Cooling System Services Stevenage
Keep Your Engine
Running Cool.
Overheating is one of the most damaging things that can happen to an engine — and it's nearly always preventable. From a routine coolant flush to a failed water pump or a leaking radiator, TGPP Autocare diagnoses and fixes cooling system problems before they become expensive engine damage.
Is Your Engine Running Hot?
Don't ignore it. Overheating can cause warped cylinder heads, blown head gaskets, and complete engine failure — often costing thousands to repair. Act early.
Our Cooling System Services
Everything Your Cooling System Needs
Whether it's a routine maintenance flush or an urgent repair, we cover the full range of cooling system work — always with transparent pricing and quality parts specified to your vehicle.
```01 — Most Requested
Engine Coolant Drain, Flush & Refill
The essential cooling system maintenance service — often overlooked until it's too late
Old coolant degrades over time — it loses its anti-freeze and anti-corrosion properties, becomes acidic, and allows scale and sludge to build up inside the system. A coolant flush removes all of this and replaces it with fresh, correctly-specified fluid that protects your engine from both overheating and freezing. Most manufacturers recommend this every 2–5 years depending on coolant type.
What We Do
- →Full drain of old, degraded coolant
- →System flush with specialist cleaning solution to remove scale and deposits
- →Refill with manufacturer-recommended coolant to correct concentration
- →Pressure test on completion to confirm system integrity
Why It Matters
- →Prevents overheating by restoring proper coolant flow and heat transfer
- →Protects against internal corrosion of the radiator, water pump and heater core
- →Restores anti-freeze protection — critical for winter
- →Removes acidic old coolant that can damage seals and gaskets
Intervals
- →Green / Blue coolant (OAT): typically every 2 years or 30,000 miles
- →Pink / Red coolant (HOAT / OAT2): typically every 5 years
- →Always follow your vehicle's manufacturer schedule — we'll check this for you
02 — Temperature Control
Thermostat Replacement
Running too hot or too cold? The thermostat is often why
The thermostat controls when coolant flows through the radiator — it holds coolant in the engine until the right temperature is reached, then opens to allow cooling. A stuck-open thermostat means the engine never warms up properly. A stuck-closed thermostat causes rapid overheating.
What We Do
- →Diagnosis to confirm thermostat failure vs other faults
- →Removal of old thermostat and housing
- →Installation of quality replacement thermostat
- →Coolant top-up and system bleed
- →Temperature monitoring test on completion
03 — Circulation
Water Pump Replacement
The heart of your cooling system — when it fails, your engine overheats fast
The water pump circulates coolant through the engine and radiator continuously. Signs of a failing water pump include overheating, coolant leaks from the front of the engine, a whining noise from the pump bearing, or coolant contamination. It often makes sense to replace the water pump at the same time as a timing or wet belt service.
What We Do
- →Diagnosis of pump failure — leak, bearing wear, impeller damage
- →Full water pump removal and replacement
- →New gasket / seal fitted as standard
- →Coolant top-up and full system bleed
- →System pressure test on completion
04 — Core Cooling
Radiator Repair & Replacement
Leaking, corroded or damaged radiator? We fix it properly
The radiator dissipates heat from the coolant passing through it. Damage, corrosion, or internal blockage reduces its efficiency — and a leaking radiator will eventually leave you stranded. We assess whether repair or replacement is the right option and advise you honestly before any work begins.
What We Do
- →Full radiator inspection and leak testing
- →Internal flow and blockage assessment
- →Radiator repair where viable
- →Full radiator replacement where required
Signs of Radiator Problems
- →Coolant puddle under the front of the car
- →Engine temperature running higher than normal
- →Visible damage, corrosion or discolouration
- →Coolant losing pressure without a visible external leak
05 — Hoses & Pipes
Coolant Hose Inspection & Replacement
Brittle, cracked or swollen hoses are a common cause of breakdown
Coolant hoses deteriorate with age and heat cycles — they can crack, swell, soften, or collapse internally without showing obvious external signs. A burst hose dumps your coolant in minutes. We inspect all hoses and replace any that are showing signs of deterioration before they let you down.
What We Do
- →Full hose inspection — all major and minor coolant hoses
- →Pressure testing to identify weak hoses and clamp failures
- →Replacement of any hose showing deterioration
- →Coolant refill and bleed on completion
06 — Leak Tracing
Coolant Leak Detection
Losing coolant but can't see where? We find it
Some coolant leaks are obvious — a puddle on the floor, steam from the bonnet. Others are internal (a leaking head gasket allowing coolant into the combustion chamber) or evaporate before they're visible. We use specialist equipment to find leaks that can't be spotted by eye.
What We Do
- →Cooling system pressure test to find external leaks
- →UV dye testing for hard-to-find seepage
- →Combustion gas analysis — detects head gasket failure
- →Visual inspection of all components
- →Full written report and repair recommendation
07 — Airflow
Cooling Fan Inspection & Repair
A failed cooling fan causes overheating at low speed and in traffic
Electric cooling fans kick in when airflow through the radiator isn't sufficient — mainly at low speeds and when stationary. If the fan fails, coolant temperature climbs rapidly in traffic even if the rest of the system is fine. We test the fan motor, relay, temperature switch, and wiring.
