oxgreen said:
It is normal for the oil pressure gauge to take its time - the needle moves quite slowly. BUT you imply that it's taking a long time for the oil pressure warning light to go out, and that is driven by an entirely separate pressure switch. Changing the gauge sender is not relevant.
On my car the light goes out within a second or so after the engine fires. That is normal - it's definitely not normal for it to be taking significantly longer than that.
It then maybe takes 8 to 10 seconds for the gauge needle to reach about 50 psi or so. But depending on what gauge sender you have, it might not read as high as that - so long as it reads 30 psi or so then it's not cause for alarm. The gauge generally doesn't give accurate readings - you should get used to whatever your gauge normally says and only worry if you see something different.
And a second or two of "chatter" (I wouldn't describe it as "clatter" - it's not at all loud) from the hydraulic lifters as they fill with oil is also normal.
What he said.On my car the light goes out within a second or so after the engine fires. That is normal - it's definitely not normal for it to be taking significantly longer than that.
It then maybe takes 8 to 10 seconds for the gauge needle to reach about 50 psi or so. But depending on what gauge sender you have, it might not read as high as that - so long as it reads 30 psi or so then it's not cause for alarm. The gauge generally doesn't give accurate readings - you should get used to whatever your gauge normally says and only worry if you see something different.
And a second or two of "chatter" (I wouldn't describe it as "clatter" - it's not at all loud) from the hydraulic lifters as they fill with oil is also normal.
Edited by Dr Mike Oxgreen on Tuesday 10th March 06:18
Plus, the reading on the gauge is an indication that the gauge is working.
It's the time taken from when you start cranking to when your oil low pressure warning light goes out that you should be concerned with.
If it's taking 8 to 15 seconds for the warning light to go out then you have a problem.
Don't strip anything at all yet. Go and start the car and time how long it takes for the warning light to go out and start from there.
Always try the simplest solution before breaking things apart.
So far, the potential problems you have had so far are:
Blocked oil pick up
Dodgy Oil Pressure Sender
Failing Oil Pressure Release (Relief) Spring and potentially a new timing cover required.
Yes, all are potential issues, but we don't know how long it takes for the warning light to go out yet.
Check the time it takes for the warning light to go out first!
No definitely not. Take the timing cover off and the oil pump is readily accessible. I bet its not the oil pump tho, they dont really ware.
Take the sump off and check for blockages in the oil pick up pipe and fit a new presssure switch in the timing cover and then see how you get on.
Take the sump off and check for blockages in the oil pick up pipe and fit a new presssure switch in the timing cover and then see how you get on.
carsy said:
No definitely not. Take the timing cover off and the oil pump is readily accessible. I bet its not the oil pump tho, they dont really ware.
Take the sump off and check for blockages in the oil pick up pipe and fit a new presssure switch in the timing cover and then see how you get on.
I would clean the pressure switch first making sure the connections and wiring are all good and if that doesn't cure it then, like you say, try a new pressure switch and take it from there.Take the sump off and check for blockages in the oil pick up pipe and fit a new presssure switch in the timing cover and then see how you get on.
I had a leak on my PRV which was causing my oil light to take slightly longer to go out. There was a bad leak from the o'ring seal. I had it replaced by Dan at Taylor TVR. It needs to be a Viton BS017 O'ring, not a standard rubber one.
As the others have suggested, it may be your sender as there are several different ones in use now and they all behave differently. My last Ebay sender that needed earthing showed a steady 60lbs when cold, 45lbs when hot idle and 55lbs hot under load. My new one supplied by Taylor TVR reads about 35-40lbs when cold and between 15-20lbs when hot. It all depends on the sender. The key thing is that the readings are consistent, so you can spot when there are changes.
The key thing is the oil light upon start-up. When cold, it could take around 2-3 seconds (depending how smooth your car is firing!). When warm, it should take about a second or be pretty much instant.
Have you had the sump off to check the oil pick-up pipe?
As the others have suggested, it may be your sender as there are several different ones in use now and they all behave differently. My last Ebay sender that needed earthing showed a steady 60lbs when cold, 45lbs when hot idle and 55lbs hot under load. My new one supplied by Taylor TVR reads about 35-40lbs when cold and between 15-20lbs when hot. It all depends on the sender. The key thing is that the readings are consistent, so you can spot when there are changes.
