Oil Pressure

[CHRI1111]

I may have done something stupid yesterday.

I had the care jacked up and on an axle stand to one side so I could remove the front exhaust and cat. Whilst it was jacked I plugged up an oil pressure tester and ran the engine as I was receiving the low oil pressure warning light.

Upon a cold startup and at idle it read 0.5 bar. After a couple of minutes it dropped to zero. I could only get a slight reading if I revved the engine.

Could it be that jacking the engine on the drivers side only had moved all the oil in the sump away from the pick up tube - and that the initial 0.5bar was from what was left in the system at the time?

Is 0.5bar at cold and idle low?

PS I've already changed the sensor, oil filter and performed a couple of engine flushes. The pressure light was still showing which is what led me to testing the oil pressure.

Chris

[Magnet]

Hello Chris, 

0.5 bar = approx. 7 psi. Expected normal psi on start up with a cold engine would be at least 50psi (3.5 bar). 
There is something seriously wrong here, and if it were mine, I would not run this engine. (In caps). 
History of car? How long have you owned it etc. 

Seriously doubt it has anything to do with jacking on one side. 

Kind regards,

Gareth. 

[CHRI1111]

Hi Gareth,

The low oil pressure warning light started to show intermittently 12 months or so ago. It would come on, then turn off for periods at a time. I assumed it was an electrical issue with the sensor and have carried on driving it to this day.

Obviously can see now I shouldn't have done this!

I changed the oil filter, sensor and did two engine flushes recently with correct grade oil. The engine light went for a little bit but has now reappeared. It doesn't seem to be dependant on driving style or revs.

Should I drop the sump to check the oil pump?

[Magnet]

Thanks Chris,

I fear ignoring this issue over a year of use, is regrettably the cause of both issues, and OK pessimistically, simply rectifying the oil pump issue isn’t going to rectify the damage already caused. 
Sorry for that opinion. 
Kind regards,

Gareth. 

[CHRI1111]

Presumably if I replace the oil filter and this resolves the oil pressure issue, although the compressions are low, it will still function albeit lower on power?

[Magnet]

But you have already changed the oil filter without improvement. 
Function is the operative word! 

[CHRI1111]

Sorry I mean oil pump!

[Magnet]

Thanks Chris. The horse has already bolted, but…

[CHRI1111]

ThanksGareth, I've give it a go.

What's your view on the compression numbers? Low but not terrible...?

Are there any oil pump brands I should stay well away from? I want a budget option but not one that will break next week...

Ridex, stark automotive, magneti marelli, engitech, NTY, Freccia, JPN, Vaico, FAI Autoparts, JapKo, Ashika, Febi Bilstein, PartsTec, Swag, ET EngineTeam?

Any of those?

Genuine part is £250 which I can't justify on a car with 150K miles and 18 years old.

Chris

[Magnet]

It l looks like you are searching Autodoc/ECP. 

If it were mine I would discount everything except Febi.

Check out Parts in Motion for great service at competitive prices. Well worth checking their eBay listings for the correct part- often a little cheaper than buying the same part off their website.

Let us know what you come up with Chris. 
Kind regards,

Gareth. 

[CHRI1111]

Many thanks

[cliffcoggin]

Forgive me butting in Chris but you seem to be turning a blind eye to Magnet's strong hints about the state of your engine, so let me be more forthright.

Running the engine for a year without adequate lubrication has spoiled the piston ring sealing in the cylinders as your compression figures clearly demonstrate. (Incidently that's likely to mean the big end and main bearings are also clapped out.) No amount of new oil pumps are going to restore the rings and bores, so there will be exhaust blow past leading to smoke, high emissions, blocked exhaust and MOT failure.

I fear you have left it to late to save that engine.

[Stevey Y]

2 hours ago, CHRI1111 said:

ThanksGareth, I've give it a go.

What's your view on the compression numbers? Low but not terrible...?

Are there any oil pump brands I should stay well away from? I want a budget option but not one that will break next week...

