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Turtle_n_Peeps's avatar
Turtle_n_Peeps
Explorer
Jul 29, 2021

Check you cooling stack!

So I felt my 2006 LBZ was getting a little more warm then it should while towing my trailer. Nothing big. It would get up to 225 in 90 degree weather and the fan would come on and take the temp right down again to 205 or so until the next hill.

So I told my mechanic to take the cooling stack apart and give it a gander. Now mind you, this is a 2 wheel drive truck that maybe has been on a dirt road twice in it's 130,000 mile life.

I went to pick it up today and ask him what he found. He said "I could not believe it." There was tons of dirt and dragon flies and even a bag!!:E But he said most of the trash was sand! Sand! I said what? This truck has never been around sand in it's life?? He said I don't know how it got there but there was tons and tons of sand stuck and packed in the fins. He said it took many, many wash and flush jobs to wash the sand out of the tube fins. He said it's all clean now and it will for sure run cooler.

Bottom line. Check your cooling stack! You might be shocked at what you find. Even if it's a road queen like my truck is.
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10 Replies

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  • BobsYourUncle's avatar
    BobsYourUncle
    Nomad
    Jul 30, 2021
    Bigfoot affair wrote:
    BobsYourUncle wrote:
    I have the same LBZ and have overheating problems too.

    I suspected a plugged rad, so I had it removed and at that time had the crud blown / hosed out of the rest of the stuff in front of the rad. A multitude of bugs and other debris came out.

    I didn't have the bucks for a new rad, so I put in a known good used one for now.

    Everything is clean in there but my LBZ still gets dangerously hot hauling my TT up a long grade.

    My next fix is a brand new rad to see if that helps. Can't believe the money they charge for stuff like this.


    Just a thought, have you replaced the thermostats? One or both may be failing.

    Yes, and the water pump too.
  • Bigfoot_affair's avatar
    Bigfoot_affair
    Nomad II
    Jul 30, 2021
    BobsYourUncle wrote:
    I have the same LBZ and have overheating problems too.

    I suspected a plugged rad, so I had it removed and at that time had the crud blown / hosed out of the rest of the stuff in front of the rad. A multitude of bugs and other debris came out.

    I didn't have the bucks for a new rad, so I put in a known good used one for now.

    Everything is clean in there but my LBZ still gets dangerously hot hauling my TT up a long grade.

    My next fix is a brand new rad to see if that helps. Can't believe the money they charge for stuff like this.


    Just a thought, have you replaced the thermostats? One or both may be failing.
  • Turtle_n_Peeps's avatar
    Turtle_n_Peeps
    Explorer
    Jul 29, 2021
    BobsYourUncle wrote:
    I have the same LBZ and have overheating problems too.

    I suspected a plugged rad, so I had it removed and at that time had the crud blown / hosed out of the rest of the stuff in front of the rad. A multitude of bugs and other debris came out.

    I didn't have the bucks for a new rad, so I put in a known good used one for now.

    Everything is clean in there but my LBZ still gets dangerously hot hauling my TT up a long grade.

    My next fix is a brand new rad to see if that helps. Can't believe the money they charge for stuff like this.


    That's why it's important to check the cooling stack. IOW's the radiator is the last in the stack. It may be spotless but if the intercooler is plugged up with sand (like mine was) the radiator can't get cool air to it to do its job.

    The whole cooling stack needs to be inspected, not just the radiator. And I do mean inspected it. A lot of people just glance at it and say, ya, looks good. You really should shine a light through the front side row after row to give it a good inspection.
  • BobsYourUncle's avatar
    BobsYourUncle
    Nomad
    Jul 29, 2021
    I have the same LBZ and have overheating problems too.

    I suspected a plugged rad, so I had it removed and at that time had the crud blown / hosed out of the rest of the stuff in front of the rad. A multitude of bugs and other debris came out.

    I didn't have the bucks for a new rad, so I put in a known good used one for now.

    Everything is clean in there but my LBZ still gets dangerously hot hauling my TT up a long grade.

    My next fix is a brand new rad to see if that helps. Can't believe the money they charge for stuff like this.
  • JRscooby's avatar
    JRscooby
    Explorer II
    Jul 29, 2021
    ferndaleflyer wrote:
    I assume you are talking about the radiator?


    Radiator, yes but it is part of a stack. Most vehicles will have a AC condenser in the same air flow. Others will add oil and power steering coolers. Few have air trans coolers. Diesel likely adds a intercooler.
    The more stuff in the stack, the harder it is to clean, and the more important it is.
  • mleekamp's avatar
    mleekamp
    Explorer
    Jul 29, 2021
    Nice tip. We have only owned our Class C for 3 years and I've not done this...but I have done this to our cars. And the C spent time this year on dirt/gravel roads down in Texas.

    Will be checking this out !!!!!!!!
  • JRscooby's avatar
    JRscooby
    Explorer II
    Jul 29, 2021
    I don't know if it really helps, but after I air up my tires for a trip I replace the air chuck with a blow nozzle and MT the compressor tank around the fan to blow out what I can.
  • azdryheat's avatar
    azdryheat
    Explorer
    Jul 29, 2021
    Several time a year I get the pressure washer out and clean the radiator fins.

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