In this guide
A buyer brought a Mercedes G500 to our Al Quoz workshop for a pre-purchase inspection. The cooling system burst at our service bay before the check began. We repaired the radiator and hoses, then finished the full inspection. Here is what happened and what every used G-Class buyer in Dubai should learn from it.
This is a real job from our workshop, written by the Mechanics team. We share it because it shows better than any checklist why an inspection matters before you pay for a used car.
If you are about to buy, see our pre-purchase inspection service.
What happened when the G500 arrived?
- The buyer booked an inspection before paying the seller
- As the car pulled into our bay, the cooling system burst
- Hot coolant sprayed under the bonnet and across the floor
- The engine was switched off at once, so it never ran dry
Lucky timing. One day later on Sheikh Zayed Road, this would have been the new owner’s problem, possibly with engine damage as well.
A failure like this releases hot coolant under pressure. It is dangerous to anyone nearby and can overheat the engine within minutes if the car keeps running.
The car looked clean and drove normally on the way in. Nothing warned the buyer that the cooling system was close to failing.
Why do cooling systems fail on older luxury SUVs?
We did not guess the history of this car, but these are the usual reasons we see cooling parts fail on large SUVs in Dubai.
Plastic tanks and rubber hoses harden and crack with years of heat.
Worn coolant lets corrosion build up inside the radiator.
V8 engines make a lot of heat and load the system hard.
Cars that sit for months can dry out seals and hoses.
How did we diagnose the failure?
With the buyer’s approval, we fixed the car first and inspected it after. The engine was fully cooled before anything was opened.
Opening a hot cooling system is dangerous, so patience here is part of doing the job safely. Once it was cold, we worked through the system in a set order, so nothing was missed and the buyer got a clear picture of what failed and why.
Damage check
We traced where coolant escaped and checked belts, wiring and the engine bay for damage from the hot spray.
Pressure test
The system was pressure tested to find every weak point. The radiator and several hoses were damaged or worn.
Cap and thermostat
The cap seal and the thermostat opening were tested, so the new parts would not be put under the same stress.
Engine health
We checked the oil for coolant and looked for signs of overheating, which matters a lot to a buyer.
What repair did the G500 need?
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Radiator replaced
The damaged radiator was removed and a new one fitted.
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Hoses replaced
All worn hoses were renewed and every clamp and connection was secured.
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System flushed
Old coolant and debris were flushed out. See what a radiator flush involves.
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Refilled and bled
The system was filled with the correct coolant and all air was bled out.
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Tested at temperature
The engine ran to full temperature while we watched for leaks and confirmed the fans worked. The level was rechecked cold.
| Part or check | Result |
|---|---|
| Radiator | Damaged, replaced |
| Coolant hoses | Worn or damaged, replaced |
| Coolant | Flushed and renewed |
| Pressure cap | Checked for correct sealing |
| Thermostat | Tested for correct opening |
| Engine oil | Checked for coolant contamination |
G-Class owner seeing coolant loss or a rising gauge? See our Mercedes G500 repair page.
Buying a used Mercedes or another luxury car? Send us the car details. We will tell you what our inspection covers and the price for that model.
What did the full inspection cover?
Once the cooling system was repaired and tested, we finished the inspection the buyer had booked.
| Area | What we checked |
|---|---|
| Engine and fluids | Leaks, oil condition, overheating signs and stored fault codes |
| Cooling system | New parts tested again under temperature |
| Transmission | Shift quality, slipping or delay on the road test |
| 4×4 system | Transfer case and differential locks working |
| Brakes | Pads, discs and brake fluid condition |
| Suspension and steering | Wear, leaks and noises from joints and dampers |
| Underbody | Chassis, rust, impact damage and leaks |
| Electrics | Lights, controls, warning lights and infotainment |
| Body and paint | Dents, repaint signs, panel gaps and rust spots |
| Interior | Seats, controls, AC and signs of water entry |
Cooling system warning signs every owner should know
The G500 in this story failed without warning, but most cooling systems give small signs first. Watch for these.
| Sign | What it can mean | What to do |
|---|---|---|
| Sweet smell after driving | Coolant leaking onto hot parts | Check level and book a check |
| Coolant level keeps dropping | A leak somewhere in the system | Pressure test |
| White crust on hoses or tank | Dried coolant from a slow leak | Inspect hoses and clamps |
| Gauge higher than normal in traffic | Fan, radiator or coolant problem | Cooling system diagnosis |
| Steam from the bonnet | Active leak or overheating | Stop safely and switch off |
| Heater blows cold | Low coolant or air in the system | Check level when cold |
Inspection or just a test drive?
