Accessing the engine compartment
Tools
These are some common tools used to work on this device. You might not need every tool for every procedure.
Note: This wiki is *partially* machine-translated (why? Because the wiki is 78 pages. Hand-translating that without assistance would take literal weeks. I did use Deepl, though, and I examined each translation by hand before adding it to the document). I machine translated it as a once-over, and then went back over and checked the entire wiki by hand several times. Despite this, my knowledge of French isn’t perfect, and some information may be misleading or even straight-up *false*. Please, if you know French, double-check the translations. Also, if you’re a mechanic (or, better yet, a French mechanic), *please* double-check the technical language, because some of it is just plain weird (see “oil cap mayonnaise” [yes, that is a real phrase that was in the source document]). Also, everyone who reads this, please compare the formatting to the original document, as a lot of it got messed up when I moved the text to my text editor (and if possible, please help fix the formatting). -shingle
Note 2: In the actual wiki, all first-person pronouns (I, me, etc.) refer to @AntonioBiscuit, the author of the original French wiki, unless otherwise stated (I may leave notes in parentheses if some of the information is unclear).
END OF NOTES
Say hello to your Twingo brothers and sisters! Maybe one day we'll bump into each other on the road!
This wiki, still in progress, aims to gather as much information as possible about the Twingo III Phase 1 and its engine.
Errors (typos, spelling mistakes, erroneous information, misinterpretation of sources) may be present. Your help in correcting and improving this wiki is most welcome!
Please do not regard all opinions, subjective viewpoints, advice/suggestions, and experiences on this wiki as automatically true! A number of factors may render them invalid in your case!
Share yours: discoveries can be made that may further enrich this wiki!
Various notations and conventions are used, sometimes with the aim of remaining in harmony with those used in the RTA (Revue Technique Automobile, known as Haynes in the USA) and the various sources of this wiki. Some cross-references/notations are used in this wiki.
Some information can only be found in the exploded views/tutorials and may have to be moved there to avoid saturation and/or to lighten the main wiki page: have a look!
Some of my projects (@antoniobiscuit):
- Continuing to improve this Wiki as much as possible.
- Retrieving Renault proprietary PIDs to obtain more information via the OBD socket.
- Continuously and massively collect various information and vital metrics thanks to a "Companion" program, developed specifically for this purpose.
- Gain access to mapping and ECU data.
- Attempt to understand and optimize existing mapping on performance (fuel economy), when the engine is running on E85, and whether prospects for improvement are possible. Without an intermittent engine light, and above all with an adapted "cold" start strategy. A correction of the consumption calculation bug is desirable.
- Target 3.0L/km TDB on a full tank via modifications and optimizations.
OEM maintenance plan
The following maintenance schedule is taken from the Revue Technique Automobile (RTA) for the Twingo III 1.0 SCe. The deadlines are given for optimal use and should be shortened for severe use.
Severe use cases concern a large number of people: they are very easy to reach.
Manufacturer's maintenance schedule in km and years:
Operation | 20000km (12,500 miles) or 1 year | 40,000km (25,000 miles) or 2 years | 60,000km (37,500 miles) | 80,000km (50,000 miles) | 100,000km (62,500 miles) | 120,000km (75,000 miles) | 140,000km (87,500 miles) | 160,000km (100,000 miles) or 5 years |
---|---|---|---|---|---|---|---|---|
Inspections | - | - | - | - | - | - | - | - |
Refill levels | - | - | - | - | - | - | - | - |
Oil change + filter | - | - | - | - | - | - | - | - |
Air filter | - | - | - | - | - | - | - | - |
Cabin Filter | - | - | - | - | ||||
Spark Plugs | - (or 4 years) | - | ||||||
Rear brake linings, cylinders, and drums | - | - | ||||||
Brake fluid | - (or 3 years) | |||||||
Accessory belt and rollers | - (OR 6 YEARS!) | |||||||
Coolant | - |
Levels to be checked and filled:
- Window Wiper Fluid
- Brake Fluid
- Coolant
Checks to be made:
Check the condition and/or wear of the following items:
- Wiper blades, windshield, mirrors, battery (corrosion)
- Exhaust system
- Brake system, pads, and discs
- Tire wear and pressure
- Bodywork and underside of the car (absence of rust)
Check the following components for leaks and tightness:
- Engine
- Gearbox (Transmission)
- Cooling system
- Braking system
- Front and rear suspension
Nickel-Copper spark plugs replace between 15,000 and 20,000km maximum or as soon as the first symptoms of ignition problems appear.
