Oil pressure takes a while to go up?

[spetz]

On start up of my car, after it hasn't run for a few hours, it takes a few seconds for the oil pressure to go up
What could this be??
It goes up to 90psi and stays stable after that. I changed oil and oil filter and still does it

[JohnL]

On start up of my car, after it hasn't run for a few hours, it takes a few seconds for the oil pressure to go up
What could this be??
It goes up to 90psi and stays stable after that. I changed oil and oil filter and still does it

What grade oil? If you used say 20W/50 then it will tend to flow more slowly and may take longer to build pressure. Hondas like thinner oil, i.e. 10W/30. You do want a fast flow / pressure build up, the great majority of engine wear occurs at start up before the oil is circulating properly.

[spetz]

No the oil is pretty thin
Unsure what oil was in it originally but the oil was then changed to 5/30 or something and still did the same thing
The engine is freshly built as well

[aaronng]

If the car has an oil cooler that is setup before the oil pressure sensor, it does that.

[spetz]

No oil cooler...
I am thinking engine has to come out yet again :(
I am so over this :( :( :(

[fatboyz39]

Its nornal... your gauge might be delayed.

[spetz]

No no not a gauge
A mechanical testing gauge was put on the car
The mechanic said it wasn't normal.
Also, because where it was checked from is closer to the pump, it would take even longer to reach the head
Also car is blowing white/grey smoke :(

[Limbo]

that's not good if its a fresh motor, take it back to the builder

[spetz]

Yeah it will be going back to the builder...
I hate this ****ing around though!

[fatboyz39]

thats badluck then. Hopefully your builder will fix it asap and no extra cost involve.

[Mr_will]

so the mechanic told you it wasnt normal but couldnt speculate as to the cause? some mechanic he/she sounds like.

[JohnL]

On start up of my car, after it hasn't run for a few hours, it takes a few seconds for the oil pressure to go up
What could this be??
It goes up to 90psi and stays stable after that. I changed oil and oil filter and still does it

How many seconds is "a few"? If it's more than about two seconds to build reasonable pressure I'd be unhappy. How quickly does it build up? Does it start to build straight away, just that it takes a "few seconds" to go right up to 90?

90psi is quite a high oil pressure, many good engines would be lower than this with cold oil, and way less with warm oil. A lot of cars will idle with only a few psi (e.g. less than 10psi), but still be OK (e.g. some Alphas and Ferraris typically have very low idle oil pressure). In reality it's not so much that you need such a high oil pressure (it's not the pressure so much that really protects the engine, the pressures in the bearings are typically way higher than the nominal oil psi because of the way shell bearings work), but you do need a good oil flow (i.e. be able to pump a lot of through the system quickly).

If you were getting say 20psi in say half a second then I doubt there's a real worry here. Low oil pressure is a concern if it's a result of large bearing clearances as you would get with substantial bearing wear, but it sounds like you have new shells?

At any rate such wear would typically be seen as generally low pressure, not so much as a slow pressure build up (i.e. if your bearing clearance were too great I'd not expect you'd ever see 90psi, unless someone had dicked about with the relief valve to disguise the worn bearings, not that this increased nominal pressure would have any affect on improved bearing protection, it wouldn't).

[JohnL]

A couple more thoughts:
How quickly does the oil pressure idiot light take to go out? If the idiot light goes out quickly then this is telling you that you have oil flow and pressure is on the rise, which is all you need at start up. If this takes a 'normal' amount of time then I'd not be too concerned that it takes a bit longer to see 90psi on the guage, unless "a few seconds" means quite a few seconds...

You don't need the full 90psi for there to be enough oil flow into the bearings for them to be properly protected, so long as some oil gets in there quickly you should be fine. The bearings are the real issue here, if it takes a bit longer for oil to reach the top of the motor and / or the bores it's not really a big deal, the oil film clinging to the cam lobes / followers and bores / rings / piston skirt will provide adequate lubrication for start up.

