C5 1.6HDI 16V,LOW OIL PRESSURE,Anyone any ideas?

[crosser69]

bought a high mileage c5 1.6 hdi 16v.
drove it 30 miles and warning low oil pressure buzzer came on,stopped the car,checked the oil and oil was ok but looked a little black.
startted it up and sounded tappety,got it to a service station on the m6,rac came out and just had a quick listen and said yes does sound like low oil pressure and that was it,has anyone any ideas if these suffer from blocked pick up pipes or oil pumps,engine sounded mint before i set off and ive never had any problems with c5 or any diesel engine before

[spider]

I don't know anything really about this unit but if its making noise its not that good. (as apposed to a faulty pressure switch)

My first thought is examining and replacing the oil filter along with whipping the sump off to check the pickup pipe / strainer.

Quite why its failed though I am not sure (well failing) I know the pumps can wear but I've not heard of one going to that extreme.

How many miles are we talking here ? 300+k or so ?

[crosser69]

its done 292k but it drives mint,it does not sound bottom ended,more like its starving itself at the top end of oil,thats why i thought i would ask before shoving my head further in to getting my hands dirty,just wondered if anyone had come across it on the 16v hdi engine,do they have a pick up pipe from the sump? i am working more or less completely in the dark.

[coastline taxis]

Try changing the oil and filter. As when oil heats up it thins out maybe put a adative in. make sure you put a good oil in with that kind of milage on it (magnatec)

[crosser69]

its done 292k,but engine sounded mint and apperently had no other problems.top end sounded dead tappetty so looks like i will try oil and filter first with some engine flush and then prob drop the sump off to look at pick up pipe to see if anything is wrong there

[CitroJim]

a 1.6HDi in a heavy car that's done nearly 300K is going to be a tad worn. It will have worked hard.

In addition to what coastline has said, put a can of Wynns oil additive in with the new oil. It really worked in a worn engine i once had that knocked on startup. use a grade thicker oil too. Say 15W/40 rather than 10W/40.

The Wynns kept the engine soldering on for another 20K or so before the car died for unrelated reasons. When it started knocking again I knew it was time for an oil change!!!!

[Kowalski]

a 1.6HDi in a heavy car that's done nearly 300K is going to be a tad worn. It will have worked hard.

In addition to what coastline has said, put a can of Wynns oil additive in with the new oil. It really worked in a worn engine i once had that knocked on startup. use a grade thicker oil too. Say 15W/40 rather than 10W/40.

The Wynns kept the engine soldering on for another 20K or so before the car died for unrelated reasons. When it started knocking again I knew it was time for an oil change!!!!

I'd agree that 300k is quite a bit of mileage, the 1.9TD and 90/110 bhp 2.0 HDI can cope with that mileage with ease. The 1.6 on the other hand is new and because its new we haven't seen lots with high mileages, so we couldn't tell you whether it'll cope with 300k miles OK or not.

A 15w40 oil will only be thicker than a 10w40 oil when it is cold (first number), once warmed up it will be the same viscosity (the second number i.e. 40). A 10w50 / 15w50 / 20w50 oil would be thicker once warm.

Your engine oil pressure can be low for a few reasons, one is that there is a blockage in the oil system, e.g. oil filter or strainer. Another is that your oil pump is worn and not able to pump oil efficiently. Yet another is that the engine is worn and all the bearings have worn and opened up so that the oil flows freely out of them. One more reason is that your oil is too thin, e.g. if it's been diluted by diesel leaking into it.

Check / change what you can, e.g. oil, strainer, filter, pump etc. If there is low oil pressure and you can't find the cause it might be time to swap engines. It's done bad things to the engine once and it'll do those same bad things again if you can't sort the oil pressure out. If you can find and fix the cause of the low oil pressure, perhaps a new head will sort things out, assuming that the wear is limited to the top end of the engine.

[Citroenmad]

I think some of the 1.6HDis are on long life servicing? So every 20K instead of every 10/12. Thats not great.

There is reports of the 1.6HDis going through turbos, this has been put down to small oil piping and long service intervals. The oil starvs the turbo of oil and it overheats. So its possible that yours has a blockage elsewhere which is causing the problem.

The 1.6 might seem a small engine, however it has the same power output and only very slightly less torque than the near bomp-proof 2.0HDi 8V. Given that most car makers are giving their cars ever smaller engines which offer similar power outputs to larger units, its somehting we are going to have to get used to.

Though the mileage on your car is impressive and it could well be worn.

Id change the oil and filter first, make sure you get the specific type and grade of oil, as the 1.6HDi is a bit fussy on oil. I always get oil from the dealers to get the correct one, its worth it and not very expensive. Id then see if that improves things. Next i would use a engine oil flush, such as Forte Flush - the only thing id ever recommend as other flushes dont have lubrication like this one, not somehting your cars needs! - run the engine for a while with that in and change the oil again. Ive used Forte Flushes on 1.6HDis before, it really does a good job of cleaning and the oils stays cleaner much longer.

After a flush i find 2.0HDi 8Vs keep their oil clean for a good while, usually up to 1000 miles before it starts to go darker. The 1.6HDi and 2.0 16v HDi seem to dirty their oil very quickly, even after a good flush.

Forte also do a range of other products, something like top end treatment might be a benefit to your car. For the price of a bottle rather than a costly engine repair it might just be worth a go.

Hopefully that will help things. Let us know how you get on, its interesting to see what a 1.6 is potentially like with high miles, as there has been few reports on here.

[crosser69]

thanks guy,im getting the car back tomorrow so will nip out and get a new filter and some decent oil and oil flush and see what happens

[crosser69]

Car fixed,was a blocked strainer in the sump,apprently they are prone for it because of the longer servicing

[jgra1]

good in the nick of time I think !

[jgra1]

I was googling oil pressure and came across this thread

I have half of one eye on a c5 HDI 2.0 16v 160hp with the suspected same fault..
it's a long way away, but it would make a nice upgrade for me, but I wonder if it could be more hassle than it's worth.. (only 120K)

What did PSA do to the 16v 2.0 to get it to 160hp? I guess I am asking if a 138 bottom end or block may go in to replace the original broken engine? but with the newer ancillaries etc.... probably not..

John

[RichardW]

There's a known issue on the 2.0 with the oil pumps failing, rather than the 1.6 where the sump strainer just blocks up with crud. I think the oil pump is 'conventional' in the sump (rather than the 1.6 where it is concentric with the crank shaft so needs the cambelt stripping off to replace). If it's cheap, and otherwise OK, it might be worth a punt to stick a new pump in it and see what happens. No idea what, if any, the physical differences are on the 138 vs 160 versions.

[jgra1]

Richard many thanks for that.. I may go for it.. its the right spec and the engine I wanted (after the hen's teeth v6 3.0 Hdi)
I will keep digging on the differences..

John