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Old 10-21-2006, 12:39 PM
Merkey Merkey is offline
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Join Date: Apr 2006
Posts: 644
Spark Plug Horror! Look!

Looking for our hot misfire on my sons 88 300TE.
Car has done 67,900 miles.
I put these plugs in new about 2500 miles ago.
Oil was changed just before that, and has been changed again last week.
The car is loosing oil, but we thought it is mainly leaking from the pan gasket.
Coolant was changed when we did the leaking radiator... 100 miles ago. We used the correct Zerex clear stuff, and the level has not moved since.
we use 91 ron gas, and we did pull the ignition timing resistor yesterday, to see if it made any difference. It didnt.
I planned to do a compression test this morning...
I pulled these plug about 5 mins ago...
We started the car from cold... drove it into the garage and pulled the plugs.

I was stunned by the condition of the #1 plug... enlarged pic below. Plugs are in order... left #6 to #1 on right.
Duty cycle was set to about 45% last time I did it about 2000 miles ago... it was about 70% before.

I will do a compression test now and post when we are done.
I will clean the plugs up and check the duty cycle again.

What the hell are those deposits????
I have never ever seen anything like that before!

Attached Thumbnails
Spark Plug Horror! Look!-plugs_igy6846468.jpg   Spark Plug Horror! Look!-plug1_ujyf984551.jpg  
1984 Mercedes 190D 2.2 209k miles

Last edited by whunter; 01-02-2008 at 02:25 AM. Reason: attached pictures
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