[Nick Gibson]

Hi Guys

I have an engine management module that can measure EGT, but as I have a petrol I have no use for this. I would like to monitor my cylinder head temp as an extra redundancy in the system.

Where do you think I should mount the probe, MGL avionics sells K-type probes that they bolt on under the spark plug, but am not sure if there is enough spact to fit it in. I thought maybe get a smaller loop and bolt one to the head directly, but where and what temps can I expect to see??

Article of website:

cht - K-type probe.jpg (47.21 KiB) Viewed 919 times

CHT probes

These "under the sparkplug" CHT probes are popular choices for CHT temperature monitoring.

One piece water cut pure copper ring and probe seat
1 meter (3ft) cable length
K-type thermocouple
Thermocouple braised to flange of ring, no joint, no risk of detaching due to wear and tear
Very fast response time due to one piece copper construction
CHT probes are available in sizes 10, 12, 14, 18 mm (inside diameter ring).
The 10mm probe is popular for use as general temperature monitoring probe and can easily be bolted down (gearbox temperature etc).

Please note: These are pure copper probes and will quickly coat with a thin layer of oxide when exposed to air. If desired, this can be removed easily with Hyrochloric acid (pool acid) but this does not affect the probes performance.

Any suggestions would be most welcomed!!

[hend]

I have a MGL avionics engine monitor on my 2.8 Tdi. I used the ring probe and bolted it to one of the head bracket bolts. I get any where from 90 to 115 degrees depending on use of the vehicle. Normally goes high when you drive in town and stop start at shops. I am sure it will go high if I lose water.

I have the alarm output wired to a very loud buzzer so when egt or CHT goes high you know about it.

[Nick Gibson]

Hi Hend.

Do you monitor your coolant temp with the MGL device aswell, in order to compare coolant temp to head temp. Eg running at 85deg C coolant = 90 deg C head temp??

What else do you monitor, or only CHT and EGT??

[hend]

I dont monitor coolant temp. The normal gauge indicates this.

[hend]

I monitor air temp in the inlet manifold which is not a critical parameter. It is interesting and provides information about how well the intercooler performs. It normally runs around 50 to 70 deg