The extra fuel consumption associated with worn spark plugs is significant. Fuel losses exceeding the cost of new spark plugs can be reached very quickly.
As spark plugs are very affordable, and anyone can replace them, there's no reason to wait until the deadline.
In my opinion, it's better to be certain of not losing money (polluting in excess), than to be certain of losing money (polluting in excess)
Severe use, factors shortening service intervals
In cases of severe use, it may be necessary to shorten oil change intervals considerably. A case of severe use exists if any of the following is true:
- Uses involving significant fuel dilution:
- Short trips. Becomes a extreme use case with E85.
- Frequent cold starts.
- Prolonged use in cold conditions (e.g. winter).
- Sporty driving.
- Debated: use of E85.
- Engine idling for long periods (e.g. cab, traffic jams, etc.).
- Frequent urban use (includes several severe use cases with repeated starts/stops, prolonged idling, acceleration, and short journeys). Can become an extreme use case with E5/E10 and, without question, an extreme use case with E85..
- Use in dusty areas (e.g. dirt or sandy roads).
- Journeys with a heavy load.
Notes:
Think of the planet: adopt an efficient mode of transport. Think of public transport, cycling, and car-sharing. Using a combustion engine in the city is extremely polluting*** and in many cases more costly than you think, both in time and money. Think about your engine too: do you really want to put it through so much trouble to cover such a short distance when a non-polluting alternative exists? E85 is by no means an excuse to ease your conscience: on the one hand, this fuel still contains a portion of fossil fuels, and on the other, there are other problems linked to its production and emissions.
E85: The main problem is the dilution of the fuel in the oil, combined with the fuel's higher production of water vapor. If the oil heats up well with each trip (long-distance use), no major problems. On the other hand, if the oil is used for short journeys, particularly in town, this is an extreme use case! Considerably reduce oil change intervals. Maximize oil change intervals to a few months and very low mileage under these conditions.
REMINDER: "HOT LDR" DOES NOT MEAN "HOT OIL"!!!
See: https://motoiq.com/e85-can-mess-up-your-...
LPG/CNG: could be beneficial on oil life: low particulate matter and lower fuel dilution, this fuel being a gas. Do not exceed maximum manufacturer's deadlines if in doubt.
What is fuel dilution?
A piston's seal is imperfect: fuel is likely to fall into the oil sump, particularly under certain conditions mentioned above. If the oil doesn't heat up sufficiently (short travel), it doesn't have time to evaporate sufficiently and accumulates there.
The dilution of fuel (of any kind) in the oil causes a detrimental decrease in viscosity and chemical reactions impacting oil quality.
Unacceptable symptoms
Many of the following symptoms are signs of neglected maintenance of certain vehicle parts.
Reminder: @antoniobiscuit: H4D, 100% E85, no box, all seasons, heel-toe 100% of the time. In my opinion, the impact of a very lightly soiled E85 sensor is inevitably greater than a "classic" configuration.
Difficulty starting from cold: ZERO TOLERANCE on E10: it's possible to start at a quarter-turn on 100% E85 in winter, subject to appropriate maintenance.
Vibrations:
- At idle, in the driver's seat:
- Check intake, sensors, and injection.
- When starting off (during slip when starting off in gear 1 or when changing gear, especially 2):
- Check intake for damage.
- Purge hydraulic clutch release bearing. Significant play is probably present in the pedal.
Engine behavior:
The following symptoms, when hot (or even when cold), may be sufficient to determine a need to clean sensors, throttle, and injectors:
- Throttle, vibration.
- Unsatisfactory shifting.
- Poor shifting into 2nd gear (even when taking into account the abysmal 1->2 ratio of the JE3 001 gearbox).
- Heel-toe screwed up in succession (even slightly) by an experienced driver.
- Pedal inaccuracy, especially on very light loads.
- Unacceptable accelerator pedal lag (during the relaunch, to achieve perfect heel-toeing, therefore very light) several times in a row.
