Jump to content

IVA - specific test and fail points


Recommended Posts

I'm going through IVA for the first time soon, and in preparation I've been trawling through a few documents to find any pointers about what actually gets cars failed.  There is a really useful 'Help to Pass the IVA' guide online on the gov.uk website which I've summarised below, and I've also made a list of the various post-IVA debriefs on the WSCC IVA-Info page.  I haven't been through all the Build Diaries to find debrief points which have only been put in diaries, so if anyone has anything which they think should be added, please comment below or PM me and I'll update this list.


Hopefully this will be useful to more than just me; but there's nothing like reading the whole IVA handbook to get the whole truth!  (And to get to sleep.)


IVA – Common Pitfalls

The following are the Top 10 issues at IVA, as described on the IVA ‘Help to get a pass’ page:




1.         Headlamp Aim:  In accordance with MOT standards, available online


2.         General Construction:  All aspects of design and construction are inspected to make sure that the vehicle is of no danger to the driver, passengers or other road users.

Insulate solenoid connectors: Non insulated terminals and insecure wiring aren’t allowed.

All pipes, wires and cables will need to be clipped into place at least every 300mm, and not rubbing on other pipes, wires, chassis etc.

Proof will be required that the petrol pipe (and fuel filler neck hose) is suitable for use if it’s unmarked.


3.         Brakes:

The whole system will be checked for:

·        its capability

·        how it works

·        whether it’s strong enough to do the job, this takes into account speed and weight of the vehicle

·        brake pipes/hoses that are twisted, kinked, rubbing against another surface and not secured


An indelible label must be fitted within 100 mm of the master cylinder that identifies the brake fluid used.

There must be a test facility to check for failure of the hydraulic braking system. This must be located within reach of the driver.  [However, the handbrake ‘On’ switch, when wired as intended by WSC, operates as this test facility]

Braking ratios between axles mustn’t be manually adjustable.

To meet the IVA required standard for brake efficiency the brakes on your vehicle must have a:

·        minimum service brake efficiency of 60%

·        minimum secondary brake performance of 25% (where testable)

·        minimum park brake efficiency of 18%

All brake efficiencies are calculated using the design gross weight or the calculated laden weight.


4.         Fog lamps

Fog lamps must be fitted at the rear, to the centre or offside rear of a vehicle for use in Great Britain, at the correct height and distance from the edge of the car

A fog lamp is a focused beam and must be fitted squarely to the rear of the vehicle

A rear fog lamp must:

·        have insulated wiring, that is secure and fitted through a grommet (where applicable)

·        have a switch that is securely fitted

·        have a warning system

·        only illuminate when dip, main or front fog lamps are lit

·        display an ‘e’ or ‘E’ mark with a ‘B’ or ‘F’ (see manual for exemptions)


5.         Exterior projections

DVSA will check for items that can be contacted with a 100 mm sphere (the sphere represents your knee) and anything it touches on the exterior of the vehicle needs to be either blunted or ‘radiused’.  Any hard part that the sphere touches must be ‘radiused’ to at least 2.5 mm or any items that project:

·        more than 5mm needs to ‘radiused’ to 2.5mm

·        less than 5mm needs to be blunted


6.         Speedometers

Speed will be checked for accuracy between 35 and 70 miles per hour

You need to be able read the speedometer at all times.

Where DVSA isn’t able to check the accuracy of the speedometer on the rollers you may be able to prove to DVSA that it’s suitable and accurate by:

·        evidence from the manufacturer of the speedometer

·        proving to the examiners satisfaction that it meets the required standard


7.         VIN

The plate must:

·        be permanent

·        be durable

·        contain the required information in the correct order

The only information allowed on the plate must be within a clearly defined rectangle and in the correct order. The order is:


·        name of manufacturer

·        approval number and/or build stage (if applicable)

·        VIN

·        maximum permitted laden mass of vehicle

·        maximum train weight (if applicable)

·        maximum laden mass for each axle in order from front to rear


A ‘stamped in’ VIN must be:

·        marked on the chassis or frame

·        permanent (stamped, hammered, etched). 

.        It can be on a separate plate, but the plate must be all-round seam-welded to the chassis.


