I installed my gauges about 6 weeks ago. I used to let the truck idle for about 4 or 5 minutes after towing my bobcat, now I just watch the pyro gauge and when it gets below 350 I shut it down. Usually only takes about 30 seconds or a minute. Worried something isn't right, I just pulled the inlet hose off my turbo and found some black light weight oil laying in the bottom of the turbo inlet. Do you think I'm not letting the turbo cool down enough, and I'm burning something up? I might start letting it cool down longer despite the gauge readings. What do you all think?

 

Are you talking a dusting -no runing , wet spots , maybe just enough to collect dust -normal , how many miles on it , what oil are you using , and how often are you changing oil and what filter???

 

I'm a dummy. It's been suggested that it is oil from my air filter, which I'm sure it is. Just wanted to double check. Don't know a lot about the turbo. It definitely is not engine oil. Thanks!

 

sounds like everything is good,i let mine cool down to 300 before shut down.

 

The turbo housing will hold heat in its bearings longer and thats why you need to let it cool.
The pyro is only telling you the egt's are cool, not that the bearings are cool.

And its the bearing temp and the oil running to them that counts.

The turbo housing represents a pretty good heat sink, so it holds a lot of it longer. The bearings are in the thick part of this sink, basically away from the instant cooling of the lower egt's. The oil that feeds and carries away their heat needs to be moving through a cool enough passage so as not to coke up as happens from a premature shut down.
Shut it down early and build up the coke. Little by little.



Jimmy

 

Which is precisely why the temperature probe should be installed after the turbo, at least when it comes to monitoring cool down.

 

Timberman is your pyro gauge pre or post turbo?

Whether it's pre or post turbo isn't important. One needs to know the temps where damage occurs (shutdown, hard accelleration). Or should I say where damage DOESN'T occur.

 

It's pre turbo. Guess I'll let her idle for a few minutes anyway. Hope I haven't hurt my turbo.

 

As a way to balance the conversation here are two possible ways to my house- one is a gentle downhill run of 1.5 miles to my door. With it being in town that means my truck is idling all the way to keep within the speed limit, so that counts as turbo cool down time. The other way in is uphill and then I have to cool it as it sits.

Some job sites are like that too. I know my turbo is working going in to some of them, sometimes working hard. Those times it gets the Full Monty cool down. Other sites its an easy run, lots of coasting or easy going - then the cool down is much shorter.
I don't get too uptight about it. Just use my sense of how much work the turbo just did.

The turbo damage is from restricting the oil supply to the bearings by way of early shut down creating a glaze that over time builds up, thus starving them.

So I don't think you have hurt anything yet.

 

It should be before the turbo... Post turbo does you no good IMO.

Eric

 

I have noticed that the pyro drops pretty fast if you let it coast for a while, that's what I've been doing when I can. I think I'll let it idle a little longer, but it definitely helps to let it roll for a few hundred yards or so.

 

I have a mechanical gauge and I've noticed after pulling if I shut it off at 300 and watch the gauge it will climb to over 450 but if I let it idle for a couple minutes after it hits 300 the temp only rises alittle over 350.

 

If I were you, do your normal routine when you go home from work, but try this, when you get home, just sit in your truck for maybe 5 minutes with it ideling and watch that guage like a hawk, I let my truck idle a standard 3 minutes regardless (plus I dont have a EGT guage yet), and this is why:
A friend of mine put on a banks kit on his 7.3 pre-stroke (no turbo) and no matter what kind of butt whippin we just handed it, or granny driving we just did, we'd set there and watch the EGT gauge drop and drop untill it bottomed out at like 250 degrees and thats where it would stay typicaly after 3 minutes everytime. For me, I dont care if it has to idle 5 minutes to reach its bottoming out temp. The cooler the better! Just think how hot that oil is getting too, circulating through that 300+ degree turbo!
just my $.02