Air flow meter fault, symptoms

Air flow meter.

I have written about this before in another post but have decided to write about it in its own right. I'm talking about a faulty air flow meter. The best way to find this fault is with a test drive and to listen very carefully to the driver's description. It is no good sticking the vehicle on a computer because as lots of you have discovered it does not show up in the fault codes. Have any of you wondered why? Finding this fault is down to good old mechanical detective work.

The symptoms:

In the initial stages it is quite subtle. The van starts and runs as usual and drives off as it should you then notice that you are having to use a bit more throttle than you used to get out of the turnings; this may go on for some time. Next, in the ebb and flow of traffic the van is not picking up as it should, almost sluggish in the way it gathers speed pointing to a possible turbo problem or a worn clutch in some cases. Finally driving away from a stand still is almost impossible! You have to push down the accelerator pedal a lot just to get up any speed to change up to second gear. On lifting your foot off the accelerator pedal to change gear the vehicle speeds up while you are changing up. On pressing down on the pedal again the van struggles to gain speed. It feels like it is holding back, this is because the air flow meter is not telling the 'brain' the airflow has increased.

I'm sorry to say changing the crank sensor will not do the trick but what is a good idea is cleaning the ERG valve because it will be close to being blocked if the vehicle is being used for a lot of stops start. The combination of these two things will make it purr like a kitten.

Lane hogging becomes a road traffic offence

This is just a heads up. How you drive is up to you.  I am not sure who said this to me:. Ignorance is no defense in the eyes of the law.

This was copied from the ITV news so if you would like to know more click the link.


 2:46 PM, WED 05 JUN 2013

Middle lane hoggers to face on-the-spot fines

Drivers who hog the middle lane or tailgate other cars face on-the-spot fines of £100 and three points on their licence, under new measures announced today.

The fine for using a hand-held mobile phone while driving or not wearing a seat belt will also rise from £60 to £100.

Report by Amy Welch.

Handbrake fails MOT.

Handbrake adjuster

This is a stressful time for the motorist; it is where you hand over your pride and joy to a third party to be poked, prodded and shaken into revealing those profitable faults for the garage. If you are an owner maintainer you should be able to minimize these unexpected failures because you regularly service and put right problems as they show up. I know in practice this is not always the case. But it is better and more cost effective if you do, than to be thrown in at the deep end when you are at your busiest.

MOT testers are human and have pet hates. As an ex-tester mine were lights not working and torn wipers. To me this indicated that it may have other MOT issues which proved to be the case on many occasions.

Brake fluid

I am not immune from the unexpected. Having checked the van over and put right the sticking hand brake again, I was confident that it should

 pass its MOT. The van and tester had other ideas. It failed! I was expecting him to say it was a ball joint but no it was that damned hand brake again. Apparently, the brake machine showed that its effectiveness was outside the permitted balance parameters - (MOT speak), and it was the offside that was less effective or put another way the nearside was still sticking.

With the vans 'back end' in the air and the wheels off, I started to check everything again. But this time more thoroughly than before. I started by loosening the hand brake cable at the adjustment in the middle of the van. Then removed each cable from the calliper first checking to see if the handbrake lever was at rest. They were both holding off by a fingernails width even though the cable was very slack.

Surprisingly with this

poxy system this small amount can make the brake bind badly. I freed off the arms as described in a previous post.  Then checked to see how free the movement was on each hand brake cable that ran from the calliper. The OS one was very rough and stiff as the cable moved back and forth in the sleeve. The NS one was less so but on the way.  I changed both to be on the safe side. what's next? The brake pads are not that old, but I checked them anyway. The near side looked OK, and the piston moved freely the same for the offside, but the pads had an unusual wear pattern. It looked like the centre of the pad had crumbled away meaning that only the outer portion was in contact with the disc; could this be the problem? I checked the brake disc carefully; the surface was reasonably flat, and I could not see any reason for the centre wearing faster than the outer edge. The only way to be sure is to replace them. I know! more expense!

Now to fit them. I started by winding the piston back into the calliper. This needs a special tool but if you do not have one you can get away with using an adjustable wrench (the type that bites your fingers if it slips off - ochhh!!) and a G clamp. It is slow and a pain but saves on the price of the tool. Basically, you wind in the adjuster several turns and then use the G clamp to push the piston back. Before you start this, you should pop the hood and take the cap of the brake fluid reservoir and place a cloth over the top to stop the brake fluid pouring all over the engine bay. This may happen if the fluid has been topped up. Once it is wound back clean the mounting bracket area where the brake pad sits and then put a little copper grease on the edges of the pad that sit on the bracket, this prevents sticking. Push the calliper into place, always use the new guide pin bolt provided with the brake pads and tighten to 35 newton meters (26 lbf ft). You should only remove one pair of pads at a time this allows you to reset the piston for the new pads by pumping the brake pedal also reducing the chance of the fluid reservoir overflowing. Spin the disc to make sure it is free and then apply the hand brake with your hand on the lever to make sure it works and releases properly. Then do the same to the other side.

