ticking noise after replacing exhaust

It's been a while since my last post. Busy working and other stuff. But bear with me on my story :

I have revived my TF from winter sleep, about 9 months standing still. Before startup I have removed the spark plugs, put some oil in the cylinders, and moved the engine by hand. After that mounted everything back together, and hoping nothing had broken due to long inactivity. Indeed it fired up fine, no issues, no strange noises, no smoke, what more could you wish fore.

There was one thing : the MOT was needed, so took it to a MG/Rover garage in NL, and the verdict was that it needed 2000 euro's of repairs : suspension arms had to much play, leaking gasket at one of the drive axels, and foremost the complete exhaust and flex pipe needed replacement because the flex pipe did not had enough structural strength anymore. It is a garage I had never been there before, my old garage has retired.

So after a week my TF was ready. On departure I heard I strange ticking noise in the engine, so went right back. According to the garage I needed to replace the engine oil with Castrol magnatic, because the tappets produce noise. I have heard this is a good remedy, so I tried it, put in 4,5 liters of the stuff and a new filter.
But no luck, and indeed I find it very strange that with the old exhaust there was no ticking noise, and after mounting the new exhaust, suddenly the tappets start making noise. A year ago at the old garage the engine head has been overhauled, new tappets and new valve seals, worked like a charm. So also very strange that new tappets suddenly would start making noise.

So I doubt the noise is coming from the tappets, usually when a strange sound appears after a repair, that would be the place to look. I have made a video with the ticking sound. I would appreciate your opinion on the noise you hear: is this surely the tappets, or is it plausible to have a different cause ?

video

Thanks for your opinion
Kind regards Theo

The car has been laid up for a long time and hydraulic tappets can dry out (valve pushed down for nine months, the oil squeezes out) and then take a while to pump up again. It should not harm the engine to get it warmed up and see if the problem just goes away after fifteen minutes. Often it does.
It might be a poorly fitted exhaust leaking around a gasket, but it is quite unlikely. Try blocking the outlets with a piece of cloth and see if the noise increases.

On the video it sounds like a wayward ignition spark. It also seems like you have a misfire.

Check the ignition- plug leads etc.

I'm with David on this one as the tick isn't constant as it would be for a tappet . Check for corrosion at the coil pack at lead that branches off .

I use to get tappet rattle on my old MGF after it had been out of use over the winter. I am sure it varied with revs.
Normally it goes away after enough oil gets into the hydraulic tappets -it can take some time though.
personally, I don't think that ignition spark arcing would be that obviously loud on a modern engine-on an old A series probably would be.
You could try some hydraulic tappet additive-it worked on my old MGF.
One other thing -if you can get a code reader on it you would read codes for a misfire

Mike

The ticking has started after the garage has replaced the complete exhaust system due to MOT. Also the ticking gets louder after the engine has heated up, so I think it could be somewhere in the exhaust system. But a new development : on the highway, the ticking got really bad, until it became a loud rattle for a few minutes, I was standing still in the traffic jam. The rattle ended suddenly just like something broke off. After that the ticking noise has almost diminished, still there when the engine is hot. I didn't come around to doing a good diagnoses,
I have also issued a complaint against the garage because the repair in general was performed poorly, they had to replace front and rear suspension arms due to MOT, but the car is now makes a cracking sound at every corner, and they had to remove the front bumper to get to the suspension arm bolt, and at re-installation they mounted the bumper crooked, not aligned with the rest of the car, also sits against the headlights while there should be a few mm space, and bolts of the inner wheel arch covers are missing. The garage did not react to my complaint so I issued a complaint at our Dutch Bovag, I want to have these issues repaired in a decent way preferably by another garage, then also the ticking noise can be investigated. And mind you, this has been an official MG/Rover garage until MG had gone bankrupt, and they still sell and service MGF and TF's, so I was mindblown about this poor quality.