HELP 318is m42 noisey VW tappet noise BUT only when HOT

[MANNO]

318 is 1991 cab

bought car - seems very nice all round

was told had been garaged and had been standing - owner had said hed started it every now and then ? maybe not so much ?

- yet to know how long stood for - my error

Idle was silent and city drive away was perfect
until Drove her home onto m5 / m6 for ... 200 mile trip

After 50 miles of effortless silent driving
the car began to increasingly make ticking noise and tappet noise ? sounds like an old VW beetle

Enote the ngine temp gauge was reading very low - ( i think stat is shot and was open - and minus temp outside on motorway kept it very cool - stat and fan also may be shot

The noise got louder and louder

and was at worst - very noisey at low revs when i slowed down and slightly less nasty at hgh revs just a faster tappet or cam chain tick

no power loss at all - car crusied very well at 65 - 80 mph

next day car started with no noise - until again when hot on A roads and then motoway at 65mph etc - but again it eased off when cooler after parking up

HELP

Ive seen advice on checking Camchain Tensioner ?

and will change oil tomorrow to a thicker oil perhaps

NO flush - scared to flush her from what Ive read

the black death comes to mind - will check inside oil cap into engine tomorrow

the car drives and sounds so well and quiet - until this intermittent motorway sound kicks in when hot and cruising
very odd - all help very appreciated and welcome

newbie here but ownerd a few cars in my time ( im 45 ! and loving middle age - the new 30 !!

[appletree]

With you saying its worse when its hot, it could be a cracked exhaust manifold, they go near were the runners go in to the multi layered plate on the head and this makes a tickity noise, mine had gone on number 1 underneath, I only found out when I stopped the engine. So have a good look with an inspection mirror for any black soot around the manifold area.

[hash]

I would agree with the above as first thing to check. With engine just started frm cold so its not hot for ur hand, move a bit of paper around underside of manifold to help identify blow, worked for me.

[B15NAC]

Yes mine was craked on the manifold so thats proberbly what it is they all go there. I would use 5w 40 fully synthetic thats what i got in mine and it stopped my tappets tapping its what the oil man said is best. But i would say if its when hot it may be a tad to bad for oil to fix?

[Saga]

If it's doing it only when hot, it's probably not the tensioner or a sticky adjuster (AFAIK that usually happens when cold), and if it's running ok it's probably not a broken guide rail (I've seen pictures of that...guide rail ended up in the valve cover!). So yeah, probably a crack.

I'd replace the thermostat and flush out the system - it's an easy job on these cars and most likely hasn't been done for yonks if the thermostat has got to the point of failure. OEM thermo is cheap, you need one paper gasket. The ally thermo housing is actually only £13 or something (might be easier than gasket scraping it and cleaning out the old one), and the top and bottom hoses about the same.

Someone was selling a fan clutch in the for sale section if that's died. You will just need a 32mm spanner (Halfrauds viscous coupling one or a regular 32 (!) will also fit, if you can't find the specialist tool).

[MANNO]

thanks for the advise - im just a bit surprised that a manifold crack could sound that loud and sound like tappets on an old VW ??

as it get progressively louder and the settles on B roads etc ?? and engine up it sounds to be coming from the rocker cover ?

Saga are you saying i replace the manifold rather that weld it - seal it - are they available or is it a phone round the scrap yards ?


a new STAT arrived today

But 'to flush or not to flush' - that is the question ? - ive read so much bad press about additives on carbible - and he really seems to know his stuff


may use 15/40w diesel oil to flush it ... bit safer

see


A question came up some time ago about using diesel-rated oils to flush out petrol engines. The idea was that because of the higher detergent levels in diesel engine oil, it might be a good cleaner / flusher for a non-diesel engine. Well most of the diesel oil specification oils can be used in old petrol engines for cleaning, but you want to use a low specification oil to ensure that you do not over clean your engine and lose compression for example. Generally speaking, an SAE 15W/40 diesel engine oil for about 500 miles might do the trick.

Read more: http://www.carbibles.com/engineoil_bibl ... z1CkjBNPtv

[Saga]

No, I meant flush the COOLING system with water (then distilled water, then refill with your mixed coolant of choice), not the sump, and replace that thermostat together with the hoses (unless they're in great condition of course), as they're cheap.

If you're going to fully flush the system, I don't see any harm in a radiator flush product. Might clear some of the crap out. I've only used it on a bike before, but it certainly seemed to help.

As far as your noise is concerned, the most likely candidate by consensus of opinion seems to be the manifold. They can usually be welded or you can track one down in good nick. They're a bit like hens teeth though.

If you determine the fan clutch is not working (but your water pump is), I pointed out someone was selling a fan clutch in the for sale section of the forums.

[MANNO]

thanks Saga - very helpfull - cheers mate

[hash]

If you think it may be from the engine and not manifold. Get a piece of small tube and hold it from the engine to your ear and you should soon hear if its comming from where you hold the tube on.