URGENT HELP! Knocking sound in engine

[onthecut]

Hi BSP.

 

Any progress ?

 

MIke.

[BlueStringPudding]

Hi BSP.

 

Any progress ?

 

MIke.

 

Hi Mike, et al.

 

Well, we cruised from Stratford to Hatton over the weekend. The knocking sound has developed from a "knock-knock" to a "noc-noc-knock" by Saturday night. By last night it had become "noc-noc-noc-knock" and it's louder, and gets louder the more the engine's revved. However sometimes you can't hear it at all. But we still haven't located the source of the sound (as we arrived in Hatton in darkness so didn't delve around in the engine too much). I'll have a peer in there if I get home from work in daylight this week, to see if it's mroe easy to locate the source of the noise now that it's developed. From where I was standing on the stern while crusing, it sounded like it was coming from the front of the engine (eg. alternator/fan belt area) but it's hard to know without having a good nose around in there.

 

As for the yellow goop in the engine bilge. That too has developed! By Saturday it had acquired a milky cloudiness (bit of rainwater mixed in with it perhaps?), and by the end of yesterday (and this was looking at it by torchlight so could be mistaken) it looked like it had some brown goop mixed in with the yellow and milky splurginess. Still none the wiser where it's coming from.

 

But the engine managed the cruise fine, and aside from a few leaves snarling up the prop, there seemed nothing untoward in the running of the engine.

[g8zpd]

Hi Mike, et al.

 

Well, we cruised from Stratford to Hatton over the weekend. The knocking sound has developed from a "knock-knock" to a "noc-noc-knock" by Saturday night. By last night it had become "noc-noc-noc-knock" and it's louder, and gets louder the more the engine's revved. However sometimes you can't hear it at all. But we still haven't located the source of the sound (as we arrived in Hatton in darkness so didn't delve around in the engine too much). I'll have a peer in there if I get home from work in daylight this week, to see if it's mroe easy to locate the source of the noise now that it's developed. From where I was standing on the stern while crusing, it sounded like it was coming from the front of the engine (eg. alternator/fan belt area) but it's hard to know without having a good nose around in there.

 

As for the yellow goop in the engine bilge. That too has developed! By Saturday it had acquired a milky cloudiness (bit of rainwater mixed in with it perhaps?), and by the end of yesterday (and this was looking at it by torchlight so could be mistaken) it looked like it had some brown goop mixed in with the yellow and milky splurginess. Still none the wiser where it's coming from.

 

But the engine managed the cruise fine, and aside from a few leaves snarling up the prop, there seemed nothing untoward in the running of the engine.

 

Our ex-black Prince boat developed a similar sound when cruising up the Thames. Finally found that the post supporting the exhaust had nearly sheared through and the whole lot was knocking against the swim or deck depending on the cruising/engine speed.

 

We replaced the exhaust and could cruise in semi-silence. We also had a coolant leak and the colour matched your description, it was a loose jubilee clip on the water pump.

 

HTH

Paul.

Edited October 30, 2007 by g8zpd

[Theo]

Again the RCR enginner knows about it and has said the seal can be replaced when the engine's next serviced. As I mentioned above, the knock-knock is not in synch with the engine, apparently. (Perhaps there's a small vole under there, complaning about all the noise!?!?! )Just been back to the boat in my lunchbreak to check on my lovely baking trays. I can confirm there is some fluid of some description under the engine. I dunno what it is, and there's not much of it - but there's definitely more than there was yesterday (as it was empty yesterday). It appears a yellowish colour and when I dunked a white tissue in it, it looked like vegeatble oil (but doesn't smell like oil).Now the oil could be residue from the bilge, floating on top of whatever fluid is in there.Any thoughts?

Engine cooling water with antifreeze?N

Some anti-freeze has a 'sweet' smell.

It was used by the Austrians in the 70's (I think) to sweeten some of their wine. Trouble is ethylene glycol is _really_ poisonous. I does in your liver. The Austrian wine trade suffered. If you drain any antifreeze keep it well away from the dog. Dogs like sweet things. Dogs have livers too. Likewise cats.N

[BlueStringPudding]

If you drain any antifreeze keep it well away from the dog. Dogs like sweet things. Dogs have livers too. Likewise cats.N

 

 

Thanks Theo,

 

I have neither a dog or a cat but I do have a boyfriend who's drink anything that looks flammable. I'll keep it away from him too!

[Malarky]

Try pushing a long socket extension bar into your ear, then press the other end against your engine in diffrent places, this gives a pretty good impression of the internal noises. Also clean arround injectors where they rest in the head, you should find a dished area here. Fill with liquid,and check for bubbles. Bubbles=Knocking Injectors, possibly loosened.Try pushing a long socket extension bar into your ear, then press the other end against your engine in diffrent places, this gives a pretty good impression of the internal noises.Also clean arround injectors where they rest in the head, you should find a dished area here. Fill with liquid,and check for bubbles. Bubbles=Knocking Injectors, possibly loosened.