- Engine refusing to drop to 0L/100km at the drop of a hat, at a precise point on a route, in identical conditions to usual, and in the highest gear usually conducive to this. Probably the MAP sensor, which has become inaccurate at low speeds.
Engine sound:
A disturbing engine sound following an oil change (large/standard change) can become ample reason to change and replace the oil immediately.
Engine oil:
Presence (even slight) of mayonnaise on the oil cap:
- Shorten oil change intervals immediately. Possible maintenance neglect.
- Excessive water condensation and/or fuel dilution (more serious with E85), easily reached under certain conditions (optimum temperatures not reached, severe use).
- Possibly caused by injection imbalance: check and clean injector tips (see tutorial).
- Poor-quality fluids: chemistry altered beyond the maximum permissible.
- Blown cylinder head gasket (unlikely, but by no means impossible).
Additional recommendations
The following recommendations are not official: they are based on recommendations from various sources and possibly for other vehicles.
"Never neglect engine oil. Change it earlier if you have to."
The H4Bt engine is fitted with an oil vapor condenser as standard, unlike the H4D, which may make some advice less critical on this engine, but in no way prevents regular checks, maximizing reliability over the long term.
Checks:check the level and quality of fluids, especially engine oilat least once a month. "Check" here means a visual check (color), but even more simply an olfactory check. An excessive smell of unburnt combustion products is enough to indicate the need for an oil change, either prematurely or immediately.
Gearbox oil: 50 to 60,000km/2 years. Replace oil immediately if gearbox behaves sluggishly and/or harshly. Applicable to JE3 XXX and DC0 gearboxes.
INJECTORS: Inspect and clean at least every oil change, especially with H4D engines (excessive clogging tendency). See chapter Injection and tutorial. Prevents IN ALL CONDITIONS: reduced fuel consumption, reduced reliability, reduced driving pleasure.
MAP sensor: clean at least every oil change. See the tutorial for the H4D engine. Recommendation is partially applicable to the H4Bt engine overpressure sensor. Install a catch-can to reduce the need for maintenance or, at the very least, reduce undesirable effects between two deadlines.
Throttle body: Clean at least once every oil change. See the tutorial for the H4D engine. Partially applicable to the H4Bt engine. Cleaning the H4Bt throttle body requires the removal of a few additional components.
Tires: see chapter Pneumatiques.
Brake fluid: see chapter Purge/Vidange of brake fluid.
If a catch-can is added: It is essential to clean the filter(s) each time the catch-can is emptied, otherwise the same symptoms as an out-of-order breather will occur over time.
***++It makes economic sense not to neglect any of the above points, especially at current fuel prices.
Stupid calculation (assumes fuel price = 1.00EUR, much higher losses with E10):
- An over-consumption of 0.1L/100km TDB causes a loss of 10EUR per 10,000km.
- It's possible to lose more than 0.5L/100km due to cumulative clogging of certain parts, i.e. more than 50EUR per 10,000km.
Engines
Twingo III models are powered by a three-cylinder in-line engine (L3) of around one-liter displacement, either naturally aspirated (1.0 SCe, H4D) or turbocharged (0.9 TCe, H4Bt). It is positioned at the rear of the vehicle, under the trunk, and at an angle of 49°. The Twingo III and Smart Forfour/Two 453 engines are identical: only their names are different.
Main technologies:
- Cast aluminum alloy block
- Dual overhead camshaft (DOHC)
- DLC (Diamond Like Carbon) hydraulic valve lifters and graphite-coated piston housings
- 12 valves, 4 per cylinder: 2 intake and 2 exhaust
- Variable valve timing (VVT) on the intake side
- Indirect multi-point fuel injection
- Variable displacement oil pump
- Cylinders offset from the crankshaft axis
Specifications
Élément | Unité | M281 E10 - H4D 400 - 1.0 SCe 70 | M281 E09 - H4Bt 401 - 0.9 TCe 90 |
---|---|---|---|
Cylindrée | cm³ | 999 | 899 |
Alésage (Bore) | mm | 72.2 | 72.2 |
Course (Stroke) | mm | 81.3 | 73.1 |
Alésage / course | φ | 0.888 | 0.988 |
Ratio de compression | φ | 10.5 | 9.5 |
Masse | kg | 81 (HR10DEg1) | 86 (HR09DETg1) |
Carburant recommandé | N/A | 95 RON, E10 | 95 RON, E10 |
Carburants "tolérés" | N/A | E65-E85 | ? |
Norme Euro | N/A | 5 ou 6 | 6 |
Puissance | kW | 52 | 66 |
À la vitesse de | rpm | 6,000 | 5,500 |
Couple | Nm | 91 | 135 |
À la vitesse de | rpm | 2,850 | 2,500 |
Pression boost max | bar | N/A | 2.3 |
Cylinder 1: distribution side.
