Coolant Leak Repair Cost: What a Leak Costs to Fix, Part by Part
A coolant leak costs between £60 and £450 to fix on most UK cars as a rough guide, and the spread is the whole point: a split hose or a clip is £60 to £150, an expansion tank £80 to £180, a plastic thermostat housing £120 to £300, a radiator £200 to £450 and a water pump £150 to £450, while a head gasket, the leak nobody wants, starts around £500. Where the coolant is going is found with a pressure test and dye before anything is replaced. This guide sets out every figure.
Coolant leak repair cost • the short answer
How much does a coolant leak cost to fix?
A coolant leak costs £60 to £450 to fix on most cars, and the figure is set entirely by which part is leaking, which is why the pressure test comes first: the same symptom, a level that keeps dropping, can be a £60 hose clip or a £400 radiator, and a garage that guesses gets to charge for both.
- Split hose, perished clip or a weeping joint: around £60 to £150. The commonest leak and the cheapest, found with the system under pressure.
- Expansion tank or its cap: around £80 to £180. Plastic tanks craze and split with age; a cap that will not hold pressure boils the system.
- Thermostat housing: around £120 to £300. The plastic housings on Ford, PSA and VW group engines harden and crack. See thermostat replacement cost.
- Radiator: around £200 to £450. The plastic end tanks split where they meet the core. See radiator replacement cost.
- Water pump: around £150 to £450. Cheapest when belt-driven and accessible, dearest when it sits behind the cambelt, where the belt is done at the same time.
- Heater matrix: around £300 to £800. A sweet smell and a misted screen. The dashboard comes out to reach it. See heater matrix replacement cost.
- Head gasket: from around £500 upwards. Coolant into the oil or the cylinders. See head gasket replacement cost.
Every figure here is a guide. The exact price for your car comes from the registration and the test, because a radiator on a Fiesta and a radiator on an X5 are different days. Send the registration through the reg check below or ring 01744 808586. For the local page on the job see coolant leak and overheating repair St Helens.
What the money buys
What you are paying for in a coolant leak repair
The part is often cheap. The money goes on finding the leak properly, reaching it, and refilling and bleeding the system so it does not overheat on the way home.
- The pressure testThe system pumped up cold with a tester and watched. A leak that only shows hot or under pressure shows up in minutes rather than after a month of topping up.
- Dye where the test is quietA UV dye in the coolant and a lamp after a drive. It finds the weep behind the pump or the pinhole in a hose that the pressure test cannot see.
- A sniff test for the head gasketA chemical tester at the expansion tank that detects combustion gases in the coolant. Rules the big one in or out before a cheaper part is fitted in hope.
- The partHose, tank, housing, radiator or pump from the manufacturers who supply the car makers. A cheap plastic housing cracks again in a winter.
- Reaching itA hose is ten minutes. A radiator is the bumper and the fans. A pump behind the cambelt is the belt job. This is where the price is made.
- The correct coolantDrained, refilled with the specification the engine is rated for, and mixed to the right strength. The wrong coolant corrodes the very parts that just went in.
- Bled properlyAir left in the system after a refill is the commonest cause of a car that overheats the week after a repair. Bled on the ramp and run to temperature.
- Pressure tested againThe system held under pressure after the repair, so the fix is proven rather than assumed.
- A written recordWhere the leak was, what was fitted and the coolant used, on the invoice.
- Payment Assist if you want itThree, four or six months at nought per cent on a soft search. See pay monthly car repairs.
The expansion tank in the photo is the first thing checked: level between the marks, the colour of what is in it, and any oil floating on it or mayonnaise under the cap. Those three observations rule half the causes in or out before the tester goes on.
If the car is due a service, the two go in together and the coolant condition is checked as part of it. See what is included in a car service.
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By part
Coolant leak repair cost by the part that is leaking
The test decides which row you are in. These are the bands we work to, fitted, including the coolant and the bleed, as a guide.