Maybe.... have you considered the oil filter? I know you said you replaced it, and implied that the problem also existed with the previous filter, but are both these filters good quality or cheap? Are they the same brand? Even if they were both good brand filters, could they perhaps be both from the same batch and therefore might both have some problem?

It occurs to me that there is a possible filter problem that could fit your symptom; the filter has an anti-drain valve inside it to prevent oil leaking back into the sump after shut down (i.e. the filter should always be full of oil). If this were not working then each time you started the engine you'd be filling an empty filter before any pressure reaches your OP guage sender unit...

Blowing white / grey smoke? Sounds suspiciously like steam to me, I'd be checking under the oil filler cap and in the rad' for the Devil's cream...

[spetz]

Devils cream you mean the blown head gasket issue?
I'll have a look but the engine has such minimal km on it that it's hard to diagnose these things
The oil was drained because it has a main end bearing sound, and checked for metal filings etc, and nothing was found. But so little km also meant the oil looked brand new, still had the gold colour and everything

The oil pressure I was told took about 10 seconds to build up. But can't remember whether it was 10 seconds to reach 90 psi, (or 80 it might have been) or 10 seconds to start gaining oil pressure

I'm unsure of the brand of oil filter, but after you mentioned it, I don't remember seeing the oil pressure light stay on any longer than normal?? If at all for that matter...

I have noticed though the car has had a lot of power loss. I never floored it as it has been running around, but even still at some stage it seemed to just go down in power. At the time of course I didn't worry as it was untuned, and running on the rich side, and without having ever floored it I thought there could be many reasons for it

Just have to call the engine builder and get it to him. I don't think he will say no to anyting but I know he'll try to get out of it

[JohnL]

Devils cream you mean the blown head gasket issue?

Yes, possibly. 'Devil's cream' being oil emuslfied in water (or vice versa). If you do have steam coming from the pipe it could just be condensation as you would get with a cold start up in the morning (which is normal and goes away when the pipe warms up), or (god forbid) water entering the combustion chamber due to a blown head gasket, or (even worse) a crack in the head or block.

Not trying to scare you! I'm just guessing because you said "white grey smoke", which is suspicious. Does water come out of the pipe?

Did this engine have a blown HG before the rebuild? If so, was the head machined flat? Was the block deck checked for 'flatness'? In my experience if the head is not absolutely dead flat then it's not unlikely that the new gasket will blow, even if the head may be within the manufacturer's 'flatness' tolerance.

The same probably goes for the deck, but I've never had to deal with a warped deck (corroded yes, warped no). Does this engine have protruding cylinder sleeves (i.e the tops of the sleeves protrude slightly above the deck to improve compression seal)? If so was the protrusion height on each sleeve checked? This is important with such engines.


I'll have a look but the engine has such minimal km on it that it's hard to diagnose these things
The oil was drained because it has a main end bearing sound, and checked for metal filings etc, and nothing was found. But so little km also meant the oil looked brand new, still had the gold colour and everything

Do you mean 'big end' or 'main bearing'? Is this an obvious sound? Is it a regular 'knocking' or more of a 'rumble'? If it sounds like a bad bearing it most likely is (or less likely something else, I don't know what but probably still reasonably serious). Did it have this sound imediately after the rebuild, or has it built up over time? Either way, it shouldn't make such a sound, and if it does then IMO you probably need to take the sump off and investigate properly. Such sounds rarely go away. It's very suspicious that you have the slow pressure build AND a noise...

Did the rebuild include new bearing shells, crank machining etc? (often modern cranks don't require machining because the metal is so good / hard wearing, but the journals need to be at least properly measured before fitting new shells). If a bearing of the wrong size were fitted, or one of the journals were significantly undersize then you might get a bearing noise without any sign of metal particles in the oil. It could be something really stupid, like a bearing cap that wasn't tightened...


The oil pressure I was told took about 10 seconds to build up. But can't remember whether it was 10 seconds to reach 90 psi, (or 80 it might have been) or 10 seconds to start gaining oil pressure

10 seconds is a long time, whether to start showing guage pressure or to build up to full pressure. I'd be concerned. How comprehensive was this rebuild? What exactly was done?


