Poor warm restart idle

[Steve Scalmanini]

Last week I was able to ask the chief mechanic at the VW/BMW 
dealer in Santa Rosa, CA about this problem.  Turns out he 
drives one of our 200q20v's also (although he's been trying 
to sell it without luck.)  

Anyway, his explaination for the hot restart & die problem 
was deposits on the intake valves.  The hotter the weather, 
the more fuel they absorb upon startup, fuel that would 
otherwise keep the engine running.  

He replaced his ISV once to try to solve the problem and 
got no improvement.  

The long-term solution to the problem is unfortunately not 
practical for our cars.  Some of you will recall from the 
mid-late 80's a service procedure for the 5-cyl 10-valve 
engines that blasted the back sides of the intake valves 
with walnut shells or some such material to remove the 
deposits.  Apparently our 20-valve heads are not conducive 
to that procedure and the valves (and head) must be removed 
to clean them.  

He recommended a few tanks with Techron or equivalent between 
oil changes, or one other more serious (concentrated?) 
treatment that he knew of but I forgot.  If anyone wants to 
know more I'll ask again when I'm there for parts later this 
week.  

Any opinions on the credibility of his claims?  

Steve 



Kneale Brownson knotnook at traverse.com 
Thu Jul 1 22:44:07 EDT 2004 



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My car starts and idles just fine when cold, but today a couple hot starts
resulted in no idle (engine died when accelerator left untouched).  Would
keep running if I gave it some pedal and then would idle fine.  Just
wouldn't idle unassisted at start-up.  Sound familiar to anyone?