| Where the coolant is going | What you notice | What is involved | Guide price fitted |
|---|---|---|---|
| Hose, clip or joint | Wet hose, crusty pink or green residue, drips under the front | Hose and clips, partial drain and bleed | Around £60 to £150 |
| Expansion tank or cap | Crazed tank, damp seam, coolant smell after a run | Tank or cap, refill and bleed | Around £80 to £180 |
| Thermostat housing | Leak at the top of the engine, temperature gauge erratic | Housing, thermostat, gasket, coolant. See thermostat replacement cost | Around £120 to £300 |
| Radiator | Wet end tanks, drips at the front, overheating in traffic | Radiator, bumper off on many cars, fans, coolant. See radiator replacement cost | Around £200 to £450 |
| Water pump, belt-driven and accessible | Weep hole staining, whine, drips low on the engine | Pump, coolant, about two hours | Around £150 to £300 |
| Water pump behind the cambelt | As above, on a belt-driven engine | Done with the belt. See cambelt water pump replacement cost | Around £350 to £700 with the belt |
| Heater matrix | Sweet smell inside, misted screen, damp passenger carpet | Dashboard out on most cars. See heater matrix replacement cost | Around £300 to £800 |
| EGR cooler, diesels | Coolant loss with no visible leak, white smoke | Cooler replaced. See EGR cooler replacement cost | Around £300 to £700 |
| Head gasket | Mayonnaise under the cap, white smoke, bubbling tank, oil in the coolant | Head off, skimmed, gasket, timing. See head gasket replacement cost | From around £500 upwards |
| Pressure and dye test | Level dropping with nothing obvious | Tester, dye, lamp, sniff test | Under an hour, and deducted from the repair |
The order of the table is the order of hope, and the test is what decides where you sit in it. A car that has been topped up for months is the one where the cheap fix has often become the dear one, because an engine run low on coolant cooks its head gasket. See coolant leak and overheating repair St Helens for the job and car repair cost for how it compares with the rest.
Finding it
Why is my car losing coolant with no visible leak?
A car loses coolant with no visible leak when the coolant is going somewhere it evaporates or burns: a pinhole in a hose that only opens hot, a water pump weep that dries on the block, a heater matrix dripping into the carpet, an EGR cooler on a diesel passing coolant into the exhaust, or a head gasket letting it into the cylinders, and each is found by a different test, which is why the pressure test, the dye and the sniff test are done in that order before anything is replaced.
The pressure test finds the hot-only pinholes and the pump weep, because the system is held at pressure while cold and the leak has nowhere to hide. The dye finds the weep that dries before you see it. The sniff test finds combustion gas in the coolant, which is the head gasket, and it is done before any cheaper part is fitted in hope on a car that has been overheating.
A sweet smell in the cabin and a misted screen is the matrix. White smoke from the exhaust on a warm engine is the head gasket or, on a diesel, the EGR cooler. A level that drops only on long runs and never leaves a mark is often the expansion cap. Ring 01744 808586 with the registration and what you have noticed, and see coolant leak and overheating repair St Helens and head gasket replacement cost for the two ends of the answer.
How the job runs
How a coolant leak repair runs, step by step
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The tank, the cap and the oil checked cold
Level, colour, oil on the coolant, mayonnaise under the cap or the oil filler. Three observations that rule half the causes in or out before the tester goes on.
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Pressure test on the ramp
The system held at pressure with the engine cold and the car lifted, and every hose, joint, the pump weep hole, the radiator tanks and the housing watched.
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Dye and sniff test where the pressure test is quiet
UV dye and a lamp after a drive for the weep that dries on the block; the chemical sniff test at the tank for combustion gas, which is the head gasket.
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You get a phone call with the part and the price
Which part, what it costs, and what can wait. A cheap part is never fitted in hope on a car that has been overheating.
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Repaired with the correct part and coolant
Hose, tank, housing, radiator or pump from the maker's supplier, and the coolant specification the engine is rated for, mixed to strength.
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Bled, run to temperature and tested again
Air bled on the ramp, the engine run to temperature with the heater on, and the system pressure tested again so the fix is proven before it goes back.
Driving on it
Can I drive with a coolant leak, and what happens if I keep topping it up?
You can drive a short distance with a slow coolant leak if the temperature gauge stays normal and the level is topped up before every journey, but you cannot keep doing it, because a system that is losing coolant is a system that is one hot day or one motorway run from boiling, and an engine that has overheated once has usually cooked its head gasket, which turns a £100 hose into a £500 upward bill.
Topping up hides the problem while it grows. Tap water instead of coolant corrodes the pump and the matrix from the inside, a system run with air in it overheats in traffic, and a slow leak from a plastic housing becomes a sudden one at the worst moment. The gauge climbing past the middle, steam, a sweet smell or a warning on the dash means stop, let it cool and ring.
The test that finds the leak is under an hour and it is deducted from the repair. See coolant leak and overheating repair St Helens, head gasket replacement cost for where topping up ends, and pay monthly car repairs if the timing is bad. Ring 01744 808586.
Related jobs
The parts a coolant leak can turn out to be
Each has its own cost page with the figures and the questions drivers ask.
