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MG MGF Technical - Engine Knocking/Tapping
|Just had the AA to have a look at my 97 VVC as the knocking noise from the engine seems to be getting louder. They said it sounds like the tappets? This means nothing to me?|
MG had a look, once when they did the 48k service & again two weeks ago & they couldn't find anything wrong. But they admit they could hear the noise.
|Gavin, any mechanical noise getting louder is likely to spell disaster, find out exactly what they have checked as VVC's of this era have a habit of dismantling themselves. Avoid driving it until you have it properly checked out preferably immediatly. If you still have problems get in touch.|
If the AA say its tappets then I would be very suprised if it were anything else - Tappet noise is very easy to identify and means the engine is fine - maybe it requires a slightly different grade of oil and a good flush out before changing
Tappets push the valves in to allow fuel into the cylinders and exhaust gases out
In the rover the tappets are operated by oil pressure - on older cars this was done mechanically
So nowadays you dont need to adjust the tappet clearance as the oil pressure should take up any wear - however the oil galleries can get a little blocked so reducing oil pressure - so creating a small clearance that results in the tapping noise - Many cars do it !
There is no definate cure for this - but it wont harm your engine - its just irritating!
Try flushing the engine oil with a good cleaner and replacing with different oil = Do you know what oil its using at present ?
|Tony, Thanks for the advice, MG changed the oil about 500miles ago when I got it serviced. It's currently got Shell Helix Plus 10w 40. I'll try the engine flush tomorrow, any specific engine flush? Also what oil should I put in then?|
Mike, I'll try Tony's idea first, otherwise I'll take it to a different MG dealer to have a look.
|A sunk down tappet gives more of a metalic clinking noise. It should clear in a few minutes. I hate to say it but your problem does sound more serious. I agree with the other writer, it sounds like one of your VVC units is on its way out - expensive.|
Same problem with my '97 VVC - hydraulic lifter on #4 cylinder. Had changes in frequency which means the lifter was slowly revolving (used a stereoscope to pick this up). Had the local garage flushed the engine (I dont do oil changes anymore pain getting rid of the old oil) - new filter etc. Running Mobile 1. Noise is amplified due to the engine being shoehorned into a very tight compartment.
Up side of the engine flush was, a lower oil temperature and a slightly quieter lifter.
Still have the occasional miss fire even after I changed, the fuel filter, removed the fuel pump, checking suction pipe, replacing the HT leads and last week replacing the battery been working in Oz for the last 5 months battery had sulphated (lack of charging).
Next step to a local dealer and have TestBook perform diagnostics on the MEMS.
|Thanks for all your advice guys, I took it to a different MGR dealer today. They found that it was acutally a spark plug that wasn't in correctly.|
Ahh, I've got it back now, excellent. It even seems a little quicker off the mark. Maybe just me though.
|Crappy, my car started tapping...|
I think I am low in oil so filling it up at the moment. Hopefully that solves the problem..
This thread was discussed between 14/12/2001 and 19/12/2001
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