Air intake system: MAF sensor, intercooler, throttle body, hoses
The engine “breathes” through several units
Air passes through the air filter housing, the mass airflow (MAF) sensor and the hoses, and on turbo engines also the intercooler, to the throttle body and the intake manifold. If the engine loses power, whistles, smokes or idles unevenly, the cause is often a small thing: a cracked hose, an air leak, a dirty throttle body or a faulty MAF sensor.
The sensor or the whole throttle body
A MAF sensor can sometimes simply be cleaned with a special cleaner. A throttle body can also be washed. Before buying a new one, ask a mechanic whether cleaning will help. But a cracked boost hose, a leaking intercooler or a broken plastic intake manifold cannot be repaired: they need replacing. On turbo engines the most common problem is boost hoses that crack with age.
What to put in your request
- Which part — air filter housing, manifold, intercooler, hose, throttle body, MAF sensor.
- Model and year — for example, Volkswagen Golf 6, 2011.
- Engine — size and code: 1.6 TDI.
- Part number — from the body of the part, for example 03L906461.
- VIN — so the seller can check compatibility in the catalogue.
- Condition — new or used.
- Original or aftermarket — Bosch, Hella or original.
- City, delivery and budget.
Example: “I need a MAF sensor for a Volkswagen Golf 6, 2011, 1.6 TDI, number 03L906461. New Bosch or original. I can send the VIN. Courier delivery to Wellington. Budget up to $120.”
How to compare offers
Describe the part in a request, and sellers will reply in the chat: brand, condition, price, dispatch time. The platform puts the best-value offer first, and seller reviews are visible beside each. Sellers see their place among the others, so they compete on terms. Your phone number is hidden. Read more on the “How it works” page.
For electronic sensors, compare how exactly the part matches: a cheap MAF sensor copy can give false readings and cause errors, while an original or a known brand is usually more stable. Ask about the warranty and return terms, because a sensor cannot always be tested without fitting. For boost hoses look at the material: reinforced silicone withstands pressure and heat better than plain rubber. For an intercooler, check the size, the position of the pipes and the core material.
Common mistakes
Buying a MAF sensor or throttle body by looks, not by number. Replacing a sensor without checking for air leaks through the hoses. Not changing the clamps and seals. A weak clamp on a boost hose can let it blow off. For related checks see the fuel system and the exhaust system, and also the engine.