Many buyers rely on a short test drive. This table shows what each one can find.
| What gets checked | Test drive only | Pre-purchase inspection |
|---|---|---|
| How the car feels to drive | Yes | Yes |
| Hidden fault codes | No | Yes |
| Cooling system pressure | No | Yes |
| Underbody and chassis | No | Yes, on a lift |
| Repaint and accident signs | Sometimes | Yes |
| Written report for negotiation | No | Yes |
Buying from a private seller or a dealer
Often a lower price
Usually no warranty. An inspection is even more important.
More choice
Check what the warranty really covers and for how long.
Dealer checked
Usually higher price. An independent check still gives a second opinion.
Whichever route you choose, ask for the inspection before money changes hands. A seller with nothing to hide rarely refuses.
What to check on any used G-Class
The G-Class is built tough, but it is still a complex luxury car. These are the areas we always look at closely.
Cooling system
Radiator, hoses, tank and fans, as this job shows.
Differential locks
All locks should engage and release cleanly with no warning.
Suspension
Bushes, dampers and steering joints on a heavy body.
Underbody
Off road use can leave dents, scrapes and rust on the chassis.
Electrics
Many control units. All warnings must be explained.
Service history
Regular dealer or specialist servicing is a good sign.
Red flags when buying a used luxury SUV
- The seller will not allow an independent inspection
- No service records, or records with long gaps
- Warning lights on the dashboard, or lights that were recently cleared
- Fresh coolant stains, a sweet smell or a low coolant level
- Fresh paint on some panels but not others
- Water marks or a damp smell inside the cabin
One red flag does not always mean walk away. It means ask more questions and get it checked properly.
Common issues we find on used luxury SUVs in Dubai
Every car is different, but these are the items that come up most often when we inspect large luxury SUVs.
| Area | What we often find | Why it matters |
|---|---|---|
| Cooling | Aged hoses, weeping radiators, tired fans | Overheating can damage the engine |
| Brakes | Worn pads and discs on heavy cars | Safety and a near term cost |
| Suspension | Worn bushes and leaking dampers | Ride, handling and tyre wear |
| Oil leaks | Seeping gaskets on older engines | Can grow and damage other parts |
| AC | Weak cooling in summer heat | Comfort and possible gas leaks |
| Electrics | Stored fault codes and cleared warnings | Hidden faults that return later |
Questions to ask the seller
- How long have you owned the car, and why are you selling?
- Where was it serviced, and do you have the invoices?
- Has the car ever overheated or had a cooling repair?
- Has it been in any accident or flood?
- Has it been used off road or in the desert?
- Are there any warning lights or known faults?
Write down the answers. If the inspection finds something that does not match, you will know which questions to raise.
Documents to ask the seller for
- Vehicle registration card, called the mulkiya
- Full service history with dates and mileage
- Invoices for any major repairs
- Accident or insurance claim history if available
- Warranty or service contract papers
- Both keys and the owner’s manual
How to test drive a used G-Class
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Start from cold
Ask the seller not to warm it up first. Listen for noises and watch for smoke.
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Drive in traffic
Watch the temperature gauge and check the AC stays cold.
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Drive on the highway
Check for vibration, pulling and smooth gear changes.
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Test the brakes
Firm, straight stops with no noise or pulsing.
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Check after the drive
Look under the car for drips and recheck warning lights.
How our pre-purchase inspection works
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Send the car details
Make, model, year and the seller’s advert on WhatsApp.
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Get the price
We confirm the checks included and the price for that model.