Adjustment settings

Now attach the hand brake cable to each side and adjust the cable. I usually put a bit of copper grease on the adjuster thread to stop it freezing. Wind the adjustment nut up until you obtain a clearance of between 0.1 and 0.5 mm between the operating lever and the stop on the back of the calliper body. You can check this by using a feeler gauge. Now spin the discs, if it feels like it is binding then back the adjustment off until it stops. Hop in the cab and pull on the hand brake several times checking how many notches it come up - one or two is about right but not set in stone. Then check again to see if the discs are binding now the cable has been settled in. If OK, it's time to box it up.

It is a tense time back at the MOT station as they check the hand brake on the brake machine. Has it passed? it looks to me as it's within parameters. Yes! A 'thumbs up,' great news! back to the day job. 


Update to post 18/8/13.

The handbrake is still working properly with no sticking to date. I have noticed that the mpg has increased since sorting out the brakes by as much as ten miles to the gallon which is astounding. So, all those bits I replaced will have payed for themselves.

Blow out

The vivaro van as a driving experience is quite lively, responsive and fun to drive. I have not driven a van with this type of get up and go since my MK3 Escort. Which I used to rattle around the streets of London in.

Tool kit.

I was on my way home late one evening from a friend when I heard this loud bang which at first, I thought was a bit of debris in the road. Seconds later I was fighting the steering wheel to keep it straight, I was three lanes in on the motorway and travelling at quite a lick, so needed to get to the hard shoulder ASAP. There was not a lot of traffic on this usual very busy section. Luckily, I found myself in a dead zone where all the other vehicles were well in front of me or far behind. The only fly in the ointment was a tractor unit in the inner most lane.

Now stopped on the hard shoulder I took stock for a couple of seconds, pulled on my high viz vest and got out of the cab to look at the front wheel. Man! That's the flattest flat I've seen since my mark three had a blow out on the M 11 all those years ago. Whoosh! - a sixty-footer went by - I need to get the van closer to the embankment if I'm going to change this wheel! First, I need to check in and let people know what has happened.

Changing a wheel at the side of a motorway is quite dangerous but standing about in cold weather waiting for someone to turn up to do the work is just as bad. Anyway, it will not take me long he says as I have changed loads of wheels for other people in the past and gotten it down to a fine art. Ten minutes should see it done and dusted. How wrong can you be. The van had a 'never been used' wheel kit under the seat. Off to a good start there! I found the special security key for the spare wheel cage and proceeded to undo this first. The kit was supplied with a basic ratchet, extension bar and toe loop that screwed in as a handle for the ratchet. I started with the spare wheel first because I knew that if I could not get the bolts undone then I was wasting my time. The special nut came loose quite easily and so did the ordinary nut to start with but there was a problem! It was just spinning round and not unscrewing. The thread was knackered! what was I going to do? I dived into the back of the van and found my largest screwdriver and wedged it between the body work and the spare wheel cage. A gamble I know but it had to be done. I finally got it off after about a twenty-minute struggle.

When jacking a vehicle up at the side of a motorway you should only have it jacked up and wheel off for the shortest possible time. The pressure wave of big sixty footers going by can pull the van off the jack. Then you're in a heap of trouble. Ten minutes later the wheel was on, back on the floor wheel nuts tight, ready to roll. This part of the job would not have been so easy if I had not put a little grease on the wheel nut threads the last time the wheel had been off and tightened to the right torque. (140 Nm 103 lbs ft) Before leaving the hard shoulder you should get your vehicle up to at least sixty miles an hour so that when you join the carriageway again you are not a slow-moving hazard to the traffic coming up behind you. This is one of the only times you should be travelling down the hard shoulder at speed.

Stop! Stop! Stop!

It has been some time since I have posted here. That is because there have been no major running issues, which belies all the things that friends, and neighbours have been telling me is wrong with this Van. That reputation is down to the way the motor trade has dealt and still deals with faults. By using a process of changing parts to eliminate them as faulty instead of following a procedure to determine what the actual fault is. Then charging the customer for the privilege.

 

The van had not been used for some weeks, so it was quite a surprise that when running it up the road to get some supplies that two red lights started to flash on the dash. The STOP and what looks like an outline of an engine. After the initial annoyance I considered whether I should do what it was saying and STOP. However I carried on. With my mechanics head on I started to reason out what could be happening. To a certain extent it looked like the light was flashing every time I hit a bump, but then it looked like it was flashing for the hell of it! I reasoned – could something be loose? or could damp have gotten in causing a short?  I decided as soon as I returned home, I would look in the owner's manual.

 

With the manual in my hands, I look for the icon page. OK the outline is of an engine. Which means: Engine. stop. See page 25. or Engine electronics, exhaust emissions. See page 26. What does it say?

•         Page 25: will light up in conjunction with STOP engine if coolant temperature is too high. The temperature gauge was slightly higher than usual but not off the scale. “It can't be over heating, can it?”

