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Hi everyone. First, I want to extend a huge thank you to this forum. This project my son and I took on was made much easier by being able to search for answers to all our questions here. It's an incredible source of knowledge and help and made our lives much easier.
Over a year ago we bought an '04 GT 6sp with lots of upgrades but low compression. We bought a reman engine from Mazda, but life being life, we did not get it installed until this past December. Slowly over the course of the winter fixed *most* of the remaining issues (it threw about 12 codes at first, that was some fun troubleshooting).
The one problem we are looking at now is an oil leak which we have isolated to the Low Oil Sensor in the oil pan. I figure it's either the the o-ring (lost likely), the sensor itself, or a damaged pan. I'd rather not spend $100 on the sensor if it's just the o-ring, but I'd also rather not drop and re-seal the oil pan multiple times to figure it out. I assume the sensor and o-ring were new with the engine, so I'm really stumped as to how this happened, but it is what it is. Once I get the pan off and can see the sensor, is there anything I should be looking for or a failure mode that's more common than others? I haven't been able to fund much on this using the search feature, but if anyone knows of an existing thread please point me in that direction.
Congrats on fitting your new engine! The oil level sensor absolutely needs the o-ring or its going to leak heavily. Unfortunately, the only solution is to drop the oil pan and inspect. It may not actually be the sensor but if it indeed missing the o-ring that's your problem.
Thanks for the reply. I may have found the solution, and if it continues to stay dry the root cause of the problem was my own stupidity.
First, I was fiddling with the sensor yesterday afternoon. I can rotate the sensor and there is a good bit of resistance so I'm confident the O-ring is installed.
While looking for solutions to other issues in the past, I've seen a lot of threads discussing issues due to overfilling the oil. When we filled this engine for the first time, I used a full 5 quart jug. I know an oil change only needs 4, but the entire system holds close to 8 (oil coolers, lines, etc.). I also know we lost a bunch of oil from the cooler lines when we had the engine out, so I figured I'd just dump the full 5 quarts in. It read overfull on the dipstick, but I figured it's going to consume that anyway, so I'll just leave it.
Since I was dealing with this leak, and I know overfilling this engine causes a host of issues, I decided I would drain some out until it read between the lines just for good measure. Turns out I had to drain a full quart to get it down into the correct operating range. Apparently we didn't lose as much as I thought we did during the engine swap.
In order to know if the low oil sensor was leaking, I had wrapped a paper towel around it and zip-tied it in place. In the past it would be completely soaked in oil after just 50 miles. Yesterday after fiddling with sensor and draining a quart, I took it for a 50 mile drive. When I got home the paper towel was bone dry.
So either rotating the sensor fixed how the O-ring was seated, or overfilling the sump was pressurizing the pan and that O-ring was the weak link. It's probably the latter, and my own damn fault. Either way, it appears to be fixed!
Just posting a follow up for anyone who runs into this issue in the future. It was still leaking pretty good even after I rotated the sensor and got the oil level correct (I just didn't run in enough before to realize that). I finally bit the bullet and bought a new oil level sensor. My son pulled the pan, swapped the sensor, and then we spent an absurd amount of time gently scraping every last bit of RTV from the engine and the pan. We reassembled it using the Pineapple Racing viton gasket just in case we ever need to pull the pan again. We followed the instructions and tightened it just enough to begin squeezing the gasket. The old sensor and gasket looked fine, but it's been a couple thousand miles now and there are no more oil spots on the driveway. Thanks again to this forum for the help!
05-17-2022, 12:48 PM