Radiator replacement cost
Split end tanks and corroded cores. See radiator replacement cost.
Thermostat replacement cost
The plastic housing that cracks on so many modern engines. See thermostat replacement cost.
Water pump
Belt-driven, accessible or behind the cambelt. See cambelt water pump replacement cost and water pump replacement St Helens.
Heater matrix replacement cost
The sweet smell and the misted screen. See heater matrix replacement cost.
Head gasket replacement cost
Where an overheated engine ends up. See head gasket replacement cost.
EGR cooler replacement cost
The hidden coolant loss on diesels. See EGR cooler replacement cost.
Coolant leak repair cost — paying over time
A coolant leak never shows up in a convenient month
Nobody budgets for the tank that keeps needing topping up. Whatever the test turns into can be spread across four months at nought per cent through pay monthly car repairs, decided on a soft search that does not mark your credit file.
The engines that do it
Which cars are known for coolant leaks?
The cars known for coolant leaks are the ones with plastic in the cooling system: the Ford 1.0 EcoBoost with its degas pipe and, on some 1.5 engines, coolant finding its way into the cylinders; the BMW B38, B48 and N47 with plastic thermostat housings, coolant pipes and expansion tanks that harden and crack; the PSA 1.2 PureTech and 1.6 HDi with their plastic housings and pipes; the VW group 1.4 and 2.0 TSI with the water pump and thermostat housing in one plastic unit; and the older Vauxhall 1.4 Turbo with its coolant bypass and tank.
None of those is a reason not to buy the car. They are reasons to have the level checked at every service and the plastic parts looked at once the car is past five years, because a housing replaced at £150 on a service is a housing that did not split on the M62 at £500 upward.
See Ford service and repair for the EcoBoost, the BMW B38 coolant leak for the BMW three-cylinder, BMW specialist for the rest of the range, and Peugeot service and repair for the PureTech and HDi.
Stop leak
Does radiator stop leak work, and should I use it?
Radiator stop leak can seal a pinhole for a while, and it should not be used on a modern car, because the same particles that block the pinhole block the heater matrix, the narrow radiator tubes and the passages in an aluminium head, so the £10 bottle that hid a £80 hose leak becomes a £500 matrix a few months later, and it makes the real leak harder to find when the car finally comes in.
The honest use for it is getting a car home once from somewhere remote, after which the system is flushed and the actual leak repaired. On a car that is used every day, the pressure test that finds the leak is under an hour and is deducted from the repair, which is cheaper than the bottle by the time the matrix is counted.
If stop leak has already gone in, say so when you book, because the system is flushed before the new part goes in and the coolant is replaced. See heater matrix replacement cost for what it blocks, coolant leak and overheating repair St Helens for the proper job, and car repair cost for how the figures compare.
The numbers
Six numbers behind a coolant leak
The figures that decide the price and the urgency.
Where the cars come from
Coolant leaks repaired for drivers across St Helens and the towns around it
Boundary Road is a couple of minutes off the A58 and the Linkway. Most leaks are tested, fixed and bled the same day.
Cars also come over from Widnes, Warrington, Wigan and Liverpool, often after a quote for a radiator on a car with a split hose. Coolant leak and overheating repair St Helens covers the job and garage services in St Helens everything else done here.
Worth knowing
Why the air left in the system matters more than the part
A modern cooling system has high points the coolant cannot reach on its own, and air trapped in them means the engine runs hot in traffic a week after a perfect repair. Bleeding is done on the ramp with the front raised, the bleed screws opened in order, the heater on full and the engine run to temperature with the tank watched, and on some cars with a vacuum filler that pulls the air out before the coolant goes in.
It is the unglamorous half of every coolant job here, and it is why the car is pressure tested again after the bleed rather than handed back warm and hoped for.
Overheating
What should I do if my car is overheating?
If your car is overheating, pull over as soon as it is safe, switch off, and let it cool for at least half an hour before opening the bonnet and never open the expansion cap hot, because a system under pressure scalds; then look at the level, and if the car has to move, top up with water only to get to a garage a few miles away, because every minute driven with the gauge in the red is a minute towards a head gasket.
A car that overheats in traffic but cools on the open road is usually the fans, the thermostat or air in the system. One that overheats on the motorway is usually low coolant, a pump or a blocked radiator. One that overheats within minutes from cold is a stuck thermostat or a head gasket, and it should not be driven at all.
