oilpressure drop

[tylex]

Hi!
My question is,could knock cause a broken main/rod bearing?I ask because yesterday i drove the ty for about 80 miles and i had a few times a knock retard of max. 5-6degrees and now i think the bearings are worn because the oil pressure is not so high as before and when i turn the engine off the oil pressure is gone!Before that the engine holds the pressure for a longer time till it drops to zero.The engine and bearings have only about 3000miles on them.Oil temp and pressure was always okay till then.
Thanks in advance,
Alex

 

[Quickstop [UK]]

Re: oilpressure drop

It's possible. Check your oil filter by cutting it open and seeing if you have any flakes in there. A brief spell of 5-6 degrees doesn't sound too bad, might be something else.

You say 3k miles on the engine so I wonder if you have a new oil pump? There were a batch of high volume Melling pumps that had a weaker casting and were highly prone to failure. Yours might be on it's way out, working but cracked at the stem thus bleeding pressure when off.

Just one idea, others will chime in

 

[tylex]

Re: oilpressure drop

Yes its a new high volume oil pump in it but i dont know if its that one you talk about.Will open the filter and when there are no flakes in it i will check the pump!But its defenitly something wrong when the oilpressure drops so fast after turning off the engine,right!?

 

[NecroWolf]

Re: oilpressure drop

i don't think and engine is suppose to really retain oil pressure after its off. how are you watching it retain oil pressure? stock guage or aftermarket mechanical or electric? what kind of oil pressure did you have and have now?

 

[tylex]

Re: oilpressure drop

I use the stock gauge.When i started the engine the pressure was always at 80 on idle.When the engine was hot it drops to 60.After turning off the engine it holds always the pressure for a long time.For example,i started it after a few hours or so and there was 20-30psi left on the gauge before i restarted it!Now the pressure when the engine is cold is only at 70 and when its warm exact in the middle about 40psi.When i turn the engine off now and switch the ignition on the oil pressure is zero!So something is different after i drove the ty.After that run the oilpressure drop was not the only weird thing.I heard a silent knocking noise from the engine when i rev it a bit.Next day i started the ty again and no knock to hear.So i think when the oil is warm and thinner the knock would come again.I am sure the bearings are broken but i wanna know if knock(5-6 knock retard) could cause this?If so,maybe only the rod bearings are worn and i will change them with the engine in.If not,and the problem is elsewhere in the oil circuit all bearings would be worn and i have to pull the motor anyway.:rant:

 

[bezerk]

Re: oilpressure drop

the stock gauge is no way an acurate thing to read up on. if may aftermarket one is at 50psi my stock is at 80.
bad knock could get your bearings toasted, but with 5 a 6kr i don''t think it will hurt them that much.
if you are not feeling safe with it. hook an aftermarket gauge up at the remote filter setup port.
maybe change the oil anyway, and see how it looks and cut the flter open for more inspection. i wouldn't really be too concerned untill you find something out that looks fishy. aftermarket oilpressure gauges are cheap and a good insurance.

 

[tylex]

Re: oilpressure drop

I have a aftermarket oil temp-,egt-,afr-,boost-,fuel pressure-gauge installed yet so it still looks like a cockpit of a boing!But you are right,must only have to find a place for it!:roll:

 

[BoostedSUV]

Re: oilpressure drop

I would suspect your gauge or sending unit is bad. In no way should your engine have any oil pressure when the engine is off. When the engine is not running, nothing is spinning the oil pump therefore there will be 0 oil pressure. 70lbs at idle cold is fine and so is 40 after warming up. if the pressure is not steady at a constant rpm or is really low I would suspect a main bearing. It is 100 percent normal for the gauge to drop to 0 almost immediately after you turn off the engine. If it doesn't there's a problem with gauge or sending unit... Change the oil and cut the filter if it makes you feel better but I don't think anything is abnormal. On a side note new oil will higher oil pressure and once it breaks down a little you could get a 10psi drop in pressure... Again, completely normal.

 

[tylex]

Re: oilpressure drop

I really hope you are right!!!

