Mercury MerCruiser Knock Sensor 806612T
Free returns on all eligible orders
You have 30 days to request a return. All sale items are final sale.
Mercury / MerCruiser Quicksilver Knock Sensor ā 806612T
The Mercury Quicksilver 806612T Knock Sensor is a genuine OEM engine detonation sensor used on many MerCruiser V6 and V8 gasoline engines. It detects engine knocking or pre-ignition and sends a signal to the engine control module so ignition timing can be adjusted to protect internal engine components.
Key Specifications
-
Part Number: 806612T
-
Component Type: Engine knock sensor
-
Mounting Location: Engine block water port above oil pan
-
OEM Brand: Mercury Marine / Quicksilver
-
Cross-Reference: Volvo Penta 3850357, Sierra 18-7677, Crusader R020027
Compatible Engines / Applications
Commonly used on MerCruiser GM-based marine engines, including:
-
4.3L V6
-
5.0L V8 (305 CID)
-
5.7L V8 (350 CID / 350 MAG)
-
6.2L V8 (377 CID)
Typically found on MerCruiser sterndrive and inboard engines from the late 1980s through early 2000s, depending on serial number range.
Function
The knock sensor monitors engine vibration to detect detonation (engine knock) during combustion. When knock is detected, the sensor sends a signal to the ECM, which retards ignition timing to prevent damage to pistons, valves, and bearings.
This helps ensure:
-
Proper engine performance
-
Protection from pre-ignition damage
-
Improved engine reliability and longevity
Symptoms of a Faulty Knock Sensor
A failing knock sensor may cause:
-
Engine knock or pinging
-
Loss of power or poor acceleration
-
Engine fault codes or warning alarms
-
Reduced fuel efficiency
Replacing the sensor restores proper engine timing control and detonation protection.
ā ļø Fitment Tip:
Always verify compatibility using the engine model and serial number. MerCruiser engines use different knock sensors depending on engine family, ECM version, and ignition system configuration.
OEM parts ship same or next day for fast Canada wide shipping.
Technical Specifications:
- Type: Knock sensor
- Compatible with: Mercury MerCruiser marine engines
- Part Number: 806612T
Shipping information
In-stock and OEM parts: ship same or next business day.
Locally warehoused items: ship within 3ā4 business days.
Special-order items: timeline confirmed after order.
Returns & warranty
Returns & Satisfaction Guarantee
We stand firmly behind the quality of every product we sell. Your confidence matters to us ā and we back it with a straightforward 30-Day Satisfaction Guarantee.
If you are not fully satisfied, you may request a return within 30 days of delivery. All returns must receive pre-approval prior to being sent back. Unauthorized returns will not be accepted.
To qualify for a return:
Item must be in new, unused condition
Product must be in its original packaging
All parts, components, hardware, manuals, and accessories must be included
Packaging must be undamaged and suitable for resale
Important:
Electronics are strictly inspected. No returns on open-box electronics. Exceptions may apply only with prior written approval. Any electronic unit that has been installed, powered, activated, or altered may not be eligible for return.
We are serious about product integrity ā and equally serious about taking care of our customers. If there is ever a product issue, contact us immediately so we can make it right.
For return authorization, please contact our support team before shipping anything back.