Clattering sound from engine bay

A

AutoAndy

New Member
Hi Everyone
My P6 2000 auto has developed an annoying rattle/clattering sound from the engine bay. At first I thought it might be the exhaust or heat shield making contact as it seems to happen after a run with the engine hot. I've now pinned it down to happening whilst stationery with the gearbox in drive be it 1, 2 or reverse. When N or P are engaged the noise stops.
Since my knowledge of automatic gearboxes is zero, I was wondering if anybody had any ideas as to the cause.
Thanks in advance
Andy
 
Hi
I've just tested again and the sound isn't present with the engine cold even in drive. It only manifests itself after a run with a hot engine.
Andy
 
There is spacer / ring inside the SC inlet manifold that quite often becomes detached and rattles. If you remove the carb from the manifold it will be apparent. Just take this ring away and the noise will stop.
It is normal to make the noise when a gear is engaged but the car is stationary, because under these conditions the engine vibrates most.
 
Thanks Demetrius & Willy
I will definitely check the carburettor spacer. I've already ruled out the bonnet prop as a source. I'm still at a loss to understand how either would only manifest themselves with the car stationery in drive and with a hot engine.
This noise is a full-on clattering that is loud enough to alarm pedestrians at 10 paces!
 
Hi If you think it's coming from the gearbox bellhousing then check the torque converter bolts haven't come loose.

Colin
 
Thank you Colin & Harvey
I shall certainly check the torque converter bolts which I assume go into the backplate? Harvey, how can I inspect the flexplate for cracks?
Sorry to be a pain but as I said, I am a complete novice with auto boxes.
Regards
Andy
 
AutoAndy said:
how can I inspect the flexplate for cracks?
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Probably the only way to get a half decent look is by removing the starter motor and looking through the aperture, but if you're going to check the converter bolts you can do those through the same hole, so at least you can do the two things at the same time, and if the flexplate is cracked then the starter has to come out to replace it. The only slight problem is the flexplate can crack all the way around where it mounts to the crank, and you'll never be able to see that, yopu'll just have to take the risk of dismantling, or take the risk of waiting until it breaks completely.
 
Thanks Harvey, sorry for delay in replying. I'm in the process of removing the starter motor but the top bolt is fighting me all the way. There just isn't enough space to get a decent socket on it!!
More problems are cropping up with each mile, not only do all water jackets leak slightly but now it appears the rear crank seal has given up the ghost.
I may have to bite the bullet and remove engine and gearbox to remedy everything. I now need to sweet talk my mate with a 4 post lift.
Aren't old cars fun!!!
 
The top bolt on the starter motor can be reached with a socket by adding lots of extensions together. There's a clear line right through to make it possible.
 
Also check the condition of the carb heat shield. They can split apart. Very easily fixed with pop rivets.

Another source of rattle is the round plate that is part of the transmission dipstick. If this comes unglued from the rubber tube, then it will rattle around. This is very easily fixed with glue, or just make sure that dip stick is rammed all the way down the hole will help as well.
 
AutoAndy said:
I'm in the process of removing the starter motor but the top bolt is fighting me all the way. There just isn't enough space to get a decent socket on it!!
Click to expand...

Two combination spanners from above.

AutoAndy said:
it appears the rear crank seal has given up the ghost.
Click to expand...

Rear main seals aren't often a problem on 4-pots, so make sure it isn't the "O" ring at the back of the head gasket leaking and running down.
 
I was convinced on my LR that I had a gearbox issue with a rattling noise coming from back of engine bay area. Turned out to be the water pump bearings, the noise bouncing off the bulkhead . Worth looking at!
 
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