[Scotty]

Try pushing a long socket extension bar into your ear

Ok, done that. But how do I get it out?

[bottle]

Find a rod of suitable length and smaller diameter, place in opposite ear and push hard.

[magnetman]

Please consult your GP before carrying out this procedure.

[David Schweizer]

What people are trying to explain is a proceedure used by motor engineers for decades. What you need is a long rod of hardwood (softwood will do but does not transmit sound as well) 12mm Ramin dowel will do fine. Glue a small (preferably slightly dished) disk about 4cm diameter of harwood onto one end and shave the other end to a rounded off point, you now have your sounding rod.

 

With the engine running, place disk against your ear and the pointed end against various parts of the engine taking care not to foul moving parts. you will hear the knocking from most places, but where it is the loudest, is the source of the problem. Then consult the workshop manual to check what in that part of the engine could be causing the knocking.

Edited November 3, 2007 by David Schweizer

[onthecut]

Hi BSP.

 

If you try the DIY listening stick and you've not done so before, be aware you will hear all sorts of whirs, clicks etc.etc., most of which will be perfectly normal. Main thing is to do it safely -- don't position the probe where it can slip and absolutely no dangling cords from clothing, long loose hair and so on. Other thing you will find is that the instant you start listening, the chap over the fence will fire up his chain saw and the heavy rock party on the next boat will start with some big speakers right by your mooring !!!

 

Mike.

[cuillean_dubh]

reading all of this convinces me that everyone should have owned an old diesel landrover before acquiring a boat. If your engine is still running with any noise then it's ok. It has to be an ancillary fitting - not the engine. you obviously have a few leaks. Renew all rubber pipe work and jubilee clips. Even if they look ok. Diesel engines are very simple - dont be afraid of playing around with them. You can save a fortune in servicing costs.

[onthecut]

Too many words in the last post ----- everyone should own a diesel Land Rover --- full stop !!

 

Mike.

[Radiomariner]

Its possible that the clue might be there in an earlier post.

I have heard something similar to this before. An irregular double knock out of sync with the engine.

Although the noise actually came from the engine, the trouble was with the alternator regulator and poor wiring connections in the battery charging circuit.

The regulator was cutting off the field coil current when the output voltage at the alternator reached its pre-determined value. This resulted in voltage at the alternator output dropping quite rapidly, (no output from the alternator and a high resistance in the wiring to the battery), the regulator would then switch on the field current again until the output rose once more and the cycle repeats itself. The knocking was the result of "slack" in the engine being taken and dropped off as the mechanical load was changed by the switching off/on of the alternator.

This theory would also fit in with you stating that the battery charging did not seem normal.

 

Again, you must run it for a wee while with the belt off. If the knock goes away try the cheapest option first. Check the wiring between alternator and battery.

 

I trust this comment is of some help.

Good luck, I hope it does not work out too expensive for you. I look forward to hearing the outcome.

 

Rgds.

[BlueStringPudding]

Well, very nice RCR dude came to the boat on Saturday for our annual engine inspection and service.

 

The yellow goop under the engine was indeed gear box oil. It was emulsifying once in the bilge, hence the array of textures and colours that it evolved through. The seal on the gear box was knackered, so RCR man replaced that and refilled it with oil. Marvellous. I'm not as surprised as I ought to be that the company who serviced the engine in June didn't pick up on that, because the engine bilge had been full of yellow goop before they "serviced" it. But they were a bunch of f*ckwits anyway.

 

The knocking sound is indeed fan belt related. The two fan belts are slapping against each other, apparently. We need someone to respace the alternators because although the sound is not too much of a problem, our fan belts will wear down quickly because they're touching - especially at low revs. So next plan is to try and find someone loacally who can do that for us.

 

RCR man was concerned that we have no temperature guage or light and we need to get one installed retrospectively. He gave an example of if these slapping fan belts were to wear out, we might be running the engine without any coolant going through it, and we wouldn't know if it was overheating. I did point out that we do have an indicator - the knocking sound would stop! Which he thought was very funny indeed (far funnier than the gag deserved!).

 

He replaced the diesel filter and put in a new seal to stop that diesel leak. The seal hadn't been put in properly and had a twist in it, so it's likely to have been leaking for some time. He also found traces of dead diesel bug in the filter, but as we use Fuelset regularly he was happy that there's no great problem there and it was all under control.

