Top end tappety type noise

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Apologies for delay......swmbo interference currently being experienced and may go on for some hours................

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QBee said:

I am eternally mystified by this strange belief on the distaff side of the house that they have some preordained right to interfere with scared mancave time.

Its amazing what a nice quiet row can do......so I have been attending to stuff and can report the following. Its amazing now how quiet it is in the house, probably be speaking to each other sometime mid week.

swapping leads 5 & 7.......................can ran a little worse, definite and noticeable missing on 1 cylinder(s) .

Swap out the following components for known good ones supplied by QBee and JoJackson

Coil, Amp, Leads, Cap , Rotor Arm

No change 5 and 7 still much cooler than all others. Pulled plug lead 7 off whilst idling no change in engine tone at all, did get massive jolt though so it is for sure getting a spark.

Plan B for tomorrow

1. Repeat Compression testing on warmer engine.
(I find its so damn hot, its difficult to work quickly enough, to get all plugs out and tester plugged in its cooled down quite a lot before testing can begin and getting squirt of oil in for wet test is also not easy)

2. Whip off the fuel rail and see how much each injector is delivering.

3. Measure valve movement (as per Steve's advice with rockers off)

4. If nothing found then heads off for internal inspection.

FWIW No evidence of oil/water contamination either way all drained oil was clean as was water. Oil side of engine inside all covers and valley really clean as said before gets frequent oil changes. Water pump bright and clean and as new fitted 3 years ago about 10 miles on it.

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QBee said:

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Apologies for delay......swmbo interference currently being experienced and may go on for some hours................

I am eternally mystified by this strange belief on the distaff side of the house that they have some preordained right to interfere with scared mancave time.

A brief yet robust exchange of views and priorities did take place, and now I have a spanner in my hands.....enough said

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Cmpression test results are in.

Warm engine

All cylinders similar numbers between 120 and 135 warm dry engine.
2 oil can squirts of oil in each cylinder raised every cylinder 15
Note its only a cheapo tester not sure of its absolute accuracy. What it does show is that 5 and 7 arent too different to all the others, or am I reaching wrong conclusions ?

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Steve_D said:

All you needed was a comparison not ultimate accuracy.
So compression is not the issue but could still be the cam.

Injectors?

Steve

Thanks Steve

Thats my thoughts too.

I did swap injectors around earlier in this saga but will do it again and compare volumes delivered and check cam lift

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Intetesting day......

Fuel injector test.
Rigged up some plastic glasses to capture fuel on cranking the engine. All 8 injectors sprayed fuel to similar amounts

Cyl 1 3 5 7


Cyl 2 4 6 8


For good measure checked the cam lobe lift

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Think we've found something.

Valley gasket distorted around No7 cylinder obstructing the intake. I must have done that on reassembly after fixing the rockers.


No wonder we, or any of you guys too, couldn't figure it out.

So when we found we had compression, spark and fuel we did but we maybe also had a huge air leak too on 7.

Will reassemble with new gasket and test to see if we get all 8 cylinders running, then on to see if we can get back track fixing the top end tappet noise.

The cam lift numbers look good I think, with 1.6 rocket factor that means

valve lift inlet mm are
1 7.7 at lobe = 12.3 mm at valve
3 7.3 at lobe = 11.7 mm at valve
5 6.8 at lobe = 10.9 mm at valve
7 7.1 at lobe = 11.4 mm a valve

valve lift exhaust mm are
1 7.3 = 11.7
3 7.9 = 12.6
5 7.7 = 12.3
7 7.2 = 11.5

Comparing these with Kent etc specs they look very healthy

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QBee said:

Do I remember from somewhere that the cylinders are linked in pairs, so if you have a huge air leak on 7, it will affect the performance of 5?

I may well be dreaming - I dreamt last night that i had left my metal detector out in the rain, which is all well and good, but I have never owned a metal detector.

Interesting, that dream means that if you do the lottery you will pick the right numbers not necessarily on the right day or in the right combination. If your metal detector gets rusty let me know as I can dream about one for you and I can lend it to you.

Regarding air leak and gasket, I feel such a pillock I have no idea how I could have folded that over refitting it. Very relieved though. Interesting about 7 & 5 inlet being linked as 5 was also colder than 1 and 3

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QBee said:

Confuscious say "if you pull everything apart, you will find every mistake"
QBee say "......and if you are QBee, you will create a whole collection of new mistakes, putting it all back together again"

Yep thats about the same on this one here
Found and fixed
Distributor.
Vac advance
Harmonic damper
3 dodgy rockers
All sump bolts needed tightening
Valley gasket end rubbers were a bit hard

Good news is these all needed attention and they are now all A1.

