2.0 Ford DOHC 8V - Clattery Head Noises
Discussion
The engine is fitted in a Forumla Ford 2000 and started at the weekend making a clattering noise from the head. It came on quite quickly so I am assuming something from the hydraulic cam downwards. It sounds like it is on just one valve. Anyone know of known weaknesses in this area of this engine or the best way of diagnosing the problem as I am not very familiar with hydraulic followers. Thanks in advance.
The engine wasn't that bad in use tbh, it served well in sierra, granada and transit.
Does the tapping sound as if it's on every cylinder or just one? (hard to describe i know, but is it constant or does it have a beat)
The Main can chain tensioner did used to pack up from time to time, but that was normally connected with poor oil change intervals. If this is to be replaced, you might as well do the chain and sprokets at the same time.
Hydraulic tappets can be tracked down with a stephoscope, to replace these the cams need to come out, and they won't come out without dropping the chain which in turn requires a new tensioner on the rebuild
so it's a catch 22.
Is the oil getting up to the head ok?
poor pressure is something often overlooked when playing with top end noises.
Does the tapping sound as if it's on every cylinder or just one? (hard to describe i know, but is it constant or does it have a beat)
The Main can chain tensioner did used to pack up from time to time, but that was normally connected with poor oil change intervals. If this is to be replaced, you might as well do the chain and sprokets at the same time.
Hydraulic tappets can be tracked down with a stephoscope, to replace these the cams need to come out, and they won't come out without dropping the chain which in turn requires a new tensioner on the rebuild
so it's a catch 22.
Is the oil getting up to the head ok?
poor pressure is something often overlooked when playing with top end noises.
Thanks for the repsonses guys. I am reasonably certain oil pressure is OK as it is a dry sump system so level isn't a problem and we have a PI system monitoring pressure which reads 40 to 50 psi. The cam chain and tensioner were changed in the rebuild over the winter so I would hope that they are not at fault. If the cams come out it will be changed again. The tapping appears to come from one cylinder, probably one valve as it is very clearly audible at low revs as a single tap rather than mutiple differing sounding taps (or perhaps I am deluding myself as to my acoustic diagnosis skills!). I strongly suspect something in one valve set. Is there any way of checking a cam follower? Is it just a matter of making sure it has some 'bounce' in it or is there something more scientific I can do? Should I expect to see witness marks for example if the cam is slapping a loose follower?
I'm pretty sure it's not timing chain related as the noise seems to be coming from the wrong end of the engine.
I'm pretty sure it's not timing chain related as the noise seems to be coming from the wrong end of the engine.
madasafish said:
Sounds silly I know, but you may have a slight exhaust gasket leak on that cylinder. Same symptons. Check for exhasut leaks: had this problem before on other cars..
Funnily enough I have. I am pretty convinced it isn't what's causing the problem as the sound is very much more mettalic and can definfitely be heard more clearly with a stethoscope (alright, screwdriver stuck in ear to be accurate) but good motivation to finally get around to sorting it.
rustybin said:
The tapping appears to come from one cylinder, probably one valve as it is very clearly audible at low revs as a single tap rather than mutiple differing sounding taps
One stuck hydraulic tappet.
May be possible to free it by pulling it in and out in a solvent bath (trichloroethane if you can get it), cleaning the oil hole out with something soft. May be easier just to replace since it's all got to come apart anyway.
If the engine's recently been apart, maybe some crap got into one of the oilways and has now made its way to the tappet.
The tappets used in this engine are an inverted bucket type, the hydraulic gubbins sit on top of the valve stem while the cam contacts the bucket assembly directly.
As you can imagine the area in contact is quite small and it's inside the buckets skirt which just about fits over the valve spring.
There isn't much room to do any poking in there.
Replacement is the only viable option really, and as mentioned, make sure the oil ways are free from debris.
A competant person can have the cams out in just over an hour.
As you can imagine the area in contact is quite small and it's inside the buckets skirt which just about fits over the valve spring.
There isn't much room to do any poking in there.
Replacement is the only viable option really, and as mentioned, make sure the oil ways are free from debris.
A competant person can have the cams out in just over an hour.
Well, I thought I'd fire it up and see if I could get a better view as to where the noise was coming from by sound alone. Hey presto, it has disapeared. However, not one to believe that these things cure themselves for anything other than a brief period I went in. The exhaust valve cam followers on cylinders 2 & 3 and the inlet on number 3 definitely feel a little slack compared to the others and one more than the others. This seems to tie in with where the noise is coming from so they seem the most likely culprits. Thanks to all who offered advice.
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