"Clatter" from engine

S

sico24

Member
Hi

I have a 'clatter' coming from the engine of my 1967 2000TC at approximately 1200-1300 revs. This happens on the way up and way down - it's non-existent at low or high revs. It seems to be coming from the top end. It's very loud! I have just changed the oil (Morrison's 20/50) and it has made no difference

Do timing chains sound like this or is it likely to be something else (carburettor heat shield?)

I realize it's difficult to diagnose without hearing it but any help would be appreciated.

Thanks

Simon
 
Hi Simon,

The sound you describe is more than likely timing chain rattle, especially if it's a metallic 'ringing' sound.
Could be symptomatic of lost oil pressure. How does the gauge read when the oil is nice and hot and you've been on a fast run? If it drops, it's a sign of worn main and big end bearings (practically a 50,000 mile service item on the 4 pot). The timing chain tensioners (1 upper, 1 lower) use oil pressure behind them to apply the optimum tension to the chains. If the oil pressure drops, the tensioners don't operate correctly, and you get a load of rattle from the chains. This might also cause a lumpy idle, as the valve and ignition timing would tend to 'wander' back and forth fractionally due to the additional play in the chain.

I have heard of cases of the bottom chain tensioner 'dropping out' and landing in the sump. In which case, all you need to do is 'stick it back in'. But if the bearings are gone, you should replace them. Either way, it's a sump-off job, but this isn't as traumatic as it sounds. Brian Northampton has a brilliant blog with a great article about tackling this job. Search Rover P6 blog on t'internet and you should be able to find it.

Michael
 
I've just done the mains and big ends job as described by Brian northampton and it really is a piece of cake. Probably took me about 2 and a bit hours all in, I had the noisy chain symptom as described and now it's done she runs lovely and quiet.
Here's a link to that very helpful article: http://www.roverp6.blogspot.com/
You have to scroll down a bit to get to it.
 
Hi

Thanks to you both - I thought it might be something like that. As it's a series 1 with the strip dash there is no oil pressure guage so I can't tell (maybe I ought to fit an after market one) what the pressure is like. The clatter does not seem worse when hot or cold, but the idle does 'hunt' a little so it could be as suggested. It's not particularly a metallic ringing sound, but I will investigate further at the weekend.

Any other ways to tell before I drop the sump?

I will look at the blog by Brian and consider doing the job.

Simon
 
If you think that the sound is coming from the top end then I'd remove the cam cover and have a look in there before removing the sump. Worn ends and mains have a very distinct sounds (knock and rumble) neither of which I would describe as a clatter, which as you suspect, sounds more like top end.
 
restojon said:
Is it worth checking if a cam cap has cracked? Could also be a possibility
Click to expand...

That's would be what I would be looking for, along with excessive valve clearances, or cracked buckets, or the top timing chain guide loose. It's amazing what you can find in there once the cover is off....

Although the cam carrier and caps should be replaced as a matched set I do have a couple of caps around here if that does turn out to be the case. Whether they would be the right ones though......

I have assumed that it's still running on all 4 cylinders, if not that adds whole world of other possibilities.
 
Hi

Thanks for all comments - ran the engine tonight for 20 miuntes.

Clatter is at exactly 1200 rpm. As I am completely deaf in one ear it's difficult to decide exactly where it's coming from. Going under car and in from above, it appears to be coming from the rear of the engine and maybe (??) louder from below. Unscrewing the oil filler cap and listening to the top chain doesn't make noise louder so seems unlikely to be top chain? There doesn't seem to be the bearing knocking and rumble?

Oil pressure light stays off all the time at idle even after 20 minutes revving, so I don't think it is low oil pressure (and light does come on with ignition so is working OK). Engine is firing on all 4 cylinders. Looks like I'll take the rocker cover off first, then think about sump after.

As I'm taking for MOT on Thursday, I'll ask my mechanic mate to have a listen too.

Thanks again for all the help

Simon
 
Aluminium especially has a nasty habit of 'transmitting' noise so it may well be coming from the opposite end of the engine to what it sounds like.
I have a long screwdriver that I use as a stethoscope for these kind of things. Put the handle against your good ear :D and the pointy end against various parts of the motor. This should help you narrow it down a bit.

Health and safety announcement: "Obviously, you need to take great care not to poke the screwdriver into the fan or anything else spinning at high speed." :LOL:

If you don't have a long screwdriver, you can use a piece of dowel or something. Also, a length of thin rubber hose can be used. This is especially good at finding air leaks but does work for rattles too.
 
it could be the carb black plastic plate? it has a steel tube pressed into it and it can come loose and start chattering around, take off the carb and look in side?
 
herts2000 said:
it could be the carb black plastic plate? it has a steel tube pressed into it and it can come loose and start chattering around, take off the carb and look in side?
Click to expand...

SC's do that, but this is a TC and they dont have them.
 
HI

Doh! Tracked down the rattle, I think. Purely by fluke, put my hand on the gearlever and it stopped. Looking at the Gearbox forum, it seems this is well known (rattling like an agry snake!) - gear lever bush 'teardrop'. Will pull the gearlever and see.

The only excuse I have is that I am completely deaf in one ear so my spatial hearing is not good!

Thanks to all who responded.

Simon
 
Glad to hear it was something relatively straightforward!
I must admit, I also have a tendency to imagine the very worst when a rattle develops - it must be a classic car owners' disease! Still, better that than ignore a potential problem, only to blow up on the motorway on a bank holiday weekend!!
 
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