8.         Seat belt anchorages

DVSA will look for an anchorage to:

·        be of adequate strength

·        be fully triangulated and braced

·        be buttressed with reinforcement

·        have fixing bolts of adequate strength

·        have bolts screwed through the locking device (if applicable)


9.         Emissions

DVSA may need proof of engine age if it’s been taken from another vehicle.

The proof can be:

·        a letter from the engine manufacturer

·        a letter from a recognised authority (such as an engine or vehicle manufacturer)

·        the original V5C from the donor vehicle


For spark ignition engine vehicles, the emissions test is based on the age of the engine.

There are different figures for different ages of the production of the engine ranging from:

·        a visual check for pre 1975 engines

·        to a maximum of 0.2% CO, 200 ppm HC and ‘lambda’ 0.97 - 1.03 for post 1 September 2012 catalyst equipped engines

It’s the age of the engine that is important and not the vehicle that the engine was taken from.

The IVA standard for both spark and combustion ignition emissions is identical to the MOT standard so you can have the vehicle checked at a local MOT station before the inspection.

DVSA will ask for the cam belt history and won’t test if there is doubt about the history or condition of the engine.


10.       Interior Fittings

DVSA will use a 165 mm sphere to see if anything in the ‘specified zone’ is contactable. Anything contactable will need to be ‘radiused’ to 2.5 mm.

Items that project from the instrument panel more than 9.5 mm must retract or detach leaving no sharp edges.

There is an exemption zone of 127 mm around the steering wheel. Anything in this zone is exempt from the inspection.  The lower boundary of the exemption zone is horizontal to the lower edge of the steering wheel.

The gear lever has its own required standard. It will be checked in all forward gear positions and if contacted by the sphere must be ‘radiused’ to 3.2 mm.

DVSA won’t accept any method of ‘radiusing’, or softening, that wouldn’t be used by a major manufacturer, ie stuck on bits of rubber, or pipe lagging. [However, many people seem to pass with U-section rubber strips stuck over potentially offending edges.]


The following issues have been experienced and/or caused a ‘Fail’ at IVA with some WSCC members:


Braking effort

Control of lights (independent side lights, and fog warning light),

Steering effort (NB recalled Westfield steering column which was causing binding)  


Self-centring steering

Brake balance (fronts must lock before rears)

2-speed wipers (speeds measured)

Fuel tank to be full on arrival (or at least: not close to empty so you don't run out during the test).  One tester said most cars pass the brake lock-up test more often with a full tank of fuel.  Another (very feasible) suggestion is that the Inspector needs to know the weight of the car with a full tank so he can work out the required braking force.  If the tank's not full, he has to work it out which could be a bit of guess-work and is something they don't like doing.  One car builder was sent to the nearest filling station to top-up, specifically for this reason.

Fuel cap restraining wire (The rule about this not being required if the key has to be removed from the fuel cap to refit the cap only applies if the same key operates the ignition)

Seat belt buckles mustn’t touch the seat itself

Wheel nut thread engagement

Dashboard switch marking

Projection of switches etc from the dash and requirement for 2.5mm radius/ blunted edges

Boot box removal to check fuel tank earthing etc (rare request)

Brake hoses hitting bodywork on full lock

Upper Ball joint nut covers

Outer end of the silencer clamp bolt mustn’t be contacted by the "cone test"

Emissions again
Brakes - rears locking first - again.  See note about having a full fuel tank above, as this may help.



Cockpit area - edges



Heat shield to sit above the underslung exhausts where they pass under the fuel tank.

Rub on the steering column where it passes through the bulkhead.

Protection/conduit to the wiring in the drivers footwell



Edited by IainCameron
Additional info - full fuel tank reasons
  • Like 4
  • Thanks 1
Link to comment
Share on other sites

A good list Iain.


One point I wasn't aware of...the data plate doesn't have to include axle weights. But as you rightly point out, if present they have to be in the order you show.


I wasn't aware of the fuel filler key having to be the same one used to start the engine. Actually makes sense, but mine passed even though the petrol cap key is not the ignition key (it is on the same ring though).

  • Like 1
Link to comment
Share on other sites

1 minute ago, corsechris said:

fuel filler key having to be the same one used to start the engine.