I'm unsure of the brand of oil filter, but after you mentioned it, I don't remember seeing the oil pressure light stay on any longer than normal?? If at all for that matter...

Turn the ignition on (don't crank it) to see if the idiot light comes on. If it doesn't you should find out why. Maybe the idiot sender has been removed, the OP gauge sender might have been installed where the idiot sender used to be? If you get an idiot light, start it up paying attention to what the idiot light does. From what you've said (10 seconds on the guage) my guess is that it will take a while to go out, but not as long as it takes for the guage to show full pressure. Listen for the bearing sound, does it stay the same, or does it diminish as the pressure increases. It's probably academic, sounds like bearing trouble to me.


I have noticed though the car has had a lot of power loss. I never floored it as it has been running around, but even still at some stage it seemed to just go down in power. At the time of course I didn't worry as it was untuned, and running on the rich side, and without having ever floored it I thought there could be many reasons for it

Did the bearing sound start around the time you noticed a drop in power? If so then I'm not sure of the significance (beyond probably not being co-incidental), I wouldn't expect a noisy bearing to have a noticable affect on power, unless it was pretty bad.


Just have to call the engine builder and get it to him. I don't think he will say no to anyting but I know he'll try to get out of it

If you get no satisfaction then you'll need a second proffesional opinion, in writing. If this supports your suspicion that something is seriously wrong present it to your engine builder. An organisation with industry standing such as the NRMA etc might be able to inspect it and write a report for you? I don't know, you could ask them.

[spetz]

The white/grey smoke I never noticed, I was told that by the mechanic here (different mechanic who built/put the engine in) about it.
The heads have been shaved by 0.5mm to raise compression ratio up, but I don't think the block had been decked, but unsure of that though. I'm sure it should have been checked though

The bearing sound is like a rumble. It's more evident on start up and then goes away, but you can still here it when free revving etc. From my memory, it didn't have that immidiately but it did come pretty soon. It's hard to say as when I first started driving it it had no muffler at all and engine noise was overpowered by the exhaust note. I really noticed this all once the muffler got fitted on. At the same time the tappets were noisy and I thought it was them makign that noise.
The builder says bearings are new, and he checked the bottom end for noise and it had nothing evident. I have a feeling though some parts that should have been changed weren't. Mainly rod bolts and head bolts. Otherwise though the heads were completely rebuilt, internals balanced, honed, new rings etc, and it was a complete strip down of the engine.
As far as big end or main end, I am unsure. It is a bearing sound but could be any bearing, I wouldn't have a clue.

I will have a look at the oil pressure warning light. With the bearing noise, the main loud one on start up goes away. It only makes that sound as the engine revs up to about 2.5K on initial start up and then the revs drop down. I know that if the engine is switched off, and then started again, it wont make that sound. It has to be off for a few hours before it does that sound again.

The loss in power, once again having no muffler on meant I couldn't really hear much of the engine. On the dyno it showed no pinging at all though, but also made no power at all. It topped at 81kw, though not sure if floored as the tuner told me once he heard the noise, he didn't push it. Either way 81kw is a joke, as the old engine before rebuilding did 112kw atw and that had no mods at all


Thank you very much John for the help, I'll try and get as much info as possible and post back up more answers.
Just hoping it gets fixed ASAP :(

[JohnL]

spetz said:
The white/grey smoke I never noticed, I was told that by the mechanic here (different mechanic who built/put the engine in) about it.
The heads have been shaved by 0.5mm to raise compression ratio up, but I don't think the block had been decked, but unsure of that though. I'm sure it should have been checked though

You intentionally raised CR for a supercgharged engine? A little unusual since you'd usually want to reduce it, but I suppose it depends on the original CR and how hard you're blowing the motor...

