Coke Posted June 19, 2011 Report Share Posted June 19, 2011 I'm trying to get to the bottom of what the thread pitch is for the sensors in the intake manifold. Professor Quest says: http://starquest.i-x.net/viewtopic.php?t=1097 The coolant temperature sensor, EGR thermovalve, and radiator fan switches, are 3/8'' NPT. Komeuppance says it is M16x1.5 Which is it? Link to comment Share on other sites More sharing options...
slowquest Posted June 19, 2011 Report Share Posted June 19, 2011 You should've made this a poll.... My vote is 16x1.5 Link to comment Share on other sites More sharing options...
87TsiOwner Posted June 19, 2011 Report Share Posted June 19, 2011 It could be either... only way to find out for sure is to run a die over the sensor. Link to comment Share on other sites More sharing options...
ucw458 Posted June 19, 2011 Report Share Posted June 19, 2011 (edited) Well it's not M16x1.5 on my thread pitch gauge. It's also not quite 3/8 NPT. Only goes in 2 threads before binding on a 3/8 NPT hole. You could force it into a 3/8 NPT hole using teflon tape to make it seal. My vote is 3/8 british pipe thread since all the other stuff is british pipe thread. Edited June 19, 2011 by ucw458 Link to comment Share on other sites More sharing options...
Komeuppance Posted June 19, 2011 Report Share Posted June 19, 2011 LOL... you quoted that all wrong, but alright. The radiator fan sensors are M16x1.5mm.Bi-Metal Type, Radiator FanSwitch M16 * 1.5 Metric Thread Normally openCloses @ 189 to 199゚FOpens @ 3 to 10゚F belowclosing temp.Mitsubishi: MB007639Wells: SW508Standard: TS-144 -Robert Link to comment Share on other sites More sharing options...
ucw458 Posted June 19, 2011 Report Share Posted June 19, 2011 LOL... you quoted that all wrong, but alright. The radiator fan sensors are M16x1.5mm. -Robert Just tested that. Correct. Link to comment Share on other sites More sharing options...
Komeuppance Posted June 19, 2011 Report Share Posted June 19, 2011 If you have one out will you test the thermovalve?? I know the CTS is a different thread than the thermovalve and fan sensor. -Robert Link to comment Share on other sites More sharing options...
ucw458 Posted June 19, 2011 Report Share Posted June 19, 2011 (edited) If you have one out will you test the thermovalve?? I know the CTS is a different thread than the thermovalve and fan sensor. -Robert Will do Thermovalve threads match the CTS threads. I believe they are both 3/8 british pipe thread. Though they will both fit a 3/8 NPT hole... sortof, A BTPT hole is the proper thread. BTPT Industry standard for "British Taper Pipe Thread" A 3/8 NPT tap is very close but doesn't quite line up with the threads properly. Further proof is I have a new unused 3/8 NPT brass T here and both sensors only go in about 2 threads before binding. A 3/8 NPT fitting goes 3-4 threads into that T before snugging up. Edited June 19, 2011 by ucw458 Link to comment Share on other sites More sharing options...
Komeuppance Posted June 19, 2011 Report Share Posted June 19, 2011 Most interesting. The fan sensor fits in the thermovalve opening, but the CTS doesn't fit in the radiator. -Robert Link to comment Share on other sites More sharing options...
quest1988 Posted June 19, 2011 Report Share Posted June 19, 2011 why dont you just pull out the sensor and check the thread pitch on the sensor. or i can do it on monday. have extras Link to comment Share on other sites More sharing options...
Metric-man Posted June 19, 2011 Report Share Posted June 19, 2011 (edited) PQ wrote"And after you chase the threads a little deeper........YOU'LL say they are American pipe threads"I think he means the internal threads are soft and a NPT tap works fine I would use a metric thread pitch gauge, first on the sensor threads then on the internal aluminum threads, and to achieve a good seal I would also use teflon thread sealant.http://www.ohiovalleyag.com/catalog/images/TruBlu.jpg http://i1083.photobucket.com/albums/j382/Starion_Cult/threadpitchandsizeimportengine-2.jpg?t=1300990695 http://www.toolking.com/hanson-12016-16-leaf-metric-thread-pitch-gauge?c_j=1&URL=http%3A%2F%2Ftracking.searchmarketing.com%2Fclick.asp%3Faid%3D832058193&c_j=1 Edited June 19, 2011 by Metric-man Link to comment Share on other sites More sharing options...
Chad Posted June 19, 2011 Report Share Posted June 19, 2011 http://starquest.i-x.net/viewtopic.php?t=3296&highlight=thread+pitch Long entertaining read, with pictures and correct thread pitch gages used. in the end PQ admited he was wrong the whole time, but refuses to post correct info because apparently it would make him look worse to admit I was right, than to post bad info the entire car is BSPT pipe threads, except for one fitting on the intake for the automatic bost/vac port, and that is a dry seal NPT (NPTF). The factory temp gage is not pipe thread, it's 16x1.5, the CTS is 3/8 BSPT. You can convert any of the BSPT threads to NPT with a tap, but it's a one way street, there is no going back. Also, if you try to cram a BSPT sensor or fitting into a NPT hole, you will be lucky if it is seals, and will ruin the threads ,but it will usualy work OK if you use a lot of thread sealant (the paste style, not the tape). Link to comment Share on other sites More sharing options...
ucw458 Posted June 19, 2011 Report Share Posted June 19, 2011 http://starquest.i-x.net/viewtopic.php?t=3296&highlight=thread+pitch Long entertaining read, with pictures and correct thread pitch gages used. in the end PQ admited he was wrong the whole time, but refuses to post correct info because apparently it would make him look worse to admit I was right, than to post bad info WOW.... just wow Link to comment Share on other sites More sharing options...
Komeuppance Posted June 19, 2011 Report Share Posted June 19, 2011 LMAO... five pages... really... -Robert Link to comment Share on other sites More sharing options...
ColdScrip Posted June 19, 2011 Report Share Posted June 19, 2011 http://starquest.i-x.net/viewtopic.php?t=3296&highlight=thread+pitch Long entertaining read, with pictures and correct thread pitch gages used. in the end PQ admited he was wrong the whole time, but refuses to post correct info because apparently it would make him look worse to admit I was right, than to post bad info the entire car is BSPT pipe threads, except for one fitting on the intake for the automatic bost/vac port, and that is a dry seal NPT (NPTF). The factory temp gage is not pipe thread, it's 16x1.5, the CTS is 3/8 BSPT. You can convert any of the BSPT threads to NPT with a tap, but it's a one way street, there is no going back. Also, if you try to cram a BSPT sensor or fitting into a NPT hole, you will be lucky if it is seals, and will ruin the threads ,but it will usualy work OK if you use a lot of thread sealant (the paste style, not the tape). You have got to be kidding me... Link to comment Share on other sites More sharing options...
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