 

[tylex]

Re: oilpressure drop

Maybe i am a bit paranoid cause its my 4th engine!:rotf:

 

[tylex]

Re: oilpressure drop

So today i cut the oil filter to be sure theres nothing weird in it.I found many many golden flakes in it!!:rant:So i think the bearings are broken.Would it be worth to change only the rod bearings with the engine in or will i have to do all bearings now?

 

[Don W.]

Re: oilpressure drop

Do 'em all. Pay particular attention to the center mains. Once you have the pan off it ain't bad.

 

[BoostedSUV]

Re: oilpressure drop

You are going to have flakes in the filter from normal wear and tear. Especially in a new engine. Generally when a bearing goes bad you will see big chunks of metal in the filter. What do you have going on? Real fine metal sparkes or bigger chunks of bearing material?

 

[Quickstop [UK]]

Re: oilpressure drop

all bearings otherwise the flakes that are in there are going to ruin the new oners too. Sorry man.

 

[Quickstop [UK]]

Re: oilpressure drop

post up some pics so people can see - the wear and tear thing is right though - might be normal...

 

[BoostedSUV]

Re: oilpressure drop

I agree with Don, if you're going to go through with dropping the pan you really should change all the bearings, both rod and mains. Also if the bearings are badly spun you should have the crank checked. It may need to be poished or cut. If you hurt the crank and just thow bearings in you will end up in the same position down the road...

 

[qbnkiller]

Re: oilpressure drop

+1 for what DaveP said...

before you begin to reassemble the engine, you have to wash thoroughly the engine..this includes with gun barrel brushes and everything. If you do it right, it should take you a couple of hours, and you're gonna be waterlogged when you're done.

This is the only way to be sure you got everything out of the engine.

Then you need to get a new oil pump, oil cooler, remote oil lines, etc. You could try cleaning them, but you will never be 100% sure you got it all out.

Good luck!

 

[Quickstop [UK]]

Re: oilpressure drop

or hot tank it....

but x2 onthe new parts.

has your builder been doing this the last few times? 4 engines is a lot - make that 5...:tdown:

 

[tylex]

Re: oilpressure drop

Yeah,i know.Four engines in nine years is to much.I bought the ty with a melt piston so this was the first engine.Put in a used engine.This engine died because of a oil line leak and i was to stupid to look at my oil gauge.Then the third engine was fully built.Forged internals,new bearings,crank etc..Drove it for one week and all bearings inclusive the crank and the new turbo were dead!!!!:rotf:Oil pressure was good but i had no oil temp gauge this time.Builder said that there was no oiling at the bearings but he dont know why.All seems okay.Weird thing was that suddenly the oil cooler was gone so he couldnt inspect it.Another guy pulled the engine in and out this time because i was to bussy.So i thought maybe he made a mistake with the cooler and hides the cooler so nobody knows who was blame!Okay,bought a crank,new bearings and let the builder do it again.This time i took the engine in by myself cause i dont trust this guy anymore.Drove the ty last year and all seems okay besides much knock retard(20deg) with full boost(15psi) and oil on two spark plugs.(Talked about that in another tread)Thought that high knock retard must cohere with this oily plugs.So i dissambled the head were i saw this two oily spark plugs and found the defect.The springs on the valve seals were broken!:rollont know how this could happen cause the heads also were built up completly new.Put in new ones and all was good exept a bit of knock retard.(5deg)But i dont worry about that cause i had put in 60lb injectors and hadnt tuned it properly till then.Drove it maybe 100miles till then and now i have this problem!!!:squint:The flakes are very fine but there are plenty of them.No big chunks.Here are some pics:

 

[Quickstop [UK]]

Re: oilpressure drop

did you put in a new oil cooler?

did you have a filter before your turbo? Man that sucks for you. I've never seen flakes before so maybe someone will say they are small and normal but I don't think so

I think it is time you learned to do the engine yourself as the people there don't seem to be helping you at all. Will the builder warranty it at all?

what are you going to do now? the engine has to come out of course :tdown: