My van is overheating
Do not drive it
Stop as soon as it is safe, switch the engine off, and do not open the coolant cap. Continuing to drive an overheating diesel is how a cheap repair becomes a new engine, and the damage can happen in a couple of miles. Once it is off, the common causes are a coolant leak, a failed thermostat, a dead cooling fan, or a water pump. If the coolant is low with no visible leak and the exhaust is steamy, start worrying about the head gasket.
Most likely causes, and what they cost
UK prices at an independent garage for a van up to 3.5 tonnes. Ranges, because anyone quoting a single figure before looking at your van is guessing.
| Cause | How you can tell | Typical cost |
|---|---|---|
| Coolant leak | A puddle, a sweet smell, or visible wet residue around hoses and the radiator. | A hose is often £80 to £200. A radiator is commonly £250 to £600 fitted. |
| Thermostat stuck shut | Temperature climbs quickly even at motorway speed when airflow should be cooling it. | Typically £120 to £350 depending on how buried it is. |
| Cooling fan not running | Fine on the move, overheats in traffic or at idle. The fan should be audible when hot. | Often £150 to £450 for a fan or its relay and sensor. |
| Water pump failure | A whine or rumble beforehand, or a leak from behind the belt area. | Commonly £300 to £700, and often sensible to do the timing belt at the same time. |
| Head gasket | Coolant disappearing with no leak, white steamy exhaust, bubbling in the expansion tank, oil looking like a milkshake. | Typically £900 upwards, and on a high-mileage van this is where the economics get decided. |
Check these first, they are free
- Switch it off. Everything else can wait sixty seconds. Heat damage is cumulative and fast.
- Do not open the coolant cap while hot. Pressurised coolant above 100C causes serious scalds.
- Look underneath and around the engine bay for an obvious leak or a puddle.
- Wait at least thirty minutes before touching the cap, then check the coolant level cold.
- If the coolant is simply low with no leak you can find, topping up with the correct coolant and going straight to a garage may get you there. If it empties again quickly, stop.
What kind of help you need
Recovery and towing
The van cannot be driven safely, or you are somewhere you must not stay: a live lane, a blind bend, a slip road, or a motorway with no hard shoulder.
Cost: If you have breakdown cover with recovery, this is usually included. Without cover, a local pay-on-the-day recovery is commonly £90 to £200 for a short tow, and motorway or out-of-hours jobs cost more. Long-distance recovery is normally charged per mile on top.
Mobile mechanic
The van is somewhere safe and legal to work on, and the fault has a fair chance of being fixed at the kerb: battery, alternator, starter, glow plugs, sensors, fuel filter, a hose, a belt, a simple electrical fault.
Cost: A mobile call-out is commonly £50 to £90 before any parts or labour, with roadside labour often £50 to £90 an hour. Expect more for evenings, weekends and anything on a motorway, and many will not attend a live motorway lane at all, which is correct and not them being awkward.
Van-capable garage
The van is drivable, or it is being recovered and you need to name a destination. Every garage we list holds a DVSA Class 7 MOT authorisation, which is the class for vehicles from 3,000kg to 3,500kg, so the ramp and the bay physically take a full-size van. That sounds like a technicality until you have been turned away by a car-only garage.
Cost: Independent van labour rates commonly run £50 to £95 an hour outside London and higher inside the M25, against £120 or more at a franchised dealer. A diagnostic check is typically £50 to £120 and good garages credit it against the repair.
Same-day van hire
The repair will take a day or more and there is work in the diary you cannot afford to drop. This is the step most people forget in the panic, and it is usually the one that saves the most money, because a lost day of work and a let-down customer costs far more than a day rate.
Cost: A short-wheelbase van is commonly £45 to £80 a day, a long-wheelbase or Luton £70 to £130, with a deposit held on a card and a mileage cap on top. Same-day and one-day hires carry the worst rates, so if the repair may run on, ask the weekly rate, which is often barely more than three days.
Onward transport
The van is out of action but the load still has a deadline. A wedding, a site, a shop opening, a customer who has booked the day off work. The van is your problem. The delivery is their problem, and they will remember how you handled it far longer than they will remember that you broke down.
Cost: A dedicated same-day courier is priced per mile on a point-to-point basis, usually with a minimum charge, and a small van run tends to work out cheaper per mile over distance than a short hop. Expect a premium for a two-person job, a tail lift, or anything out of hours.
Questions people ask
Can I put water in it and carry on?
Plain water will get a van a short distance in an emergency, but it lowers the boiling point and offers no corrosion protection, so it is a get-to-the-garage measure and nothing more. If you can find the right coolant, use that. Either way, the leak is still there.
Is it safe to drive a short distance if it has cooled down?
Only if you found and understood the cause, and only to somewhere safe or a garage, watching the gauge the whole way with the heater on full to shed heat. If the gauge climbs again, stop again. If you do not know why it overheated, do not drive it.
Why does it only overheat in traffic?
That pattern points strongly at the cooling fan rather than the coolant system, because at speed the airflow through the radiator does the cooling for you and in traffic the fan has to. A fan, relay or temperature sensor is usually a far cheaper repair than the alternatives.
Where are you?
Put your postcode into the console on the home page and we will give you the safety steps for where you are standing, verified van-capable garages near you, and the rest of the options.
This page is general guidance for working vans, not a diagnosis of your vehicle. Costs are typical UK ranges and will vary by van, area and garage. If anyone is in danger, ring 999.