Backing what dogger said, yes idling is cooling the turbo. The oil is circulating through the turbos bearing as the turbo housing is cooling off. Prefered shut off temp to reach is around *300 as to not cook the oil in the bearing. And since you dont have a Pyrometer to measure your EGT's then a bit of info is that when running the AC in summer or defrost in winter it makes for slower cool down times and higher idle temps. Trying to cool the turbo while idling on a hot summer day with the AC cranking away will take a long time so make sure the AC is off. I also second what was said earlier, just take into account when you think you will be shuting down and drive a little more mellow so your EGT's are lower to make idle times as short os needed.

 

Do EGTs really = oil temp in the turbo? It makes sense to me that you want oil temp < 300 to keep it from cooking (or coking) but my pre-turbo EGT only gets down to 300 when it's pretty cold outside with the engine idling. Usually it's just above that (about 325) so I've been shutting down when it gets to there. Can anyone with a post-turbo oil temp gauge say whether EGT = oil temp at idle?

 

My pyro is pre-turbo and when I let off the throttle, it will drop immediately to around 200*.

Your temp pre turbo seems off to me.

The oil temp probably is not nearly as high as the exhaust temp; as, the oil is constantly being pumped through.

 

Just for anyone who may be interested. One of the members who is running 2 EGT probes, one pre-turbo and one post turbo states that on the highway unloaded sees 300-400 degrees F difference and loaded sees up to 500 degrees F difference. This may help you decide where to mount your thermocouple.

L8r,...........dogger

 

Wouldnt the oil temp be the same as the current operating temp of the block itsself?

 

EexhaustGasTemperature's dont designate the oil temp because the oil is constantly circulating through the turbo's bearing and also through the oil cooler. But EGT's do regulate the temperature of the turbos housing. I have a picture of a engine that must be on a dyno and the turbo/manifold is glowing bright red. Its a rare example but it proves a point. The cooking or coking of the oil is when you shut down with a hot turbo housing and the oil then is forced to sit in one very hot spot and not carry the heat away.
I highly suggest mounting a pyro thermocoupler pre-turbo because there you get the most accurate EGT readings and that's most important when you dont want to melt down your pistons. As you already read there is quite the variance between pre and post readings. You shouldnt care if your AROUND a certain degree while towing that heavy load, you should know exactly.
As for idle temps, *300-325 after a few minutes of driving and *250-275 after a long time idling (depending on the outside temp) is about normal. Now given this is for a manual tranny and I dont know if there is a difference with an auto. Also to add to that, running the AC/defrost will result in a slower drop of idle EGT's and a higher overall EGT's at idle.

 

If you get digital guages like the X-monitor you can get a timer that will shut the engine down by EGTs instead of time. And if you are interested, I have an X-monitor with the Cool Engine Shutdown for sale again (buyer backed out)...

 

Careful won't cut it...getting that old button off. That glue is TUFF. Just get a
new button and buy the glue at WallyWorld for $2. The new windshields come
with the buttons already mounted, so you might pick one up at a glass dealer
off an old Dodge windshield. That's what I did....unfortunately, the old windshield was MINE. I broke it trying to get to button off.

I've never seen pyro temps of under 300. I shut mine off at 350/400...got 57k
miles so far.

ps: If you do go with the 4 gage overhead mount, fill the fp gage line with
antifreeze BEFORE you install it in the pod, assuming you plan to use an
isolator.

 

I have to admit I chickened out and went with the A pillar and one on the steering column. Don't know how it will look, but the whole windshield deal just didn't seem worth it. Plus, the mount wasn't really meant for a 99. Oh well, at least I will be Gauged, way too long without em. Now I'm wishing I'd waited and got the smarty. The freaking VA is still not here. I ordered all four gauges from dieselmanor, great folks to deal with. All Isspro EV black/black/red pointer. Got the fuel isolator too. Should be here tomorrow. At some point I may try to relocate the gauges, if that's possible, just want to stick em in there for now.

 

I let mine cool back down to idle temp prior to towing(depending on outside temps) but generally 200-250...
Doesnt take but a minute or two either, but the heaviest ive towed is an 18ft car hauler and a 3500~lb car...