Nissan Sunny is a legendary car that is still popular today due to its reliability and ease of maintenance. However, even such time-tested machines have weaknesses. One of them is heater radiator, which over time becomes clogged, leaks, or ceases to effectively heat the interior. If you notice that the car is cold even with the heater running, and there are puddles of antifreeze on the floor on the passenger side, it's most likely time for a replacement.
In this article we will look in detail at how to replace a stove radiator with Nissan Sunny (models B13, B14, B15) with your own hands. You will learn what tools you will need, how to avoid common mistakes and save money at a service station. And if you already have repair experience, check yourself with the help of our expert advice and checklists.
Signs of a malfunctioning heater radiator on a Nissan Sunny
Before you start replacing, make sure that the problem is in the heater core. Here are the key symptoms that indicate its failure:
- 🔥 Poor interior heating — even at maximum temperature, barely warm air blows from the deflectors.
- 💧 Antifreeze leak — puddles under the front passenger seat or a wet carpet.
- 🌫️ Fogging of windows — due to a coolant leak, steam appears in the cabin.
- 🚗 Engine overheating - if the heater radiator is clogged, this may affect the circulation of antifreeze in the system.
- 🔊 Noise under the dash — gurgling or gurgling noise when the heater is operating.
If you observe at least 2-3 signs from the list, the probability of a malfunction of the heater radiator is close to 100%. But before replacing it is worth checking thermostat, pump And antifreeze level - sometimes the problem lies in them.
⚠️ Attention: If antifreeze gets on the electrical wiring under the dash, it can cause a short circuit. Before replacing the radiator, be sure to dry the interior and check the contacts!
- B13 (1990-1993)
- B14 (1994-1998)
- B15 (1998-2006)
- Other model
What tools and materials will be needed
To replace the heater radiator with Nissan Sunny You don't need fancy tools, but do prepare in advance. Here's the full list:
| Category | Name | Note |
|---|---|---|
| Tools | Set of sockets and ratchet wrenches (8-14 mm) | Required with extension cord |
| Tools | Phillips and flathead screwdrivers | Preferably with a magnetic tip |
| Tools | Pliers and wire cutters | For clamps and hoses |
| Materials | New heater radiator | Suitable for your model (see compatibility chart below) |
| Materials | Antifreeze (5-7 l) | Only original or high-quality analogue (for example, CoolStream A-110) |
| Consumables | Clamps (4-6 pcs.) | It is better to take worm-type ones rather than spring ones |
| Consumables | Sealing rubber or sealant | For sealing connections |
Also prepare container for draining antifreeze (at least 5 liters), rags And flashlight — without it, working under the panel will be extremely inconvenient. If you have a model with air conditioning, you may need gauge manifold for refilling freon after dismantling the radiator.
Before purchasing a radiator, check its part number using the VIN code of your car. On Nissan Sunny B14 Radiator from Nissan Almera N15 (article 27100-4M000).
Step-by-step instructions for replacing the heater radiator
The process of replacing the stove radiator with Nissan Sunny can be divided into 3 stages: preparation, dismantling the old radiator And installation of new. Let's look at each of them in detail.
1. Preparing the car
Before starting work, complete the following steps:
Drain the antifreeze from the cooling system|Disconnect the negative terminal of the battery|Remove the glove compartment and the lower panel under the steering wheel|Prepare the work area (lighting, tools)|Check the availability of all spare parts and consumables-->
To drain the antifreeze, place the car on a flat surface and unscrew drain plug on the radiator (it's in the lower left corner). Don't forget to substitute the container! Also unscrew the plug on expansion tank - this will speed up the process.
⚠️ Attention: Antifreeze is toxic! Wear gloves and do not dump it on the ground. For disposal, use special collection points.
2. Removing the old radiator
This is the most time-consuming stage. On models Nissan Sunny B13/B14 The heater radiator is located behind the center console, and on B15 - a little to the left. Algorithm of actions:
- Remove decorative trim for center console (it is attached with latches and 2-3 screws).
- Unscrew instrument panel mounting bolts (usually 4 pieces: two on top and two on bottom).
- Loosen the clamps and remove antifreeze supply and return hoses from the radiator. Be prepared for the remaining liquid to leak out of them.
- Disconnect heater fan electrical connector (if it interferes).
- Carefully remove the radiator by pulling it towards you. On some models you will have to bend the metal tubes a little.
On Nissan Sunny B14 with air conditioning, the heater radiator is integrated into the climate control unit. To remove it, you will have to remove it air conditioner evaporator and disassemble the heater housing. If you do not have experience working with car air conditioners, it is better to contact a service station - dismantling it yourself can lead to a freon leak.
3. Installation of a new radiator and assembly
Before installing a new radiator, check it for leaks (you can blow it with compressed air) and clean the seat from dirt. Next:
- Reinstall the radiator, making sure it fits tightly without distortion.
- Connect the hoses and tighten the clamps. Do not overtighten - this may damage the pipes!
- Connect the electrics (if you disconnected the fan).
- Reassemble the panel in reverse order. Pay special attention to securing the glove compartment - it often dangles after assembly.
- Refill with new antifreeze (see section below on correct refilling).
After assembly, start the engine and check the operation of the stove. If hot air comes out of the deflectors and it’s dry under the passenger’s feet, you’ve done everything right!
On models with air conditioning, after replacing the heater radiator, be sure to check the freon pressure. If it drops below 1.5 bar, refueling will be required.
How to properly refill antifreeze after replacing a radiator
Errors when filling antifreeze can lead to engine overheating or repeated failure of the heater radiator. Follow this instruction:
1. Use only original antifreeze or a high-quality analogue (for example, CoolStream A-110 or Sintec Unlimited). Do not mix different types of coolant!
