RTH: Troubleshooting Overheating Issue

[elripster]

RTH: Troubleshooting Overheating Issue - Saga continues..

My family and I are in the process of moving out west and I'm following them in the 60. We are currently just outside of TX on I40. The 60 is an 85, runs well, is loaded down pretty bad, but otherwise fine. I'm having overheating issues at freeway speeds. In fact, as the ambient temp climbed through OK today I went from AC, to no AC, to having to have the heat on to keep the gauge out of the red.

Now I have replaced the thermostat, water pump, rad, and rad hoses last fall. I flushed the system before we left 2 days ago and filled it with dexcool.

The waterpump is a NAPA brand, the rad is an Autozone brand.

I'm stumped at what's wrong with this truck? Are the loads and headwinds just too much? Seems like it should be fine, I'm cruising 60-65 MPH inidicated (have 31's).

I have lots of tools with me but I really don't have the time or space to do the replace it until it's fixed routing. I already fired all the guns there doing the cooling system last fall. I need to know how to determine if I even have an issue or just crazy gauge syndrome. If I have an issue, how can I figure out what it is and fix it right?

I don't have an IR thermometer but will gladly get one if it will help.

Maybe I should just scope an cruiser mechanic near I40 between Shamrock and Gallup NM? I fear I won't make it over the mountians into Albequerque and then Flagstaff (heading to San Diego).

Frank

 

[048642]

Is your radiator cap pressure correct?

 

[elripster]

That is a very good question. I will attempt to ascertain.

Frank

 

[elripster]

There is nothing pressure related stamped on the rad cap, just the usual warnings. I'll looking into getting another one just for piece of mind.

Frank

 

[Spike Strip]

An IR thermometer will help tell you if you're actually overheating or just experiencing the notoriously inaccurate Land Cruiser temp gauge.

Harbor Freight stores all over TX ...

 

[Kurtis]

I hate to say it but more likely than not when its overheating in those conditions and you have replaced the said items and double check that it really is overheating alot of times it is a head gasket starting to go. Leak down test would be helpful at that point.

I would take a small sample of your oil and look to see if its watery and check if there is oil floating around the overflow and inside the radiator.

Is your waterpump belt tight enough? Fan and clutch working ok?

 

[elripster]

Looks like I could hit up the Harborfrieght in Amarillo tomorrow AM. One thing which I'm not sure about is how to measure the temp when it's actually reading hot. It's fine at low speeds/loads. It's only on the freeway that it gets hot. I could probably just pull over on the shoulder and check it when the temp climbs.

I should see if they have a thermocouple reader.

Frank

 

[Michael Hanson]

Check to see the rad. is totally full. Park uphill tonight and then pull the rad. cap in the morning, is the rad. full? Any water leaks, look good, rear heater leaking,oil cooler leaking. Mike

 

[elripster]

I will check that. I do know I burped it really well and it's echanging coolant with the resevior returing to the same level.

Frank

 

[elripster]

I figure I will check the rad in the morning. I'm going to hit up the Harborfrieght for an IR thermo too. Worst case I saw in the Cruiser Mechanics section UnderCar in Edgewood NM where I will see if I can get further assistance.

Frank

 

[FJ60Seth]

I didn't see any mention of fan clutch replaced or checked.

 

[klinetime574]

I didn't see any mention of fan clutch replaced or checked.

x2

If you don't hear that fan roar when the clutch engages you found your problem.

Also what kind of coolant mix are you running? I run a strong water mix. Like 25% coolant 75% water. Water cools better than anti-freeze.

I had a bad fan clutch and I would overheat at highway speeds. Hope thats your issue!

 

[elripster]

I was thinking about the fan clutch. When I left I could clearly hear it cycling but now I'm not sure. Either it's on all the time and I'm used to it or it is not on at all. I do know it is on when I first start the truck and then turns off like normal. That's another thing I will check when I hit the road this morning.

Frank

 

[elripster]

Now the fun part, if it is the fan clutch, where to get one...

 

[elripster]

What are thoughts on flex fans if even only a temporary fix? It will be hard to find a clutch fan on su nay.

 

[Spike Strip]

The fan clutch will lock up when the ambient temp in engine compartment is around 190* to draw air past the radiator at slower speeds. At highway speeds, it isn't doing much. But as a temp fix, I've seen people put a bolt thru the fan to "lock" it so it does not slip. Your gas mileage will go down somewhat, until you replace that.

If it is actually getting hot, I'd look at the stuff mentioned above plus Radiator Cap. You can get a pressure tester at an Autozone, free rental ...

 

[elripster]

Its the belt. This will be the third one.

 

[Spike Strip]

Water pump belt was slipping ?

 

[Clonestocker]

I'm having the same problem with in town driving. It's been about 107-110* in Tucson. My new aftermarket waterpump has a different impeller and I don't think it gets the job done. Another member linked my previous thread to a waterpump thread. Good read. Good Luck on the rest of your trip.


matt

 

[jfnall]

i have been using a fan clutch from O"reilly. no problems with it. lots cheaper than OEM and readily available. but i know OEM is better.

also run a low temp thermostat from MAF. i think it is a 160 degree.

on the dexcool - i think that is a bad idea. GM got away from it i think. it will cause stuff inside to go bad. change that back to the green stuff when you get a chance.

have you thought about the heater core maybe not flowing good?

try this. worked for me so far. a temporary fix, but its getting me by for now, and might help narrow down the problem. Mine heater core blew while on a trip. I have the rear heater removed so things are alot simpler on my truck... but - where the heater hose goes into the firewall, the hose below the heater control valve, take a straight jaw visegrip and clamp the rubber line so that water can't go into the heater core. leave the lever in the cab on vent only. You will still have AC, but the flow is cut from the heater core. I did this out of necessity when on a trip so I could get home without losing fluid. my temp gauge (a mechanical gauge with actual numbers) reads 5-12 degrees cooler than it did before.

worth a try maybe.