The read on the tool shows the fan and thermostat commands and the temperature the engine actually reached, which is how the cause is told apart. See coolant leak and overheating repair St Helens, thermostat replacement cost and head gasket replacement cost. Ring 01744 808586 from the roadside if you are not sure whether to drive it.
Been quoted a radiator or a head gasket for a level that keeps dropping?
Send the registration and the quote. We tell you whether the diagnosis has been tested or guessed, what the test would show, what our price would be for the part it turns out to be, and the next free slot.
Coolant leak repair cost — get in touch
Tell us the car, how fast the level drops and what you can see
A damp hose, a sweet smell, a puddle at the front, white smoke, or nothing at all but a tank that needs topping up. That tells us which test to start with, and the price follows the part it turns out to be.
Fastlane Autocare, 232-254 Boundary Road, St Helens, WA10 2PZ. Open Monday to Friday 8:30am to 5:00pm and Saturday 9:00am to 12:30pm. Ring 01744 808586, use the contact page, or send the registration over and we will look the engine up before you arrive.
Whatever it needs, it is diagnosed first and priced before work starts at Boundary Road: car repair in St Helens.
Coolant leak repair cost • straight answers
Questions drivers ask about coolant leak cost
A coolant leak costs £60 to £450 to fix in the UK as a rough guide, fitted, and the part decides the figure: a hose or clip £60 to £150, an expansion tank £80 to £180, a thermostat housing £120 to £300, a radiator £200 to £450, a water pump £150 to £450, and a head gasket from around £500 upwards.
The pressure test that finds the part is under an hour and is deducted from the repair. See coolant leak and overheating repair St Helens and car repair cost. Ring 01744 808586.
You find a coolant leak with a pressure test first, the system pumped up cold on the ramp and every hose, joint, the pump weep hole, the radiator tanks and the housing watched, then UV dye and a lamp after a drive for the weep that dries before you see it, and a chemical sniff test at the tank for combustion gas, which is the head gasket.
Guessing the part is how a radiator gets fitted to a car with a split hose. See coolant leak and overheating repair St Helens and head gasket replacement cost.
A car losing coolant but not overheating has a slow leak that the topping up is keeping ahead of: a pinhole in a hose that only opens hot, a water pump weep that dries on the block, a crazed expansion tank, a cap that will not hold pressure so coolant is lost as vapour, or a heater matrix dripping into the carpet, and it stays cool right up until the day it does not.
The pressure test and dye find it in under an hour. See coolant leak and overheating repair St Helens and thermostat replacement cost, or ring 01744 808586.
You can drive a short distance with a slow coolant leak if the gauge stays normal and the level is topped up before every journey, but not for weeks, because a system losing coolant is one hot day from boiling and an engine that has overheated once has usually cooked its head gasket, turning a hose into a £500 upward bill.
Steam, a sweet smell or the gauge past the middle means stop and let it cool. See coolant leak and overheating repair St Helens and head gasket replacement cost. Ring 01744 808586.
A radiator leak costs £200 to £450 to fix as a guide on most cars, because the radiator is replaced rather than repaired when the plastic end tanks split, and the figure covers the radiator, the bumper and fans coming off on many cars, the coolant and the bleed, with premium and larger cars above that band.
A weep at a hose clip on the radiator is a £60 job, which is why the test comes first. See radiator replacement cost and radiator replacement St Helens.
A water pump leak costs £150 to £300 to fix as a guide where the pump is belt-driven and accessible, and £350 to £700 where it sits behind the cambelt, because the belt is done at the same time since the engine is already stripped to reach it, and a pump left weeping ends in a seized bearing and a snapped belt.
The weep hole staining under the pump is the sign. See cambelt water pump replacement cost and water pump replacement St Helens.
The signs of a head gasket leak are white smoke from the exhaust on a warm engine, mayonnaise under the oil filler cap or the expansion cap, bubbles in the expansion tank with the engine running, coolant loss with no visible leak, oil in the coolant or coolant in the oil, and overheating that comes on within minutes from cold.
The chemical sniff test at the tank confirms or rules it out in minutes before any cheaper part is fitted in hope. See head gasket replacement cost and coolant leak and overheating repair St Helens.
A car that smells sweet inside has a coolant leak into the cabin, almost always the heater matrix behind the dashboard, and the sweet smell is joined by a windscreen that mists on the inside, a damp passenger footwell and a coolant level that keeps dropping with nothing to see under the bonnet.
The matrix is the dearest common leak because the dashboard comes out to reach it. See heater matrix replacement cost and coolant leak and overheating repair St Helens.
