Tapping from engine bay
 

I've got a 940 Wentworth turbo, 94 K plate with an auto gearbox. Generally runs like a swiss watch but has recently started making a tapping noise at low revs. Seems to happen more at the start of a journey, and dissapears as soon as you get up to a decent speed. The problem seemed to start just after I'd topped the oil up.

I used to have an old Austin 1100 with a BMC pushrod engine. Used to rattle like the very devil. This sounds a bit like that (although nothing like as bad).

Bit worried as I'm going on holiday in a couple of weeks and don't want to end up on the back of a recovery truck.

All sugestions welcome

RE: Tapping from engine bay
 

We need a little more information to go on. Like how many miles has the car done? Did you inadvertantly overfill the engine? It is possible that a valve may have become sticky or a tappet may have come out of spec. It may also be something catching on the fan blades. There are so many causes for ticking noises under the bonnet.

All the best, Peter.

RE: Tapping from engine bay
 

Its done 123,000. Ive had it since 96,000 (about 2 years). Serviced every 10,000 with an oil change every 5,000. It doesn't get thrashed and does a lot of urban driving. It gets used for towing about half a dozen times a year, and then only a trailer.

I go over it once a week checking the usual stuff. There have been no dramatic dives in fluid levels. Seems to get through about 500ml of oil between changes - which doesn't seem bad to me. No obvious leaks.

The noise seems to be coming from the cambelt end of the rocker cover. Sounds a bit like my wifes sewing machine. Goes off once you get above 15-20mph.

Regards

Simon

RE: Tapping from engine bay
 

A high probability is that one or more of the injectors is suffering from a bit of dirt. I would suggest that you use a fuel/injector cleaner (fluid) in a full tank of fuel and monitor the noise over the use of the tankfull. It may clear but even if it does not your fuel system in general will benefit. The treatment is designed to keep the system clean for up to ten refuellings. It would be a good idea to ensure that each injector's electrical plug is making good contact with the injector. A slightly loose tappet clearance could also be the cause.

All the best, Peter.

RE: Tapping from engine bay
 

Discovered what may be the problem. Exhaust manifold gasket has failed, and is blowing when the engine is cold. I'm replacing that and we'll see if that fixes it. Thanks for the tip about fuel injector cleaner though. I've never done that, and I ought to really.

I'll keep you posted

Cheers

Simon

RE: Tapping from engine bay
 

To confirm that replacing the exhaust manifold gasket cured the problem.

Simon

RE: Tapping from engine bay
 

Thankyou for the information Simon. I should imagine that the gasket being like a hole allowed some tappet noise to filter out with the gasses.

All the best, Peter.