Renault Fuel Injectors
Diesel and petrol injectors are not the same purchase. On the 1.5 dCi, cars.co.za notes that clogged injectors "can arise if the vehicle hasn't been maintained correctly or has been run on poor-quality fuel" — which is a live concern on South African diesel. Petrol injectors on the three-cylinder cars are a far simpler and cheaper proposition. Which engine you have changes everything here.
- Trade counter at 89 Chris Hani Road, Briardene
- Collect from the counter, or courier with the carriage in the quote
- Price, condition and fitment settled on a written quote
Fuel Injectors, explained
Whether this is a modest job or a serious one comes down to one question: petrol or diesel.
Petrol injectors on the three-cylinder Renaults
Petrol injectors on the three-cylinder Renaults are relatively simple items operating at ordinary fuel pressures. They get dirty, they leak, they occasionally stop responding, and replacing one is not a dramatic undertaking.
Diesel injectors on the 1.5 dCi are precision components
Diesel injectors on the 1.5 dCi are precision components working at pressures many times higher, and the tolerances inside them are measured in microns. That is why fuel quality matters so much: cars.co.za says of the second-generation Duster that clogged injectors can arise if the car has not been maintained correctly or has been run on poor-quality fuel. On South African roads, where fuel quality varies by region and by station, that is a live consideration rather than a theoretical one.
Two honest notes
Two honest notes. First, diesel injectors are normally dealt with as a set rather than one at a time — a fresh injector working alongside three worn ones tends to expose the other three rather than fix the car. Second, on the question of whether Renault diesel injectors need calibration codes written into the ECU when they are fitted: that requirement is documented in the trade for Renault's 1.9 and 2.0 dCi engines, neither of which is in the SA models we deal with.
We have not found a source confirming it for the 1.5 dCi specifically, so we will not tell you it is required — we will check with the workshop fitting them.
How you know fuel injectors are on the way out
Recognise any of that? Tell us the model and year and we will go and check what we can get hold of for you.
The questions we ask before we price fuel injectors
Strip away the catalogue language and what you are actually choosing between here is petrol or diesel — because the two systems have almost nothing in common.
The petrols run port injection at ordinary pressures. The 1.5 dCi is common-rail diesel, where the tolerances leave no room for contamination — cars.co.za notes that clogged injectors on the second-generation Duster can arise where the car has been run on poor-quality fuel, which is a live concern on South African diesel rather than a theoretical one.
So we price fuel injectors against your specific car, not against a badge. Send through the engine, and whether the fuel filter has been changed at the interval, and we will come back to you on what fits , what it will cost, and how soon we can have it moving.
Further reading on fuel injectors
Independent sources, not ours. Worth a look if you want the background before you enquire.
Fuel Injectors — what customers usually ask
What happens when a diesel fuel injector fails?
It stops metering fuel accurately. Too much and you get black smoke, a knock and poor economy; too little and you get a misfire and low power. The failure worth taking seriously is a leaking injector, because raw diesel washing the oil film off a bore does real damage to the engine, and in the worst case dilutes the sump. A diesel that has developed a new knock is not a car to keep driving while you think about it.
What are the symptoms of a bad fuel injector?
Rough idle, a misfire that shows up on one cylinder, hard starting, worse fuel consumption and smoke of one colour or another. On a petrol car a check-engine light with a cylinder-specific misfire code is common. The reason this needs testing rather than guessing is that coils, plugs and compression problems all present the same way, and injectors are the most expensive of the four to replace on spec.
What is the most common cause of injector failure?
Contamination. Water, dirt or poor-quality fuel getting past a neglected filter and reaching parts built to tolerances that leave no room for it. That is exactly why cars.co.za ties clogged injectors on the 1.5 dCi to poor maintenance and poor fuel. Changing the fuel filter at the interval is the cheapest injector insurance available.
Can I drive a diesel with bad injectors?
Not for long, and not safely. A leaking injector can wash the bore, dilute the oil, and put unburnt fuel through the particulate filter — which then clogs, which then puts back-pressure on the turbo. One failing injector turning into a turbo and a DPF is a genuinely common way for a small bill to become a large one.
Should I replace one injector or all of them?
On a diesel, the usual advice is all of them, or at least to have the set tested. They have worn together and a single new one alongside three tired ones rarely gives the result people expect. On a petrol engine, replacing one is more often reasonable. Tell us which engine you have and we will quote it the way it is normally done.
Do used injectors need coding to the car?
For Renault's 1.9 and 2.0 dCi engines, the trade documentation says yes — each injector carries a calibration code that has to be written into the ECU, and if it is not done the car runs in limp mode. Whether that applies to the 1.5 dCi in the SA Duster and Captur, we have not been able to confirm from a source we trust, so we are not going to assert it either way. We will raise it with whoever is fitting them, because it is a cheap question and an expensive assumption.