Is this metric fine? 13.2mm X 1.25mm Installing water temp sender in Head

[MisterCruiser]

I robbed the pics below from a decade old thread. I'm looking to install a water temp gauge to see what temps my cruiser is actually reaching as I have read the standard temp gauge is very inaccurate. I removed the spare blanking bolt from the yellow circled port in the pic. With my head gasket gone, it has never over heated going by my standard gauge and I'd like to keep an eye on the temp in case it does decide to over heat.

Do any other members here have a temp sender installed in this place on the cylinder head of a 1KZ-TE?

It measures 13.2mm X 1.25mm thread pitch. I believe this is Metric Fine. I'm assuming it's M13 X 1.25 which is a bit of an oddball size.

My query is, most temp senders are like NPT and UNF, is there a version of these that is very close to M13 X 1.25mm?

The 2nd pic shows what one member did by getting an adaptor from a hydraulics place and then screwing the sender into the adaptor. But I'd still have to find a M13X1.25mm adaptor.

I don't think any temp senders are available in M13X1.25mm size? I was hoping to get a VDO gauge and sender to match an existing gauge I have.

 

[Beastrider]

The blanking plug looks to have tapered threads. Is that correct?
If so, judgeing by your measurements, it may be 1/4 NPT which has 18 threads per inch.

 

[Shayne]

Drill and tap the original bolt so your sensor screws into it .

 

[MisterCruiser]

Good shout Beastrider.

I've since confirmed it to be 1/4" NPT in a hydraulics shop today, might help someone in future. It's a handy spot to install a sensor.

 

[MikeJak]

most ports on the block are NPT, I added a temp gauge too but went for the easy way and added it in the top rad hose with a splice adapter.

 

[MisterCruiser]

I used the top hose adaptor method before on a different car. On the cruiser, I actually think the top hose option is the harder of the two. The head is literally the removal of one fairly accessible bolt, I didn't have to move anything out of the ay to get to it, needed a wobble extension though to slide around the oil filter and some metal fuel pipes.

What temp does your top hose gauge read when the standard gauge reads 90 degrees?

 

[Shayne]

If thermostat says 80c that what you should get with maybe 3c give and take if it says 70c ........... take the thermostat out and temperature keeps increasing on any engine though you can get away with it for a long long while depending on your driving habits and location .

Coolant is 50/50 dormant and active whats in your radiator is doing nothing but cooling itself down so it can replace the stuff in your engine when it gets to hot .

 

[MikeJak]

I used the top hose adaptor method before on a different car. On the cruiser, I actually think the top hose option is the harder of the two. The head is literally the removal of one fairly accessible bolt, I didn't have to move anything out of the ay to get to it, needed a wobble extension though to slide around the oil filter and some metal fuel pipes.

What temp does your top hose gauge read when the standard gauge reads 90 degrees?

sorry should have said, I have the 5VZFE 3.4 petrol, the top hose reads 84 to 90, when the temp gauge on the cluster is at normal op temperature, feels pretty accurate as the 5VZFE has an 84C thermostat adn can tell it climbs slowly but steadily to 83-84 when warming up and then it stays for a while at 84-85 once the thermostat has opened so feeels pretty accurate and indicative of teh temp. it's only 25-30 cm away from the exit of the block so not much time to loose temp, being at the top is likely the hottest reading I can get