No Compression

I have a 2013 Ford Police Interceptor with a 3.5. The 2nd shift security guard parked the vehicle at 11 pm in there spot with no issues other than they have been complaining about low power. The next morning at 7am the first shift officer went to start the vehicle and it just turned over and over. My students and I went to check it out and it sounded like it had no compression at all! We got the vehicle back to the shop and pulled the front plugs out, all spark plugs gas fouled and has no compression. We put 3 shots oil in the cylinders and compression got to 25psi on 1 cylinder. Camshafts are turning inside the valve cover, engine looks really clean on the inside. Is it possible that the chain just jumped some teeth the minute he tried to start it that morning. Of course this vehicle sets at idle for hours at a time during its use but only has 68,000 miles on it.

Yes that is very possible, all it takes is a chain tensioner to collapse and you're out of time.

Sounds like you're also dealing with cylinder wash.

Any Codes?

Now is a good time to break out the Scope for your students and perform a Cam Crank Correlation,  here is a known good.

 


 

So I don't know why we are getting this type of pattern. We just got this snap on scope and still trying to navigate it.

Interesting, You're capture of the four cams is the older style 3.5 engine.

I do not have a known good, but I do recall the waveforms nestle right into each other, your yellow and red overlay at a hump and so do the other 2,  However, are they correct to the CKP?

It's been a few days, what other testing have you performed?


 

Here is, yet, another 3.5L variation. This is a 2012... Vin T

If the only thing that they changed was the type of sensor, maybe these can help.

All Cams


Bank 1


Bank 2

You are positive it is not a 3.7l engine? The 3.7 seems to fearure 4 VR cam sensors.....

You'll find the caputers on the rotkee waveform library if  you want to play with them