Ignition order: 1, 3, 2.
Notes:
- SCe = Smart Control Efficiency and TCe = Turbo Control Efficiency
- RON = Research Octane Number: this corresponds to pump specifications in Europe.
- H4D: Euro 5 without Stop & Start and Euro 6 with Stop & Start under NEDC.
- Euro 6 under WLTP for all engines
Fuel consumption and economy
Fuel consumption figures
Fuel consumption figures are taken from Renault brochures. They vary according to actual use and fuel used (+30% with 100% E85).
NEDC Cycle
Engine, BVM | 1.0 SCe 70 | 1.0 SCe 70 Stop & Start | 0.9 TCe 90 |
---|---|---|---|
CO2 (g/km) | 105 | 95 | 99 |
Urban Cycle (l/100km) | 5.6 | 5.0 | 4.9 |
Extra-urban cycle (l/100km) | 3.9 | 3.7 | 3.9 |
Combined cycle (l/100km) | 4.5 | 4.2 | 4.3 |
WLTP Cycle
Engine, BVM | 1.0 SCe 70 -18 | 1.0 SCe 70 Stop & Start - 18 | 0.9 TCe 90 - 18 |
---|---|---|---|
CO2 (g/km) | 125 | 108 | 111 |
Urban Cycle (l/100km) | 6.8 | 5.6 | 6.1 |
Extra-urban cycle (l/100km) | 4.7 | 4.2 | 4.1 |
Combined cycle (l/100km) | 5.5 | 4.7 | 4.9 |
Notes:
The original tires used for homologation are probably Continental EcoContact 5 (recurring model on brochure images). Fuel consumption with 16" wheels:
- Front: Class B
- Rear: Class C
The oils used in the engine and gearbox during homologation are probably the same as those recommended.
It is not impossible that the mapping of WLTP-certified engines has been slightly improved compared to NEDC-certified engines, or that very minor modifications have been made elsewhere.
Actual achievable fuel consumption
The following fuel consumption figures were achieved by AntonioBiscuit with 100% E85 using an H4D engine, 100% E85 without box or modification unless otherwise stated.
The overconsumption factors indicated are considered reliable within the possible measurement tolerances and/or at least with a tolerance of less than 5%.
- Engine oil: ELF EVOLUTION R-TECH SPORT (0W40, RN17RSA)
- Gearbox oil: ELF NFX (75W)
- Tires: New Michelin e.Primacy (Front and Rear) at recommended pressures on all values shown here. Tests with higher-than-normal tire pressures are in progress: any results would then be indicated with the pressures used.
- Spark plugs: Bosch Iridium, to original specification.
4 people on board, trunk loaded with suitcases (worst-case scenario):
- 100km/h: 4.8L/100km TDB, fuel consumption factor = 1.3, i.e. 6.24L/100km actual. Constant regulator, from Roncq (France/Belgium border) to Oostzaan (Netherlands), freeway.
- Round trip France-Amsterdam + stopover in Rotterdam center possible with a single tank of E85. Final consumption at the French border (Roncq): 4.6L/100km TDB, i.e. 5.98L/100km actual, reserve indicator not yet reached.
Driver alone, boot empty:
- Average on Eure department roads (long distance): 4.1L/100km TDB, overconsumption factor = 1.3, i.e. 5.33L/100km actual.
- Highway, 100km/h regulator: 4.4L/100km TDB, overconsumption factor = 1.3, i.e. 5.72L/100km actual.
- Lisieux-Caen (not freeway, at busy times): 4.0L/100km achieved (5.2L/100km actual @x1.3 over-consumption, 100% E85 summer), 3.9L/100km or even 3.8L/100km achievable in better traffic conditions and with tri-colored lights in better mood.
Note: Lower fuel consumption is achievable with a lower load and potentially by using RN17 (5W30) oil rather than RN17RSA (0W40) oil.
