Problems with VW T4 Transporters

It is vitally important to read up on the common problems with VW T4 Transporters to avoid potentially expensive consequences. There are some repairs that you do not want to be paying for in your first few months of ownership.

Our VW T4 Transporter problems

Owning a VW T4 Transporter can be an absolute pleasure however finding the correct one is becoming exceptionally important as the youngest of the models are now heading for 20 years old, some are closer to 30 years!

In many insurance companies’ eyes, you can now insure a VW T4 as a classic!

Common problems of a VW T4

The good thing about researching common problems of a VW T4 is that they have now been tried and tested over decades of use and abuse, so there isn’t much that we don’t know about them. A well kept, well serviced example can rack up in excess of 300,000 miles and still have a residual value on the second-hand market.

There are not many vehicles that have been built over the years that can claim that title.

The reliability of the VW T4 is renowned to be the best in class from the 1990 through to early 2000 era however finding one that has been kept in good serviceable condition is important.

VW Transporter T4 service intervals

The VW T4 had quite a few variations of engine size and type over the years and there are a few different service plans depending on model however in a nut shell:

  • The pre 1999 1.9 models with engine code ABL and the 2.4-liter models with engine code AJA VW T4 service schedule should have the oil and filter changed every 6,000 miles (some even say 5,000 miles here) or 6 monthly to prevent sludge build up which can be fatal to the engine.
  • Other models should be serviced every 9,300 miles (15,000 KM)

You can view the full guide on VW T4 servicing below:

VW Transporter T4 running costs

Running any vehicle that is 20 to 30 years old is going to come with a higher maintenance bills than a new vehicle.

The offset to this higher cost however is that you don’t have to suffer the heavier depreciation that you would get on the newer models of T5 and T6.

The VW T4 is now at the turning point where good example are appreciating in value so if you pick the right one you can justify it as an investment for the future!

As a good rule of thumb, and from experience of owning three T4’s over the last decade (a mix of 1.9 and 2.5TDI models) if you budgeted £1000 per annum for service/repair of your VW T4 you wouldn’t be too far off the mark for relatively low mile use (less than 10k miles).

A budget of £1000 allows for around £300 per year for your standard service and around £700 buffer for extra work that may be flagged up at MOT or problems that develop along the way. There maybe some years that you have to spend a little more but it does seem to average out over time.

What are the common problems with VW T4’s

New arches on T4

Rusty Suspension mounts on VW T4’s

It is becoming more and more common to see MOT failures and advisories given on rusty VW T4 suspension mounts. If the structure of the metal within a certain radius of the mounts is showing significant decay then you will not pass the MOT.

You normally get a couple of years warning on this by looking back at the MOT advisories – if they have been completed thoroughly. The first place to look when viewing any T4 is at the history of advisories to see if the repair has already been carried out or if it is noted within the advisory section.

If you see an advisory for rusty suspension mounts on a VW T4, then you need to budget around £400-£500 for the rework. If a garage quotes you more than this, it is likely they do not really want the work.

Many garages will shy away from this repair as the fabrication and weld is something for well seasoned fabricators/welders. A level of skill & patience that not every garage has in the UK at least.

It is a skilled bit of fabrication and welding as the shape of the metal near to the mounts on a T4 is an awkward shape. To my knowledge you cannot buy premade replacements for this job so it is not a simple “cut and weld” job.

As a slightly simpler fix, some T4 owners head to the breakers yard to see if they can salvage the bit of metal out of an old Transporter. Failing that, you will want to find a good fabricator that is not necessarily a motor mechanic but preferably a skilled welder/fabricator.

Rusty wheel arches and sills on VW T4’s

This one is a big one! Do not underestimate how much a set of sills and arches will cost you if you are not able to do the welding your self. For a set of 4 arches and both sills you should budget somewhere between £1.3k and £1.8k depending on the amount of corrosion that needs to be cut out.

The parts them selves cost no more than £300, most of the cost is in the labour as there are no real short cuts to the task.

Rusty T4 arches
Bad example of a rusty T4

If you are buying a rusty T4 you need to factor this repair into your purchase price. If the rust is not too severe then you can likely get away with sanding the area back to metal, applying some rust treatment/preventative and then topping with a couple of coats of paint.

Some owners fit arch trim to extend the life of their arches to avoid the costly repair however be wary if this is on a T4 that you are viewing as it can also mask problems that you will need to address further down the line.

If this is a problem that you are facing, you may also like to read about – Best Wheel Arch Trim for a VW Transporter

New arches on T4

Check the lower runner rail on the sliding doors

One other area that suffers badly from rust when basic maintenance is not followed in the lower runner rail on the side door. It collects crud, mud, grime, grease, old screws, leaves, old cig butts… you name it!

It then gets wet and stays wet. This corrodes the metal and also messes us the runner of the door. It is an expensive weld job when this lip fails.

