New Mk4 owner - some technical questions

[RobTheKench]

Evening all,

So, for better or worse, I've just picked up a Mk4 GT TDI that a wife of a friend of a mechanic was selling.
 £500 for an 03 that's done 180k miles and has a little bit of service history, but a full year's MOT.  If it lasts the year and passes its next MOT I'll be thrilled.

Naturally there are a few niggles, and I'm hoping that the more experienced mechanically-minded guys amongst you will be able to tell me which are worth me chasing and which are not going to be feasible.  I'm a fair weather driveway mechanic with access to a haynes manual, most types of borrowed tools, and plenty of optimism.  If it's going to require ramps, or welding, then unless it's keeping me off the road it'll have to wait until later in the car's life when I've got a better feel for its longevity.

1)  When sat on the drive at idle, occasionally it will do 10 seconds worth of "pulsing" or "throbbing" (can't think of better words) at about 2hz.  RPM seems stable.  Does this sound like anything?  Am I better off trying to video it and share the love?

2)  Temperature gauge never rises.  Is there any common fault that's an easy fix?  Clearly I'm not in the market for complex electrical snags for minimal value added.  That said, will the lack of temperature be sending the ECU duff info and be affecting my efficiency or anything?  It is a little smoky.

3) MOT has an advisory for a CV joint gaiter having a "slow grease leak, though it prevents debris ingress" or words to that effect.  How is access likely to be?  If it's a split gaiter, how long have I got before it goes bang?  How much of a job is changing one?

Touch wood I can get some bargain motoring out of this one.  All it's required to do is 8 miles to work and back, and really I should be cycling more.  But I'd like it to be capable of the odd long Journey if needs be.

Thanks in advance for your help - hopefully the good things I've heard about the Mk4 community are true.

--Rob.

*Mods - I've realised that I've dual posted this in the New Members section as well.  Sorry if it makes things untidy.  Feel free to delete or tidy or tell me off or whatever

[Ajamesc]

Gaiter is easy to change ring of Allen keys bolts hub nut and lower ball joint to remove drive shaft easy job.
My tdi had a slight murmur/miss on idle now and then. I was told it was the injector loom. After a while mine would take ages to start then would cut out after a few minutes then take ages to start again. The fault with mine was no1 injector. When it went on the vw computer you could see that injector was massively over fuelling. Once the injector was done the murmur was gone. But your fault could be completely different

[itavaltalainen]

Temp not rising could be thermostat or coolant temp sender.
Have you checked measuring blocks in ECU and cluster are matching? If they are likely the thermostat is faulty, if they don't by quite a margin the sender or its wiring might be faulty.

Throbbing, I would check the ECU for fault codes and look at air mass and injector values in measuring blocks for any irregularities.

[bgbazz]

With those sort of miles, I would take her in for an injector service. Not familiar with this mob in the UK, but over here the Bosch Injector Service centres do a great job and are very reasonably priced.