advice re engine problem / MOT

morg_monster

Hi
My car is a P-reg Vauxhall Astra. My parents bought it in 1998 (it had previously been a fleet car I think) and I bought it from them in 2004. So it has a FSH, its been looked after well and has a lowish mileage for its age of about 65,000. Now I live in London and tbh could manage without it, but it is useful to have and I feel its worth more as a reliable car which i know the history of than I could ever sell it for. However now I'm not using it much, max once a week, sometimes it goes for a few weeks without being driven which I'm sure is related to the fault I want to pick someone's brain on:

just before christmas, I started the engine, went to reverse out of the space and the engine stalled. It had done this a couple of times winter 2005 so I waited 15 minutes, started again, pumped the gas as I was turning the ignition and then spent a minute revving/idling the engine and then off I went, no problems. Now I wasn't too worried at this point because the car hadn't been driven in 3 weeks, and it was a very cold morning. Drove it a few times over the next few days, no problems.
Xmas eve we drove 100 miles, no problems. Boxing day lunchtime, same problem, revved it a bit but obviously not enough, because as a did a 3point turn again I stalled. Again, waited 15 minutes, revved it a ton, and then off we go.
After christmas it wasn't driven again for about 2 weeks. This time we started it in the evening, and we couldn't even get the engine to 'catch' at all, the starter motor was just turning but the main engine wasn't starting (can you tell I'm no expert!). Battery light also flickering. Waited 15 mins, same again. My bf was getting a bit desperate so he just waited a few minutes, tried again, pumping the gas, now it was sounding better but still wouldn't catch. 2 more tries a few minutes apart, and it finally starts. Again, a minute of revving, and off he goes.
Each of these times, if I stopped revving the engine after starting, you can hear and see the revs going down until it would stall.

Last servicing/MOT the mechanic told me that only 2 of the 4 cylinders of the engine were firing when the engine first started, and that was causing it to occasionally not start properly. After a bit of revving the 3rd one would kick in, and after a few minutes driving the 4th would. So he charged me a couple of hundred quid to fix this, and it was fine. (He is a mechanic my family have used for a long time and we do trust him.)

I'm guessing it is the same problem again this time, probably made worse by us not driving frequently, maybe the battery is losing charge too. Unfortunately due to money issues I'm keen not to do a full service with the MOT as usual in February. so my questions are, for someone who knows a bit or more about these things:

is this a MOT failure if I don't get it fixed?

if I make an effort to drive the car frequently over the next few weeks (and take it for a long drive before its MOT!) will the problem subside/disappear for now?

should the replacement engine parts to fix it last time have lasted longer than a year given that the car could probably be looked after better? (if so I can take it back to the original mechanic and ask him to fix it again under parts warranty?)

I'm just worried about taking it back to the mechanic and him finding the same problem but saying its not his fault and it costing me more money. Obviously I want the car to be safe, but I'm happy with an old banger and reasonably happy with having to take a bit of care when starting the car in winter. Also the mechanic is in a wealthy area and I wonder if it is more expensive going to him than someone else in wandsworth where I live - but at least I trust this guy and don't know anyone locally to recommend a mechanic to me.

wah i'm getting in such a state about this but it really isn't that important is it. but if you could help i would appreciate it as I don't have any mechanically-minded friends I can ask all my silly questions to!!! basically how can I spend the minimum of cash to have a safe roadworthy legal car.

moonrakerz

It probably would fail the MoT. The physical state of the engine is not part of the test. However if you have cylinders not firing you will have unburnt fuel coming from the exhaust and the car would fail on emissions.

I would take it back to the man who "fixed" it last time !

rizla01

Definitely HIS problem.

The mileage at the time he repaired it should be on the invoice so he should see you haven't had fair use out of car since repair.

morg_monster

Cheers thanks a lot guys. I just don't have a clue about these things. I doubt it has done 2000 miles since the last service so it will be good to go to him feeling in the right about this. He has always been a decent fair guy to us so hopefully will have no problems with this.

tomstickland

Ask him what it was last time.
IIRC the engines used coil packs and these can fail.
If it was my own car I'd start by reading up on coil pack failure for that model engine via internet research, check out the trade price for replacement parts from motor factors. I'd also consider the HT lead condition and general wiring. It's often worth cleaning out the connectors and spraying with WD40.

