High mileage E91 - Low oil pressure
Discussion
Hello all,
My recently acquired 2010 E91 320I has developed a Low oil warning light issue amongst other Nox related prorblems.
The car has 164k miles on the clock and generally drives ok, with no engine rattles or stuttering issues.
Now, the other day the car threw an oil pressure warning light while driving (the red can without the waves) so I stopped and checked the oil level. All appeared fine so I carried on driving it home. I then hooked it up to an Icarsoft diagnostic computer which revealed the code 30CI (Plus 30EA and others) - This together with the 212 code from the onboard computer points to an oil pressure problem.
Now, this is where I get a bit confused. Using the Icarsoft to log real-time oil pressure data, the car peaked at about 5.5bar (80 psi) of pressure while driving and fluctuated between 1.25 (18psi) and 1.55bar (21 psi)at idle. These engines should idle at 1.5bar so it doesn't seem that far off unless the 1.25 bar is a problem, or the tool is useless.
I'm hoping for some advice or guidance before booking it in for a proper diagnosis.
My recently acquired 2010 E91 320I has developed a Low oil warning light issue amongst other Nox related prorblems.
The car has 164k miles on the clock and generally drives ok, with no engine rattles or stuttering issues.
Now, the other day the car threw an oil pressure warning light while driving (the red can without the waves) so I stopped and checked the oil level. All appeared fine so I carried on driving it home. I then hooked it up to an Icarsoft diagnostic computer which revealed the code 30CI (Plus 30EA and others) - This together with the 212 code from the onboard computer points to an oil pressure problem.
Now, this is where I get a bit confused. Using the Icarsoft to log real-time oil pressure data, the car peaked at about 5.5bar (80 psi) of pressure while driving and fluctuated between 1.25 (18psi) and 1.55bar (21 psi)at idle. These engines should idle at 1.5bar so it doesn't seem that far off unless the 1.25 bar is a problem, or the tool is useless.
I'm hoping for some advice or guidance before booking it in for a proper diagnosis.
Thanks.
I’ve done a search - most point to issues with oil starvation, perhaps from the pick up tube from the oil pan. Some even point to disintegration of the timing chain guides, that can break up and block oil pick up. I bought a mechanical pressure gauge to rule out a defective pressure sensor but the reading seem fine from the diagnostics and it’s a PITA to get to the sensor.
Another that I noticed this morning was a ticking sound from the engine - perhaps the lifters, but I’m not sure. The chain is tight as a gnats **** with no movements when accessed from the engine, although again I’m not sure whether there should be some play on the chain or not.
I’m trying to figure out the best course of action. I’ll top up the oil, but I’m at a loss thereafter.
Any advice on steps for a process of elimination would help. Or I’ll just take somewhere to tear it down and see.
Thanks
I’ve done a search - most point to issues with oil starvation, perhaps from the pick up tube from the oil pan. Some even point to disintegration of the timing chain guides, that can break up and block oil pick up. I bought a mechanical pressure gauge to rule out a defective pressure sensor but the reading seem fine from the diagnostics and it’s a PITA to get to the sensor.
Another that I noticed this morning was a ticking sound from the engine - perhaps the lifters, but I’m not sure. The chain is tight as a gnats **** with no movements when accessed from the engine, although again I’m not sure whether there should be some play on the chain or not.
I’m trying to figure out the best course of action. I’ll top up the oil, but I’m at a loss thereafter.
Any advice on steps for a process of elimination would help. Or I’ll just take somewhere to tear it down and see.
Thanks
It could be one of many things. It has the N43, widely considered to be the worst four cylinder petrol engine ever made by anyone. 164,000 is a very good innings if it the original. Coil, injector and NoX issues are just the tip of that little iceturd.
But, you need to drop the sump (engine lifted and subframe dropped) and inspect the pick up strainer for bits of lower chain guide. It will have broken up, I can pretty much guarantee you that. Continue driving it and you will destroy one or more big ends as the strainer picks up more bits of orange plastic.
At that mileage the balance shaft bearings will be worn out and leaking off a lot of oil pressure. Again, sump off, remove the balance shaft and oil pump and inspect it all. You should be able to find a good used one and there is a way of running it without balance shafts thus curing that drama. Basically, you remove the balance shafts and refit the housing with the oil feed blocked off. They run just the same without them.
Could be the electronic oil pressure solenoid behind the alternator. It could be a faulty thermostat so it runs too hot. This is the oil light flickering on at idle after a 5 mile drive but it shouldn't make any noise unless it's knackered.
Apart from that they're OK.
Alternatively, get rid of it and sharpish.