2. Fill with antifreeze thin stream through the expansion tank to avoid the formation of air locks. Periodically squeeze the upper radiator hose to help expel air.
3. After filling, start the engine and let it run for 5-7 minutes at idle speed. Then add antifreeze to a level between MIN And MAX.
4. After 1-2 days, check the level again - topping up may be necessary. Also inspect the connections for leaks.
⚠️ Attention: If after replacing the radiator the heater blows cold air, most likely there is air left in the system. To release it, place the front of the car up on a slope and sharply press the gas several times (up to 3000 rpm).
Typical mistakes when replacing a stove radiator and how to avoid them
Even experienced car owners sometimes make mistakes that lead to repeated repairs. Here are the most common ones:
- 🔧 Using low-quality clamps — spring clamps weaken over time, which leads to leaks. Always use stainless steel worm clamps.
- 🔥 Re-upholstery of pipes - This may damage rubber hoses or aluminum radiator tubes. Tighten the clamps with a force of 1.5-2 Nm.
- 💨 They forget to bleed air — air pockets block the circulation of antifreeze, and the stove does not heat. Always check the system for air!
- 🔌 Damage to electrical wiring — when dismantling the panel it is easy to touch the connectors. Before starting work, take photographs of all connections.
- 🚗 Incorrect panel assembly — forgotten screws or a crookedly installed console can cause squeaks and rattles.
Another common mistake is saving on radiator. Cheap Chinese analogues often leak within 1-2 years. The best option is the original radiator (Nissan 27100-4M000) or quality brands like Denso, Nissens or Behr.
What happens if you don't change the heater radiator?
If you ignore a radiator leak, antifreeze will constantly leave the system. This will lead to overheating of the engine, corrosion of metal parts and even jamming of the pump. A persistent sweetish odor will appear in the cabin (from ethylene glycol in antifreeze), which is harmful to health. In addition, moisture under the mats will cause the body to rust and short circuit the wiring.
How much does it cost to replace a heater radiator on a Nissan Sunny?
The cost of replacement depends on whether you do the work yourself or contact a service station. Let's consider both options:
| Expense item | On your own | At the service station (Moscow/regions) |
|---|---|---|
| Heater radiator | 1 500 — 4 000 ₽ | 2,000 - 5,000 ₽ (with extra charge) |
| Antifreeze (5 l) | 800 — 1 500 ₽ | 1 000 — 2 000 ₽ |
| Clamps and consumables | 200 — 500 ₽ | 300 — 800 ₽ |
| Work (dismantling/installation) | 0 ₽ | 4 000 — 8 000 ₽ |
| Total | 2 500 — 6 000 ₽ | 7 300 — 15 800 ₽ |
As you can see, replacing it yourself can save you up to 70%. However, if you do not have experience working with auto electrics or air conditioning (on models with climate control), it is better to trust the professionals. Mistakes when disassembling a panel can be more costly.
Average time to replace a stove radiator Nissan Sunny:
- ⏳ Without air conditioning - 3-5 hours.
- ⏳ With air conditioning — 6-8 hours (due to the need to disassemble the evaporator).
Owner reviews: real experience of replacing a stove radiator
So that you can better understand what you will have to face, we have collected reviews from owners Nissan Sunnywho have already gone through this procedure:
Alexey, Moscow, Nissan Sunny B14 1996:
“I changed the heater radiator myself, without an air conditioner. The most difficult thing was to get to the panel mounting bolts. I had to remove the steering column, but in the end I did it in 4 hours. The heater now heats like new, and there is no smell of antifreeze in the cabin. Advice: don’t skimp on clamps!”
Igor, Ekaterinburg, Nissan Sunny B15 2002:
“On my car with air conditioning, replacing the heater radiator turned out to be a hell of a task. I had to remove the evaporator, and then also refill freon. In the end, I spent 2 days and 12,000 rubles (including refilling the air conditioner). If I had known how much hassle, I would have given it to a service station.”
Dmitry, Krasnodar, Nissan Sunny B13 1992:
“I bought a radiator for 1,800 ₽ (non-original), a year later the pipe started leaking. I had to buy the original for 3,500 ₽. Conclusion: it’s better to immediately invest in a high-quality part than to redo it later.”
As you can see, everyone's experience is different. The main thing is be realistic about your strengths and don’t take on a job if you’re not sure of success.
FAQ: Frequently asked questions about replacing the heater radiator on a Nissan Sunny
Is it possible to drive with a current heater radiator?
In the short term, yes, but it is fraught with consequences. Antifreeze is toxic, and its leakage leads to engine overheating. If the radiator is leaking heavily, it is better not to risk it and replace it as soon as possible.
What antifreeze should I put in Nissan Sunny?
For models B13/B14/B15 suitable antifreeze based on ethylene glycol (class G11 or G12). Original antifreeze Nissan Coolant L248 - the optimal choice. You can also use CoolStream A-110 or Sintec Unlimited.
Do I need to drain all the antifreeze when replacing the heater radiator?
Not necessarily. It is enough to drain the liquid to a level below the heater radiator (about 2/3 of the total volume). However, if the antifreeze is old (more than 3 years), it is better to replace it completely.
Why does the heater blow cold air after replacing the radiator?
Most likely there is air left in the system. To bleed it off, place the car on a slope (front up), remove the expansion tank cap and sharply press the gas several times (up to 3000 rpm). Also check if the hoses are connected correctly.
Is it possible to clean the old heater radiator instead of replacing it?
Theoretically yes, but in practice it is ineffective. Heater radiator Nissan Sunny It has a complex design with small honeycombs that are almost impossible to rinse properly. In addition, if the radiator is already leaking, cleaning will not help - only replacement.