I can't recall where I found this gem, but it makes sense like you say, Chris.  I need to add a chain and hook to my cap, just in case they go for the letter of the law... at the moment the cap comes fully off with the key in it (like yours, I think).

Link to comment
Share on other sites

I think it depends on how you interpret the reg. Mine is lockable and key can't be removed with the cap unlocked and that passed (and my tester was very very hot on small details such as this)


A cheap DIY tether is a no brainer tho to cover all bases. 

  • Like 1
Link to comment
Share on other sites

I did put a tether on the cap at first but it felt clumsy, so I modded the lock on the cap to prevent key removal in the unlocked state.

  • Like 1
Link to comment
Share on other sites

Great info. On the rear wheels locking before the front, my tester told me that this was one of the most common fails on Westies. He also told me the most common cause of this was the fuel tank being empty, and he'd seen every one subsequently pass with a full tank of fuel. 

  • Thanks 1
Link to comment
Share on other sites

FW front mudguards, the edges require an edge protector, about £15 from ebay to do both wheels.

fog hazard and reverse lamps don't bolt flush to the inside of the panel, they will point up, this was a failure.

there is sufficient thread on the studs to mount them in line with the outside of the rear panel.

speedo calibration, test centres cannot check the speedo on an undriven wheel.

Westfield will provide a calibration certificate with your vin number for the tester, mine was accepted with no problem.

  • Thanks 1
Link to comment
Share on other sites

All you need to do is book in at Kidderminster and ask for Chris!

  • Haha 1
Link to comment
Share on other sites

19 hours ago, BobP said:

FW front mudguards, the edges require an edge protector,

Do you mean the standard cycle wings, Bob?  I thought the usual GRP versions from WSC were ok, as the IVA handbook says that edges must be turned in to the wheel (IIRC) and this is how the standard ones are supplied.  I can't quite see how the 100mm sphere would be able to contact the edges on these?

Link to comment
Share on other sites

40 minutes ago, IainCameron said:

Do you mean the standard cycle wings, Bob?  I thought the usual GRP versions from WSC were ok, as the IVA handbook says that edges must be turned in to the wheel (IIRC) and this is how the standard ones are supplied.  I can't quite see how the 100mm sphere would be able to contact the edges on these?


Not sure about the GRP ones, but the carbon effect ones definitely need edge protection. 

  • Like 2
Link to comment
Share on other sites

GRP ones are fine without edging. I have some on my project and they have plenty of thickness for a decent radiused edge - no issue at IVA.

  • Like 1
Link to comment
Share on other sites

  • 2 months later...

A quick note about my IVA fail points:


Emissions:  I had passed at an MOT station, but failed at the IVA.  Easily sorted by leaning the mixture on my Weber 40s, but may be worth a secondary check just before the IVA.


Speedo:  I had this checked on the rolling road, but I suspect they 'checked' the wrong way round.  The speedo needs to read above the true road speed at all speeds from 35 to 70mph.  DVSA gave me a chance to rectify using the 'Pulse' setting, but I didn't quite adjust it far enough, and I was out by 2mph from 50-70mph.


Noise:  I hadn't realised that DVSA use the max engine speed that you state in your application for the noise test.  They use 75% of 'Max Stated RPM' as the engine speed to check noise.  I had stated 6000rpm as max engine speed, and the exhaust note went banzai above 4000.  It may have been a sensible precaution to preserve engine life, and state 'Max Engine Speed' as 4500 rpm....

Link to comment
Share on other sites

1 hour ago, IainCameron said:

It may have been a sensible precaution to preserve engine life, and state 'Max Engine Speed' as 4500 rpm....

Not sure if this was meant humorously or not, but just in case…


For anyone else following for IVA tips, be VERY careful here. If you’re departing wildly from the figure for the engine that will show up in any technical searches, be ready to justify your figures, or you may jest earn yourself the most in-depth IVA in the history of the test. The testers I’ve had, have all been enthusiastic and knowledgable, they use all that experience and knowledge to get a feel for a car and it’s presenter very quickly, and the whole nature of your test can change from that point on.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


  • Create New...

Important Information

Please review our Terms of Use, Guidelines and Privacy Policy. We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.