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Hams930T Hams930T is offline
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Join Date: Jun 2013
Location: Plano, TX
Posts: 792
Originally Posted by Nextjato View Post
In the seller's description of the car he states that he put in new spark plugs. Would any of you put in new spark plugs without doing a compression and leak down test?

My limited knowledge of these cars is that if you are going to go to the trouble of getting to the spark plugs, you are 95% of the way to completing a compression test. Right or wrong?

My thoughts are that the seller may have already done the compression/leak down test.

Thanks for your help guys, I appreciate the education.

I wouldn't do a compression/leakdown test during any maintenance routine like changing plugs unless I suspected something was wrong with the motor. It's easy enough to do once you get everything out of the way to do plugs - but it's not like I would just do it for no particular reason.

Granted - it's certainly a pain to remove all the crap to get good access to the plugs if the car is stock, but like others mentioned - it is a good indication of the engine's health and I would certainly offer to pay to have it done. If not, you need to be okay with the unknown.

Like others mentioned - if the seller is reluctant to have the service done, I would be cautious. I wouldn't run.... I would rather decide if you really want that car or not. If you do, then I would work on a price and make the compression/leakdown a condition prior to purchasing the car. Offer to pay for it (I certainly wouldn't do a compression/leakdown for free unless the buyer is going to pay me for my time). Judge the results for yourself.

Best of luck.

1986 930
2015 991 GT3
2016 Cayman GT4
2012 911 Cup
Old 07-11-2014, 10:31 PM
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