Ridex, stark automotive, magneti marelli, engitech, NTY, Freccia, JPN, Vaico, FAI Autoparts, JapKo, Ashika, Febi Bilstein, PartsTec, Swag, ET EngineTeam?

Any of those?

Genuine part is £250 which I can't justify on a car with 150K miles and 18 years old.

Chris

Hi you say the compression figures were low, as in how much lower than the figure quoted for ideal?, most oil pressure systems put on the light when the pressure drops to 4psi if it sinks any lower you will hear the big ends knocking, either way it wont do it any favours as Gareth said driving it like that, rather than lashing out on a new oil pump it will be better to drop the sump and remove the the caps on the crank one at a time and check that the big end shells are not scored or excessively worn if you do the first one and they are scored or the crank journal has scores dont bother with rest of them as you can guarantee the rest are the same or worse, in this case either get a refurbished engine or have your unit reconditioned with a new oil pump, personally I never use anything other than O.E. pumps and if you use reverse logic, if the original pump has managed 150k there is no reason why it wont do it again.

Steve.

[CHRI1111]

Hi, it made no noises at all. I would have stopped for sure otherwise. Seemed to run fine just with the oil pressure light on which led me to suspect faulty sensor at the time.

Il take the caps off and take a look as was going to drop the sump anyway for the oil pump.

I suppose what's still unclear in my mind is whether the piston rings are likely toast based on the compression readings previously given. The readings vary between 10 and 11 with exception to Cylinder 4 which is between 9 and 10. Can I get away with such readings for MOT purposes? Sorry, bit confusing as the compression readings are in another recent thread.

Chris

[Stevey Y]

11 minutes ago, CHRI1111 said:

Hi, it made no noises at all. I would have stopped for sure otherwise. Seemed to run fine just with the oil pressure light on which led me to suspect faulty sensor at the time.

Il take the caps off and take a look as was going to drop the sump anyway for the oil pump.

I suppose what's still unclear in my mind is whether the piston rings are likely toast based on the compression readings previously given. The readings vary between 10 and 11 with exception to Cylinder 4 which is between 9 and 10. Can I get away with such readings for MOT purposes? Sorry, bit confusing as the compression readings are in another recent thread.

Chris

Hi the compression readings should be between 140 and 175psi with no more than 10% variation between each cylinder, if its running rough I would seriously get it plugged in to see what else is wrong before throwing any money at it, dont get it done on a mates cheap code reader thats suicidal it either wont pick up true faults or pick up generic codes that dont relate to anything.

Steve.

[CHRI1111]

So the compression readings are:

Cylinder 1: 9.5 bar

Cylinder 2: 9 bar

Cylinder 3: 10 bar

Cylinder 4: 9 bar - although it seems take take a couple more cranks to get there.

You mention a minimum compression of 140 psi although Haynes suggests 11 bar. If it is 140 psi (9.6 bar) cylinder 3 is within tolerance only. If its 11 bar all cylinders are outside of tolerance.

Although readings are low none vary by more than 10%.

I'm going to inspect the big end bearings. Is it possible to remove the piston and connecting rod assemblies from the sump, as I don't want to have to remove the Cylinder head?

Chris.

[Magnet]

Hello Chris, 

Saying it as it is:- 

The patient has been diagnosed with a serious heart complaint, and as a result, more organs have been damaged to a life threatening extent, and you are fussing about relatively minor detail of slightly low compressions etc. The engine is almost certainly damaged to an undesirable extent and you now want to do fairly major dismantling to try to find out that extent. 

I think it’s worth you just leaving this well alone except buying a new oil pump and sucking it and seeing, or decide not to throw anymore good money after bad -at this stage - when you should have taken notice some year (or more?) ago when the oil pressure warning was doing its best to let you know. 
For goodness sake just fit a new oil pump, assume the worse and hope for the best! 
Kind regards,

Gareth. 

[daveyboy1967]

Reading this reminds me of a girl I knew nearly 40 years ago who stuck a piece of chewing gum over her oil light because it was annoying her being on all the time. That ended well too...

[CHRI1111]

I wish I'd have thought if that.