But, you need to drop the sump (engine lifted and subframe dropped) and inspect the pick up strainer for bits of lower chain guide. It will have broken up, I can pretty much guarantee you that. Continue driving it and you will destroy one or more big ends as the strainer picks up more bits of orange plastic.
At that mileage the balance shaft bearings will be worn out and leaking off a lot of oil pressure. Again, sump off, remove the balance shaft and oil pump and inspect it all. You should be able to find a good used one and there is a way of running it without balance shafts thus curing that drama. Basically, you remove the balance shafts and refit the housing with the oil feed blocked off. They run just the same without them.
Could be the electronic oil pressure solenoid behind the alternator. It could be a faulty thermostat so it runs too hot. This is the oil light flickering on at idle after a 5 mile drive but it shouldn't make any noise unless it's knackered.
Apart from that they're OK.
Alternatively, get rid of it and sharpish.
^^ Thanks for stepping and helping out, I appreciate it.
So I’ve had a look at the oil filter and all seems fine, so I replaced it along with the O rings while I was in there. With the oil cap off you can see the top of the chain guide (pink coloured) and the chain is taught, immovable, so I’m guessing that part of the lower chain guide must have broken off and is blocking the pick up tube thing, which may result in intermittent oil starvation.
I drove it to Stanstead airport the other day - 100 mile round trip. No oil light, no issues, but the 30C1 oil pressure static code is still there.
The car is parked up for now, but Im thinking my next step should be to replace the chain, chain tensioner and drop the pan and clean it all up. There are companies on eBay quoting £500 to do the job so I might go down that route.
It would be easier to just sell or px it, but Im not into that sort of thing, so I’ll try and fix it and/or drive it until it gives up the ghost and sell as is.
So I’ve had a look at the oil filter and all seems fine, so I replaced it along with the O rings while I was in there. With the oil cap off you can see the top of the chain guide (pink coloured) and the chain is taught, immovable, so I’m guessing that part of the lower chain guide must have broken off and is blocking the pick up tube thing, which may result in intermittent oil starvation.
I drove it to Stanstead airport the other day - 100 mile round trip. No oil light, no issues, but the 30C1 oil pressure static code is still there.
The car is parked up for now, but Im thinking my next step should be to replace the chain, chain tensioner and drop the pan and clean it all up. There are companies on eBay quoting £500 to do the job so I might go down that route.
It would be easier to just sell or px it, but Im not into that sort of thing, so I’ll try and fix it and/or drive it until it gives up the ghost and sell as is.
Me again, still looking for help and/or guidance - don’t be shy folks.
So I’ve had a chat with a mechanic this morning, who suggested that I scope the pressure sensor before going down the timing chain replacement. His opinion is that there’s no way these engines could last 164k miles without a timing chain replacement, so it’s perhaps on a replacement chain already.
Now, I’ve got a mechanical pressure gauge and a multimeter. The question is, what is the easiest and least complicated way of accessing the sensor on one of these engines? From my research it looks like a real faff. Has anyone replaced one that can guide me?
So I’ve had a chat with a mechanic this morning, who suggested that I scope the pressure sensor before going down the timing chain replacement. His opinion is that there’s no way these engines could last 164k miles without a timing chain replacement, so it’s perhaps on a replacement chain already.
Now, I’ve got a mechanical pressure gauge and a multimeter. The question is, what is the easiest and least complicated way of accessing the sensor on one of these engines? From my research it looks like a real faff. Has anyone replaced one that can guide me?
I’m still wrestling with this issue so any guidance or pointers welcome.
I’ve since changed the oil and filter - no metal shavings or anything odd in the oil. What is strange however, is that the oil level doesn’t appear to be reading accurately. Before I changed the oil, the onboard computer was showing ‘OK’ and 3/4 full. My diagnostic tool showed that it was half full. I’ve since carefully measured 4.25 litres of oil but the levels haven’t changed, so I’m guessing there’s an issue with the oil level sensor. The question is, would a defective oil level sensor affect the oil pressure sensor, which continues to read 1.5bar at idle?
I’ve since changed the oil and filter - no metal shavings or anything odd in the oil. What is strange however, is that the oil level doesn’t appear to be reading accurately. Before I changed the oil, the onboard computer was showing ‘OK’ and 3/4 full. My diagnostic tool showed that it was half full. I’ve since carefully measured 4.25 litres of oil but the levels haven’t changed, so I’m guessing there’s an issue with the oil level sensor. The question is, would a defective oil level sensor affect the oil pressure sensor, which continues to read 1.5bar at idle?
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