triplenickel

Mine is in the same place as Dielsejunkie, I too used a Makita cordless, but a smaller one. With this one I went in from under the hood straight into the manifold.


http://www.makita.com/menu.php?pg=pr...et&tag=6019DWE

Dieseljunkie

I didn't drill it, but I watched as it happened, and it was a tight fit, but a standard corded drill fit in there, just barely.
Scott

Ramtough

As i said in another post, pre turbo you may or may not be risking your turbo. post turbo you may or may not be risking your engine. Which is the cheaper alternative to you? if your really that worried just change the pre turbo probe every so often ( 2 years or ?? mileage) later whatever. that way the probe wont be old and brittle as some sugest thats what they wrory about happening.

But like i said id rather know if my pistons are near melting on my $6000 + engine than worry about wether my probe could kill my $1000 turbo.

cheff

I have mine pre-turbo just like the pic that Dieseljunkie posted. And this one statement here has eased all the doubts I could have about its placement. Not that I had any

RustyJC

Our company is a manufacturer of large industrial engines (2 and 4 cycle, gas fueled, dual fuel and diesel), compressors, turbochargers, gas turbines and associated control systems. We provide as standard equipment a thermocouple on each power cylinder exhaust elbow and a thermocouple at the turbocharger turbine inlet (pre-turbo). A post-turbo thermocouple is supplied only as an option if the customer wants it, and even then it is generally used to monitor inlet temperature to a waste heat boiler, catalytic converter, etc.

Draw your own conclusions. My truck's thermocouple is mounted pre-turbo.

Rusty

staarma

I guess I'm confused as to how the thermocouple could damage the turbo. The inlet side is where the turbine is and that is hooked up to the intake tube. How the thermocouple could get in there is puzzling me. Wouldn't it just go out the 4" exhaust vein? I realize the exhaust pressure turns the turbine but I guess I just can't visualize what damage the tip could do in there.

Just trying to learn I guess.

whooptide

i've come across a good number of these threads here, but i've never seen a post from somebody who actually had a failure of the thermocouple into the turbo. it's almost like an urban myth....anybody actually have this happen?....please no: my friend's uncle's father-in-law....lol.........

Jeff in TD

starrma,

The turbine in the intake tract is driven by another turbine in the exhaust tract...

The turbo is spun by exhaust pressure to speeds up around 140,000 RPM and is precision balanced, and runs with pretty tight clearance with the turbo housing. If a probe in the exhaust manifold (or anything else solid, for that matter) fell into the exhaust side impeller, it would easily cause extensive damage.



I'm with Whooptide, though, in that I have never talked to anyone who claimed to have an EGT probe go through the turbo.

Though I think there are lots of people who have managed not to melt their engine with a post turbo probe (or even with no pyro at all) I’m about to mount mine pre-turbo.

I don’t think there will ever be a “once and for all� answer to the pre v.s. post turbo probe issue, other than “it’s your truck, do what you want�.


P.S.

I did once hear an interesting theory regarding the issue that I’m not sure I believe, so I’ll throw it out there for the experts…

The theory was that OEM’s put the pyro post turbo because there are significant pressure variations in pressure in the pre-turbo manifold (that exhaust pressures can be significantly higher than boost at times, and down to atmospheric pressure at other times). Since the temperature reading of a gas rises as the pressure rises, this can effect the reading of a pre-turbo probe, and that a post-turbo probe (in a pressure stable area) produces a reading that is more correlated to the temps of the internal parts of the engine…

What do you guys think? Anyone know what the pressure of pre-turbo exhaust is? Or how many degrees difference in temp that pressure would cause?

staarma

Thanks. Makes sense to me now.

jk1364

So does that mean that I can run 1300/1400 if I am pre-turbo?

John

pcburnout

I Think someone should get a poll going ( pre or post ) Turbo !

Big Joe

I believe there has already been a poll, cant remember who won.

zog

I put my probe PORT-TURBO for a couple of reasons. Primarily because thisis my first ever diesel and turbocharged engine, I was extremely reluctant to goof it up. I contacted Cummins and they indicated that post turbo was more stable and also there was no chance of breaking the turbo if the probe broke off. This made sense to me...

I read lots and lots about pre vs. post turbo, so I took a good hard look at the engine. It seemsed a lot easier to drill and tap the cast iron post turbo elbow if I removed it from the truck...I had never drilled and tapped anything before, and I thought this was an easy/cheap part to replace if I goofed it up.

Also, I heard horror stories of drill shavings getting into the turbo from drilling into the manifold.....oouch!!

SO, I opted to be cautious and do the deed post turbo. Now that I have owned the truck and few months, changed the oil a few times, installed the rest of the gauges and an MBRP muffler, I realize that I was very OVERLY cautious...Pre turbo would be a piece of cake and I thought about adding a second pryo (pre turbo)....but why bother. I'll live with what I have and maybe the next truck will get a preturbo probo...on the other hand?????

As long as I know that I should not go too far over 1100 degrees with a post turbo probe, I am fine....if it was pre-turbo, I know I can hit 1400 or more and still be fine...

The long and short of it to me is that personal preference, ease of installation, and reliability are the important factors....OR....does it really matter????