Email Tim with your questions

Hello Tim,

I wonder if you can help me. I recently bought a rover 75 converted to LPG. I bought it on e-bay and was told it ran perfectly. After driving it I realised it wasn't running properly on gas. It runs perfectly on petrol but it judders all the time on gas, it sometimes cuts out if you slow right down. I have replaced the coils and the plugs but no change. I wonder if you could throw some light on the problem.

Cheers.

Scott Morrison, UK

The perils of buying on e-bay! You need to concentrate on things that are only related to the LPG part of the system – the plugs and coils are common to both, so it wouldn’t run on petrol either if they were to blame. The LPG part more or less mirrors the petrol injection system and yours should be a multipoint sequential type which is the most complex, so diagnosis from the information you’ve supplied isn’t really feasible. The car needs to go to an approved LPG specialist for any work to be done – for your nearest agent, check http://www.drivelpg.co.uk/AI/

As a general piece of advice to anyone considering LPG as an option to reduce fuel bills, make sure the car is thoroughly tested running on petrol and on LPG before you part with any money.

Has anyone emailed you about these conversions which introduce Hydrogen into the fuel mix? They claim to burn all the fuel instead of 85 / 90 per cent and so increase the mileage of the car, per tankful. The ones I've seen have an electrical device which fools the computer to think the mixture is normal, and so a leaner mix is achieved, and so one gets better mileage. I'd welcome an expert view of them, if you've seen any.

Kind regards,

Jeff, UK

My “expert” view is that they are a complete waste of time and money, dressed up with some technical sounding babble that pretends to be science. It isn’t science and it isn’t correct. Claims that an engine only burns 85 per cent of the fuel are complete nonsense, although it is a claim often used to justify the bogus theory behind lots of these worthless devices. The real facts are:

1) A modern engine burns between 98 per cent and 99 per cent of the fuel in the cylinders.

2) The explanations of how the hydrogen helps to improve the efficiency are irrelevant for a normal petrol engine without extensive modification (and I don’t just mean messing about with the sensor values), but even if they were true, the maximum improvement would be 1 per cent to 2 per cent.

So, beware of anything that claims to improve power, fuel consumption or emissions by improving the efficiency of combustion. There’s hardly any improvement to be made. And before you part with any cash for something that promises to improve power, performance, economy, emissions and all the other fatuous claims, just ask yourself why the manufacturers don’t fit it. They are about to pay huge penalties if they don’t improve fuel efficiency on all cars sold in Europe. And I mean huge penalties – millions of euros in fines. If something knocked up in a shed for a few quid would do the trick, do you really think they’d be ignoring it?

Why should you take my word over the advertisers and con men? It needs a little maths and science, but nothing complicated and nothing mysterious. Click here to find out

I have been driving on my wife's car insurance for several years, as my no-claims bonus lapsed. I am purchasing a new car in December and would like to have my own policy. Are there any insurers out there who would give me a no-claims bonus based on my and my wife's record?

Bob Williams, Scarborough, UK

Quite a few people are in your position these days – people who have had a company car for years, for example. Recognising this, most insurers will give an introductory no claims bonus (although they like to call it a no claims discount these days – doubtless there’s a sound marketing reason for that). My old colleagues at the AA say they would probably offer 30 per cent for the first year, but ring around to compare prices and deals. You can get a nasty shock at renewal time however, because something most people don’t realise is that this generous discount is often only for a year – after that, assuming you’ve made no claim, you will probably drop to a 1 year no claims discount, usually 10 per cent and then work your way up from that. So, ask what happens at year 2. It’s also worth asking your wife’s insurers what deal they can offer you, since you’ve been named on her policy.

Hi

A friend recommended I get in contact with you about my 06 Tigra. The car has a Tiptronic gearbox which I drive as an auto all of the time. I have now had copies of all of the work that they have done under warranty - they have undertaken £2000 of work. I am still banging my head against a brick wall as I have a leak when it rains through a seal in the roof.

They have replaced everything and they have had an engineer down from Vauxhall who has measured the roof etc and yesterday they said that it didn’t leak under pressure from a jet washer. But again the other week when driving it started to rain and the drip started. They have offered no explanation as they cant find anything. I am also told to expect water to run in if I get in the car when its raining and the door is then shut (never used to do this before the water started approx 3 months ago - never had any issues with previously).

The second issue is the gear box - sometimes it doesn’t change up automatically it seems to get stuck at 4-5000 revs. They have put it on the diagnostics system and nothing shows up. Doesn’t do it all of the time. It clears it self after about 5-10 seconds. Apparently there are no known issues.

Motor sales in Harlow have said they wont buy the car off of me however i can look to trade it in. I would still like a convertible and I don’t want Vauxhall or Citroen or Saab.

