Series 2 2.25 engine noise diagnosis

Hi

I've got an annoying noise on my rebuilt 2.25 which hopefully you can hear on the attached vid. Does anyone have any experience of what this is?
https://photos.app.goo.gl/2tb3fc3hDiheiTry6

It's the "duck noise". Otherwise everything is very sweet indeed. Only happens when hot. Sometimes the noise is not there.

It is not water pump or alternator. Sounds more back of engine than front.

If you've heard the noise before and know what it is, would be pleased to hear.

Running on 10/40 semi synthetic. Was thinking of trying an additive in desperation....,.

That link didn't work for me.

Col

I use standard mineral oil such as Halfords Classic oil in my series engine, they don't like synth or semi synth. Try changing the oil.

Col

Here is a link to You Tube.

Point noted on oil but this is a remanufactured engine and engineering firm specifically said use 10w/40 I guess reflecting the improvements in engineering over the last 50 years.

Sounds to me like a small exhaust manifold leak,before it heats to much run your hand around and feel for it. Rubbish video by the way.

Video not the best. I keep suspecting the manifold may have a leak but didn't associate it with what I call the duck noise......

I would go for manifold leak, eaither exhuast or inlet. Not an exact science but they can make a duck sound.
Have you checked for actual ducks?

Thanks all. The head has been on and off but with the manifolds and carb attached so the gaskets have not been done recently.

I will do them in two weekends time and follow up on whether the problem duck has gone! Be nice if that's it.......

Fingers crossed it's a simple fix.
You can actually now buy 20w/50 oil in semi synthetic or even fully synthetic if you prefer. (Millers Oils)

Land Raver said:

Fingers crossed it's a simple fix.
You can actually now buy 20w/50 oil in semi synthetic or even fully synthetic if you prefer. (Millers Oils)

Click to expand...

You can get Race spec Fully Syn 20w50 but i think it would pour out of an old 2 1/4

So the adventure continues.

Took manifolds off. Separated manifolds. Renewed all intake and exhaust manifold gaskets. Checked for being flat,
Re-assembled.
It is still there. It is impossible to pinpoint. I wonder if it is the lift pump, I did renew the diaphragm a while ago ans yoiu have to admit they do sound like ducks when you prrime them off the vehicle.
Anyway resorted to sorcery and and put some snake oil in the fuel and the rest of the bottle in the oil.

Anyway, this is a brief update video (again a poor qualiity video!!!!)

Much better video any way, dam ducks.

Could it by induction noise? I see you are fan of snake (Mystery) oil too. I did some research on the ingrediants, it has one that dissolves hard carbon and that isn't in many other products, can't remember what it was but it does explain why it is different.

Have you tried running with the air filter off the carb? Listen to the air intake see if that gives you any clues

Solihull225 said:

So the adventure continues.

Took manifolds off. Separated manifolds. Renewed all intake and exhaust manifold gaskets. Checked for being flat,
Re-assembled.
It is still there. It is impossible to pinpoint. I wonder if it is the lift pump, I did renew the diaphragm a while ago ans yoiu have to admit they do sound like ducks when you prrime them off the vehicle.
Anyway resorted to sorcery and and put some snake oil in the fuel and the rest of the bottle in the oil.

Anyway, this is a brief update video (again a poor qualiity video!!!!)

Click to expand...

the gasket looked sooty showing its leaking, when you fit the 2 manifolds both faces have to be perfectly aligned so youd normally fit them with the 4 bolts holding the 2 manifolds together slack with a new gasket between the 2 so the 2 can move a little in relation to each other

Thanks for the replies. I didn't see the notification email to tell me I got replies.

I did fit the manifolds loosely to each other (by the 4 long bolts) with new gaskets so ithey should be aligned ok. But I had problems with no.4 exhaust sealing previously and on watching my video again, I have to say well spotted @jamesmartin the gasket is sooty on no.4 . I was so convinced the gasket would be blown that I didn't examine it. I did note the far manifold bolt being sooty, so all the evidence wss there and I ignored it.

I will take out that manifold bolt and if there's any soot on it, then that is the issue. I'm pretty convinced I need to redo the job and pay a bit more attention this time. Also a smidgen of exhaust assembly paste on the problem area may help or is that a bodge?

I will remove air cleaner too and see what that tells me. I fear my mystery marvel will be decoking everything at precisely the time I need it to seal with soot!

Progress at last!
I did take the manifolds off again. There was no obvious sign of exhaust manifold leak this time.
My thoughts were thast if it wasn't the manifold then it could be the head gasket leaking out but again, no obvious signs.
Manifolds are reasonably true - like all things Landrover, it is a quetion of degrees and they are probably 50 years old and would benefit from re-facing.
I gave the one-piece gasket a coat of heldite jointing compiund (good to 350 degree celsius 660F) and all seems to be good now.
Thanks all for the constructive comments.

Good, sorted.

Ah, the well known Heldite duck repellant! Glad its sorted.