I should have my gauges this coming week and was wondering if I should mount the pyrometer thermocouple pre or post turbo? I heard pre is more accurate and post is safer for the turbo, in the event the thermocouple breaks down. Pros and cons???

Cheers,
Andrew

 

Pre-turbo.

Rusty

 

IMHO the only way your thermocouple will break down is if it gets hit with molten piston, at that point it wont matter Go pre and be happy

 

Pre-turbo

 

pre turbo for sure, but remember that there is a divider for the front-back half of the motor in the middle of where the turbo bolts on. you gotta go to one side or the other, let them debate on which side to put it on. i would put it on the back half of the motor IMO

 

Pre turbo monitors whats coming out of the engine, where as post turbo tells you whats coming out of the turbo. In your case you need to be positive what the EGT's are coming out of the engine, not the turbo. Problem being is that the EGT's read from the post location are in average *300 degrees lower than pre turbo. This means you always have to calculate the difference in temperature as you read the gauge. But the dangerous part (as I read from others) is that the *300 can vary and that doesnt give you solid ground to measure off of. Anything over *1350 for more than a few seconds will melt your engine, your turbo can withstand much higher temps.

 

Ok, pre turbo it is!

Is it necessary to remove the turbo to do the drilling or, with the use of a shop vac and some grease, can I drill and tap with the turbo in place? I've heard you can do either, but is there any drawbacks I should be aware of?

 

Look at all these old beaten subjects that get brought up when the search function is down

 

Use the search box down at the bottom of every page, it always works. It will do a google search for the entire web or just this site. Actually works better than the this site's search even when it's working right.

Pre turbo only. After seeing two turbos creamed by metal shavings the only way I'll drill and tap is by removing the turbo. You don't really need to totally remove the turbo, just remove the four bolts holding it to the manifold, you can then pull it away enough to slip a piece of cardboard in-between. After drilling and tapping leave the cardboard on the turbo side and move the turbo a little further to the side and prop an opening, I use a screwdriver handle. Start the engine and blow it out for few seconds.
Besides being 100% certain that the shavings are all out this method is faster and easier than fooling around with greased tools and magnets.

 

I was originally going to use the method infidel described, but my stubborness got the better of me, so I left the turbo in place. I greased a couple bits to step out the hole slow, greased the tap and cut the threads slowly...cleaning the tap and checking thread depth a couple times. From start to finish installing the probe was less than 30 minutes. Cleanup of the manifold was a magnet & shop vac over the hole. Almost three months & 6k miles....no problems.
Pics are in my gallery of the common probe placement.

 

Thanks guys!

I do try to use the search function, but, most often than not, the administrator has it turned off! That forces me to use another diesel site for research. When I don’t find it there, unfortunately, I have to post the question. Maybe questions as common as these should be placed in a FAQ database? Just a suggestion.

Looks like I’ll take the turbo off!

 

That is the point. The seach function at the BOTTOM of the page is available even when the search button at the TOP of the page is not.

BTW, if you want to help with not having the site's search function temporarilly turned off, look at the thread about the new server fund and make a donation.

 

What I haven't seen posted is any estimates on the life expectancy of a probe pre-turbo. Does anyone check theirs periodically for deterioration or would this show up with erratic temperature readings?

Paul

 

Sorry, I've never scrolled down that far to see the search field ... thanks for the info!

 

No reason to be sorry. I just found out about it myself.