Violent Shudder

Hi Neicy,

Thanks for providing the link to Hobbit's webpage. That page shows how the variable intake valve timing works, and comes from the Toyota tech docs.

Note that each drawing contains a black semi-ring, depicting exhaust valve timing which remains constant. The white semi-ring in each drawing shows intake valve timing which is advanced or retarded depending upon the engine's operating condition.

The box in the lower right corner of the page shows that intake valve timing is fully retarded upon starting and stopping the engine. However, the box is silent regarding the question as to whether an optimal crankshaft position exists for engine shutdown.

 

Obviously I have a limited understanding of what's going on, but that's all I could find that is written by a knowledgeable member. I have lots to learn yet since valve position is different from crankshaft position. :der:

 

My 2004 Prius just started shuddering tonight and I've had it for 3 years. I've never felt it shudder like that before. Definitely not that little shudder when the engine shifts. It was definitely "wrong". It also has been monsoon raining all day today (thanks Fay). The check engine light came on after the shudder, and although it did not shudder again on my way home, there was a "hot" smell, like something was burning.
Anybody experince any of this in response to tons 'o rain, or should I be calling my toyota dealer for an appointment?
Thanks!!

 

Maybe you have an engine misfire problem. 2004/2005 Prius are known to have a problem where water drips from the cowl onto the engine valve cover. The spark igniter rubber O-rings do not form a perfect seal, so water can enter the spark plug wells, causing engine misfire. See TSB EG063-05.

You definitely should have your dealer check the problem out. If the problem is water leaking from the cowl, the solution is to apply a bead of sealant on the center of the cowl, and replace any parts (spark plugs or igniters) damaged by the water. The 3 year/36K mile warranty covers this issue, so you will have to pay for the repair unless you have extended warranty coverage.

 

This sounds allot like what my wife's car was doing so I did what was suggested on this thread. Looking at the valve cover, is appeared that a Rat had taken up residence in the plug valley.



So after a minute with the shop vac I removed the igniters. only one of the 4 had a bad seal, and it was bad, a mix of brown goop that looked like a little septic tank.
I pulled the plug cleaned it and cleaned the igniter and no more studder.

so far........

 

A rat in plug valley...

Very interesting 1st post! I hope the valley remains unpopulated.