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phazed said:

Frank, us old guys have to show we have it all together, just lie, tell the forum guys it was mice, they gnawed through some wiring, be discreet!

Looking further at the gasket area I have found small teeth marks in the gasket. You can clearly see them in the photo. Plus there were clearly mouse droppings on valley gasket.
Now I am no wildlife expert but am now convinced that this has been done by a mouse.

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Assuming I still have the original noise........I just read this

[i]
https://www.ametech.co.uk/engine-noise-15-c.asp

Rattle that starts at 3000rpm - suspect low oil having caused hydraulic tappet damage and subsequent  rattle noise (see 'Noisy Hydraulic tappets' above) try some RESTORE and make sure to keep the oil level at the top of the dipstick. If the oil level drops the rattle will return at 3000rpm or 60 mph..[/i]

As the cam looks good and cam and tappets should be together what about buying new hydraulic tappets and swapping the internal components over is that doable ?

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Belle427 said:

If it were me i would change the cam and lifters for peace of mind.
Bit of a pita if the cam looks ok but doing it should hopefully guve you years of trouble free service.

Thanks for that and I hear what you're saying, with unlimited funds I might well do that but if it didn't 'cure' the noise then I would then have to look at pistons little ends etc and it could end up as a creeping engine rebuild, I would rather look at a "short engine" than a creeping rebuild.

Have done a bit more research and several posts on various forums have suggested that it could well be sticky, dirty lifters or a blocked oil way. So I am going to get the lifters out and dismantle and clean them and maybe fit new internals from new lifters. If that doesn't cure it then New Cam and lifters for sure

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Belle427 said:

How much mileage has the bottom end got on it?

Good point.
Just been through the history I have from previous owner. Whilst the car has 240,000 the bottom has only 45k on it.
Internally it looks really clean so if I can avoid short engine I dont think its a bad move.
Like your thinking.

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phazed said:

As my conversation with Alun earlier.

I would retard ignition to eliminate pinking.

If the tapping noise was still there, given that I have the facilities, I would pull the engine and check and renew all the bearings on it.

Otherwise.

Next move, I would put in a new camshaft and set of lifters before going any further.

Doesn’t have to be expensive, actually I have a new camshaft at home which may well be a standard grind. If you are interested, let me know and I’ll have a look.

Thats good advice Petwr, unfortunately I'm doing this on a gravel driveway so pulling the lump is a no go. Will look into camshafts, the one I have is Stealth, car goes like stink on it so am mindful of possible performance loss going standard LR.
Have seen others eliminate tappet clatter just by stripping cleaning and refitting the lifters. Given that I now have ability to get that done easily might well give that a go first before fitting new cam and lifters

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QBee said:

Ok, mine isn’t a TVR cam, so doesn’t have TVR tax as well as VAT, but IIRC my standard Range Rover cam was about £85. Plus VAT.

Thats interesting thanks.

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Just a quick update.

Fitted Qbee's distributor ( much appreciated the box of bits you sent me they have been so so useful) and got the whole thing back together and the engine now runs the best ever in my ownership.

It purrs at tickover of 950 rpm and short term trim ascillates around zero and all other parameters are normal too.

The tappety noise at 3k is still there

So now its running sweetly I will strip it once moore and clean the tappets. Research suggests they maybe sticky/dirty. If it works great I will plan for new cam in future if it doesnt I will go for a new cam now. Opens can of worms .....what on earth to fit ?

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ITS FIXED.........

I had a chance meeting with an old mate mechanic/engineer who took 2 minutes drive to declare "big end a little worn"

So big ends removed and crank and conrods inspected a micced up all in superb order.

All the bearings showing a bit of wear but worst was on No3 piston. Down to the copper in the middle section. This one bearing was about 5 thou thinner than new ones all the others between nothing and 3 thou.
Checked all the crank journals for roundness and all good at around 2.185 inch including no3.

New bearings fitted and reassembled and all is good. Oil pressure up a tad to(dash gauge)

Had an hours test run out and not a hint of any noise all way up to 5000 tpm.

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indigochim said:

Good result, sounds like you've had quite the journey on this. At least you know everything's right now.

Yes been up some blind alleys with this but have learnt so much about the quality of whats under the skin on the engine. Discovered a few issues and dealt with them too.

Well pleased and the support from everyone has been outstanding. Hope I can repay each and everyone of you in some way, you know who you are.