What We Do
- →Fan motor testing — load and RPM check
- →Temperature switch and relay testing
- →Wiring and connector inspection
- →Fan blade inspection for damage
- →Fan motor or assembly replacement if required
08 — System Integrity
Coolant Pressure Testing
The definitive test for cooling system integrity
Pressure testing is the most reliable way to confirm a cooling system is holding correctly and has no leaks — whether they're visible or not. We pressurise the system to the correct specification and monitor it over time. Any drop in pressure indicates a leak that needs tracing and repairing.
What We Do
- →System pressurised to manufacturer specification
- →Pressure monitored over time for any drop
- →Radiator cap pressure test included
- →Full visual inspection while pressurised
- →Result and recommendation provided in writing
09 — Reservoir
Expansion Tank & Reservoir Inspection
Small component, big consequences when it fails
The expansion tank (also called a coolant reservoir or overflow tank) stores surplus coolant as the system heats and cools. Cracks, leaks, or a faulty cap allow the system to lose pressure and coolant — eventually leading to overheating. These are often overlooked until they fail completely.
What We Do
- →Full reservoir inspection — cracks, leaks, cap seal condition
- →Pressure cap testing — a failed cap causes constant coolant loss
- →Reservoir replacement where required
- →Coolant refill and level check on completion
Know the Signs
Warning Signs Your Cooling System Needs Attention
Cooling system problems rarely appear without warning. Act on these signs early — the cost of a repair is always far less than the cost of an overheated engine.
```Temperature Gauge Rising
If the gauge is climbing above its normal position, pull over safely and switch the engine off. Don't keep driving — overheating causes rapid, serious damage.
Steam from the Bonnet
Steam means coolant is escaping or boiling somewhere it shouldn't. Stop immediately. Do not open the bonnet until the engine has cooled completely.
Puddle Under the Car
A sweet-smelling, often coloured puddle (green, blue, pink or orange) indicates a coolant leak. Oil and water don't mix like this — get it checked promptly.
Coolant Level Dropping
If you're regularly topping up the coolant reservoir, coolant is going somewhere. Even with no visible leak, it could be leaking internally into the engine.
Sweet Smell Inside the Car
A sweet, slightly sickly smell through the vents often indicates a heater core leak — coolant seeping into the heating system. Your windows may also mist up unusually.
No Heat from the Heater
If the heater is blowing cold air when the engine is warm, it often points to low coolant, a thermostat stuck open, or a blocked heater core — all cooling system issues.
If Your Engine Is Currently Overheating
Pull over safely and switch the engine off immediately. Do not remove the coolant cap — the system is under pressure and boiling coolant can cause serious burns. Let the engine cool fully before checking anything. If you're unsure, call us on 01438 232556 and we'll advise you.
Coolant Types
Using the Right Coolant Matters
Not all coolants are interchangeable — mixing the wrong types can cause internal corrosion and actually damage the system they're meant to protect. We always use the manufacturer-specified coolant for your vehicle.
Green / Blue (IAT / OAT)
Traditional inorganic coolant. Typically requires renewal every 2 years or 30,000 miles. Common on older vehicles. Do not mix with HOAT or OAT2 types.
Pink / Red (HOAT / OAT2)
Longer-life organic acid coolant. Up to 5 years or 150,000 miles on many vehicles. Common on modern European and Japanese cars. Do not mix with green coolant.
Orange / Yellow (HOAT)
Hybrid OAT coolant, common on GM, Ford and Chrysler vehicles. Do not mix with other types — cross-contamination leads to gel-like deposits that block the system.
Why TGPP Autocare
Why Choose Us for Cooling System Work?
Cooling system work requires the right knowledge, the right parts, and the honesty to tell you what actually needs doing — not just what generates the biggest invoice.
RAC Approved Garage
Independently inspected by the RAC every year. Our cooling system work is carried out to the same exacting standard as every other job, with a mandatory 12-month guarantee.
Properly Diagnosed First
We don't replace parts at random. We identify the specific fault — whether it's a thermostat, water pump, hose, or head gasket — before recommending any repair.
Manufacturer-Spec Coolant
We always use the correct coolant type for your vehicle — not a generic one-size-fits-all fluid. Using the wrong coolant can cause corrosion rather than preventing it.
Transparent Pricing
You'll receive a written quote before any work starts. Nothing is carried out without your approval, and there are no hidden charges added after the job.
Responsible Fluid Disposal
Used coolant is toxic to animals and harmful to the environment. We dispose of all old coolant responsibly through licensed waste contractors — never down the drain.
Same-Day Service Where Possible
Most cooling system repairs — flushes, thermostat and hose replacements — are completed the same day. Call us and we'll tell you how quickly we can get you booked in.
Engine Running Hot? Don't Wait.
Book your cooling system service or repair at TGPP Autocare today. We'll diagnose the problem, give you a clear quote, and get it fixed properly. Serving Stevenage and Hertfordshire.
