No Oil On Cams... Lifter Noise And Clatter, Please Help

[Stephen Thorpe]

R33 Series 2 1997 RB25DET

Rattle from cold coming from top end.

Doesn't reduce, as it gets warmer.

Never run for more than a minute as it sounds scary.

Oil Cap off whilst running has no oil sloshing or splashing inside.

Cam lobe on show is almost dry

Oil Pressure on guage seems to stay a little elevated

Normal Service History and Oil/Filter changes

Oil is a little dark but not too bad

Noise all of a sudden came on according to Driver

Car has now been parked gathering dust

160k on odometer.

Blocked Oil Feed Galleries?

Is there a screen filter installed somewhere in the head/block or into camshaft followers ?

Where does the oil enter the Camshafts

Any ideas... apart from Oil Flush and Change.

Is there something that could be blocking the oil access to the top of the head ?

Very perplexing...

[89CAL]

Normal service history means what exactly?

There are check valves in the oil feeds/restrictors if they are factory which stop oil from draining back if I remember correctly

If it were me I would start by pulling the cam covers off and having a proper look. Probably also worth pulling some cam caps to make sure that the oil starvation hasnt caused major issues (pull them off one at a time or pull them off evenly)

There is no real way to diagnose it without starting to pull it apart. There is still oil pressure which is a positive signt that the bottom end is likely still getting oil. It also points to a problem in the head or where the head gets its oil feed from the block which is through the restrictors and up through the studs holes

[Stephen Thorpe]

Thanks Callan,

From what I understand, normal service history means regular oil changes although, I am not sure the grade of oil.

Coolant looks good, there are no leaks and apart from a couple of broken exhaust manifold studs the engine appears to be in good order aside the poor clatter from the top end and the obvious lack of oil in the head.

So there are restrictors in the head for the oil supply? Where are they and can you clear, or change them from under the rocker covers?

Good idea on pulling the rocker covers off and having a look... I will try that soon.

Stephen

[89CAL]

They are on top of the block. Head off job

[Sinista32]

Is it worth putting through an engine detox or engine flush plus (leaving it in longer) or is it way past that ?

[Ben C34]

Some times loosening up all the crap will be more likely to block oil galleries , so I wouldn't bother in this case.

Sounds like it's minimum head off, and to do it properly it's engine out.

I would go head off. Poke into restrictors to clear blockage, crank engine to spit out chunks in the oil, repeat. Or tap a thread into stock restrictors to pull them out and crank engine over to get rid of blockage and swarf caused by tapping. Then replace with new restrictors. Assuming the engine is worth saving.

[Stephen Thorpe]

Is it worth putting through an engine detox or engine flush plus (leaving it in longer) or is it way past that ?

Going to try that first... bathe the top in some oil and then add some cleaner and see if the noise disappears or changes.

[Stephen Thorpe]

Some times loosening up all the crap will be more likely to block oil galleries , so I wouldn't bother in this case.

Sounds like it's minimum head off, and to do it properly it's engine out.

I would go head off. Poke into restrictors to clear blockage, crank engine to spit out chunks in the oil, repeat. Or tap a thread into stock restrictors to pull them out and crank engine over to get rid of blockage and swarf caused by tapping. Then replace with new restrictors. Assuming the engine is worth saving.

There are no visible signs of damage and it has been only ran for seconds not even a minute. Sure it will be fine.

Edited November 16, 2014 by Stephen Thorpe

[89CAL]

Have you pulled a cam cap or two to check the cam?

[Stephen Thorpe]

No I haven't... car is just parked for the moment. I will do this soon though. The one cam lobe I can see looks really good so hopefully all the bearings and cam is the same.

[jjman]

are you sure its not just the usual lifter noise that these motor can develop when older like they all are these days?

Im unsure of your experience with the origin of the problem based on your write up. is it your car n it just started one time or is it a car you are helping out on? did it start on a drive or on a start after sitting for a long time?.

[KiwiRS4T]

You get some oil via the VCT as well. Your engine is not going to get anywhere near operating temperature in one minute. When did you last have an oil and filter change?

[jjman]

what exactly does it sound like?

https://www.youtube.com/watch?v=HtKMpKTZFYo

otherwise

are you sure it isn't some form of cam belt n harmonic noise that a lot of people experience?

https://www.youtube.com/watch?v=m7RvBYe1o4A

https://www.youtube.com/watch?v=YgKneqCQLi4