What does the Pyrometer show? Are there any other gauges that are important for a diesel?
I have a 91 F250 with a 7.3, and a4od trans.
Thanks
Lars

 

i love diesels! i am a diesel mechanic for new england truck, i can tell you just about anything you want to know about diesels.....
a pyrometer tells you exhaust gas tempurature. why would you need to know this? well...diesels do not have vacuum on the intake side, however if for some reason there was restriction, by nature diesels will start putting out very hot exhaust, and this is what your pyrometer will tell you. another sign is smoke, but that can be caused by many other things. the pyrometer sensor should be located just after the exhaust exits your turbo on your 7.3. if not a turbo diesel, then it would just be about 6" from the end of the manifold. other helpful things to have on a diesel would be oil pressure in block (#psi, not hi/lo), oil pressure before turbo, oil temp, voltmeter, water temp at front and rear of block, fuel temp (cold climates), turbo boost guage, and if you are towing with an auto, just for the hell of it i like to know just how hot my tranny is getting so if need be i can take a pit stop and let her cool a bit. now of course all of these guages arent necesarry, but i hid them all in my center console just because i like to know whats happening under that hood. of course i also have intake temp, 3 propane pressure guages, and a NO2 pressure guage on my hot rod 7.3

 

Burly...are you saying to locate the pyro sender.... post turbo...after the turbo????? most other posts seem to prefer the location BEFORE THE TURBO....in the manifold?????


Have a new 2003 6.o turbo diesel on order..and want to protect that $ 70,OOO CANADIAN!!!!!!!

great forum!

Steven Rupp
Williams Lake , B.C Canada

 

a pyro measures exhaust gas temp. egt is very close to the actual temp of the cylinders and pistons. the gauge tells u the temp of them. since aluminium melts at i think 1250 degrees, which is very possible to reach with a restricted air intake or over fueled condition,u could melt the pistons down in your engine. it is not likely to happen in a stock engine since the factory has designed them to be worry free. but in a hopped up diesel engine that is really burning some fuel 1250 can be reached real fast. my dodge will go from 600 to 1250 plus if i floor it pulling a trailer uphill in 5th gear in just a few seconds. you are better off putting the temp probe pre turbo. that will give you the most acurate reading of the pistons. the reason people put them post turbo is so they can tell what temp the turbo is at before shutdown. if the turbo is too hot at shutdown the oil in the bearings will cook and form deposits inside the bearings causing premature bearing failure. the only problem with this is the egt has cooled off some by the time it reaches the probe. one other thing to point out about pyro's is that they always read history. that means if your diesel is capable of reaching 1250 easily by the time the gauge reads 1250 the actual temp inside the engine may be a couple hundred degrees higher. same thing with a post turbo gauge. not a big deal if your engine is stock and cant reach the meltdown point or gets there slow. but like in my case whear mine will reach 1250 in seconds 400 degrees difference could mean a blown up engine. sorry for the long post.

 

I placed the probe for my EGT gauge post turbo due to the fact I have heard stories of these probes melting/breaking off and going thru the turbo itself , causing some nice damage. I was told by Geno's garage that if you place the probe post turbo , add 200 to the reading on the gauge for an accurate temp.....

 

Heard the same from several sources who had seen it happen so I went post-turbo. Its not as accurate as pre-turbo and I believe the fact that it isn't always a 200 degree difference, but it wasn't worth the risk to go pre-turbo.

I've also been told that the temps aren't quite as critical as they once were now that they are using sealed bearings etc.

Running the SCMT in either mode (not towing) I haven't seen the temps climb above 800 degrees. Now throw a slide in camper and its amazing how much difference that will make in EGT's.

If you plan on doing any towing, I'd strongly recommend one.