Engine/Transmission (1998.5 - 2002) How long do thermocouples last?

[JJ Jackson]

I've had my exhaust temp probe in for 4 years now. Should I be thinking of replacing it before it deteriorates and ends up in the turbo? Thanks, Jim

 

[ROADWARRIOR]

Mine looked as good as new once I cleaned the soot off. This was with 5 1/2 years and 55,000 miles of use. I had it out while I upgraded the manifold.



Dan

 

[DOWG]

Mine, (pre-turbo) failed at about 160,000 miles.

 

[NickSullivan]

Anyone have a picture of the Thermocouple? I'm just curious what the sensing element and cable looks like and how it's built. I'd like to build my own.

 

[JStieger]

Mine, (pre-turbo) failed at about 160,000 miles.

What did it do when it failed? Was it just electrical or did the probe come apart? Thanks

 

[Gary - K7GLD]

My 1/8 inch Westach probe failed at about 30,000 miles - they normally seem to last FAR longer than that, mine was just an exception. Replacement was about $30. Mine began drifting lower in EGT readings, then quit completely.



I seriously doubt its practical to try to make your own - the meters are usually designed to function most accurately with a specific probe and lead length...

 

[JJ Jackson]

So when you say failure you mean that it electically failed not broke and went into the turbo. So I guess I dont need to be too concerned. Thanks guys.

 

[Gary - K7GLD]

IF/when they fail, it's usually an electrical failure INSIDE the probe - a probe physically disintegrating and falling apart inside the exhaust system is extremely rare - the composition that makes up the probe will take FAR more heat than the engine parts it's installed on - in other words, the ENGINE will most likely melt and fall apart sooner than the probe will...

 

[PKleine]

As Gary said, it is extremely rare for a probe to physically fail. So rare that even in aircraft use there is no requirement to replace them based on time in service. They will fail electrically, espically if 'disturbed' after being in service for awhile.



Electrical failure is simply described as when they quite working. Usually what happens is the engine is running with 0 egt or else a full scale reading. In the case of the latter, changing engine speed will not make any difference to the indicated egt. And almost always the failure is to 0 egt.



PK

 

[KcoleKennyc]

Have over 200,000 miles on mine with no problems. I have new manifold on order and will probably replace it at the same time.

 

[DOWG]

Mine just started acting wierd; sometimes it would work and some times it wouldn't and then it just quit all together. Physically, the probe looked fine. Changed it out, just the probe with the short wire, did not change the long wire all the way back to the guage. 20 minute job.