Engine clatter

[John Wilkinson]

Good morning all, I have a "clatter" from somewhere apparently at the front of the engine. It starts and runs just fine, but sounds like something is loose in the clutch area maybe? or a starter motor bendix not fully returning? It's there all the time but seems to be drowned out by engine noise as the revs go up. It is much "clatterier" than the sound on the recording, I think my phone has too much propensity to record bass notes, it's that duller rumbling on the video, (not the tappeti-ness). Any ideas anyone? John

 

[jcarruthers2]

Hi John

Do you notice any differences when you depress the clutch pedal? Notice anything when you pass through all the gears?

 

[John Wilkinson]

Just been out to the garage and started up, the noise is still there when I depress/release the clutch...I am pretty sure what gear it's in makes no difference, but it's pouring down here in Calne, and the car isn't allowed out in the rain

 

[jcarruthers2]

Hi John

I was trying to rule out the clutch and gearbox. It's hard to tell exactly what is causing the clatter with the background noise. Have you checked whether the radiator fan blades are touching the radiator cowling at all? With the engine turned off, check for chewed up bits of plastic on the blades and inside of cowling. This was happening on an R4, I used to have with the Billancourt engine.

 

[John Wilkinson]

No, nothing fan related, I did think the belts were a bit slack, so adjusted them up and hoped that might do it, but no joy there. It's unfortunate that the phone recording just doesn't really pick it up very well..thanks for the input anyway. John

 

[jcarruthers2]

Hi John

As an afterthought, I can hear that the tappets could do with adjusting. If the tappets were adjusted, you would have a quieter engine and it might be easier to detect the source of the rumble in the background.

 

[John Wilkinson]

True, perhaps I should get on with that first..

 

[laxeian]

I have found one of these to be good at finding where strange noises are originating from, just by touching probe on engine/gearbox, touch it on rocker cover to hear which tappets are the noisiest tappets too, takes the guess work out of problem, louder the clatter the closer you are to source.

 

[John Wilkinson]

Must be worth a go, under a tenner on Amazon, so I've got one ordered..thanks

 

[André4Renaults]

Some very early 747cc Renault 4s suffered from an engine "rumble", which was eventually diagnosed by Renault's engineers as "camshaft whip". I think the later 848cc engines had re-designed camshafts, that ran in a different type of bearing. I'm not saying this is what your engine is suffering from and it's odd that it's come on now, as opposed to being there for some time. Checking the tappets would be a good place to start and if they're incorrectly adjusted this might affect the camshaft in some way.

 

[John Wilkinson]

Thanks, I will def. have a look at the tappets next. It sounds like something much looser that "camshaft whip"...such a pity I can't seem to catch the sound better on my clip. J

 

[laxeian]

The stethoscope method of location has saved me the tool cost many times over since having one and putting it to use,

 

[angel]

Check also the inlet/exhaust manifold and its gaskets. A blown exhaust port gasket produces a loud knock, oddly.

 

[John Wilkinson]

Thanks will do

 

[Piet]

I had a very similar problem on an 845 cc engine. It turned out to be a loose fanbelt pulley on the camshaft. The three bolts (setscrews actually) that hold the pressed steel pulley on hadn't been tightened up properly allowing the bolts to back off and let the holes in the pulley hub to wear and elongate so the pulley can shimmy around torsionally in relation to the camshaft at it's characteristic whipping frequency.. Check to see if they are the culprit or similarly if the fan is loose on its pulley. If holes are elongated will need new pulley and new setscrews, which are standard high tensile metric automotive ones of the correct diameter and length, easy to get and thankfully not a weird size.

 

[John Wilkinson]

That all sounds plausible, thank you. I’m away from home today, but will let you know how it goes. John

 

[John Wilkinson]

Hello everyone who has kindly taken an interest in this thread. I'm back home now. My Amazon delivery of a stethoscope was waiting on the doorstep, so I unpacked it and had a good listen around, but really only found the expected "enginey" whirrs. I looked at the integrity of the bolts securing the fan etc., ( more on that in a minute ) and found everything seemed in order. I took the opportunity to tighten up both belts and restarted the engine. The phantom clatter seemed much reduced, and when it did occasionally appear was much less noisy. I stopped the engine and had another poke around and noticed the central nut which I think holds the fan/pulley to the water pump spindle looked like there was some space between it and its locking washer, so I found the correct spanner and started to tighten. It seems to be a non original nylock nut. So, round and round I went, but felt no resistance, and nothing got any tighter. It seems to me that if that shaft is turning independently from the pully, that the woodruff key has either not been fitted or sheared. Can anyone confirm whether or not it should be possible to turn the shaft without the pulley also following ? John

 

[Piet]

That’s great you found what could be the problem. I’d suggest it’s unlikely the key is missing, I’d look to see if the thread on the nut is stripped. Try undoing it and if it comes off inspect the threads on the nut and the shaft. Hopefully just dodgy threads on the nut and that can be replaced. Alternately if it does not appear to come off it could be the shaft turning. You can confirm this with a dental mirror and look at the end of the shaft while you turn the spammer. The shaft might not be held by a woodruff key on to the impeller, many are just pressed together., so in that case would need to investigate further ie remove and rebuild/replace water pump.

 

[John Wilkinson]

So...just removed the radiator...what a pig of a job that is... and, as more or less expected, the bolt securing the pulleys was stripped. The pulleys themselves were, however, very well seated on the shaft, took quite an effort to actually get them off, so no play causing a rattly fan, so still no nearer christening the noise. New pump ordered today, should be here in a few days.

 

[John Wilkinson]

So...water pump arrived today...now fitted and back running, but the noise persists. If you haven't all bored of this, and there's anyone out there still following, my latest thoughts are: when I got the car, the clutch was stuck on after years of non use. I freed it by jacking up the front end starting it up in 2nd then yanking on the hand brake. It worked, the clutch released...but when I put it back on the ground and tried to drive forwards it seems I'd also caused the left hand drive shaft to dismantle itself and spit oil and ballbearings all over the floor. I obviously replaced that, but wonder if I have done some damage to the clutch release plate...the noise does seem to be around that area. I made a new video, which I think captures the clatter better. Also removed the oil filler cap, but all I can hear in there are the usual tappet noises. I'm beginning to think I will throw in the towel and just run it until in manifests itself catastrophically.