[karlb]

Hi there, have been investigating an "Oil pressure insufficient" warning for around the last month, my old thread for this was here but I thought I'd make a new thread with a much more detailed description of the problem and everything I've tried so far, just to get all of the details in one place rather than having to read the whole thread.

Car is a 307 S Diesel HDI 1.4L 2003 with 155k miles on the clock.
Engine starts up fine with no funny noises or warning lights. After about 5-10 mins of driving, the dashboard begins to beep 3 times, usually with no warning message or light to start with. It will beep 3 times and then pause for around a minute or so and then beep another 3 times, but as the engine warms up, the pause in between the beeps gets less and less until it is more or less beeping constantly.

After a few minutes of beeping, a warning message starts to flicker up where the radio is, saying "OIL PRESSURE INSUFFICIENT" and the oil light on the dashboard flickers. When the message first shows, it will only flash for a split second, not even long enough to be able to read the message and then it will wait a while before it flickers again, but again as the engine warms up, the flickering gets more rapid and eventually it will stay on more or less constantly.

It has been taken to a garage who have done an oil change, replaced the oil filter, fitted a new oil pressure sensor and oil temperature sensor. They have tested the oil pressure with a gauge and it was 3.5 bar, which apparently is very good. Although I'm not sure if they did this test while the engine was hot or cold. If they did the test when it was cold then that might not be indicative of what the pressure is when it's hot. From this page, I've read that the oil pressure is higher when you first start a cold engine and then begins to get lower as it warms up, because the oil gets thinner and it can slip through the bearing clearances more easily.

It seems like there are either two causes:
-Oil pressure is actually fine and it's just the electronics that are faulty (can only be ECU or wiring as the sensors have been replaced).
-Oil pressure is actually insufficient but the garage tested the engine while it was cold so didn't get a correct reading.

It's worth noting that the diagnostics software the garage has gave the error as: "Oil temperature sensor reporting incorrect value", which seems strange as the sensor has been replaced. I'm thinking that maybe it's getting the codes mixed up between oil pressure and oil temperature? I've also read that a faulty coolant temperature sensor may give this error as well.

The people at the garage have been really helpful, but they have said that honestly they have no idea what to do next. They say that doing a full test of the electronics is beyond their capability, and even if I took it to a more experienced garage then a full electronics test would be very expensive.

I've taken the car back as it is, and it drives fine, but I need to fix it soon for 3 reasons:
-The beeping is extremely annoying
-If the oil pressure truly is insufficient then this will damage the engine
-I'm assuming that it will fail an MOT like it is (which is due in a couple of months).

The only idea I have next would be to get it up on some ramps, drain the oil, take the bottom off of the sump and give anything I can see a thorough cleaning with an old toothbrush to get any sludge out of all areas such as the oil pickup screen.

Is this worth doing, and does anyone have any other ideas at all what to do?

Would appreciate any help as this has been a really aggravating problem for the last few weeks.
Thanks

 

[daedric]

Question, on the original thread, you stated:

Car has done 155k miles and it is a 2005. Engine is 1.4L diesel.

Now you state that:

307 Diesel 1.6L 2003 with 155k miles on the clock.

I'm not sure if there were 1.6HDi in 2003, but anyhow, the 1.4Diesel is quite diferent from the 1.6Diesel.

Clear this one out before we continue...

 

[karlb]

Yes sorry, got the year wrong on the original post and the engine size wrong on my last post. Will edit and correct my last post.
It is definitely a 307 S HDI 1398cc 2003

 

[Dave_P]

Maybe time to find a local planet owner who could look at the bsi history and then observe the live data untill it plays up.

Of course sods law says that the

beeping, a warning message

won't happen :nod:

 

[karlb]

Yes, If anyone around Leeds, west yorkshire has planet then I'd be very grateful if they could help. Will drive to your location and be happy to give a small payment for your services.

