I have a 2005 xB AT ThunderCloud on order in a wave 3 state. I expect it in June or July and am planning my aftermarket mods. I want to add an engine water temperature gauge and have searched around a lot and found one that I think would look good.

I like the VDO Cockpit White part # 310-239:

with the single Black VDO mounting cup part # 240-016

I have 2 questions:

1) I want to get feedback on whether owners think this combo would like clean and good mounted on the left top dash, to the right of the left speaker, in the far left of the tray in front of the steering wheel.

2) I need to know which VDO 250F sender unit to order. Specifically, which thread size and how and where to install it. The Toyota/Scion parts guy looked very carefully at the Scion and Echo diagrams and parts lists for the 1NZ-FE engine. He concluded that dash temp idiot lights (blue cold engine & red hot engine) were connected to the ECU and not to a separate removable sender unit. See the following link for specs and pics of VDO senders:

http://www.egauges.com/vdo_send.asp?Sender=250F_120C

Thanks for feedback on my questions.

 

There is a water temp sensor on the cylinder head near the radiator hose connection on the drivers side of the motor, and there is an oil pressure sensor right above the oil filter, you can probably tee into both places for guages. Also somebody here used a fitting for the water temp that was placed in the radiator hose, and a oil pressure port that was sandwiched between the block and oil filter, but i dont remember who they were made by. I have the guages, but havent been bored enough to rip my engine compartment up to connect them. Hope this helps...See Ya, Louie
http://hometown.aol.com/slopoke21m/scionxb.html

 

I have a water temp gauge. As far as the size of the sender goes, that really depends on how you are going to mount it. I cut my top radiator hose in half and put an adapter in between and then screwed the sender into this. The adapter was made by AC Autotecnic and was like $20. You would want the 1 3/8" inch adapter size. I don't know if you can get different sized holes to screw in the senders, but if you call AC and ask they will be able to tell you what size sender will work with the adapter. The name of the guy I talked to there is named Ivan (technical support guy). You can get the number off their web site. Below is a picture of the adapter I'm talking about

 

This is definately the best method. This is pretty much the same thing I used with my Pectel PCM on my old Focus. Best thing to do is look for a coolant hose which already has a coupling about the same size as the adapter. Take out the factory coupling and replace it with this new coupling w/sending unit bung. I know Ford likes to use these couplings, but I'm not sure if the Scion has any.

I wouldn't rely on tapping into the factory sending unit only because it could void your warranty on the entire wiring harness/ECU. Definately not a good idea.

 

In the 1980's, my friend and I actually made one of these adapters from scratch for my new water cooled VW. We used a steel pipe with matching ID and OD for the pipe and hose. We drilled a hole in the side of the pipe and welded the metric threaded brass nut in place and mounted the adapter and temp gauge sender inline with the coolant hose and secured it in place with stainless steel band clamps. It worked great! I'm glad to hear that this technique is still considered good practice.

Thanks for all the great feedback on my question #2. I plan to order the AC adapter.

I still would like to know what xB owners think of the look of the gauge, cup, mounting idea and position that I am proposing. Does it match and look good? Negative or Positive. Thanks.

 

I'm personally not a big fan of the mounting cups unless it is an outside gauge (i.e. mechanical fuel pressure gauge mounted to cowl). Why not just flush mount it in the dash next to the speedo/tach? Seems to be the perfect place to mount a gauge, and it would almost look factory.

I must also say great choice on the VDO guage. I have a pair of Vision Series VDO gauges pillar mounted in my SVO and they are of excellent quality compared to the Autometers I am use to seeing. You may want to look into the Vision Series as opposed to what you pictured above: black face w/backlighting for the numbers/letters. With a clear bulb (particularly a white LED) the numbering and needle would practically match the xB's fuel level and tach. They look just about OEM. Just something for you to think about.

 

I used one of the AC Autotechnic adapters for my water temperature sensor ... I really like the design, especially the grounding terminal. Unfortunately it's made of softish aluminum and the threads are easy to strip (at least that was true of mine). It looked OK at first but after flooring it on a 104 degree day it started to leak.

Now I've gone back to the drawing board ... I may try the Blitz Cooling Performer hose, or I may tee into the throttle body bypass lines.

 

I looked at the Blitz hose. It looks good; but $100 for a radiator hose is out of my price range.

I've read that if you tee into engine coolant water that the sender unit may not accurately read the temperature.

Sorry to hear about your bad experience with the AC adapter. I would not have expected leaks and stripped threads.

I guess it's back to the drawing board for me too. Thanks for all the feedback.

 

Well, after much consideration, I ordered the AC Autotechnic gauge and adapter from ScionSport.com.


AC Autotechnic S7 52MM Water Temperature Gauge (AC GR-7004) $44
(includes sender unit sensor)


AC Autotechnic 1 3/8" Water Temperature Adapter (AC GS-AW07B) $19


VDO 2 1/16" (52MM) Black Mounting Cup (# 240-016) $14
(ordered from Yogi's - their picture is wrong on their site)

Even though it may seem odd, I am planning on mounting the gauge and cup on the left top dash, just to the right of the left speaker. I think it will be easily visible there and balance out with the large round stock speedo on the right. I may repaint the cup dark bronze or dark gray instead of black. I'll post pics in July (I'm waiting for my '05 xB).

I hope I don't experience leaks and stripped threads like sithscripter reported.

 

Use a thread sealant or teflon tape to prevent leaks.

 

I found this quote on egauges.com "Frequently Asked Questions" section for installing gauges and senders:

I know the AC adapter has a separate grounding nut, but a sealant on the sender threads would insulate the sender from the body of the adapter.

 

I measured the resistance of the threaded joint with and without Teflon sealing compound -- the difference was like 1-2 ohms.

 

Sounds like I shouldn't worry about insulation and should use the Teflon.

Thanks sithscripter.

 

What I actually did (because I forgot to use a thread sealant or teflon tape) was to put a ring of silicone sealant around the outside rim of where the sender meets the adapter. It's not the prettiest solution, but works. I have no idea if what you heard about the ground is correct or not, but you are probably gunna want to put some sort of sealant on there weather it be on the inside or out. Also, if you use a tread sealant, just don't put it on all the threads. If you read the instructions on the back of most thread sealants they tell you not to put it on the first few threads anyways. This should allow you to make a ground while still providing a good seal. One day, when I'm really board and run out of other stupid things to do to my xB, I'll probably buff the silicon off the outside and seal this way.

 

I received shipment of the gauge and adapter today. At first, I thought that the adapter size was wrong. ScionSport.com, and a previous message in this thread, listed the correct size as 1 3/8". I reported this to ScionSport. They replied that their site was wrong and the correct size is 1 3/16".

I will follow the advice provided and will put no sealant on the first half of the sender threads and put sealant on the last half only. That way I'll get good grounding and a good seal. Now all I need is my 2005 xB...

Thanks all.

 

yup i put a caliper to it and it comes out to 1.25" I.D. so 1 3/16 will work