Black smoke is excess fuel, so that doesn’t fit. Grey smoke (light grey) might be oil smoke, but why would you be losing that much oil into the chamber (or maybe into the exhaust ports?), though the rings may not yet be properly sealing (shouldn’t take long though). White ‘smoke’ is typically water vapour. Grey / white smoke might be water vapour mixed with either some black smoke or some grey smoke, or might possibly be white ‘smoke’ mixed with carbon particles from inside the pipe (i.e. you might be ‘steam cleaning’ the inside of the pipe).

I can’t tell if you have a gasket issue just from the ‘smoke’, but if you have ‘smoke’ that might be steam, and it happens for longer than a few minutes on a cold morning, I’d be at least a bit worried. Typically you’d expect other symptoms as well with a blown gasket, but they may not show up until the problem worsens (if there is a problem). You at least need to verify whether this is smoke or steam.

The bearing sound is like a rumble. It's more evident on start up and then goes away, but you can still here it when free revving etc. From my memory, it didn't have that immidiately but it did come pretty soon. It's hard to say as when I first started driving it it had no muffler at all and engine noise was overpowered by the exhaust note. I really noticed this all once the muffler got fitted on. At the same time the tappets were noisy and I thought it was them makign that noise.
The builder says bearings are new, and he checked the bottom end for noise and it had nothing evident. I have a feeling though some parts that should have been changed weren't. Mainly rod bolts and head bolts. Otherwise though the heads were completely rebuilt, internals balanced, honed, new rings etc, and it was a complete strip down of the engine.
As far as big end or main end, I am unsure. It is a bearing sound but could be any bearing, I wouldn't have a clue.

Can you tell whether the noise is coming from the bottom or top of the engine? The cams run in plain bearings, they might possibly make a noise if bad? (though I have seen a cam bearing that was obviously loose, engine ran fine, bearing made no noise). Could it be an oil pump bearing? Or even a water pump bearing (different kind of bearing though)? What about the balance shaft bearings? Timing belt idler pulley bearing?? Some of these bearings obviously couldn't be related to slow pressure rise.

Bad big end bearings make a pretty unusual and unmistakable sound, heard it many times (doesn’t sound like loose tappets, tappets make a ‘tinnier’ sound, kind of ‘tappety’). A bad big end bearing makes a rapid and regular ‘knocking’ sound that speeds up and slows down with rpm (which makes perfect sense!). It can be quite loud, but not necessarily, and it’s loudness will probably increase with rpm and load.

It’s caused by the big end journal literally banging on the bearing shells (twice every revolution of the crank) because the clearance is too great for the oil keep the journal and bearing shells from metal to metal contact (the clearance doesn’t have to be large, just enough for the oil film to break down, and the clearance needs to be pretty close to prevent this).

On the other hand bad main bearings are much rarer, and I’ve never actually come across one (or heard one to my knowledge). Main bearings are far less stressed than big end bearings, why their failure is rare, the big ends usually go first. The noise of a bad main bearing has been described to me as a “rumbling sort of noise”, but ‘rumbling’ might be something else too.

I would think the most likely cause of main bearing failure would probably be oil starvation (could equally be an issue with big end bearing failure), possibly caused by a blockage in an oil gallery in the block (or in the case of a big end failure, in the crank itself, or, if there is a blockage in a block gallery, this could starve both a main and a big end bearing). This could occur as a result of inadequate cleaning prior to re-assembly (stray swarf or other dirt). Such a failure is most likely shortly or immediately after the sort of major work you’ve had done…?

If left for long (not very long!), the bearing shells will start to disintegrate and the particles will show up in the oil. If it hasn’t been happening for long then there may be metal to metal contact, but the shells may not yet have started to fall apart, and you might not (yet) see metal in the oil.

Things don’t ‘rumble’ for no reason, it might or might not be a bearing, it might not be a big problem, it might be a big problem. The business that performed the work does have an obligation (legal and ethical) to ensure you get what you paid for, it’s their responsibility to identify the cause and rectify it.