At TGPP-Autocare in Stevenage, we understand the importance of a properly functioning cooling system. Overheating can lead to serious engine damage, so we offer comprehensive cooling system services to keep your vehicle running smoothly and safely.
Our Cooling System Services:
Engine Coolant System Drain, Flush & Refill:
We perform a complete drain, flush, and refill of your engine's coolant system. This service removes old coolant, debris, and contaminants, ensuring optimal cooling efficiency and preventing corrosion.
- Includes:
- Draining the old coolant
- Flushing the system with a specialized cleaning solution
- Refilling with high-quality coolant (recommended by the manufacturer)
- Pressure testing the system for leaks
- Benefits: Prevents overheating, removes contaminants, protects against corrosion, and ensures optimal cooling performance.
Thermostat Replacements:
A faulty thermostat can cause your engine to overheat or run too cold. We replace worn or malfunctioning thermostats with high-quality replacements to ensure proper temperature regulation.
- Includes:
- Removal of the old thermostat
- Installation of a new, high-quality thermostat
- Coolant level check and top-up
- System testing for proper operation
- Benefits: Maintains proper engine temperature, improves fuel efficiency, and prevents engine damage.
Water Pump Replacements:
A failing water pump can lead to overheating and engine damage. We replace worn or leaking water pumps with reliable replacements to ensure proper coolant circulation.
- Includes:
- Removal of the old water pump
- Installation of a new, high-quality water pump
- Coolant level check and top-up
- System testing for proper operation
- Benefits: Ensures proper coolant circulation, prevents overheating, and protects the engine from damage.
Radiator Repair and Replacement:
Radiators can become damaged or corroded, leading to leaks and reduced cooling efficiency. We repair or replace damaged radiators to ensure proper cooling.
- Includes: Radiator inspection, leak testing, repairs or replacement, coolant refill.
- Benefits: Prevents overheating, restores cooling efficiency, and extends radiator lifespan.
Hose Inspection and Replacement:
Coolant hoses can crack, leak, or become brittle over time. We inspect and replace damaged hoses to prevent coolant leaks and overheating.
- Includes: Hose inspection, pressure testing, hose replacement, coolant refill.
- Benefits: Prevents coolant leaks, ensures proper coolant circulation, and prevents engine damage.
Coolant Leak Detection:
We use specialized tools and techniques to locate coolant leaks, even those that are difficult to find.
- Includes: Pressure testing, dye testing, visual inspection.
- Benefits: Pinpoints coolant leaks, prevents coolant loss, and prevents overheating.
Cooling Fan Inspection and Repair:
Electric cooling fans are vital for proper cooling, especially in traffic. We inspect and repair or replace faulty cooling fans.
- Includes: Fan motor testing, wiring inspection, fan blade inspection or replacement.
- Benefits: Ensures proper airflow through the radiator, prevents overheating in traffic, and maintains cooling efficiency.
Coolant Pressure Testing:
We perform pressure tests to check for leaks and ensure the cooling system is operating at the correct pressure.
- Includes: Pressure testing the cooling system, visual inspection for leaks.
- Benefits: Identifies leaks, ensures system integrity, and prevents overheating.
Coolant Reservoir/Expansion Tank Inspection and Replacement:
The coolant reservoir or expansion tank stores excess coolant. We inspect and replace damaged or leaking reservoirs.
- Includes: Reservoir inspection, leak testing, reservoir replacement, coolant refill.
- Benefits: Ensures proper coolant storage, prevents coolant loss, and maintains system pressure.
System Cleaning:
Over time, mineral deposits and sludge can build up in the cooling system, reducing its efficiency. We provide system cleaning to remove these deposits.
- Includes: Cooling system cleaning with specialized chemicals, flushing the system, coolant refill.
- Benefits: Improves cooling efficiency, removes deposits, and prevents corrosion.
Importance of Regular Cooling System Maintenance:
Regular cooling system maintenance is essential to prevent costly engine damage. Overheating can lead to warped cylinder heads, blown head gaskets, and even complete engine failure. Regular maintenance helps to identify and resolve potential issues before they become major problems.
Signs of a Cooling System Problem:
- Overheating
- Coolant leaks
- Low coolant levels
- Steam coming from the engine
- Sweet smell of coolant
- Temperature gauge reading high
Types of Coolant:
There are different types of coolant available, including ethylene glycol and propylene glycol. We follow manufacturer recommendations for the correct type of coolant for your vehicle.
Manufacturer Recommendations:
We adhere to manufacturer recommendations for coolant type and service intervals, ensuring that your vehicle is serviced to the highest standards.
Environmental Considerations:
We dispose of used coolant responsibly, protecting the environment.
Why Choose TGPP-Autocare for Your Cooling System Services?
- Experienced Technicians: Our technicians are experienced in diagnosing and repairing cooling system issues.
- Quality Parts: We use high-quality parts and fluids to ensure reliable repairs.
- Transparent Pricing: We provide clear and upfront pricing with no hidden fees.
- Fast and Efficient Service: We quickly diagnose and resolve cooling system issues, minimizing downtime.
- Customer Satisfaction: We are committed to providing exceptional customer service.
- Local and Trusted: We are your trusted local garage in Stevenage.