Thread: EGT sensor in blanking plate

Hi,

If that thermocouple probe is part of an American-sourced gauge such as an Auber or Scintex, the thread on the fitting will be 1/8" NPT (American National Pipe Thread).

[The 1/8" refers to the nominal bore of a steel pipe with this thread on the outside. The OD of the thread is about 3/8" or 10 mm (i.e. 1/8" ID plus 2 x 1/8" pipe wall thicknesses.)]

Like BSPT (British Standard Pipe - Tapered), NPT threads are tapered threads - their threads get slightly larger in diameter as you go back from the tip. They are designed to tighten into the female thread before all the threads are engaged. DO NOT try to put a nut on the inside of the mounting plate. The risk of it coming off and destroying your turbo is too great.

Also, the probe in your photo looks like it has a sealed tip (known as 'fully sheathed') That type is OK for pre-turbo installations. (Tho' I'm not too keen on that crimped joint that will be inside the manifold.)

I'd not recommend ever using an 'exposed tip' thermocouple pre-turbo. They can shed bits of hard ceramic-like insulation through the turbo.

Have a squiz here: ThermoGuard Instruments for info on using the EGT gauge once it's installed.

Single NPT and BSP threads can be bought from industrial suppliers like Blackwoods etc. The tapping drill size is 11/32".

Hope this helps,

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I was being a donut, thought I had to screw the end of the sensor bolt through the plate when in actual I needed to drill a 11.5m hole and attach the nut and bolt, tighten and used a little high temp sealant to ensure totally sealed. All working well, max temp so far 550 degrees up steep hill.

Amazed how much the turbo temp goes fluctuates especially how quickly the temp drops when cruising down a hill.

Many thanks for all the helpful advice.

Dragon gauge eh? Expect some flickering after a while. Can you post a photo of sensor mounted in egr plate?

550 well there is 150 room for pump tweaking

Sent from my GT-I9305T using AULRO mobile app

Thanks for the help, so far no issues with my inexpensive gauge. I worked on the principle that if you can buy a meat thermometer for $5 which goes up to 300 degrees, the science behind cannot be too hard. Time will tell, I would like to have bought an SAAS gauge, but budget not permitting at the present time.


Last week I received new map from Jose (Stage 2), and have received a second up-rated one overnight, so looking forward to seeing if any further improvements, but have to say it already makes a very considerable difference. 90kmh and then foot down in 4th is extremely enjoyable !


That said I do get frustrated at the LR auto gearbox, when it is peaking at 3,000 rpm and not doing a great deal going up hills etc, you know that when it does finally change you get that small push back in the seat as it lurches forward with a heap of torque and you wish the car had done that 5 seconds before. I will have to drive an up-rated manual one day.....

Or change the torque converter for a heavier duty one 😉

Originally Posted by surfingooner

That said I do get frustrated at the LR auto gearbox, when it is peaking at 3,000 rpm and not doing a great deal going up hills etc, you know that when it does finally change you get that small push back in the seat as it lurches forward with a heap of torque and you wish the car had done that 5 seconds before. I will have to drive an up-rated manual one day.....

Stick with the auto, and talk to a good auto guy. If you are ever in the Dandenongs talk to Dave at Omega. Knows his stuff imo.

So update with bad ending ! Gauge had faded in temp ranges, still working but guessed it was either faulty or gunked up. Took the plate off and yes the sensor was black. So de-greased and whilst fitting back on, I lost one of the bolts and found a couple of spares that came with the UK EGR removal kit and fit that on, was a different metal, copper coloured and whilst tightening it broke off. I am now guessing these ones were for blanking off the heat exchanger maybe ?

So at the moment it still is snug whilst ticking over, but no idea what will happen under load. So where do I go from here, what do I need to do to get the broken bolt out and how bad is this ?

Unhappily. Matt

After a week or two of suffering crap performance and an unhappy engine I refitted the original 4mm blanking plate with gasket sealant and with the one bolt it is holding and there are no leaks. Now planning to get the leaking manifold skimmed and fixed at end of Jan and sort out the bolts to get it permanently leak free. (engineer uncle coming out from Uk for his annual visit). Will get the blanking plate fixed properly at the same time

So what can I do to stop the sensor gauge from coking up again ? Is it just because I bought a crap quality unit, does the same happen with a thermoguard unit or similar for example ?

Any help greatly appreciated.