Save fuel
- Use an alternative mode of transport if the vehicle is not required for the journey.
- Maintain the vehicle to ensure optimum performance.
- Simply maintaining optimum tire pressure 100% of the time helps prevent a significant drop in fuel economy while maintaining an adequate level of safety. Use only an accurate/electronic gauge (to within 0.05 bar, 5% of a bar max). Caution: Some analog gauges, even new ones***, can drift by more than 0.5 bar (half a bar), endangering the user!
- When in doubt: Use the original tire pressures, indicated on the label, as a compromise guaranteeing a certain road holding. Any lower pressure will have a negative impact on fuel economy.
- I'm aware that pressures impact SAFETY and I KNOW what I'm doing: Depending on the tire model, the axle in question, weather conditions, and speed, the pressures chosen can optimize one or more of the following 4 axes: comfort, safety, fuel economy, wear. A slight over-inflation can sometimes bring a slight gain in fuel economy but against a negative impact on safety (different road holding) and an accelerated wear of tires, and shock absorbers. ***++In the best-case scenario, up to 2% fuel savings can be expected by adjusting pressures upwards. The additional cost of tire wear due to inadequate pressure (not necessarily the official pressure) must in this case be taken into account to obtain an adequate economic balance.
- Choose quality fluids and tires and/or tires complying with standards: these are not necessarily much more expensive to buy, but they pay for themselves in the long term through savings.
- Make the most of cruise control, even in town: an engine particularly appreciates running at a constant speed. Acceleration is very costly. Excessive speeding is limited, and costly speed camera fines are potentially avoided.
- Exploit the vehicle's inertia to the maximum: the brakes should be used as little as possible. Any non-emergency use of the brakes means that the driver has accelerated too much or released the foot too late. Brakes are thus saved and 0L/100km times maximized to partially "payback" acceleration phases.
- Use gear ratios to the maximum. When in doubt, follow the gear suggestions on the dashboard, even if the user can sometimes override this suggestion to save even more.
Economical suggestions (flat terrain, constant speed), H4D + JE3 001:
- 3: ~30km/h
- 4: >40km/h
- 5: >60km/h
Please note: Suggestions applicable at fixed speed only. Optimum gear ratios during acceleration are different and vary greatly depending on the situation. Optimum ratios will inevitably be different with the H4Bt engine, which has different speed ratios and a different optimum torque curve.
Refer first and foremost to the instantaneous consumption indicator and on-road experience as the authoritative data.
Notes:
The use of cruise control and the pursuit of fuel economy must not affect the SAFETY of the driver, passengers, and other road users.Mastering heel-toe and rev-matching makes for more responsive gear changes, and can help save fuel if used wisely. However, this control can have the perverse effect of encouraging sporty driving, which eliminates any potential gains and even leads to over-consumption
.
Gearboxes
JE3 00x manual gearboxes
- 5 synchronized forward gears with two rings (1, 2) or a single ring (3, 4, 5) + one non-synchronized reverse gear.
- Two drive shafts.
- Helical gearing for forward gears, spur gearing for reverse.
- Differential integrated into the gearbox.
Twingo III models feature a number of JE3 gearboxes with different ratios according to the engine (see speed/RPM curves):
{ table
|width=30%
|format=30%l:l:c
|! Engine
|! Box model
|--
| H4D
| JE3 001, [...]
|--
| H4Bt
| JE3 003, [...]
}
At least 6 variants seem to exist, with mixtures of numbers of teeth varying over several ratios and with different primary shafts.
The different variants coincide with the different characteristics of the two engines. It is possible that the ratios were chosen precisely to optimize fuel consumption in the NEDC/WLTP tests. As a result, the ratios could have changed when switching from one test to the other.
The following ratios are taken from the RTA Twingo 1.0 SCe 70, JE3 001 gearbox:
{ table
|width=20%
|format=30%l:r:c
|! Report
|! Ratio
|--
| Reducing torque
| 0.2679
|--
| 1
| 0.2683
|--
| 2
| 0.4884
|--
| 3
| 0.7179
|--
| 4
| 0.9714
|--
| 5
| 1.2188
|--
| R
| 0.2821
}
DC0 semi-automatic box
This gearbox is also known as EDC (Efficient Dual Clutch). It is manufactured by Getrag.