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Bring the car in
The car comes to our Al Quoz workshop for the inspection.
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Receive the report
Written findings and photos, with any repairs quoted separately.
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Decide with confidence
Buy, negotiate or walk away, based on facts.
Has the car been used in the desert?
Many G-Class owners in Dubai enjoy dune drives. That is what the car is built for, but it leaves signs we look for.
- Sand packed in the radiator fins and engine bay
- Scrapes and dents on the underbody and chassis
- Extra wear on suspension, steering and drive shafts
- Air filter and intake condition
Desert use is not a reason to walk away. It simply means the cooling, underbody and suspension deserve a closer look.
What should G-Class buyers learn from this?
Radiators and hoses age with heat. This car gave the buyer no warning.
Look for coolant changes and cooling work, not just oil services.
Past overheating can affect the engine. An inspection looks for it.
Luxury SUV parts cost more. Use the report to negotiate.
City traffic, highway and full engine temperature.
An inspection by someone with no interest in the sale.
Full checklist for any used car is in our pre-purchase car inspection guide.
How much does a pre-purchase inspection cost in Dubai?
Our planning range is AED 400 to 1,100. Luxury SUVs like the G500 sit at the higher end because there are more systems to check.
- Price confirmed for your car before booking
- Repairs quoted separately in writing
- Nothing repaired without your approval
Compared with the price of a used G-Class, the inspection is a small cost. In this case it stopped the buyer from inheriting a failed cooling system.
After you buy, what should you do first?
Even a car that passes inspection benefits from a fresh start. These first steps help you know exactly where you stand.
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Change oil and filters
Unless the seller has invoices showing a very recent service.
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Check coolant and brake fluid
Renew them if the history is unclear or the fluid looks old.
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Fix the items in the report
Start with safety items like brakes, tyres and cooling.
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Start your own service record
Keep every invoice. It protects the value when you sell.
Plan a budget. Set aside money for the first year of servicing and any items the inspection flagged. It avoids surprises.
What you receive in the report
Condition of each area in plain language.
Pictures of any leaks, damage or worn parts.
Stored codes and what they mean.
Costs for anything that needs fixing.
Book an inspection before you pay the seller. Send us these details on WhatsApp.
- Car make, model, year and mileage
- When the car can be brought in
- The seller’s advert link
Questions buyers ask us
Can an inspection find a cooling problem before it fails?
Often, yes. A pressure test and checks of the coolant, radiator, hoses and cap show weak points. Not every failure gives warning, but the risk drops a lot.
Who pays for repairs found during an inspection?
That is agreed between buyer and seller. We give a written quote you can use to ask the seller to fix it or to lower the price.
How long does a pre-purchase inspection take?
It depends on the car and the checks included. We confirm timing when you book. Luxury SUVs take longer because there is more to test.
Do you inspect cars still with the seller?
Yes, the car can be brought to our workshop in Al Quoz. Send the details on WhatsApp and we will confirm timing and price.
Is a G-Class expensive to maintain?
Running costs are higher than an everyday car because parts and labour cost more. A car with good history and an inspection report helps you plan for them.
Should I buy a car that had a cooling repair?
A proper repair with new parts and invoices is not a bad sign. The key is checking that the engine was not overheated and that the work was done correctly.
Can you check a car bought from a dealer?
Yes. Dealer cars can also have hidden faults. An independent inspection gives you a second opinion before you sign.
Do you check other Mercedes models?
Yes. We inspect all Mercedes models and most other brands. Send the car details and we will confirm the price.
What if the inspection finds a major fault?
You get the facts in writing, with photos and a repair quote. You can then negotiate, ask the seller to fix it, or walk away.
Does a clean car mean a healthy car?
No. A fresh wash and polish can hide leaks, rust and repairs. This G500 looked clean and drove in normally before its cooling system failed.
Can an inspection check if a car was in a flood?
We look for water marks, rust in unusual places, damp carpets and electrical faults. These signs help show if a car has been in deep water.
Can I be present during the inspection?
Ask us when you book. We are happy to explain the findings and show you any issues on the car.
