Oil light, loud engine noise

[Yungog]

Well I'm having yet another issue with my cmax 1.6tdci.

Yesterday I was on my way to get my daughter from school and the oil light flickered on for about a second . thought nothing of it then it happened a second time.

Pulled over engine sounded louder and could hear a knocking noise. Checked oil level ,all was good.

Said feck it I'll look at it when home. 

On the way home the light came back on but stayed on.

Thought maybe because I hadn't serviced it yet,I usually do it at 6,000miles but was 7,000 miles since I last did it.

So gave it a service,oil and filter and air filter.

oil light now doesn't stay on,but noticed it takes a few seconds longer to go off now tho.

Engine noise is still there,sounds like tapping.

Now there's a bit of an oilly black liquid around the injector area and was told it may be a leaking injector. Its been there awhile since haven't gotten a change to do it.

Was told it would be OK.

Dreading it now as I've had plenty of issues with this car but always got them sorted straight away. Will kick meself if it fecks this engine over not servicing it bang on 6,000miles as I usually do or over a leaking injector.

Any ideas what this might be?

[TomsFocus]

oil starvation issues, usual DV6 issue...  The oil pump is probably full of sludge so it's not getting to the head which is causing the extra tapping.  The cam chain tensioner also uses oil so that could be causing a rattle as well.

The leaking injector adds to the problem (they should be fixed immediately tbh) but ultimately the oil ways are likely to be quite well blocked up inside now.  You could risk an oil flush but that could make the problem worse.  

[Yungog]

1 hour ago, TomsFocus said:

Oil starvation issues, usual DV6 issue...  The oil pump is probably full of sludge so it's not getting to the head which is causing the extra tapping.  The cam chain tensioner also uses oil so that could be causing a rattle as well.

The leaking injector adds to the problem (they should be fixed immediately tbh) but ultimately the oil ways are likely to be quite well blocked up inside now.  You could risk an oil flush but that could make the problem worse.  

Thanks tom.

What would cause the pump to be full of sludge? I know this engine has issues with oil and about servicing on time. I've always had serviced this at 6-7,000 miles.

Whats the best thing to do do you think? Get to the oil pump and clean it or replace it?

 

[TomsFocus]

Even servicing every 6-7k doesn't stop the problems unfortunately.  Have you owned it from new?  How many miles has it done?  The poor sump design means some oil is always left behind after an oil change, so the sludge builds up over time, made worse by diesel in the oil (short cold trips and failed regens if DPF model) and injector/EGR issues can add excess soot/carbon to it as well.   

Personally I'd recommend to drop the sump, clean that out, replace the oil pump, turbo oil line and then put an oil flush through - basically the same procedure as if the turbo had been replaced due to carbon issues. 

However, I've always said I'd just cut my losses and sell the car if mine gets the carbon issues while I've still got it - not worth the risk of lumps of carbon being missed by the engine flush and getting into the oil pump/turbo a week later - that's just my opinion though!

[isetta]

Not sure where the oil pressure light sensor is on these engines. eg. whether it is very close to the pump, before or after filter, or after some other oil ways that could get blocked.

On my brother's Audi TT it had a problem with the oil light coming on (meaning low oil pressure). this turned out to be caused by blockage in the oil filter. Mind you it had not had an oil or filter change for something like 50k miles. He never gets around to these things.  The oil filter is not a sealed canister on DV6 - did it look bad? - mind you I don't know if the flow goes from outside of filter to inner or vice versa

Over the years other problems I have had with oil light coming on have been caused by:

The end of the hexagonal oil pump drive shaft wearing to a circle so it did not turn the pump (Ford V6 3 litre). I do not know how the oil pump is driven on DV6.

The oil pressure relief valve spring breaking (Triumph TR7). Do all cars have such a spring? I would have thought so but don't know for sure.

I pretty much agree with what TomsFocus says

[Yungog]

Bit of late update.

Decided to tackle the leak on the engine.

Took the injectors out,they were all good.

So took the cambox apart and the chain tensioner  the piece of plastic that holds the chain tight had broken apart!!!!

So that would explain why the car was running like s**t and sounding like a tractor! I'm shocked at how it has kept running. This would explain the oil around the engine, it had caused an oil leak. Got a replaced and put it together. Sounded a lot better!

Now to tackle the oil pressure.

I replaced the pressure switch twice but did nothing.

So dropped the sump and found bits a metal in the sump,the oil strainer(I think that's what its called) had fragments of metal on the filter so must have been restricting oil flow. There's obviously some kind of bearing wearing. It seems when the plastic tensioner broke off pieces of it went to the sump and caused this.

Took it apart, cleaned the strainer, and the sump.

Put it back together.

Got two bottles of oil treatment ,put them in, put new oil in.

Car runs a lot better now,and no oil light 2,000miles later!!!