Radiator stop leak can seal a pinhole for a while and it should not be used on a modern car, because the particles that block the pinhole also block the heater matrix, the narrow radiator tubes and the passages in an aluminium head, so a bottle that hid a hose leak becomes a matrix a few months later and makes the real leak harder to find.
Its honest use is getting home once, then a flush. See heater matrix replacement cost and car repair cost.
You can use water instead of coolant to get to a garage a few miles away, and you should not run on it, because plain water has no corrosion protection, so it attacks the water pump, the matrix and the aluminium head from inside, it boils at a lower temperature than coolant, and it freezes in winter and cracks what it is sitting in.
The system is refilled here with the specification the engine is rated for, mixed to strength. See what is included in a car service and car servicing St Helens.
The cars known for coolant leaks are the ones with plastic in the cooling system: the Ford 1.0 and 1.5 EcoBoost, the BMW B38, B48 and N47 with their plastic housings, pipes and tanks, the PSA 1.2 PureTech and 1.6 HDi, the VW group 1.4 and 2.0 TSI with the pump and thermostat in one plastic unit, and the older Vauxhall 1.4 Turbo.
None is a reason not to buy the car; all are reasons to check the level at every service. See the BMW B38 coolant leak and Ford service and repair.
A coolant leak repair takes an hour for a hose or a tank, two to three hours for a thermostat housing or an accessible water pump, half a day for a radiator where the bumper and fans come off, and a day or more for a pump behind the cambelt, a heater matrix or a head gasket, with the test done first so the time is known before the car is stripped.
Most are done the same day. See coolant leak and overheating repair St Helens and courtesy car for the longer jobs.
A car that overheats in traffic but is fine on the motorway usually has a cooling fan that is not coming on, a thermostat that is sticking, or air in the system after a top-up or a repair, because at speed the airflow through the radiator does the fan's job and at a standstill nothing does.
The read on the tool shows whether the fan is being commanded and whether it answers. See thermostat replacement cost and coolant leak and overheating repair St Helens, or ring 01744 808586.
If your car is overheating, pull over as soon as it is safe, switch off, let it cool for at least half an hour, never open the expansion cap while it is hot, then check the level and top up with water only to reach a garage a few miles away, because every minute driven with the gauge in the red is a minute towards a head gasket.
A car that overheats within minutes from cold should not be driven at all. See coolant leak and overheating repair St Helens and head gasket replacement cost. Ring 01744 808586 from the roadside.
A coolant leak fails the MOT where it is dripping enough to be an environmental defect or where it has caused an engine management light, and a car that arrives at the test overheating is turned away, so a leak that has been topped up for months is worth fixing before the test rather than after a fail sheet.
Where the test is done here the repair is in the same building. See MOT St Helens and coolant leak and overheating repair St Helens.
A thermostat housing leak costs £120 to £300 to fix as a guide, because the plastic housing is replaced with the thermostat and gasket inside it and the system refilled and bled, and it is the commonest leak on Ford, PSA and VW group engines once the plastic has hardened with age and heat.
A housing done at a service is a housing that did not split on the motorway. See thermostat replacement cost and Peugeot service and repair.
A coolant level dropping on a diesel with no visible leak is often the EGR cooler, which passes coolant into the exhaust where it burns off as white smoke, or the head gasket, and the two are told apart by the sniff test at the tank and the smoke on a warm engine, before either expensive part is fitted.
It is the leak that hides best. See EGR cooler replacement cost and DPF cleaning cost for the diesel side.
A coolant leak is not expensive to fix in most cases, because the commonest leaks are a hose, a clip, a tank or a housing at £60 to £300, and it becomes expensive only when it is left, because an engine run low on coolant overheats and cooks its head gasket at £500 upwards.
The under-an-hour test is what keeps it at the cheap end. See car repair cost and pay monthly car repairs.
You can spread the cost of a coolant leak repair over three, four or six months at nought per cent with Payment Assist, decided on a soft search that does not mark your credit file, which matters when a leak turns out to be a radiator, a matrix or a head gasket rather than a hose.
See pay monthly car repairs for how it works and car repair cost for the figures, or ring 01744 808586 and we set it up when you book.
We repair coolant leaks at the workshop on Boundary Road in St Helens, for drivers from across the borough and from Haydock, Prescot, Rainhill, Newton-le-Willows, Billinge, Widnes, Warrington, Wigan and Liverpool, because the pressure test, the dye and the proper bleed need the ramp and the equipment.
Recovery can be arranged for a car that is overheating. See the contact page for directions and garage services in St Helens for everything else done here.