I did go though the diagnostics software that the garage had but it wasn't peugeot planet, it was one of these softwares that could do pretty much any make and model, but it seemed not very good. I wouldn't be surprised if it had some of it's codes mixed up. I couldn't find the option to look at the bsi history.

Like I said, the garage did manage to make it display the error: "Oil temperature sensor reporting incorrect value" (or something along those lines), but the next day when I went to have a further look in order to write down the actual code, I could not get it to bring the error back up.
I was actually scanning whilst the dashboard was displaying "OIL PRESSURE INSUFFICIENT", and at the same time, the software was just displaying "No codes present" !! Kept scanning and even reset the connection a few times but no codes!

 

[daedric]

From what i understand, cables and software read error codes from ECU, but they only get the P1234 code. After that, they lookup the code either on a local generic table of codes, or a online one. YMMV
So, P1234 might be "Oil pressure insufficient" on generic code reader, but actually be "Oil pressure insuficiente or jumpered to live" on PP2k.

Only PP2K can access all ecus and get reliable LIVE data.

Question, you say that the car only makes this when HOT. If you park the car, and wait 10 minutes with engine off, and retry, does it take as long to popup errors or it's just as fast ?

What oil was used to fill it ?

Is the oil level stable ?

Is the coolant level stable ?

Is there a visible leak somewhere on the engine ?

Can you relate frequency of the oil light and the error to anything you do the car ? Like accelerating, or braking ? Maybe only when turning left and braking, or right and acelerating ? Maybe only on a certain RPMs ? Perhaps only UNDER 1800rpms....

Take a good lock at the BSI and BSM, do you see anything that might have been a water ingress ?

Take the oil filter off (carefull with spill) , see if there's a little cross in the middle.

 

[karlb]

From what i understand, cables and software read error codes from ECU, but they only get the P1234 code. After that, they lookup the code either on a local generic table of codes, or a online one. YMMV
So, P1234 might be "Oil pressure insufficient" on generic code reader, but actually be "Oil pressure insuficiente or jumpered to live" on PP2k.
Only PP2K can access all ecus and get reliable LIVE data.

Yes, this is why I was unsure how reliable the message was that the code reader gave at the garage. It may be getting the right error code but what it then looks up in it's own table may just be useless and not indicative of the real problem.

Question, you say that the car only makes this when HOT. If you park the car, and wait 10 minutes with engine off, and retry, does it take as long to popup errors or it's just as fast ?

If the car is hot, and then I park it with engine off for 10 mins and then retry, the error comes on more or less straight away. The engine doesn't cool down much after being parked for 10 mins, so this would indicate that it is correlated with temperature rather than time.f

What oil was used to fill it ?

It was 5w40 fully synthetic. Gave halfords my number plate and this is what they recommended after looking it up in their database.

Is the oil level stable ?

Yes, has been stable for the last 3000 miles or so.

Is the coolant level stable ?

Yes.

Is there a visible leak somewhere on the engine ?

Not any that I can see.

Can you relate frequency of the oil light and the error to anything you do the car ? Like accelerating, or braking ? Maybe only when turning left and braking, or right and acelerating ? Maybe only on a certain RPMs ? Perhaps only UNDER 1800rpms....

I don't really notice any correlation between how I'm driving and the frequency of the error. To be honest, once it has warmed up to a certain temperature, the message and beeping will be absolutely non-stop no matter what I do, even if I'm stationary and the engine is running it will still carry on beeping and flashing until the engine is turned off. (Although the Oil pressure insufficient message seems to flicker like a lightbulb that has a loose connection. But the flickering doesn't correlate with anything I'm doing).

Take a good lock at the BSI and BSM, do you see anything that might have been a water ingress ?

I'm unsure what BSI, BSM and water ingress means?

Take the oil filter off (carefull with spill) , see if there's a little cross in the middle.

I will do this at the weekend when I have the time. Do I need to drain the oil before taking the filter off?

Thanks for your help.

