Innovative Products of America 7894 Flexible Compression Whistle

Best invention ever to find TDC. It was a snap to adjust the 4 push rods on my 2003 Indian Chief Vintage Motorcycle, with a Powerplus 100 cu. in. motor, After jacking the motorcycle up on a floor jack motorcycle lift, I put the transmission in 5th gear, then rotated the rear wheel until I heard the whistle on each of the 4 push rods (2 intake and 2 exhaust). That whistle told me that each valve was exactly Top Dead Center (TDC). It took more time (20 minutes required per valve spring) to bleed down each of the 4 valve springs before making the necessary wrench adjustments on the 4 push rods, than it did to find TDC. Before I bought this remarkable tool on Amazon, I could not adjust the the push rods like I can now. Great tool to have in your tool box.

Best tool ive used for finding TDC. Makes it an easy one man job.

I’ve found that this tool is most useful in vehicles with a deep spark plug well. It works best for newer cars with coil packs. When I needed TDC on a small block 1989 Ford F-150 5.0L 302, I needed a helper to hold it in place. Also required a helper to hold it in place on a small block 1999 Chevy 2500 5.7L 350 Vortec heads. I ended up having to remove the valve covers on both of those engines to watch the valve movements. That’s the only reason for giving the tool a 4 star review. It did great on a 2015 BMW M3 S55 to set timing (which is very easy to do anyway) and worked nicely on a 2010 Chrysler 300 to do leak down tests.Noise of the whistle is kinda subtle. It’s there, but but not very loud. Turning the crankshaft is usually small turns anyway, so you have to listen for the whistle, it’s not a loud and very obvious noise and only as long as the turn of the crank.I purchased it for $15 in 2023 from a seller that no longer sells them, but they are still half the price of the Mr. Gasket style. I recently purchased the Mr. Gasket 8016MRG TDC Whistle to diagnose a 2003 Ford Ranger 3.0 with misfire code P0304. I won’t have a helper available and that one screws into the spark plug’s threaded hole to do a leak down test, which on a Ford 3.0 is 90% failed valve seats anyway. Still… very useful tools to assure compression stroke. The last thing anyone wants is to be in the exhaust stroke and end up with bent valves during a timing reset.One method that will work if you have a hard time hearing the whistle noise would be to put a balloon on the end of a leak down adapter or compression hose (without gauge or Schrader valve) to verify compression stroke. Both valves still need to be closed, with the piston of the cylinder all the way up.Happy TDC Compression Stroke Finding!

A must have tool for you box to get TDC without watching for a screwdriver or piece of toilet paper. The rubber end came off on the first use a quick addition of ear-lock compression clamps from the plastic fuel hose kit fixed it right up.

I used this the other day for the first time, to find TDC compression. It worked just fine. I don't care for the lazy feeling of just pushing a rubber tip into the spark plug hole, but I suppose it was convenient. And it did work. It just doesn't feel all that positive going in, leaving you to wonder if it will work. I used it on a 302 EFI Ford Mustang though, and #1 is at a bit of an angle to get at it. And yet it worked just fine. I would buy it again.

Absolutely terrible fitment. It does seal and "fit" but you definitely need a second set of hands to hold it in place. It may fit something else better but in my 97 Chevy Silverado with a 5.7 it did not without help.

So far I used this on my Ford 289. It was my first time trying to replace a distributor. I thought I had the engine on the right cylinder but wanted to confirm. I was able to hold this in the spark plug hole and hand crank the engine to get a slight whistle. Probably would have been louder if I had someone to help hold it, but it still worked. Glad I purchased it.

Love this little guy! It starts making noise as you come up on the compression stroke and helps you nail down right where TDC is - like advertised. Goofy sound cracks me up, too - I guess that isnt bad.