first gen cooling questions

[djr99]

So, being a relatively new turbo diesel owner, I was wondering about a 'normal' engine temp gauge reading for moderate to heavy hot summer driving in the BC mountains... . my gauge has climbed as high as halfway up(middle of the gauge, or straight down position). This happens mostly while climbing in the 1600 rpm range, and keeping it in the 2000rpm range will bring the gauge down... . The gauge will also 'bump' up at idle. The rad itself looks good, and the stat and fan have been replaced recently, as the head gasket. The engine has shown no sign of boiling over, but has gotten hot enough to peel the paint on the injector lines, etc. The engine could be running a little rich, as stepping on the pedal below peak will result in a big cloud of black. The turbo has been downsized with a 4" exh. , and I beleive the plunger lift is 1mm above spec.

Comments or suggestions?

 

[JLEONARD]

Don,

You need to fill in your signature or tell us what year truck you have.

If you;'re non IC then ou have a top flow radiator... if IC then it's a cross flow.

The latter is the more efficient of the two.

Turbo was "downsized"? Better explain that to us. That's not a normal mod.

Jay

 

[dpuckett]

Your temp gauge readings are right on par- the FSM (Factory Service Manual) shows the middle to the line right of middle as normal operating range.



1600 is a little low to be working hard- get it up over 2000, and you can stay cool all day long. These particular diesels can run all day long against the governor and not hurt anything except your MPGs. Low RPM/ high torque is mainly for flatland economy and getting the load moving. Not to say you CANT pull at 1600-1800RPM, but the turbo wont move enough air to work efficiently, building up more heat than necessary. Heck, some of the old farm trucks I've driven (N-14, BCII & BCIII) can turn 2200rpm and be fine.



4" exhasut is VERY good- get the exhaust gasses out, minimal back pressure allows turbo to operate at peak efficiency.



There is really no such thing as "rich" in the diesel world. The diesel has an infinitely variable air/fuel ratio, unlike the 14. x to 1 of a gasser. The turbo is exhaus tdriven, so when load is increased, air flow is increased as well.



If you have a factory tach, you are definitely intercooled. If it is aftermarket, hard to say. ALso, I tell newcomers that if it looks at first glance like you have 2 sets of radiator hoses, then you are intercooled.



Daniel

 

[djr99]

The engine is a 91. 5 intercooled 5 spd with a 16cm2 turbo housing installed by BD. I'm starting to think that it might just be the gauge from reading the posts... .