•         Page 26: Control indicator lights up when ignition is switched on. Goes out shortly after engine starts. There are then two headings here, one about flashing when engine is running, which is the one I took note of for obvious reasons because it states: For fault that can lead to destruction of catalytic converter. Look to another Page 94. I did look at the other page for reference. Talk about strike the fear of God into you that you now may have a bill coming the size of the national debt. I have got to say I took this statement with a pinch of salt until I knew for sure that all indications lead down this route. If it does oh man!

 

There was nothing I could do as I had a long trip planned for the next day. Just have to see what happens. I know a break down far from home means an expensive tow. I'll cross that bridge when I come to it. The long trip gave me time to think about what could be happening. I've got to say that it was running really well so it cannot be the converter. (As both lights flash for the hundredth time) I looked at the dash from time to time when the lights were flashing but noted nothing else wrong. Then it went out and stayed out for the rest of the trip.

 

The trip home started well no flashing lights at all. Then we hit a major down pour could hardly see out of the windscreen at double wiper speed. Then I noted that the same two lights were flashing again. By the time I arrived home there had been some further developments the head lights were sort of flashing getting brighter and softer I also noticed that the temperature gauge was oscillating in time with the lights. When I turned the engine off, I notice the cooling fan was running.  This is looking like a cooling temperature sensor problem.

 

With the bonnet up it's time to track down this fault. I still have it in the back of my mind that it is a dodgy connection. But until I find this allusive sensor, “where the hell have, they hidden it?!” Sometime later I track it down to the right-hand side of the engine behind a number of pipes with the sensor facing the bulkhead. Now I have to thread my hand through the pipes like a snake (what a joke) to feel if the connector is loose. There is a bit of movement but not enough. After some fiddling, the connection is removed and reconnected. Oh Well here goes. The engine has now been running for a couple of minutes, no flashing lights.  Better take it for a spin to check and make sure. While I'm out I'll get a cooling sensor.  

 

Since doing the connection I have not had the time to replace the sensor due to workload and the fact you have to drain the whole cooling system down. I hope to come up with a solution that negates this, If I do, I will let you know. But I'm happy to say that the red lights have not flashed again. Bad connection!? Time will tell.  

 

When it comes to red lights flashing on the dash, I am not condoning that you should ignore them and carry on regardless. The situation in which it occurs needs to be taken into account and then the appropriate action taken.

Winter checks

This post is a little behind the curve when it comes to those winter checks. Those who were on the ball would have dealt with these important checks part way through the autumn months. Then again with the way the climate is going you could have snow in the middle of summer.  Knowing when to do it has become a bit of a guessing game. Let's just say that historically the autumn is the time to do it.

 Things that should be checked:

•         Anti-freeze,

•         Battery,

•         Wind screen wipers and screen wash.

•         Tyre pressures and tread depth.

Anti-freeze

The most critical thing you should be checking is the strength of the anti-freeze. Nowadays it is more than an additive that stops the engine freezing, popping a core plug and/or stripping a cambelt. It also stops sludge building up causing blockages and retards corrosion in the engine block.

It is quick and easy to check with an anti-freeze tester.  Which is basically an overgrown eye dropper with discs in it. With the cap off the expansion tank, you place the tube of the tester into the fluid and draw it up into the clear tube once the flow has stopped and the discs have stabilized into two groups some floating and others sinking you can work out how strong the mix of anti-freeze is. It is far better to have more dices floating, giving you the protection needed nowadays for double minus figures. Over recent years this has become more important with temperatures dropping to an unprecedented minus twenty-five degrees centigrade.

 Battery.

Most modern-day batteries are sealed and filled with a gel, so the main check here is to see if the terminals are clean, tight and not corroded. If they are, you can use boiling hot water to remove it. Be careful using this method and only do one terminal at a time so you do not short the battery out. Once done smear a small amount of petroleum jelly on each terminal to stop the corrosion coming back. If you have the older lead acid batteries that need to be topped up with de-ionized water, you are more likely to find the terminals corroded. The same clearing method applies. You will also need to check that the level of the water in the cells is covering the plates, if not they will need topping up with deionized water.

Windscreen Wipers and screen wash.

Windscreen wipers are one of the most neglected items on a vehicle along with tyres. Some people will not replace their wiper blades until they are hanging off and even then, wait till the next service. It beats me how they see out the window to drive in the pouring rain and not hit what is in front of them. The freezing weather destroys the efficiency of your wipers faster than at any other time of the year. When they slide across that ice cover screen it makes minute nicks in the wiping edge. That is if they have remembered to un-stick them from the screen not burning out the wiper motor, it still surprises me how often this happens. You have been warned. When the temperature drops so the strength of the screen wash should go up. This prevents it freezing so you can use it.

Tyre's. 

What can I say, Tyres are the most neglected safety item on the vehicle! You should check the pressures regularly as the right pressures will save you money on fuel. If the tread depth is down to the wear bars (one point six millimetres you should replace them as this increases the chances of aqua planning and increases fuel consumption among other things.

If you look after your vehicle, it will look after you.