The key thing is the oil light upon start-up. When cold, it could take around 2-3 seconds (depending how smooth your car is firing!). When warm, it should take about a second or be pretty much instant.
Have you had the sump off to check the oil pick-up pipe?
Edited by Chuffmeister on Tuesday 10th March 11:12
The sound change when the light goes out would tend to indicate there is a change in lubrication and I would suggest that its taking time for oil to reach the cam and tappets. This could cause very fast and premature wear.
I had lots of experience with an issue on a Rover V8 oil pump in Chim engine but on a different car.
If its taking a while to achieve pressure then first, as already stated, drop the sump and check the pickup pipe is clear.
If that's OK look for any leaks around the oil pick up pipe where it could be drawing air.
Although unlikely it could be that your pump is draining down and repriming upon start up.
It would be advisiable to get this resolved sooner rather then later to avoid the potential for needing a new cam and followers at best.
Of course, we could be missing the obvious - There is sufficient oil in the sump, isn't there?
I had lots of experience with an issue on a Rover V8 oil pump in Chim engine but on a different car.
If its taking a while to achieve pressure then first, as already stated, drop the sump and check the pickup pipe is clear.
If that's OK look for any leaks around the oil pick up pipe where it could be drawing air.
Although unlikely it could be that your pump is draining down and repriming upon start up.
It would be advisiable to get this resolved sooner rather then later to avoid the potential for needing a new cam and followers at best.
Of course, we could be missing the obvious - There is sufficient oil in the sump, isn't there?
carsy said:
No definitely not. Take the timing cover off and the oil pump is readily accessible. I bet its not the oil pump tho, they dont really ware.
Take the sump off and check for blockages in the oil pick up pipe and fit a new presssure switch in the timing cover and then see how you get on.
^This Take the sump off and check for blockages in the oil pick up pipe and fit a new presssure switch in the timing cover and then see how you get on.
strainer gets by vote, you wont get rapid rise of the oil pressure gauge as the sender has a damper built in to stop rapid fluctuations J400GED said:
What he said.
Plus, the reading on the gauge is an indication that the gauge is working.
It's the time taken from when you start cranking to when your oil low pressure warning light goes out that you should be concerned with.
If it's taking 8 to 15 seconds for the warning light to go out then you have a problem.
Don't strip anything at all yet. Go and start the car and time how long it takes for the warning light to go out and start from there.
Always try the simplest solution before breaking things apart.
So far, the potential problems you have had so far are:
Blocked oil pick up
Dodgy Oil Pressure Sender
Failing Oil Pressure Release (Relief) Spring and potentially a new timing cover required.
Yes, all are potential issues, but we don't know how long it takes for the warning light to go out yet.
Check the time it takes for the warning light to go out first!
The mechanic said it was the oil pressure relief spring, is replacing the timing cover the only solution?Plus, the reading on the gauge is an indication that the gauge is working.
It's the time taken from when you start cranking to when your oil low pressure warning light goes out that you should be concerned with.
If it's taking 8 to 15 seconds for the warning light to go out then you have a problem.
Don't strip anything at all yet. Go and start the car and time how long it takes for the warning light to go out and start from there.
Always try the simplest solution before breaking things apart.
So far, the potential problems you have had so far are:
Blocked oil pick up
Dodgy Oil Pressure Sender
Failing Oil Pressure Release (Relief) Spring and potentially a new timing cover required.
Yes, all are potential issues, but we don't know how long it takes for the warning light to go out yet.
Check the time it takes for the warning light to go out first!
Recent oil change along with a new cam mc1 kit!
More likely the plunger sticking as they can get stuck with the tinest bit of debris or corrosion. Don't ask me how I know.
However, I would be checking the oil pick up first as about 3 other in this thread have already said.
It is very common for the sump to have been refitted with silicone and any excess can easily break away and clog the pick up gauze on the pipe.
It is by far the easiest think to check first and has the added benefit of being able to clean any accumulated gunge out of the sump.
However, I would be checking the oil pick up first as about 3 other in this thread have already said.
It is very common for the sump to have been refitted with silicone and any excess can easily break away and clog the pick up gauze on the pipe.
It is by far the easiest think to check first and has the added benefit of being able to clean any accumulated gunge out of the sump.
Gassing Station | Chimaera | Top of Page | What's New | My Stuff