I even logged a call 2 weeks ago with Vauxhall Customer services who have not called back - mind you the man i spoke to didn’t even know if I would get a call back within 24 or 48 hrs! Any help or advice you can give me would be appreciated.

Kind Regards

Caroline Mcintyre, UK

Three questions in one here, so let’s take them in turn.

1) Soft tops never leak when you put a hose on them – the water isn’t hitting the roof the way it does when the car’s driving through rain. Tigra Convertible roofs are well known for leaking through the seal between the roof and the window and, sadly, no-one seems to have a cure for it. The plus side is that anyone buying it will probably be aware that the roof is liable to leak.

2) There are no common problems with the auto box. Yours sounds like a sticky actuator or poor contact. An auto specialist might be better at diagnosing the problem than the dealer – auto boxes are a bit of a mystery to most ordinary garages. Try someone from the delightfully named FATE (Federation of Automatic Transmission Engineers:

http://www.fedauto.co.uk/memfind.htm

3) I don’t do car reviews, but the Mitsubishi Colt CZC Cabrio seems OK so far. The Peugeot 206 CC is quite pretty – BUT they suffer from problems with the roof mechanism and the auto gearbox. Where have you heard that before?

Hello,

I recently purchased a Mazda RX8 second hand. On driving it home down the motor way an alarm/beeping sound started when I went over a certain speed. I don't have a speed limiter on the car. The Mazda dealership tell me that there has been some sort of limiter/warning programmed in (probably by the previous owner) - but they don't know how to turn it off. They have apparently contacted Mazda technical department to find out how to re-program/disable this but Mazda have not got back to the dealership as yet. Any thoughts on how to stop the beeping? It's incredibly annoying!

Thanks

Name and address withheld

If this is a feature that the dealers aren’t aware of, make sure the car isn’t a grey import. If it is (and possibly if it isn’t) a member of BIMTA might be able to help you.

I've been told by my local tyre fitters that my Subaru Forester is running on the wrong tyres and should only use Yokohama tyres recommended by Subaru as the insurance would be invalid after an accident. Is this true or just marketing ploy?

Adrian Fisher, Cowbridge, UK

Provided your tyres are the right size and specification they will be fine and won’t compromise your insurance. Fitting tyres of a lower speed rating or load rating can cause problems, so you do need to check the whole specification carefully, not just the size, but there are certainly alternatives to Yokohama that meet the spec. However, Subaru strongly recommend changing all four tyres at the same time to avoid any damage to the differentials.

I have an Audi TT, Quattro 225ps 1999, 80k miles, with some Audi service history. The car runs great but whenever it is in very heavy traffic for more than about 10 minutes it overheats (temperature gauge heads towards red). I have found that by increasing the revs, which I assume gets the fan going, the temperature gradually comes down. I've also discovered that just switching the air conditioning on increases the revs sufficiently to prevent the overheating if done soon enough - after maybe 5 minutes of queueing.

Audi have had the vehicle for a couple of days and could not get it to overheat with the engine left running - the fan kicked in every time as it should. They fitted a new water pump and timing belt which has had no effect. They have suggested it could be a problem with the 'pod' giving false readings, however I am reluctant to part with £1000 to replace this, if it may not be the problem. It seems unlikely as the car only overheats when in jams and not irregularly which might indicate a faulty reading.

I've put up with this fault for over a year now, but I am planning to sell the car soon and would prefer not to have to explain why I call the aircon button the overheating button.

I would appreciate your thoughts.

Regards

Name and address withheld

I’m not sure there’s anything wrong with the car. TTs do run hot and if you have always turned the aircon on before the needle gets too high, you may be pre-empting the car’s own cooling arrangements. When the aircon is turned on, the radiator cooling fan runs permanently and another big fan comes on, which will cool the engine down, but I suspect that the radiator fan would have cut in on its own before the temperature got too high. You can simulate the “jam” conditions and do a bit of investigation. First, take the car for a 10 to 15 mile run to get it thoroughly warmed up, then park it on your drive or somewhere convenient and safe, but leave the engine idling. Stand by the bonnet, leave the aircon “overheating” switch alone and listen for the cooling fan starting up. Do keep an eye on the temperature gauge, but don’t panic unless it gets right into the red without any noise from the fan. Increasing the revs simply increases the water pump speed and circulates water more quickly, so cooling will be improved but that doesn’t mean it is insufficient at idle. Keep your cool and give the car a chance to show you that it can keep as cool as it looks.