Make sure you clean the lip frequently and give it a squirt of wd40 for good measure.

Oil the VW T4 runner rail rust problem
Clean and oil the bottom rain runner every few hundred miles

Dual mass flywheel on a VW T4 2.5

Clutches don’t last forever on any vehicle however it is an important consideration when buying a VW T4. Depending on how well they are driven, the standard clutches can last anywhere between 100,000 and 160,000 miles!

The 2.5TDI’s suffer the most significantly with this problem as they have a dual mass flywheel as well as a higher BHP output than the 1.9’s, thus putting more wear and tear on the clutch.

What you don’t want is to buy a T4 that is at the end of it’s clutch life as it is a major repair to get it changed.

A clutch replacement on the T4’s involve the unbolting of the engine mounts as well as a lot of the ancillary items to allow enough free movement in the engine to enable you to slide the gearbox out.

The labour itself is pricey but so is the part. If you have the 2.5TDI model you are going to be looking at a repair bill of around £700 including labour.

Many would advise changing the cam belt/water pump etc at the same time even if it is not quite due. This does increase the cost of the job but saves you on a major service further down the line.

Heat sensor problem on VW T4

The VW T4 does have a reputation for dodgy sensors unfortunately. The sensors are of course getting old and need periodic replacement & routine inspection, however bad connections or corroded electrics also lead to issues.

It is not uncommon to hear of the heat sensor going off irrationally on the T4 especially over bumps! It certainly isn’t something that you want to ignore as it could be a genuine alarm.

Heat sensor T4

If your dashboard keeps flashing up with heat warnings then pull over and check your fluids as your first step. If there are no obvious signs of genuine over heating then the best course of action is to change the sensor as they are less than £10.

Clean the connections for the wires leading to and from the sensor when you change it out and chances are that will fix your problem.

VW T4 headlights

The section deserved its own article as it is such a common complaint! Click below to find all about the VW T4 headlights and super cheap options to upgrade.

VW T4 Headlight upgrade
Dim head lights on a T4…

Upper and Lower ball joints on the VW T4

It is common for the upper ball joints especially to go on the medium to higher mile examples of the VW T4. You will hear knocking especially on bumps.

Early signs are knocking only on bumps when the Transporter is mid bend as a higher weight distribution is applied to a particular side of the Transporter. A good test if you are on a test drive is to aim for a bump mid bend on left and right steering lock and listen carefully.

Over time you will get more obvious knocks on every bump and every turn.

The upper and lower ball joints themselves are actually very cheap however the job of changing said ball joints is not one for the faint hearted.

I have heard of garages in the UK shying away from the task and turning down the job. I guess working on 20-year-old rusted bolts + ancient ball joints is not as fun as working on newer models.

Even with the right tool to remove the upper ball joints it is rarely a simple process to remove the old part so if you are doing it your self, expect a challenge.

To replace both upper ball joints you can expect to pay somewhere in the region of £400. Don’t skimp on the replacement ball joints either, the cheaper pattern ones do not last well in the T4 and have been known to fail in less than 10,000 miles.

VW T4 oil in coolant

An exceedingly kind VW T4 enthusiast dropped me a note to include this section (thanks for the prompt!).

I personally have never suffered with coolant in the oil or vice versa (oil in the coolant) however it is something to watch out for especially on the 2.5 (petrol and diesel) models.

There are a few early warning signs to look out for:

  1. A milky residue under the oil filler cap indicates coolant is leaking into your oil.
  2. Having to top up your coolant more frequently indicates you may have a leak. This could be an external leak (e.g. a bust hose or leaky radiator) or it could be leaking into your engine/mixing with your oil.
  3. Check your coolant reservoir for signs of oil. Dip your finger into the water and around the inside of the plastic reservoir bottle. Look for signs of oil residue. Oil floats so will naturally find its way to the highest point in your cooling system.
Check under the filler cap for any signs of oil/white scum

Upon finding oil and water mixing the first thought here is head gasket failure however don’t panic yet! The VW T4 isn’t renowned for head gasket failure, it has a pretty strong head on it.

The most common cause is either:

  1. Check the oil heat exchanger (the oil filter screws to it). These are prone to leaking and when they do, the symptoms are the same as a head gasket failure but a fraction of the cost.
  2. Water pump failure. Check for the last time it was changed, most recommend changing them every 60,000 miles or 4 years.
  3. If it isn’t the above 2 issues, then you could be looking at a new head gasket/cracked head if you are really unlucky but this is much rarer than the top two.

Why does the oil heat exchanger leak?

The VW T4 oil heater exchanger passes oil through a matrix (looks like a mini radiator) that travels close to the coolant system. The coolant is used to cool the oil before being pumped back around the engine.

VW T4 oil heat exchanger

The fins on the heat exchanger are thin. They corrode or become easily damaged over time. If you have a pin hole leak, then the high pressured oil passes very easily into the coolant system.

