Txakura Posted October 4, 2011 Share Posted October 4, 2011 Before my used but good ej22 donor sensor could go bad, I painted it with two coats of 'liquid electrical tape' before I installed it. Figured that'd stop the water from getting in and maybe keep the cracks in the housing from spreading. Just a thought. Quote Link to comment Share on other sites More sharing options...
nipper Posted October 4, 2011 Share Posted October 4, 2011 Nope. It is phenalic (sp?) which is a kind of plastic. Many many cycles of expansion and contraction from heat and vibration eventually catches up with some of them and they crack or fail. Quote Link to comment Share on other sites More sharing options...
bheinen74 Posted October 4, 2011 Share Posted October 4, 2011 Really don't think water has anything to do with them getting hairline cracks. None of my cars get water on the engines, but i have pulled some with cracks. I am not one too ever use water under the hood. Kinda like fine stereo equipment, water just doesn't belong near. Quote Link to comment Share on other sites More sharing options...
nipper Posted October 4, 2011 Share Posted October 4, 2011 Also these are basically little microphones, you may have changed how it listens for ping. Water happens, especially when you go wheelin Quote Link to comment Share on other sites More sharing options...
Fairtax4me Posted October 4, 2011 Share Posted October 4, 2011 Water does't make it crack, but water/oxygen exposure is what makes it corrode and stop working correctly. You wouldn't need the plastic housing if the sensor were made of something that wouldn't corrode. Quote Link to comment Share on other sites More sharing options...
Txakura Posted October 4, 2011 Author Share Posted October 4, 2011 (edited) Never said water made it crack. Only meant I didn't want crap getting in mine, which was cracked already but still serviceable. Don't think I changed the acoustics painting the outer covering only, and not the mating surface. But, since I need a lawyer to proof read my posts before I put them up, by all means, disregard the idea of putting a flexible, impermeable covering on a cracked one. Edited October 4, 2011 by Txakura Quote Link to comment Share on other sites More sharing options...
mdjdc Posted October 4, 2011 Share Posted October 4, 2011 Personally, I think it may be a good idea. So what if it doesn't work. It is worth a try to save the cost of an 80.00 part. I do agree though, that the real failure is due to corrosion at the mating surface. I have wire wheeled a few and gotten them back to functioning condition. I have also purchased a few off ebay for 20.00 or so and they are working just as well as the real expensive ones. Quote Link to comment Share on other sites More sharing options...
danbennett2u Posted October 4, 2011 Share Posted October 4, 2011 Never said water made it crack. Only meant I didn't want crap getting in mine, which was cracked already but still serviceable. Don't think I changed the acoustics painting the outer covering only, and not the mating surface. But, since I need a lawyer to proof read my posts before I put them up, by all means, disregard the idea of putting a flexible, impermeable covering on a cracked one. You posted a thought and people commented, no need to get defensive. I think everyone was thinking by "Preventative Fix" in the title that you meant to keep it from cracking in the first place, and that you had thought water was causing it to crack. I do see what you mean though, it might help prolong the life a cracked but still functioning one by keeping it protected some, but I really dont know how they work. Quote Link to comment Share on other sites More sharing options...
Txakura Posted October 4, 2011 Author Share Posted October 4, 2011 Yes I was a little crappy, seemed the point was being missed and over analyzed. The device is a coil that generates a low voltage when certain frequencies are 'heard' or rather 'felt' through direct contact with the block. (A frequency, or range of frequencies, corresponding to detonation in the engine). The low voltage signal is sent to the ECU which retards the timing to prevent further detonation. It's in a less than ideal environment, cycles of hot and cold, petroleum products, vibration and dissimilar metal corrosion all work on it. The phenolic covering becomes embrittled and cracks allowing outside air, moisture etc to cause it to rust and fail. I had a code for it, and when I removed my old one there were pieces from the cover missing and the coil inside was rusted. I removed another from a junk engine lying around and although it was cracked the computer is satisfied with it and the CEL has gone out. Before I installed it to the engine, I hit on the idea of cleaning the outside with a dry rag and painting the casing with two coats of liquid electrical tape. The small existing cracks were filled by the 'tape' and there is now a continuous flexible water tight, and petroleum resistant coating on it. Perhaps, I will never change it again, perhaps it will fail tomorrow. Since it is fairly easy to get to, and since they all seem to be prone to failure, maybe it would make sense remove it and seal it with a flexible covering before it does fail, hence 'preventative' fix. Yes, I apologize for being crappy, but you have to admit the line about the lawyer proofing the post is somewhat humorous. Reagrds. Quote Link to comment Share on other sites More sharing options...
GeneralDisorder Posted October 4, 2011 Share Posted October 4, 2011 When you do get around to replacing it - you can always wire up a connector for a newer model sensor - they are all the same with respect to operation but it is much more common to find good used sensors on the newer models..... though a new sensor is pretty cheap on rock-auto - I think around $25..... so it's hard to justify much work either preventative or otherwise. GD Quote Link to comment Share on other sites More sharing options...
nipper Posted October 4, 2011 Share Posted October 4, 2011 http://www.engineblox.com/?p=65How it works .. Quote Link to comment Share on other sites More sharing options...
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