FAQ
TL;DR: Citroën C4 II 1.6 HDi injector clamp bolt: 7 Nm + 80°. "Stage 1 7Nm, Stage 2 80°." This FAQ helps DIYers and techs set hold‑down torque fast and correctly. [Elektroda, WloczykijMalaMi, post #18697122]
Why it matters: Correct torque prevents leaks, misfires, and cracked injector clamps on PSA 1.6 HDi engines.
Quick Facts
- Injector clamp bolt torque: 7 Nm, then +80° (Citroën service confirmation for C4 II B7 1.6 HDi). [Elektroda, cichy koksik, #18697232]
- Replace clamp bolts on reassembly or if previously over‑torqued. "Screws are a must." [Elektroda, WloczykijMalaMi, post #18697268]
- Over‑torque can crack the clamp ("paw") and cause exhaust smell in the cabin later. [Elektroda, mariuszgawor, post #20449530]
- Some PSA docs list flange‑nut setups: 0.5 ± 0.1 daNm pre‑tighten, then +65° ± 5°. [Elektroda, madamsz1, post #18696765]
- Avoid 27 Nm—the clamp screw is long and thin; that value is excessive here. [Elektroda, madamsz1, post #18697230]
What is the correct tightening torque for the injector clamp bolt on a Citroën C4 II B7 1.6 HDi 92KM?
Use torque‑angle: 7 Nm, then tighten a further 80 degrees. This figure was confirmed from Citroën service information. As one member summarized: "You were right - 7Nm +80°." Apply it to the injector hold‑down clamp bolt. [Elektroda, cichy koksik, #18697232]
Is 27 Nm acceptable for the injector clamp?
No. 27 Nm is excessive for this long, thin clamp screw and risks damage. As noted by a contributor, "27 is probably too much," given the fastener’s design. Re‑set using the 7 Nm + 80° method instead of a high static torque. [Elektroda, madamsz1, post #18697230]
Do I have to replace the clamp bolts after removal or over‑tightening?
Yes—replace the clamp bolts. They are treated as single‑use in practice after removal or any over‑torque. As one expert put it: "Screws are a must, don't even think about it...." New bolts help ensure reliable clamping at the specified torque‑angle. [Elektroda, WloczykijMalaMi, post #18697268]
Can I reuse the injector clamp (“paw”), or does it need replacement?
Inspect the clamp carefully. If it was over‑tightened or shows any crack or distortion, replace it. A user who tightened “by feel” later found the clamp had broken and noticed exhaust smell inside the car. That failure mode indicates the clamp was compromised. [Elektroda, mariuszgawor, post #20449530]
Is the fastener a screw or a nut on the C4 II injector clamp?
On the C4 II described, the injector is held by a clamp with a screw, not a nut. The torque‑angle spec still applies to this clamp bolt configuration. Always identify your exact hardware before tightening. [Elektroda, cichy koksik, #18697139]
I found 4 Nm + 65° for Ford 1.6 TDCi—does that apply to my Citroën?
That 4 Nm + 65° figure appears in Ford’s PSA 1.6 TDCi context. It does not automatically apply to your Citroën. Always follow the specification for your vehicle and hardware. "In Ford, this engine has 4Nm +65° - 1.6 tdci PSA." [Elektroda, madamsz1, post #18696732]
I saw 0.5 ± 0.1 daNm + 65° in some Citroën docs—when is that used?
That value is listed for an injector mounting flange nut configuration in Citroën documentation. If your setup uses a flange nut, this may apply. Quote: "Injector mounting flange nut: Pre‑tightening 0.5 ± 0.1 daNm; Angular tightening 65° ± 5°." [Elektroda, madamsz1, post #18696765]
How do I correctly torque the injector clamp—what’s the step‑by‑step?
- Pre‑tighten the clamp bolt to 7 Nm.
- Using an angle gauge or marked reference, rotate the bolt a further 80°.
- Stop at 80°. Do not add extra torque beyond the angle step.
These two tightening stages set the correct clamping load. [Elektroda, WloczykijMalaMi, post #18697122]
Can I tighten the clamp by feel without a torque wrench?
Do not tighten by feel. One user did so and the clamp later broke, with exhaust odor entering the cabin. After redoing it at "7nt 80 degrees," the setup was fine. Use the torque‑angle method to avoid clamp damage and leaks. [Elektroda, mariuszgawor, post #20449530]
Do I need a low‑range torque wrench for this job?
Yes. The required tightening level is low, so a torque wrench with a low scale is necessary. The original poster noted they lacked a wrench calibrated that low, which complicates accurate tightening. Use a suitable low‑range tool for reliability. [Elektroda, cichy koksik, #18697294]
How can I verify torque data if I can’t access free manuals?
Cross‑check multiple reputable sources, then obtain official data. As one member advises: "The last option is a purchase for information on the manufacturer's website or from a person who makes Lemons every day." Professional confirmation reduces risk. [Elektroda, WloczykijMalaMi, post #18697205]
Which exact engine/trim does this FAQ address?
This thread and guidance target the Citroën C4 II B7 with the 1.6 HDi 92KM engine variant. Confirm your VIN and hardware before applying any figures. [Elektroda, cichy koksik, #18696651]
What injection system was referenced on the car in this thread?
The car discussed uses a Bosch injection system, as stated by the original poster. This context supports the clamp bolt torque guidance here. [Elektroda, cichy koksik, #18696747]
Should I replace injector sealing washers when refitting the injectors?
Yes, replace the sealing washers when you remove and refit injectors. The original poster planned new washers and seals during injector work, which aligns with good sealing practice to prevent combustion leaks. [Elektroda, cichy koksik, #18697232]