Cumbrian_Male

Check on the honestjohn website for known faults on your model.

I would be replacing Distributer cap, rotor arm and all the plugs and HT leads. I would be looking for some good silicon leads. Damp can cause problems if your spark isn't getting to the plugs.

If you use the car irregularly then you aren't getting thr heat under the bonnet to dry it out.

As tom said check the coil or coil packs, once all replaced get them all coated in some wet start or WD40 to stop damp penetrating.

DavidHM

If the cylinders are firing once the car is started properly and the car has compression in all cylinders then it should be fine for the MoT once warm. I would look first of all at the plugs/ignition coils/leads etc., depending on what was fixed previously.

On a ten-year-old car it wouldn't be surprising if the battery were failing too and that might explain reluctance to start on the second attempt (as there's just enough charge kept to get the car going once).

Whilst the car probably doesn't need a full service at MoT time, it's sensible to replace the oil and filter as the oil degrades over time and short journeys mean that the car doesn't get up to temperature, causing more engine wear. You may also find that the age of the car has caused the car to need other parts replacing which, whilst they're not strictly service items, can be expected to fail as the car approaches old age.

albacore1854

Sounds very similar to what used to happen when my old vauxhall idle valve packed in, would either suddenly conk out, or not start. If it is, its a cheap fix, take the idle valve off, spray carb cleaner in it and shake it about, then drain it, and reassemble.

Quinny_2

Without seeing the car,it would be hard to diagnose what the problem is,despite the fact that you've given an excellent description of the fault.

I too,would be looking at an electrical problem first,before delving any deeper,and costing you more.If,as you say,the pistons are firing intermittently,it would almost certainly seem that there is no spark to each of the cylinders you say,and then once the engine is running,and charge is getting to the battery,it then looks like there is just enough power via the battery,to spark the relevant plug,which in turn,is firing within the cylinder.

Firstly,borrow a multimeter,and set it to 20v DC,and then put the probes on the relevant polarity on the battery,while the car is not running.If the reading drops significantly while your doing this,I would be inclined to say,the battery is kaput.Then fire the car up,and take another reading.It should read about 13volts while the engine is running.If not,and it doesn't rise,then it's looking like the alternator isn't working/charging the battery,so everything after that part of the circuit,(Battery/coil/spark plugs) isn't getting full power.

If the above 2 are ok,then take each spark plug out in turn,preferably with the dodgy 2 first,and with the lead attached,and the engine not running,place the plug on the side of the block,just touching,crank the engine,and look for a strong spark from the plug.Do this with them all,but don't touch the leads while cranking,unless you are insulated.

If there is a lot of difference,or 1 or more doesn't spark,then you have a dodgy plug,or lead,but when you replace any spark plug or lead,replace with a set of 4.

If all 4 don't spark,and from what you describe,that doesn't seem the case,then the coil pack will have probably have died.

By doing it this way,your starting at the beginning,and eliminating each component in it's sequence,and narrowing down the possibilities on the electrical side.

All of the above should take you no more than half an hour,and all you'll need are the multimeter and a plug spanner.And by doing the above yourself,you won't be lining someone else's pocket,and you'll be able to tell them what you've eliminated so far.

Hope the above helps you,and please do post back once you've sorted it.

Ken.

morg_monster

Thanks Quinny, very helpful post and appeals to my logical mind!
I will try your suggestions this weekend. I'll drive home for some assistance from dad (who is almost as clueless as me) but more importantly my Haines manual which I left there for some reason and the more mechanically-minded neighbours!

morg_monster

Update - I really should have got this info when I first posted!

I've just dug out last year's MOT and service info. The MOT failed for a big hole in the exhaust, so I had a new exhaust fitted and it was retested and passed later that day.
The engine items which were replaced were: HT lead set, distributor cap and rotor arm. So Cumbrian Male was spot on!

So another question - assuming the same things are wrong this time - should these parts last longer than 1 year / 3000ish miles? Or will the mechanic just say that is a consequence of driving infrequently and I'll have to pay again?

Thanks again!
Rachel