What's this knocking noise? (with video)

[Termite]

Hi

Some of you might have read my post about not being able to get my van to idle (http://forum.earlybay.com/viewtopic.php?f=4&t=71797&p=576796#p576796" onclick="window.open(this.href);return false . Well it is now idling after putting a .60 idle jet in and backing it out a touch (it had a .55 before), but now it has developed a knocking noise which I've never noticed before.

I've uploaded a video here: https://youtu.be/teWb19xkp3E" onclick="window.open(this.href);return false;

I have also done the old screwdriver to the ear trick to help try and Trace the noise which is at it's loudest if I put it between the fan belt onto the generator pedestal.

It doesn't make a noticeable knocking noise when I've put the screwdriver to the carb, generator, or either rocker covers.

What's causing my engine to run like a back of sh*te having just run for 2,000 round France without an issue? Any ideas?

Thanks in advance (as always)
Termite

 

[Dave.P]

I would do valve clearances and an oil change while your at it.

 

[Termite]

I put 2.75 litres of oil in it on the trip, so it's virtually had one already :mrgreen:

I'm going to do the valve clearances tomorrow evening so it's cold.

 

[Dickie524]

Erm, could it be preignition? (pinking?)

 

[chug]

Take belt off and run for a (very) short while to eliminate generator/ alternator or fan.

Valve clearances as suggested.

Oil change, with the old oil in a washing up bowl or similar, spin it with your finger and see if there is any shimmering to it, suggesting bearing or other component break down.

Does it disappear when revved? I've just had the same sort of knock which started as a valve type tapping, after stripping the engine down I found one of the cam bearings had munched itself.

I did also find in mine a load of brass filings which looked like the distributor drive gear, the gear was fine so put it down to a previous gear failure which someone didn't clean up properly leaving the brass particles in oil galleys and the oil cooler which they didn't change.

Hopefully yours is just a simple oil change and valve adjustment

 

[Termite]

The knocking does disappear when revved up, either that or the general engine noise is a lot louder so you can't hear it!

I'll try the valve clearances tonight and let you know.

 

[Bluesnailman]

I put 2.75 litres of oil in it on the trip, so it's virtually had one already :mrgreen:

I'm going to do the valve clearances tomorrow evening so it's cold.

My Tom Wilson book talks about burning oil.. you burnt just under 3 quarts in 2k, so that makes about 670miles per quart. in his words, between 500 and 1000miles indicates a slightly wide clearance somewhere in the engine, less than 500 miles per quart the engine needs attention.

i wonder if you have poor compression in a cylinder?

 

[Termite]

I will have a look. Before I went away, all four cylinders when cold had a compression rating of between 129psi and 133psi. Tested each cylinder 4 times and took and average.

I'll do the valves tonight and if I've got time without peeing the neighbours off, get the timing gun out and check.

What can cause the timing to change if I've not touched the distributor?

 

[Dickie524]

What can cause the timing to change if I've not touched the distributor?

In all likelihood, nothing, but the points could just concieveably have burned or slipped - happened to me before on an Austin Maxi I had, they slipped miles and it ran like crap until I found it!

It probably is mechanical though as the others have said...

 

[Termite]

So the results are in...

The valves on Cylinders 1 and 2 all needed slightly tightening.
The valves on Cylinder 3 were tight. The left hand valve (embarassingly I don't know which is exhaust and intake!?) was too tight to pass the feeler gauge through. The right hand valve was a touch tight and the guage really dragged through it.
The valves on Cylinder 4 were ok and needed no adjustment.

Also in the rocker cover on side 3 and 4 was the cylinder head bolt and washer from the left hand side. I have had issues with torquing this one before and I think it is now pulling the engine stud.

Valves all adjusted to 0.15mm, cylinder head bolt back on with a touch of loctite (not that that is going to do bugger all, but makes me feel a bit better) and I've ran the engine again. It will idle with the 0.60 idle jet backed out a touch (and this now has a blob of my new favourite blue liquid to hold it in place). I still need to do a full oil change, but don't have any new sump stud washers, but do have a couple of spare paper gaskets if you think I can get away with reusing the washers?

Also checked the timing and the timing gun flashes on a mark that's on the pulley before TDC, so I am assuming that it's correct. The marks also move as the engine is revved up as expected.

Three videos below:
https://www.youtube.com/watch?v=teWb19xkp3E" onclick="window.open(this.href);return false; - This is the original Engine knock video I posted
https://www.youtube.com/watch?v=fHL5XQ8hG-A" onclick="window.open(this.href);return false; - This is the engine Idling post adjustment
https://www.youtube.com/watch?v=p81zthQavhE" onclick="window.open(this.href);return false; - This is of a couple of presses on the throttle and then turning it off. I thought turning it off sounded a bit rough, but might be a touch of paranoia and hearing every sound going at the moment.

Any thoughts for the videos? I think the engine will need pulling to address the cyclinder head bolt issue, but I'd like to leave it until the Autumn/Winter if I can and attempt to get some use out of it this summer. There's the standard 101 other jobs that I'd like to do when the engine's out and it won't be going back in in a hurry.

I have this current engine and two other engines in the garage (of unknown quality unfortunately), so I should be able to strip one of the other two down for a rebuild and keep this one going. Again though, I'd like to keep that as a winter job and get out in the van. I'm getting withdrawal symptoms after all that driving in France! :mrgreen:

 

[Termite]

Well I did an oil change and it was quite sludgy. I also noticed a few brass fragments/fillings in the bottom of the oil pan I drained it into. Any idea what that may come from?

I also pulled each HT lead off each plug. 1,2 and 4 all dropped revs a touch, but pulling off on number 3 the revs dropped a lot and the knocking noise was extremely noticeable .

 

[Termite]

Did a compression test and checked the plugs. All plugs were a nice grey colour. Compression test however wasn't as good...

Cylinder 1 - 105 psi
Cylinder 2 - 115 psi
Cylinder 3 - 70 psi
Cylinder 4 - 102 psi

Before I went away they were all around 130psi.

Can I draw the conclusion that something is seriously buggered?