If you paid someone to do the work, then there is some sort of warranty, even if only an implied one. ‘Implied warranty’ does have legal standing, you don’t need a written guarantee. The receipt for work undertaken ought to be adequate, unless there is a statement on it that specifically exludes any warranty, implied or otherwise (though even in this case such an exclusion clause may not be legally valid, though ‘motor-sport use’ could possibly scuttle things…). However, you do want to deal carefully with the engine builder and come to an amicable arrangement, courts can be uncomfortable and time consuming places…

You can usually get away with re-using head and rod bolts etc with no problems, but it’s better not to and a definite no-no on a high performance / stressed engine.

I will have a look at the oil pressure warning light. With the bearing noise, the main loud one on start up goes away. It only makes that sound as the engine revs up to about 2.5K on initial start up and then the revs drop down. I know that if the engine is switched off, and then started again, it wont make that sound. It has to be off for a few hours before it does that sound again.

That’s just a bit weird! It crosses my mind that it might possibly be a partial blockage in an oil gallery? On start up it may take longer than it ought to for cool (thicker) oil to pass through a partial blockage, meaning that for a short while the bearing is starved of oil, but after a short while oil gets through in an adequate quantity?? With hot oil it might take less time for the oil to pass into the bearing and more oil will flow in, so the noise doesn’t occur?? This is all just speculation…

The loss in power, once again having no muffler on meant I couldn't really hear much of the engine. On the dyno it showed no pinging at all though, but also made no power at all. It topped at 81kw, though not sure if floored as the tuner told me once he heard the noise, he didn't push it. Either way 81kw is a joke, as the old engine before rebuilding did 112kw atw and that had no mods at all

My bet is that this is probably a partial throttle reading.

Thank you very much John for the help, I'll try and get as much info as possible and post back up more answers.
Just hoping it gets fixed ASAP

You must be finding it hard to sleep at night, you must outlaid a fair bit of cash on this, and it seems to be turning into a bit of a nightmare!

[JohnL]

As a reference for you, the OP idiot light on my CB7 goes out immediately the engine fires, which takes about two revolutions of the crank (at a guess, i.e it's pretty quick). And this is with a high KM motor (nearly 250,000km.), with a freshly rebuilt unit you'd expect it to be even faster. The OP light will be calibrated to go out at a pretty low pressure, all it's really telling you is that adequate oil pressure is actually present.

Thinking about the posssibility of a blocked oil gallery as I suggested in previous post, I'm not sure. This might explain the bearing noise but not the slow pressure rise. The oil pump, pressure gauge and idiot light will all 'see' a blocked passage as a 'tight' bearing clearance, and if anything this would tend to increase the rate at which pressure builds up. It doesn't fit with taking 10 seconds to see decent pressure on the guage.

Another thought (thinking music on), there might be a big clearance at a main bearing, meaning that pressure is leaking from the main bearing causing slow pressure build up AND a main bearing noise? This is implicit in some of my earlier thoughts on this , but I'm thinking it may have other implications, i.e. even if this isn't causing a main bearing noise, because pressure is (may be) being lost at the main bearing there may as a consequence be less oil flow to a big end as well, simultaneously causing a slow pressure build up (because of the main bearing clearance) and a big end bearing noise (because of starvation to the big end)?? Or, there might be a big clearance at a main bearing (causing slow pressure build up), AND a blockage in the crank gallery causing starvation to the big end (causing big end bearing noise)????

It's all quite strange really. More speculation; a big clearance in the main bearing might be caused by damage created by swarf / dirt, this swarf / dirt might then be carried through the crank gallery to the big end either blocking the gallery or getting into the big end and damaging that bearing as well???

[Limbo]

i think it would be easier to take it to the builder and ask him to explain. If he built the eninge he should know what is wrong with it. There should be some sort of warrant also. Don't waste your time, just take it back and get it fixed properly.

[JohnL]

i think it would be easier to take it to the builder and ask him to explain. If he built the eninge he should know what is wrong with it. There should be some sort of warrant also. Don't waste your time, just take it back and get it fixed properly.