- electro-mechanical dry double-clutch gearbox
- 6 forward speeds + 1 reverse
- 3 driveshafts and two sub-transmissions, each with its own clutch
- Gearbox-integrated differential
Fuel supply
Fuel tank and pump
==
The fuel tank is located at the rear of the vehicle, partially under the rear seats. It is made of extruded HDPE coated with EVOH. Its nominal capacity is 35 liters, with the expansion volume inside.
The tank level is read by a float/lever sensor integrated into the pump block.
A non-return fuel system is used. The pump, part no. 17 20 249 44R, delivers fuel at a load-dependent variable pressure (max. 5.2 bar) to the fuel rail. The pressure regulator and a lifetime filter are integrated into the pump block. There are no other fuel filters.
Bosch fuel pumps are approved for use with E20.
ATTENTION: the gauge on the dashboard does not always correspond to the real level read by the float. When using E85, this is FALSE!!! (see E85 chapter)
Injection
H4D and H4Bt engines are all equipped with multi-point indirect injection. The 3 injectors are supplied with pressurized fuel via a fuel rail. As these engines have 2 valves per cylinder, the injectors are chosen to offer a double jet, each targeting one of the 2 valves.
The intake is designed to optimize tumble, helping to achieve a more homogeneous mixture in the cylinders and better efficiency.
The RTA Twingo III 1.0 SCe mentions the possibility of entering injector characteristics into the ECU using a diagnostic tool.
++Perfect injectors are crucial to optimum engine performance.
Important recommendation: inspect and clean injectors at every oil change if necessary, especially with H4D engines
.
One or more dirty/defective injectors will cause:
- Poor fuel atomization: the air/fuel mixture is less homogeneous.
- Inconsistent flow from one injector to another: a mixture of rich/lean cylinders: non-optimal richness.
- Ignition advance is adversely affected by inconsistent mixtures.
- Reduced efficiency and performance.
- Increased pollution and fuel consumption.
- Increased oil contamination (fuel dilution and particles).
- Increased carbon build-up.
- Vibrating, unpleasant behavior.
- Longer pedal response times.
Notes:
E85 doesn't foul the inside of the injectors in the medium to long term, quite the contrary: @antoniobiscuit, at 90,170km (i.e. ~40,000km at 100% E85): Extracted the 3 injectors from their manifold, looking for any deposits. Interior as new (injectors and manifold). The brake cleaner did not remove any deposits.
H4D engine
The H4D engine is equipped with injectors manufactured by Deka / Siemens. The injector part number is 166009685R or A2810700046 at Mercedes-Benz.
N-Heptane/min flow at 3.0bar | ? |
---|---|
Max. supported pressure | ? |
Resistance | 9 to 17 Ω (RTA) |
Connection | Nippon Denso |
Jet shape | Double (Left + Right) |
Number of holes | 2 * 3 |
ENCRASSMENT: Two observations (at ~85,000km and at 90,069km), then every 1,000km later indicate a serious sensitivity to fouling of H4D's injectors. Deposits clog the injectors from the outside at relatively low mileages (see picture).
***Significant impact on fuel economy, reliability, and driving pleasure.
Fouling is definitely caused by oil vapors:
- The throttle body, MAP sensor, and intake thermometer are already affected by oil vapors.
- The closer the injector is to the oil vapor breather, the more it is systematically covered with deposits. From worst to least worst: injector 3, 2, 1 (see picture).
- In the pictures, the injector tip necks are covered with deposits which, by their position, could only come from oil vapors, and not from the fuel circuit.
- No internal clogging of injectors and fuel rail at their very first cleaning at 90,170km. E85 hardly seems responsible for external fouling.
- @antoniobiscuit: The external fouling of my injectors has been significantly reduced since the addition of a catch-can.
Notes:
Survey of @antoniobiscuit's injectors at 85,000km:
- Cylinder No. 3: particularly affected: one side was completely plugged (3 holes), more than half of the tip was covered with a thick layer of deposits
- Cylinder No. 2: same as cylinder n°3 but lighter (2 holes plugged).
- Cylinder No. 1: relatively clean.
Several factors could affect the rate of injector clogging: temperature, nature/duration of journeys, driving style, type of oil...