Hello guys;

I've read a number of threads on odd noises from the engine on cold startup. And of course, there is always the dreaded tensioner "death rattle."

About a week ago, a new noise sprang from my engine bay on startup, and has been present every cold startup since that point. Here are the basics:

- No odd noise at actual cold startup
- Loud clicking at throttle blips just after cold startup
- Clicking lasts just a second, then disappears until next throttle blip
- Seems to be coming from the top of the engine block
- Once the engine has warmed a bit, the noise does not return until throttle blips at the next cold startup.

My car has the second generation plastic tensioners...have had no problems to date and never a "rattle" at startup...and again, this noise does not seem to be coming from the front of the engine. More from the top.

My hunch is that it's the fuel injector solenoids. Here is a link to a quick video with sound...filmed from my phone...and the clicking noise is SIGNIFICANTLY louder than can be heard in this video...but you'll hear it.


Would appreciate the finely tuned ears of the techs on this one.

Thanks very much.

Video - Engine clicking sound at throttle blips after cold startup

 

The AJ26 has 2 position VVT and the solenoids could be 'slapping' the intake cams advanced with the cold oil and higher pressure???

I would change the secondary tensioners to the metal ones if the car was NEW and had NO miles. They are almost 15 years old (if they are the originals) and it's not worth the worry trusting the plastic.

The way I would diagnose the 'clack' is to unplug the VVT solenoids one-at-a-time and both to see if the noise changes/stops.

You will set a DTC if you disconnect the 'B'bank solenoid but you can clear it after the test (the 'A'bank has no position sensor). If it is the VVTs then I would call it normal and forget about it.

bob gauff

 

Thanks Bob-

I'll take a closer look at the VVT solenoids. This car is new for me, and my investigations into things like this have more to do with learning about the car's systems than worry.

The tensioners were replaced with second generation plastic about 10 years ago. I'm slowly building up the courage to tackle the tensioner upgrade job myself. Not quite there yet, but getting closer. So many potential ways to screw up!

That being said, I'm 99% sure this is not a tensioner noise I'm hearing, so I'll get a stethoscope and listen to the VVT solenoids.

Thanks again.

 

You can't hear the solenoids with the engine running as they make a very quiet 'click' when they are activated. What you hear is probably the intake cams 'clacking'.

bob gauff

 

Coupe - If / when you do decide to do the tensioners ( sooner rather than later would be best from many comments here ) there is a wealth of good info here to help.

Its even been known for some members to get together if, reasonably local to each other and do the job together. It might be a possibility?
Failing that, I'm sure we'll all help out as much as we can to help you get the job done!