Not wishing to overthink this, or stand in the way of you and a good grimy time, but wouldn't it just be a damned sight less hassle to take to to a garage?

No.

I don't think there's a great deal I can add to what's been said, but, and I hate to say this - are you sure this is something you want to get into?

I find playing with cars to be great fun and a brilliant break to computers, but they can also be endlessly frustrating and it can be easy to get into to trouble. The RAC/AA will not look kindly at turning up to your half taken apart car :D

Other than that, what do you mean by your spark plugs being faulty? Like any component, they CAN fail, but spark plugs generally just degrade - they rarely cause actual issues. More likely to be a coilpack issue if you definitely think it's electrical. The good news is, though, if they're accessible then Spark Plugs are a piece of piss to change but BE GENTLE. If you cross thread them, you've fucked your engine.

My personal top tips:

• Get a Haynes manual by default
• Don't believe everything you read in it, or indeed on the Internet
• Most things on cars are pretty strong and bolts corrode TIGHTLY, you may need to hit things with hammers
• Get a torque wrench and use it (Especially important for spark plugs)
• ALWAYS, ALWAYS, ALWAYS ensure you use the right size sockets/spanners. You will ruin things if not.
• Expensive tools are great, but don't be afraid of cheaper stuff to get started. I still use the sockets from my very first £10 socket set from Wickes 10+ years ago
• Get someone to help - even if they know nothing too, EVERYTHING is easier with an extra set of hands and eyes
• Start early in the day - there's no fun in realising you need a tool or part at 5:00pm on a Sunday
• The mechanics of a car are rarely the complicated and difficult part - it's the rusty bolts and seized components that will fuck you over.

I changed my cat 5 years ago. Would have been a simple job if it wasn't for the rusted bolts. Not having any experience with undoing rusty bolts I tried loads of WD40, hammer on the spanner and a blowtorch. Think I got all but one or two undone and had to drill them out. Was a pain in the bum.

Sparkplugs are simple. Changed mine this year as my car was misfiring and the plugs hadn't been changed in 6ish years. They'd completely worn our, surprised it was still sparking. I should get a torque wrench for next time though.

Next job is the oil filter and oil on Sian's car.

Top tip: oil goes in the car, not on it!

You're welcome.

> are you sure this is something you want to get into?

If I didn't rely on my car, it'd be a curiosity, and lower priority than a bunch of other stuff I want to learn, but since I expect it to work when I need it, not understanding isn't really acceptable for me.

> what do you mean by your spark plugs being faulty?

Just a theory so far, someone mentioned it a while back of being a possible cause of sometimes taking a few tries to start, and since the battery has been replaced it has twice failed until I left it 5-10mins with the heating on. It might also be cold/damp, but one of those times was about 90 minutes after having been driven, and I read something suggesting that in those conditions it can cause an issue with the sparkplugs being confused about temperatures or something (I'm not describing that very well, and I didn't bookmark the page. :()

I've also recently been getting judderyness when driving, which I've also seen suggested as a spark plug issue, though that's got a variety of other possible causes too.

And that's the thing, I'd like to be able to accurately diagnose an issue - I don't need to be able to fix everything, so long as I can at least have an idea about it.

Really? I thought it was meant to cover the bodywork to make it more slippery through the air. Why would I put it in the car and get oily clothes when I sit down?

What do you mean by judderyness when driving? What *exactly* are you doing when that happens? And is it something you feel as a vibration, through the steering wheel or through the pedals or the gear stick?

Spark plugs rarely cause that kind of issue unless they are cracked or fouled. Fouled plugs misfire at idle generally whereas a cracked plug might only do it under load or when damp.

You likely have a secondary ignition issue if it misfires under load; a bad COP (Coil On Plug) or ignition wire will exhibit that condition. A cold start issue or hot restart problem could be lack of fuel pressure from a leaky check valve at the fuel pump, a leaking injector or a leaking fuel pressure regulator.

If the Coolant Temperature Sensor (CTS) is not sensing the correct temperature when cold, it may cause hard starting. That sensor effectively acts like a choke, to over-simplify things. I don't know what alphabet soup gets used over there so the nomenclature for Engine Management sensors may be quite different to what is used in the U.S.; even at that, none of the manufacturers here can agree to what things should be called.

If you rely on your car and you're not naturally mechanically inclined, all the more reason to get someone who knows what they're doing to look at it.

You don't spill it over the seats, fool. You keep it in a bottle in the boot in case you have a deep-fry emergency.

Sheesh!

Is that a regular emergency in Scotland?

One thing I've found with problems like that is it's not really possible to try things without buying expensive parts that may or may not fix the problem.

Juddering on my car was fixed by changing the spark plugs. It's still there occasionally so I think the coil pack may have been worn oout by being over worked with worn plugs. Have you changed the plugs? And the coil pack fixed the problem on our old Clio. Not sure if either of those would affect stastarting the car though.

Might as well ask a question too.

What might be the cause of the revs staying high when taking my foot off he accelerator? Doesn't happen all the time but it will often stay at 3000rpm when changing gear.

Juddering could be a slipping clutch too especially on pulling away.

Out of interest, what make/model of car is it?

> What *exactly* are you doing when that happens?

Driving. I haven't narrowed it down more than that (it doesn't happen in the same places/scenarios; or at least I'm not noticing if it does). It didn't happen on my drive to/from Tesco just now (~4 miles total), though it has happened before on that route - I wasn't (consciously) driving differently.

I don't think I feel it through the wheel/pedals/gear stick - rather it's the whole car... It could be like switching between having too much / not enough power, or that might be imagination bias. It doesn't last long - maybe judders a handful or half dozen times - generally enough to think "it's doing it again, yep definitely not my imagination, I don't think I'm doing anything wrong, oh it's gone."

It's not being in too high/low a gear, or bad clutch use (I'm plenty familiar with jerkiness caused by bad gear changing).

> [If] you're not naturally mechanically inclined

I think that's where you're reaching the wrong conclusion - I'm not not naturally mechanically inclined.

I like fiddling with things, I just don't presently know how (and am a little apprehensive when it comes to fiddling with large heavy fast moving things).

 

> to get someone who knows what they're doing to look at it.

And when I'm in the middle of nowhere at midnight with a broken mobile... how do you propose getting in touch with the RAC and letting them know where I am? :/

I'd rather make use of the things that make me human and be the one that knows what they're doing.

All: Thanks for the various comments/suggestions/etc so far. :)

I'll respond to anything I haven't currently another time. Need to eat and stuff now.