Oil Temp Sender - mounting location discussion
 

A lot of people seem to be connecting the sender unit AFTER the coolers. Oil temp is being monitored to make sure it does not get hot enough to damage bearings and distort other parts (right?). Unless there is a way to figure out how much heat the coolers remove from the oil, under varying conditions, I don't see much value in readings that are taken at the end of the system.

Assuming nobody disproves my conclusion above, I need to find a place to figure out where I can mount the sensor. Here are my thoughts:
1. Connectors: A few companies make -10, 10, 10 'T' unions. The problem is 1 or more additional connectors would have to be added to taper down to the sender size. Not exactly a clean install, more potential leaks, and there isn't much room to work with.
2. Find an Oil T-stat that has a temp sensor bung.
3. Weld a bung onto the Oil T-stat
4. Weld a bung onto the front cover.

Thoughts?

Oil Pan?

I don't think it matters if you read the temp before or after the cooler as long as you keep the sensor placement in mind when deciding what temps you want to see. My engine builder recommended I put mine after the cooler. So, I drilled and tapped my stock oil filter base and put the sensor in that... right next to my low pressure warning sender. For reading pre-cooler temps I'd agree with Wrankin and say weld a bung in the oil pan. That way you don't have to disturb your oil lines and add more turbulence to the flow.

I would have to say that the temperature after the cooler is better to know. If your oil cooling system is not up to par you would not know this from a reading before the cooler.

Why not pull both readings so you know the temp exiting the engine as well entering the engine. This will tell you how much heat the oil is sucking up from the engine as well as how well your cooling system is working.

-billy

we asked jim mederer of racing beat a different question, but he answered this one. i'm paraphrasing his answer

once the input temps get too high you run out of delta T. he gave an example too, if the oil temp is over x, that means its over y inside the motor, and if y is too hot, then the oil cant absorb any more heat.

so this sort of implies theres a relationship between the input and output temps, and that the temp we're really concerned with is somewhere INSIDE the engine.

so thats why the input temps are measured at racing beat.

You can find an oil T-stat that has locations to read both pre-cooler and post-cooler temps.
Most, if not all, will at least have them available post-cooler and then a simple tap can do the other side.

The oil pan is a good and very easy place take temps.

I've seen some people tap into the banjo bolt. Couldn't you just tap into both banjos, in & out?


-s-

And as a followon question: what temps should you be seeing before and after the coolers? I have dual coolers in the FC, plumbed in series with the lead cooler getting dedicated air through the nose of the car. My temp sensor is plumbed into the filter base using a spacer block (along with a pressure sensor). Both coolers have their thermostats removed and the bypass blocked.

On the track I'm seeing oil temps at the filter not getting too much above 160. Water temps ran around 200. This was in May at VIR, so air temps were in the low 80s.

Is this too cold for proper operation? I was thinking of reinstalling a thermostat in the coolers, which should get the temps up to 180 or so.

-bill

Nice link. Thanks for the info.

So 160F is about the bottom range of what I want to see. Sounds good.

-bill

I'm just asking because I don't know - is there a reason you wouldn't go with a $25 sandwich adapter and take your oil temp and pressure readings at the filter pedestal?

I have measured after the cooler, and have measured in the pan. When I went to the in the pan location, measured oil temps went up about +20 deg F.

Ideally, it would be nice to have both locations measured. If there were problems with excessive temps, then dual measurements would help you diagnose if the cooler suddenly stopped cooling, or if the engine suddenly raised the amount of heat it was putting into the oil.

An oil pan sender is the easiest installation. Some companies make a sender that replaces the drain plug. Just remove the old plug, bolt in the sender in its place, and you are good to go. My oil temp sender is made by VDO, to go with my VDO gauges.

Well as you can see in the link above, Mazda Competition gives guidelines for temps in the pan, so that's what I'm using, although both ways have their arguments for and against.

I used the sandwich style oil pedestal adapter - just remove the oil filter, bolt the adapter on, then screw the oil filter back on for 4 tapped NPT pickups. I needed a separate oil source for the turbo, though, too, so I have 2 fittings in use.

Old thread...ARISE FROM THE DEAD!!!!

I have a couple questions, I just want to verify that it'll be ok.

I don't have stock gauges in the FD anymore, switched to Speedhut. So I'm thinking about deleting the stock oil pressure sender and putting the aftermarket (Spa Techniques) sender in its place. I'm switching from a Power FC to Adaptronic Select...it shouldn't cause any issues with the ECU, correct? I've been told the stock pressure sender feeds info only to the gauge cluster, not the ECU, but I wanted to make sure.

Also, since I'll only need one more port for the oil temp sender, I've been thinking about getting rid of the sandwich plate I've been using, but I'm trying to think of a good place to mount the sender. I've thought about mounting it in the bottom of the stock oil filter pedestal or in the Mocal thermostat before the oil coolers. I think I've seen someone mount it in the thermostat. If I do either of those I want to make sure it's not obstructing oil flow. Any suggestions?

I found this a simple and inexpensive solution for an oil temp sender

CORKSPORT Rotary Banjo Bolt

I have AN lines now, and I want to read oil temp at the hottest point, so I got one of these to put between the fitting on the front cover and the oil cooler thermostat.

Wouldn't you want to read the temp of the oil that's going into the engine, at the oil filter.

The AN adaptor is a nifty alternative for those running AN fittings BTW

I've been reading it at the oil filter for a few years now. I wanna see what the hottest temps are. I'm putting the oil pressure sensor in place of the stock one and I'm planning on just getting rid of the sandwich plate altogether. I've been running the pressure and temp sensors in the sandwich plate.