 

He did alas discover two other diesel leaks from the Eberspacher!!!!!!!!!!!!! We've had the damn thing fully serviced twice in six months and it STILL has 2 diesel leaks! One from the coupling where the pipe joins the unit itself, and another from a narrow little Eberspacher pipe by the diesel filter. He attempted to tighten one of them, but it remained a little moist with diesel. Bloody thing...

 

He's happy that the batteries and starter battery are charging as they should be. We need to give them a top up with battery water, but other than that they're fine.

 

And that's that! All in all quite pleased that the knocking sound and the yellow goop are all fixable/fixed.

[carlt]

Too many words in the last post ----- everyone should own a diesel Land Rover --- full stop !!

 

Mike.

Yuk! Worst vehicle I've ever owned. Unreliable, slow, noisy and as thirsty as a petrol jobby.

 

Fine if you're knocking round the farm on cherryade but totally pointless masochism, otherwise.

[Supermalc]

Really pleased you've got your problems sorted BSP, without resorting to buying a new engine

 

Carl, you've surprised me, as once again I totally agree with you.

[Keeping Up]

Well, very nice RCR dude came to the boat on Saturday for our annual engine inspection and service.

 

...

 

And that's that! All in all quite pleased that the knocking sound and the yellow goop are all fixable/fixed.

Quite pleased ??? I would expect at the very least a surfeit of skips and a round of rigadoons.

 

Really pleased for you BSP, so glad it wasn't as expensive as you feared (it rarely is; it's usually the things you suspect of being "just a small problem" that turn out to be the real big ones!)

[Supermalc]

Quite pleased ??? I would expect at the very least a surfeit of skips and a round of rigadoons.

 

[BlueStringPudding]

Quite pleased ??? I would expect at the very least a surfeit of skips and a round of rigadoons.

hahaha! May be I am doing exactly that!?!?!

Really pleased for you BSP, so glad it wasn't as expensive as you feared (it rarely is; it's usually the things you suspect of being "just a small problem" that turn out to be the real big ones!) Zoiks... don't even go there.

[onthecut]

Hi BSP.

 

I don't see why you should need to replace the alternators because the belts are touching. It should (generally !) suffice to slightly space one of them out, along its pivot bolt (with a corresponding shim in the clamp bolt, if necessary). It does however beg the question why, if they weren't knocking, they suddenly started -- unless one became loose. I would second your chap's assessment that a temp gauge or warning device is a good idea. Modern engines have very little tolerance to overheating.

 

Mike.

[bottle]

Hi 'Blue'

 

I agree with Mike, why have the belts suddenly started to slap each other, check the mountings of the alternators and the alignment of the pulleys.

 

That very nice man from RCR could have done that for you, while he was there.

 

If they need to be aligned then shims (posh word for washers) in the correct place on the alternator mountings will help to move it back or forward.

[BlueStringPudding]

Hi BSP.

 

I don't see why you should need to replace the alternators because the belts are touching. It should (generally !) suffice to slightly space one of them out, along its pivot bolt (with a corresponding shim in the clamp bolt, if necessary). It does however beg the question why, if they weren't knocking, they suddenly started -- unless one became loose. I would second your chap's assessment that a temp gauge or warning device is a good idea. Modern engines have very little tolerance to overheating.

 

Mike.

 

Erm... the alternators don't need replacing...? Maybe I didn't phrase it well - the RCR man did indeed advise me to get someone in to respace the alternators.

 

The only thing that might need replacing as a direct result of the fan belts hitting each other, is the fan belts themselves, as they're likely to wear out quicker.

[BlueStringPudding]

That very nice man from RCR could have done that for you, while he was there.

 

He didn't have time to do that too as it was outside of his "service" remit and he had other appointments to go to after us. His concern was that to tweak the spacing on the alternators might lead to him needing to tweak other things to ensure the pulleys are lined up etc, and it could take more time than he had to give me. He spent 2 and a half hours on the inspection and service and was very patient and happy to talk me through what he was doing so that I know what to check and look out for too. Of course it would have been great if he could have sorted it out, but I'd have been miffed if he'd had to do a rush job and something wasn't perfick.

[StoneHenge]

Sorry to hijack here. I wonder if we will get your man. I am waiting on him being available to come out to us either today or tomorrow.

 

We are moored up around a mile or so away from our home mooring at present, and we noticed the engine coolant water has gone from a nice shade of green, to a yucky shade of brown. We siphoned this off over the weekend but the brown has come back, and we think this may be oil getting into the water.

 

If this is the case, and the head gasket has gone, we could be in trouble, big trouble. Hoping it's not bad news as that would be carp before Christmas, and not great for such a young engine. I hope the RCR man has some good news for us.

 

Glad yours is now fixed and looking good BSP. You must be very pleased indeed!