Low oil pressure. Wanting to fix

[Noxangelus]

I've got a 2.8 Mu 1992. It has done only 160,000km, I think previous owners have not changed the oil on regular basis as I think theres alot of sludge build up. I think theres sludge build up because when I check the dipstick after the car has been warmed up and shut off for a few hours the oil is still way over the fill mark. Though in mornings its at the line always. I've had another 2.8 Mu and it never took this long for the oil to collect at the bottom, and the dipstick indication was more accurate after it had been running. Also when putting oil in seems to take awhile before finding the dipstick and re-checking the dipstick can give different levels.. I wish I knew more about engines

Theres also a hammering sound that comes and goes on idle which has recently started, I'm not sure what is wrong with my car as i'm no expert.

The pressure on cold is 4 when reved and idling sits at 2, once its very warmed up reving it shows 2 and idle is 0.5.

I was hoping to get some advise about taking off the sump cover and cleaning out the strainer? I've seen the thread where someone had low oil pressure and cleaning out the sump helped.

Thanks

[geeves]

That pressure is low so cleaning the strainer and a oil flush could be worthwhile. Be very careful with this though as sometimes flushes can dislodge goo causing blockages in the turbo etc. I will let someone that has done this tell you any tricks. Bad oil pressure and bad oil changes are both very bad for this engine and scored bores and bearings could occur.
The hammering noise could be a bad bearing which could also cause bad oil pressure but the optimist would try spraying a little water on the fan belts first as worn fan belts can also make this noise.
I would also be suspicious of that mileage. When was the last road users bought?

[Noxangelus]

Ahh ok, my fan belts have been slipping when cold for the last month. Would any damage occur from this? The sound comes from the top of the engine block at the firewall. And about the flush I've already done one engine flush and it did help the pressure reading a little, also the pressure builds up faster now once the engine is started. But it still needs alot of improvement. The RUC is legit, at least it appears to be, only bought the car in feb.

[geeves]

A common taletell is to look at the date on the ruc sticker. If the speedo has been disconected the ruc will show that it was bought far longer ago than one would expect. Ive seen cars where a 5000km ruc was bought 5 years ago and still has 4000 to go but the car has recent tyres with plenty of wear.

[kcsoft]

viewtopic.php?f=23&t=2235

[mudslinger]

pull the sump off check the sump for sludge, even take the oil pump out and check the teeth clearances and check if they are in tolerance and go from there, maybe fact gauge is playing up try a after market or get a mechanic to hook up a guage and get to take for a drive. process of elimination really

[kcsoft]

i'd flush it first... it's cleaner and you'll eliminate most sludge. just be prepared to let it drain for a few hours.

[Noxangelus]

Well I discovered after taking off the strainer and blowing it out that it was clogged with red gasket bits and lots of aluminum flakes. The sump cover has been damaged and the paint has flaked off inside, but there is too many flakes to all come from the paint of the sump.
The pressure has improved only by 0.5 and seems more clogged as under rev it will only raise by 1cm. It now starts badly when cold, it takes me 3 trys to get it started and it will stutter like its not getting diesel until I give it abit of pedal. The pressure comes up faster than before and on the terrible cold starts it raises to 4 on normal idle.

After its at normal operation temperature it still runs at 2 under rev and 0.5 on idle.

I'm thinking theres another build up of the flakes somewhere, maybe in the oil pump? Are they as easy to take off as the strainer was, and does the pump have another filter where it could be clogged up.

I also did a flush and changed the oil and filter in the process of cleaning the strainer.

Thanks

[turnturn]

Like Mudslinger said above, you also need to eliminate the gauge from the equation.
Hook up an after market gauge and see what it reads.

[geeves]

Was it aluminium or white metal? Bearings are a aluminium/tin alloy. Only place aluminium could come from is the sump if the crank was hitting it.
Red gasket bits should not be there either
Dont sound good

[electrifying]

i believe that there are two restrictors/flow control valves somewhere next to the oil filter, they have very small holes in them, you could try un-bolting one of them (the location is in the engine manual, it's like a large bolt thing).
& no, the pump is not that easy to get off. from what i know (after attempting to take it off) you have to pull the whole sump off to get at it.
Perhaps try & eliminate other easier things first.

Also, make sure that the strainer is well cleaned out, as i had to clean my one with an air gun & push the mesh stuff back a bit to allow the oil to flow through the mesh better. (when it clogs up the mesh shifts & gets pushed up against the exit hole, then you have much less surface area for the oil to flow through, unless you push it back to it's normal position.)