Innova 3612 Compression Tester — 0–300 PSI Dual-Scale Gauge, 14mm Adapter, Release Valve | Air-Cooled VW & Porsche Engine Health Check (3612)
On backorder.
Innova is out of this one right now. You can order it and we'll ship it the day it lands on our dock — but we don't have a date from them yet, and we'd rather tell you that than guess.
If you need it this week, call (657) 438-7002 and we'll tell you what we can do.
Couldn't load pickup availability
- Vendor Innova
- SKU 3612
Not sure it fits? Call the shop: (657) 438-7002.
Innova 3612 Compression Tester
Short answer: The test to run when an engine still idles rough after a by-the-book tune-up. Screw the 14 mm adapter into each plug hole, crank the engine, and read each cylinder on the 0–300 psi gauge. Even, healthy numbers mean the problem is fuel or ignition. One low cylinder means a valve, ring or head gasket problem, and a squirt of oil tells you which.
Our VW Tune-Up Spec Lookup gives the factory compression figures where VW published them, and the procedure to get a reading you can trust.
Vehicle & Engine Fitment
- Air-cooled VW Type 1, 2, 3 and 4: 14 mm spark plug threads.
- Porsche 356, 912, 911 and 914: 14 mm spark plug threads.
- Also fits: 12 mm and 18 mm plug threads with the included adapters.
Key Features & Benefits
- 2½" dual-scale gauge: 0–300 psi and 0–2,100 kPa, so a reading matches either manual.
- Side release valve: holds the reading until you've written it down, then resets without disconnecting the hose.
- 15" fuel-rated hose with brass fittings: reaches the plug holes behind the cylinder tin.
- Three adapters: 12 mm, 14 mm and 18 mm.
Technical Specifications
- Part Number: Innova 3612
- Gauge: 2½" dial, 0–300 psi / 0–2,100 kPa
- Hose: 15", with side release valve
- Adapters: 12 mm, 14 mm, 18 mm
Frequently Asked Questions
- How do I test an air-cooled VW? Engine warm, all four plugs out, throttle held wide open, coil wire disconnected so it won't start. Crank each cylinder for the same number of strokes and write the reading down.
- What's a good reading? VW's manual gives 114–142 psi new and 100 psi minimum for the B and early AE 1600, and 107–135 psi new and 85 psi minimum for later AE, AH and AK engines, with no more than 28 psi between cylinders. The spec lookup shows the figure for your engine.
- One cylinder is low. Now what? Squirt about a teaspoon of engine oil into that cylinder and test it again. If the number comes up, the rings are worn. If it doesn't, it's a valve or the head seal. A tight valve is the first thing to check: adjust the valves and test again.
Installation
Tech Note: Pull the coil wire from the distributor cap and ground it before cranking, so the engine can't start and the coil isn't sparking into the open air.
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Doing the full tune-up? Start at the VW Tune-Up Spec Lookup, then browse Tools and our engine parts.
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