I hired a car on Friday 5th September, it broke down on Saturday 6th, and I could not get any assistance until Monday 2pm. Got back from the breakdown to the hire office (172miles) at 6:30pm to be told there would be a £500 insurance charge for causing the breakdown as they say driving through 4 to 5 inches of water had caused the breakdown. how is this possible? The car never missed a beat, I had stopped 120 yards further along a single track road to let a caravan pass, then went to move off and the engine made a thump noise and died. Any help with this would be much appreciated.

Peter Dixon, Scunthorpe, UK

Engines are designed to compress air, which is a gas and therefore squeezable. Water is a liquid and isn’t. When water gets into the cylinder and the piston tries to compress it, it’s like hitting a brick wall, but to make matters worse, one of the other pistons is firing and forcing this piston ever harder into the solid mass of water. Something has to give, and it’s usually the rod that connects the piston to the crankshaft. Fixing it means an engine rebuild. Even a few inches of water can be a problem if you cause a bow wave or splashing that reaches the level of the air intake. In your case it seems that the water entered the air filter, but the speed of the air rushing into the engine of air held it around the filter casing (like rain held up on the windows by the airspeed while you’re driving). Then, while you waited for the caravan with the engine idling the airflow slowed enough for the water to gather in a pool in the bottom of the filter. As you revved the engine to set off again, the airflow picked up a lot of water and it got sucked into the cylinder, followed by a bang as the innards broke. It’s not uncommon, so other drivers beware, especially given our current floods. Diesel engines seem particularly prone to this, but I’m not sure whether it’s because of the higher compression involved, or because diesel drivers think they’re impervious to floods and are therefore more likely to drive through them too quickly.

I have noticed a product on the market which is a "plug & play" diesel tuning system which is priced at £129.99 and promises to do what chipping can at a lower cost. It appears to be some sort of connector cable that can be self fitted. It offers up to 25 per cent more power and torque and 5-7mpg increases. I was wondering whether you are aware of the product and thought it was worth fitting to my wifes' Nissan Almera 2.2 DCi 136? (I noticed it at www.carperformancepartsuk.com). It almost seems too good to be true at that price.

Many thanks,

Adrian Corney, Market Drayton, UK

It is indeed too good to be true – at any price. Another load of unproven claims relying on the fact that no-one will fund the very expensive testing programme that would be needed to refute them. More power, more torque and less fuel. Why, that’s just amazing. I wonder why the manufacturers never thought of it.

2007 Mondeo Ghia Estata 2.0 TDCi 130 Ghia. In August I towed my caravan to Spain once we arrived I attempted to reverse the caravan up a slight incline to put it on its pitch whilst doing this I burnt the clutch the smell was horrendous any way we gave up and got the other campers to man handle it on to the pitch. Whilst I felt worried about the clutch I carried on using the car without problem for two weeks although the smell didn’t go away. We decided to leave early and go to another camp site 40 miles up the road as we approached the camp site the clutch started to slip. So I decided to contact the AA who recovered the car and took it to the local Ford dealer. They immediately assumed the caravan was to heavy for the car and quoted a minimum of 1,500 Euros to put it right (which isn’t true I went to great lengths to choose a light weight caravan) because of this they concluded this was definitely not a warranty job.

The AA where now able to withdraw any additional help as the car could be repaired and anyway your caravan is to heavy.

I contacted ford dealer in UK they suggested might be warranty if not around £500 to put it right . As the cars clutch only slipped whilst towing we decided to put the caravan into storage in Spain (220 Euros for the year) and we travelled home without any problems. By now the smell has gone and I took it into my local Ford Dealer who cant find anything wrong with the clutch no slipping and was reluctant to take it apart when their doesn’t appear to be a problem. I now have the car back working perfectly. What happens next year when I attempt to tow the caravan back home?

Ian Moffatt, Cambridge, UK

The Mondeo has just been named as Tow Car of the Year for the second year by Caravan Club and should be well up to the job. To check the clutch, try to find a steep hill (not easy around Cambridge, I know) and accelerate up it from about 30 mph in top gear. Any slip will be immediately obvious. Assuming the clutch is OK, I would check the brakes on the caravan very carefully. They could be sticking on (a frequent problem on any trailer because of relatively infrequent use) or there might be a problem with the reverse brake interlock mechanism. Since you were able to manhandle the caravan (albeit with the aid of other campers) it obviously rolls, but a stiff mechanism can make the brake very slow to come off after operating, so try applying the park brake firmly, then releasing it and immediately try to move the caravan. Then hitch it to the car, brake firmly from about 30 mph and once again try to move the caravan straight away. You certainly should get the brakes checked thoroughly before setting out back to the UK.

I am driving my Peugeot 206CC from London all the way to Killarney in Ireland via ferry in Wales on a road trip/holiday. Do you have any advice about driving through Ireland and what checks should I do on my car before I take the long trip?

