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Re: untightened sparkplugs
While in Europe on vacation several years back I rented an econobox car
which had so-so performance and gas milage as bad as my 1974 454 suburban.
After about the third fillup in 400 km I decided to look under the hood. I
found 2 of the 4 plugs nearly ready to be catapulted out of their sockets.
After tightening them, the car took off like a rocket and the fuel economy
was more like a Metros (why can't Chev. make cars that get 45 mpg and haul
The moral: The looser the plug the worse the economy and performance.
P.S. I have a 200TQ5S and your milage is about what mine is.
From: Phil Rose <firstname.lastname@example.org>
Cc: 200q20V mailing list <email@example.com>
Subject: untightened sparkplugs
Date: Sat, Jun 06, 1998, 17:21
Yesterday I decided to check the sparkplugs in my recently acquired '91
200q. All 5 plugs were the Audi-specified ones and seemed in fine condition
and with the proper gap and a small am't of medium-grey deposit on
electrodes. But most of them had been installed barely beyond
finger-tightness (!!!!), and in two very loose ones there was a thick, oily
deposit around the threads and washer. However the electrodes of these
plugs appeared identical to the others. I cleaned and reinstalled all at
the specified 22 ft-lb torque--anticipating some significant improvement in
engine performance (although I had no real complaint to begin with).
A short, low-speed test drive seems to show no immediate effect of my plug
"maintenance". Might there be a fuel economy improvement, I wonder? I've
gotten 26-29 mpg in highway cruising so no complaint there, but perhaps my
short-run gas mileage will improve, since the around-town mpg has been no
higher than 17.
Is it possible that _un_torqued spark plugs will _not_ degrade engine
performance? I wonder if this will depend greatly on rpm and engine
Phil Rose Rochester, NY
'91 200q firstname.lastname@example.org