What he said. Sort of like what I said, but without the technical conjecture!

[spetz]

Hey guys,

Well the car is at the mechanic as of yesterday. I was meant to call today but I completely lost track of time. Hopefully tomorrow I'll have a better idea of what is going on

As for a bit of an update on the car, I checked the idiot light, and it switches off as soon as the engine fires up? I thought it was weird...
Also, the noise coming from it has no specific pattern. The noise comes and goes on cruising every few seconds, but they are inconsistent variables, ie no pattern in the noise at all
The noise is pretty tinny sounding. I didn't pay too close attention where from though. That initial rumble sound is still there though on cold start up

Hopefully there will be some answers tomorrow I guess
Also, the car isn't supercharged, it's NA, and yes it is causing unbelievable headaches :(
I'm just wondering if everyone goes through this or just me.
On the bright side of things, from about 10 things being wrong (suspension, gearbox, driveshaft etc) now there is just the issue with the engine left and after that there aren't problems
But then I have to sell it to go overseas :(
Before I even get to enjoy the thing...

[JohnL]

Why did I think it was turbo? Must be confusing this with some other thread!

The idiot light going off almost instantly is a good thing, and what it should do. Still shouldn't take 10 seconds to see max pressure on the guage, maybe the guage is 'stiff'? It's a pity we can't hear the noises it's making, might (?) make diagnosis a bit easier!

Oh, it's just you, no-one else ever has such problems, God must hate you!

[Nepolian]

Was the oil pump upgarded?? Dodgy pump maybe pumpimg oil even though wont supply enough volume.

But on the other hand losing 30kw or so is alot of power and I would be putting it to the builder.

[spetz]

God must hate you!

Sometimes it really does feel like that :(

In fact it seemed to have lost power during the initial running in period
Though I didn't do anything wrong, I not once even came close to WOT, and I gradually raised the revs. Always warmed it up, always had a lot of 98 octane in it, checked the oil/fluid levels etc
The car was running slightly rich during this period, but there was no pinging or anything like that
I just hope everything goes ok and the problem isn't serious and is rectified completely

[JohnL]

Sometimes it really does feel like that :(

In fact it seemed to have lost power during the initial running in period
Though I didn't do anything wrong, I not once even came close to WOT, and I gradually raised the revs. Always warmed it up, always had a lot of 98 octane in it, checked the oil/fluid levels etc
The car was running slightly rich during this period, but there was no pinging or anything like that
I just hope everything goes ok and the problem isn't serious and is rectified completely

FWIW, if it were my car I wouldn't be driving it until it's sorted, unless I had absolutely no alternative. A loss in performance could be caused by internal friction, if so then things could go from bad to much worse very quickly and with little or no warning.

You poor bugger!

[spetz]

I'm not driving it, I trailered it down to sydney
I just drove it from the local mechanic which was supposed to fit and tune my e-manage and noticed the problem. That would have been about 10km if not less

As soon as the builder finds out what the problem was, I'll post it up here

[JohnL]

As soon as the builder finds out what the problem was, I'll post it up here

Please do, I'm facinated to find out what the problem is!

I'd be interested to find out; if you pulled the plugs and attempted to turn the motor by hand, would it be stiff? Might not be so might not tell you anything, but if something were to be tightening up enough to be affecting performance...?

[spetz]

Got a call from the mechanic
Cylinder #3 is "leaking" in a leak test
He's closed for a week now though :(

[JohnL]

Got a call from the mechanic
Cylinder #3 is "leaking" in a leak test(


Might explain poor performance, not the pressure issue though.


He's closed for a week now though :(

Don't you hate Xmas?! Still, only a week, could be worse!

[spetz]

A week is a week still :(
And being anxious and nerved up worrying about the car for even longer

[Riced_Civic]

bring it back from the dead...

just wanted to know if 1kg is 10psi so know thats im reading the oil pressure guage right

[spetz]

1kg/cm2 is 0.98 bar so about 14.5psi


By the way, the car had a stuffed conrod bearing and scarred the crank