David Shelley, London, UK

This is a longish journey but well within the capabilities of any modern car without any special preparation other than routine checks. Of course, if a service will be due through mileage or time before you return, have it done before you go to be on the safe side. The “routine” checks I’m talking about are oil, coolant, windscreen washer and brake fluid levels, tyre pressures and condition, lights and windscreen wipers (if they smear the windscreen or make that horrible scraping noise, fit new blades). It’s not a bad idea to take a set of spare bulbs (you can get kits in a box them from accessory shops, or occasionally very cheaply from Lidl or Aldi).

You must have the original registration document (log book) and your insurance certificate, and make sure you insurance covers you for the trip. You also need a GB sticker. Heavy cars like 4X4s need a warning triangle, but as you car is under 1524 kgs it’s not compulsory for you.

Driving in Ireland is fine, although in very rural areas the rules can be interpreted flexibly! Some roads in rural areas are very narrow and twisty, even though they are main roads, so always drive according to the conditions. Distances and speed limits are in kilometres now, so remember that 50 kph is about 30 mph, 80 is about 50 and 100 is about 60 and you’ll be fine.

Above all, don’t be tempted by the excellent hospitality in the pubs and hotels to drink and drive. And enjoy the holiday.

I have a Corsa X Reg Automatic which rolls back when in Auto. Also when I am reversing and am in R the car rolls forward. I can only drive automatic and I have been told that this is what this car does?

Mandy Betts, Romford, UK

I think your problem is that the car rolls backwards on a hill when in A, rather than your previous cars which would stay stationary. I hear this complaint quite often from people who have just bought a new automatic and it’s not a fault. Older cars tended to creep forward when in drive even thought the engine was idling. This wasn’t really a design feature, it was simply because the torque converter still exerted a drag on the engine at low speeds. This was handy for hill starts and for inching along in traffic jams, but because of that drag the engine was using more fuel at idle than it would when bolted to a manual gearbox. Modern auto transmissions are designed to minimise drag so that the engine doesn’t waste fuel when the car’s stationary, but the drawback is that you no longer have that handy way of stopping rolling back on a hill. You are in the same position as someone with a manual gearbox – you can use the handbrake to hold the car still. As a matter of interest, some autos now offer a “hill assist” option which is a box of tricks that holds the brake on for you until you want to move forward.

Hi Tim,

The problem is with a 2 year old B180 CDi with Sports Pack. The car has done 65K miles and has, over the last few months, developed a voracious appetite for front tyres. This has been accompanied (over the last 30K miles or so) by a considerable amount of what can best be described as graunching/squeaking/groaning from the front suspension. On the first time this was noticed by the Dealer (3rd visit...) the front o/s upright was replaced but to no avail. I have now lost count at the number of times the vehicle has been in since to look into this problem; the problem is more pronounced the drier the weather, and appears to be made worse when the front suspension is put under load (turning into a junction from a main road when the suspension 'loads up'; speed bumps are a nightmare as are country roads). Whilst this 'groaning' has been going on, the front tyre wear has accelerated; I have gone through a set of front covers in less than 2500 miles and it always wears the inside edge down to below the legal limit across about 2 inches of the tyre. When this happens - tyre(s) replaced, vehicle booked in, tracking/camber/toe-in checked and re-aligned. Wait 2-3000 miles and repeat.

The car has never been in an accident nor has it been 'kerbed' heavily. It is always serviced as per schedule.

The car is a Lease vehicle but they do not seemed to be bothered about having tyres changed at this rate (and price!); I am becoming very concerned about the overall integrity of the front suspension and, bearing in mind things like ESP etc. and braking systems, tyre wear and front suspension alignment would seem to play a pretty important part in these systems working properly.

I have tried the dealers many times; changing dealer is not an option as they are all part of the same franchise. Short of taking it to MB World at Brooklands and abandoning it there I am getting to be at a loss as to what to do next. Shame as the car as a long distance vehicle is unmatched and huge and very versatile inside.

Comments/ideas/suggestions very welcome.

Neil Owen, UK

This is quite ridiculous. There’s clearly a fault with the suspension or alignment and I’m astonished that Mercedes haven’t found it. The “graunching” makes me suspect a joint, but it sounds as if the dealer keeps jacking it up to investigate and some faults with suspension joints are only obvious when the suspension is in its normal position. Jacking it up can pull the joints into a position where play isn’t apparent. I would get it to an MOT centre with a modern ramp that can check everything under load – hydraulic rams shake the wheel in every direction so that any play can easily be seen. If that doesn’t reveal any problems, get a full laser wheel alignment check on all four wheels. I’m surprised that the leasing company hasn’t made more of a fuss, but it would be worth contacting them as well, since they will potentially have the problem of selling a faulty car at the end of the lease.