Jump to content
SAU Community

Recommended Posts

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...

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

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

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.

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.

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 by 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.

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?.

  • Like 1

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?

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

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • I hope it's actually possible. This is a write off in insurance world.
    • Yup. 2-way with shallow ramp angles. Still works.
    • That was the first session so not a lot to take from the day. It was low 20s ambient and the coolant had got to 110 (and obviously had some pressure!) so that still needs to be addressed. I haven't downloaded the data yet but will. I had refilled the auto trans with Redline DT6 because it claimed the best viscosity I could find at 100o. It wasn't really long enough to get a good feel for that; while the trans got to 100o in the session it still wasn't shifting crisply as I hoped. I think I'll try a few more sessions before judging. No steering motor overheat but I'd hope not in only 1 session! But finally the suspension; it was night and day over the standard stuff and the car was a couple of seconds quicker on the same crappy tyres, which is a huge difference. I'll stick with that and get some sway bars and a mechanical diff sorted too and see how that all goes together
    • I guess it’s partially a compromise of how my car is used, wanting to be able to switch from drift to grip with track side on-car adjustment. Also partially with the way the knuckles are set there is more static camber but less dynamic camber gain. 
    • OK, so update from the track day on Friday It was a classic "an unfortunate series of events'. There were a few cars around and when i checked my mirror coming out of the fish hook I notice some smoke from the rear of mine. Looked again and it was getting much worse, I figured I'd blown a turbo or something to got off it and pulled off the racing line. However.... since it is a left hairpin into a right kink, I was on the inside of the next corner. There was a car passing me on the left and a big drop off over the ripple strip on the right......and someone had knocked the witch's hat that was on the apex about 1m onto the track. So, between those 3, I decided to mow down the cone and not damage my car/the other car. Right choice, but surprising result.  The car decided the cone was a small pedestrian so it blew the rear bonnet hinges up to protect their head in the upcoming person to car impact....I didn't see that coming and like an airbag deployment it happened super fast. Straight into the pits from there, everything was driving fine but it became clear it was a coolant leak not smoke, it was billowing up onto the windscreen. Onto the trailer and home. I'll do a separate thread about the repair (once I work out what it is ), but the immediate problem was the bonnet wouldn't open because the front was pinched onto the front bar and would not release. Ultimately we unbolted the hinge from the bonnet, pulled it back a little and it released from the front OK. "There's your problem", the top radiator hose had popped off at the radiator.
×
×
  • Create New...