Hi Guys, This is carrying on form my 'clack' thread - but I think that's got a bit 'what if' so I thougth a specific question deserves a new thread - of not then apologies.

So I have still not separated the gearbox/engine as I've not been that well lately - however I have been Googling like mad! I found a video with EXACTLY the same noise I get when the engine is warm:

Engine noise

So this got me thinking if there were any solutions to do woth the oil rather than a mechanical issue in the bellhousing....

I found this video:

Loose Oil Pickup

So today as I feel a bit better I raised the old boy up and took the sump off..... but the pickup is rock solid... damn that quick fix idea is gone now!

So a bit more Googling raised this:

Engine noise

The thread suggests it's all down to the oil thinning too much...... a few people put in cooler thermostats and thicker oil... but that got me thinking about the oil pump itself. Bearing in mind he has 170K on the clock almost it must be worn right? I wonder if all the engine work I did stirred up enough much that it caused enough wear in the pump to cause it to not give enough pressure when the oil is hot? I knwo I can hear the noise more on the bellhousing are, but listenign to the videos that seems to be generally the same, maybe it's just acting like a resonator?

I guess I might be barking up the wrong tree but thought I'd throw myself on your collective knowledge and ask first..... it just seems to me to be more 'oil' based that 'cracked flex plate' as it happens as soon as it warms up?

Thanks

It's valvetrain related from the speed of it. Mine made a similar noise when I first got it at 204,000, slightly deeper, more of a clunk, and not as loud but at the same speed. It never got any worse but at around 270,000 I decided it had to be a dodgy cam follower so replaced them, no difference. At 287,500 the engine came out and went to V8Developments but before taking it in, I dropped in to talk about what I wanted doing to the engine and discuss when. They had a listen to it, declared it an odd one and it sounded similar to something serious like a liner problem but as it wasn't drinking coolant or pressurising, it couldn't be that. The engine went in and came back with new top hats, big ends, mains, pistons, rings, camshaft, followers and oil pump and drive. While that was being done the heads were treated to new valves and guides. Put it all back together and the noise was still there and still is, no different, after 45,000 since the rebuild. I've tried starting it with the serpentine belt off to make sure it isn't something silly like the power steering pump and still the same.

Now the only thing that hasn't been changed when the engine was rebuilt is the rocker shafts and rockers. Although mine is outside the range that were affected by the sinking insert problem on the rockers, I thought it could be that. Although I've heard an engine suffering that problem and the noise sounded completely different, it sounded like the standard tappet rattle that you get on pushrod engines with adjustable tappets that need adjusting. So far I've had one rocker cover off and all of the rockers are fine and will get around to checking the other side sooner or later. However, I had to trailer another car over the V8Developments last week (a long and very sad story) so asked Ray to have a listen. From the front, it sounds like it is coming from the right, from the right it sounds like it is coming from the left, from the left it sounds like it is coming from the right, from underneath it sounds louder suggesting it is coming from there. Ray tried an engine stethoscope on it and declared it to be coming from the engine, it wasn't possible to identify from where though. So, even the expert doesn't know, maybe I'll find something when I pull the other rocker cover off.

I'm going to disagree on valve train and go for a small end or piston skirt or, dare I say it, slipping liner.
Because I'm bored and sitting at the PC that has all my sound recording software on it, just for fun I analysed the clacking and there are 2 different clacks with each repeating at roughly 12 Hz and equally spaced. That comes out as 720/min which is engine idle speed.
So, with the appliance of science, that's my deduction. Bet I'm not even close :)

That video isn't mine exactly - I can't record mine now as the oil is drained and the sump is loose LOL - but it was very similar. It quietens when the engine speeds up too as said on my other thread - which made me think maybe the oil pressure rises then?

I agree with a valvetrain issue, reg. the speed of it, although the last vid from underneath the sound is at loudest.
Indeed with covers off let it run idle and place your finger at each rocker to find out which one it can be, put it indrive if needed (handbrake on).
If it gives peace of mind put an oilpressure gauge in the senderunit and see what the pressure is, cold and hot.
If it's a loose pickup and sucks air that will be translated in less pressure.
And sometimes you have to wait until it gets worse, not our nature of course.

Just had a thought - If i tried thicker oil and it doesn't clack would that point towards the pump more? I Honestly want to try and do some diagnosis before starting to strip it apart.

Also someone said you can screw a pressur eguage in somewhere to check the oil pressure properly as the light only comes on when it's REALLY low - I can't find anywhere that tells me where to screw something in , plus what guage to use either!

So annoyed with all this as I have him all lovely inside and then immediately he makes terminal sounding noises that he has never made before!

The pressureswitch is the place to be, screw it out and with the right adapter you can screw a gauge in. Can't you rent a set somewhere?

This looks like it'll do the trick
http://www.ebay.co.uk/itm/Wave-Box-Oil-Pressure-Meter-Test-Kit-Tester-Gauge-Diesel-Petrol-Car-Garage-Tool-/222210263596?

Pressure switch is a real pain to get to on a GEMS, you can't even see it from above or below.

Thing is, even if the oil pressure is proved to be low (as AE says he wants to do diagnostics before digging in) that, in itself, won't diagnose anything. Low pressure can be caused by a huge number of different things, from contaminated oil through worn shell bearings to knackered pump- the list goes on.
To find out what is causing the knock is going to take a degree of stripping down. Start at the rockers and move down from there.

OK - So if i Take the rocker covers off am I just looking for movement of the rods? or other stuff? I woudl have though if anything 'broken' it would be all the time not just when warm?