 

[daedric]

You might have a drop of pressure (or lack of it) between the place where they measured the pressure and where the sensor does.

There are reports around the web that pressure release valve in the oil filter can be stuck opened. When the car is cold, the oil has more viscosity and the sensor gets it's pressure, but as it warms up, the oil thins and the pressure drops.

 

[karlb]

I thought that the oil pressure gauge screwed into the hole where the oil pressure sensor does? so it would be measuring from exactly the same place?

Is the pressure relief valve the cross thing inside the oil filter? I will have a look at this tomorrow.

Cheers

 

[reliable406]

Pressure relief valve is inside the oil pump and we had a 1.6 doing the same thing checked all the same stuff and came to the conclusion that the pump was pumping oil but was tired and can no longer pump enough when hot.

We were going to investigate further but then the gearbox decided it wanted to be in 3rd gear permanently so we just replaced whole engine and box

 

[wynb]

The valve in the oil filter is a one way valve to stop oil draining back into the sump when the engine is not running so when you re-start there is still oil at the top of the engine. Pressure releif valve is a completely different animal!
I would bite the bullet and remove the sump so the oil pump & strainer can be examined.

 

[daedric]

I was under the impression, oil filters were designed so that IF the oil demand is above a certain value, the valve would simply open and let unfiltered oil pass through.

Most pressurized lubrication systems incorporate an overpressure relief valve to allow oil to bypass the filter if its flow restriction is excessive, to protect the engine from oil starvation. Filter bypass may occur if the filter is clogged or the oil is thickened by cold weather. The overpressure relief valve is frequently incorporated into the oil filter.

 

[karlb]

we had a 1.6 doing the same thing checked all the same stuff and came to the conclusion that the pump was pumping oil but was tired and can no longer pump enough when hot.

That makes a lot of sense. How many miles had the car done at this point?
I've checked with the garage and they say that they tested the oil pressure when the engine was hot, so I'll take their word for it, but I am open to the idea that there's a small possibility they made a mistake in their testing.

I would bite the bullet and remove the sump so the oil pump & strainer can be examined.

Yes, I will get the car up on ramps tomorrow, remove the sump and inspect everything, as well as give the strainer / pickup screen a good scrub with an old toothbrush to remove any sludge buildup.

 

[wynb]

Could be wrong, but I don't think modern cartridge filters have this blockage by pass facility.

 

[daedric]

They do... almost sure.

 

[Dave_P]

Repeating the oil pressure test (cold / warm / hot) may be easier and a lot less mucky

 

[rustyroger]

It's the oil pump that has the blocked filter relief valve incorporated. And nearly all pumps still have this, any oil is better than no oil, but anyone who keeps up with maintenance should never experience this.
3.5 bar pressure when cold is fine, 2.5 bar above idle speed with a hot engine is what to look for.

Roger.

 

[karlb]

Sump almost off. All bolts loosened. Took several hours as some were in a very tight and awkward position.
Will report back in a few hours. I'm expecting to find a lot of sludge and gunk, given how old the car is.

 

[karlb]

Took off sump and removed oil pickup pipe and screen. The sump and pickup pipe were not as dirty as I thought they would be. There did not seem to be any blockage of the pickup screen or pipe. Gave the sump, pickup pipe and screen a thorough cleaning anyway and then fitted back to the engine.
Couldn't inspect the pump, it seems that it is further up in the engine rather than being partially inside the sump like some other cars.

Put oil back in and restarted car and went for a test drive. The error still shows . It has not helped at all. In fact, the error came up only within 2-3 minutes of starting the engine. I drove it for about 15 mins to make sure but it would not stop beeping. Although the engine runs fine and quiet.

I am out of ideas for what to try next. It seems that the only thing left that it could be is faulty wiring? What do you guys think?

 

[hartjon]

Hi there.
Any joy with this? I've had an identical issue and chucked hundreds at it and still no joy.
Changed the pressure sensor, the sump filter, oil changes, etc.

Thanks.