GENERAL
Battery booster pack
Q In my household we have my 2014 Skoda Superb 2.0 TDI, plus two Citigo’s (a 2012 and a 2013, both 1-litre MPi) plus a 2011 Skoda Fabia 1.6 TDI. Can you recommend a battery booster/ engine starter device that would start these engines if any have a battery failure?
Your advice is much appreciated.
Andy Scholey
A I would certainly recommend using one of the newer smaller lithium packs as these are far more convenient to carry and use. Most do also include the safety features that prevent the polarity being incorrectly reversed. They also often come with a USB port meaning they can be used to power up a dead phone or other accessory.
The power of the unit will be dictated by the largest of your vehicles and this would be the 2.0 TDI Skoda. So, a pack such as the Ring RPPL300 at under £75 would be a good option.
Other packs to consider are the NOCO Boost Plus GB40 1000A 12V for around £110, the Laser 7405 Jump Starter which has a power output of up to 700A at around £116, or the Clarke JSM350 Multifunction Micro Jumpstart/Portable Device Charger Power Pack which a peak current 500A – and also has a light – for around £106.
All the above are rated as sufficient to easily spin over the 2.0 diesel engine in your Skoda if needed.
FORD FIESTA
Spark plugs
Q I have a 2008 Ford Fiesta 1.25 which is a 2007 Mk6 model. When I purchased the vehicle just under five years ago the mileage was around 43,000 miles and it has now covered a total of 59,000 miles. When purchased, I put a set of FoMoCo spark plugs in and I have not taken them out since. The engine has run fine. Then it started to get sluggish, so I cleaned the valve body and took out the spark plugs. Three were fine but number one looked as if it had been hit by something. The gap was closed down to about 0.3mm. The electrode is still solid and not cracked, I put another set of spark plugs in and the engine is back to normal.
My concern is why did this happen?
Adrian Prince
GENERAL
Power tools
Q I’ve been a long-time subscriber of Car Mechanics and have been messing around with cars for many years and there not too much I won’t do – however I hope you can answer me this question?
I decided to purchase an impact wrench a few months ago. A great tool, specifically a Milwaukee M18FHIWF12-502X (18-volt) along with two 5Ah batteries and a charger. And of course, a selection of Sealey impact sockets. This boasts a tremendous torque (unless I’m misunderstanding something), but this weekend I had an issue as follows:
Front caliper carrier bolts on a 2009 Qashqai were somewhat tight and the impact wrench could not release one of them.
After soaking with PlusGas and a freeze spray (don’t know if these work), it still wouldn’t budge despite the Milwaukee being on the highest setting. Both batteries were tried – they are fully charged I might add. As a last resort I put a long bar on the impact socket and with all my weight I eventually loosened it. So, my question is why?
Surely the impact wrench should have done this. What am I missing here as I do not understand?
Jim Laing
The Milwaukee M18FHIWF12 Impact Wrench.
A The impact gun you have should give a torque of 1897Nm of nut-busting torque, which is as you say a tremendous torque, but this is only a very short burst of torque, and does only refer to the very first strike of the hammer action. When the bolt is seized a more sustained pressure is required to shift the bolt.
Depending on the length of the bar you used I would expect that around 1400Nm could be applied with a reasonable force, but this would be a constant pressure as opposed to the rating of the Milwaukee gun which gives the maximum torque in very short bursts, and while this is great for fixings which are simply tight, it will not always be sufficient to counteract the effects of corrosion on the threads, or threads that have been coated with a locking compound in the same way that a constant slowly applied pressure will.
The main reason for this is the bounce effect, and It can be the case that short burst given by the gun will allow the bolt to bounce but remain in the same fixed position, whereas the bar will give a slow and steady pressure that will slowly move the bolt. Impact guns are good, but for the really tight stuff, I like to use a very long bar and a steadily applied pressure.
GENERAL
A The spark plugs in your 1.25 engine should last for around 37,500 miles or 36 months. As the replacement has solved the sluggish engine problems then hopefully the problem will not reoccur.
It is difficult to say what may have caused the problem and without seeing the spark plug any suggestions I have are of course purely hypothetical.
A bent electrode on the spark plug would normally suggest that the spark plug thread reach is too long for the engine head – or that foreign matter has entered the combustion chamber.
As the spark plugs had been in so long I would not expect them to be incorrect and so the only theory I can suggest
