Oil Pan and drain plug threads

[Beaknose]

Dear fellow NSX owners,

I had the oil changed in my '91 last fall at Superior Acura in Lenexa, KS. I normally change oil in all of my cars, the dealership however had a pretty good deal going for this job. I bought this car last summer, so the dealership changing the oil was the first time it was done while in my possession. It also gives me a chance to see under the car when it is on the lift. When the tech re-installed the oil drain plug, it would only go in about half way by hand. He had to use the wrench the remainder of the way with just a little of resistance. This tells me that either the threads on the plug or on the oil pan drain hole are slightly stripped. The car does not leak any oil. Has anyone ever used the appropriate size tap and die on the drain plug and oil pan to "clean" the threads so as to allow free spinning of the drain plug? If so, what was the correct size? Can anyone recommend this procedure, or could it cause more harm than good? Thanks.

John
'91 Red/Ivory

 

[drew]

the plug on my NSX has needed a wrench for quite some time now...I'd leave it alone...that way you'll get plenty of warning before it backs out completely.

Drew

 

[ATERPAK]

I agree with Drew on that one. If he can thread it in by hand half way, then its probably the drain plugs threads near the end are slightly off. As long as it torques up ok and comes off with the right tool, it should be fine. Just don't over torque this bolt. Take care.

 

[NSXTech]

Yeah, running a tap is a great idea- as long as you don't mind an oil pan and engine full of metal shavings, that is. :wink:
I see this daily. The threads are not strpped, they are pulled. If you look at the drain plug, you will notice the edges of the threads are very sharp and have a barely percievable tilt. Comes from overtightening.
Do nothing, IMO.

MB