These are the most common cause for oil being found in the cooling system on a VW T4 and is a cheap and easy fix. Make sure you check this before looking into the more expensive water pump or head gasket repairs.

How to fix an oil heat exchanger leak?

You can test the oil heat exchanger for leaks in the same way you might test a bicycle inner tube.

  • First remove it from your system, drain it of oil and coolant. Seal one end of it and then attach an air pump of some kind to the other end. You don’t need too much air pressure here so a bicycle pump works well.
  • Submerse the oil heat exchanger into water and gently pump air into the one end. Look for bubbles rising from the fins of the oil heat exchanger.
  • Assuming you find a leak, buy a new exchanger (they are only £30 or so example HERE). make sure you buy the right one for your T4 model.
  • Before fitting the new VW T4 oil heat exchanger, you need to ensure that you thoroughly clean the coolant system. Oil residue left in the system can lead to other problems further down the line.
  • To do this you can either buy chemicals to use to flush the system (examples here) or a weak mix of washing up liquid and water works. You can then flush the system through with a hose pipe.

VW T4 emissions MOT fail

Over the years the emissions test that vehicles have to pass to obtain an MOT has become harder in the UK. You can view latest changes to emissions on the gov.uk webiste here. Unfortunately this left a lot of VW T4 owners scratching their heads when their pride and joy fails!

You can also read specific emmision critia for your MOT here.

Old vehicles are always going to struggle with these criteria as in most cases the emissions of the vehicles when new were already higher than current models. With a worse starting point, it leaves less room to move between best case and “fail”.

A quick fix to this which occasionally works is to make sure you give your VW T4 a very good run before the MOT. Just before the MOT, keeping it in a high gear and using all of the rev range will ensure that your engine is fully warm and as much of the built up carbon is blown out of the exhaust before the MOT.

Adding some fuel cleaner additive a few weeks before the MOT is a good tip.

How to fix high emissions on a VW T4

If the quick fix above doesn’t work, you have a more expensive problem on your hands which can take a bit of trial and error to sort. Problems that lead to high emissions are

  • Faulty Catalytic converter
  • Faulty Lamda sensor
  • Over fuelling – frequently caused by faulty oil or coolant temperature sensors
  • Timing out of engine (a common issue caused after a cam belt service as setting the timing can be tricky to those not well versed in the process)
  • Fuel pressure issues

Locking and electric window problems on the VW T4

If you are one of the lucky ones and have a high spec T4 with original electric windows, mirrors and central locking. Make sure you check that they work ok as over time the harness within the door cavity tend to fray.

Electric windows on VW T4
Not many T4’s came with the standard electric windows. If you have these, you are lucky!

This isn’t an expensive or time-consuming repair, however, can be frustrating as a new owner if you didn’t notice when purchasing.

VW T4 Cold start problems

If your VW T4 does not start on the first turn of a key (once the glow plug light goes out), even after several days of none use, it is likely that you have a problem. T4’s when running correctly should fire up almost immediately without hesitation.

Glow plug starter light on T4
Glow plug starter light on left and side should be off before you turn the engine over

Setting the timing on the T4 is actually fairly tricky and it is very common to find the timing ever so slightly a drift from recommended tolerances. If you have a cold start problem this is one of the first places to check, especially if it has just had a major service.

It is worth pointing out that a little bit of back smoke when you first start a T4 is standard and nothing to be concerned about. If the smoke continues once it is warm however, you should investigate.

VW T4 radiator issues

This isn’t a common problem however it is worth pointing out that now most VW T4’s are over 20 years old, it is worth checking to see if it is still on the original radiator.

Radiators can last well into the 150,000’s easily however over time they start to lose their efficiency and develop very minor leaks.

Check around the radiator for signs of “green” residue that signifies coolant escape.

This isn’t a major problem if sorted as a new radiator is only in the region of £50 to £80 however a lot of owners neglect the radiators importance and leave it until it fails to replace.

When radiators fail it is usually when you are in heavy traffic or on a long upward hill when the engine is at it’s hottest.

The high water pressure blasts a hole in the radiator and you are left in a plume of very embarrassing smoke (typically with Bongo owners slowing down to gloat as they pass… As this is normally their problem!)

Next time your VW T4 is in the garage it is worth swapping the radiator out for a new one if it is over 20 years old and showing signs of damage.

How reliable is the VW T4

Ignoring the few common problems explored here of a VW T4, they are extremely reliable if maintained.

You should have trouble free motoring well over the 200,000 miles which is why they hold their value so well on the second-hand market. You may also like to read about How many miles will a Transporter do?

Make sure you take your time when shopping for your first T4 and allow around £1,000 a year for routine maintenance. Catch the warning signs early and you should never be left at the side of a road or on the back of an AA truck.

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