2000 5.9 Over heating

Jaeger62 · Aug 3, 2014

I recently bought a 2000 1500 Sport 4x4 with a 5.9 The truck has 185,000mi on it and the previous owner had put an electrical after market radiator fan system.

We removed that system and installed a new fan, fan clutch, and shroud to get it back to OEM. It all ran fine until the other day when I drove it about 50miles to my destination and when I got there, the engine had just started to get very hot so I shut it off. The radiator fluid was boiling hot so I let it sit. When I went to leave, the engine was cooled again so we drove the same 50 miles or so home with no problems. Ran a couple errands and then drove a few miles home and when I got home, the engine temp was once again starting to climb.

Any suggestions on what could be causing the engine to run fine for a good distance, get hot, cool off, then drive fine again? I'm wondering if it's the thermostat, but would that cause it to over heat faster than 50 miles down the road?

Thanks

jbmobbs · Aug 3, 2014

Jaeger62 said:
I recently bought a 2000 1500 Sport 4x4 with a 5.9 The truck has 185,000mi on it and the previous owner had put an electrical after market radiator fan system.

We removed that system and installed a new fan, fan clutch, and shroud to get it back to OEM. It all ran fine until the other day when I drove it about 50miles to my destination and when I got there, the engine had just started to get very hot so I shut it off. The radiator fluid was boiling hot so I let it sit. When I went to leave, the engine was cooled again so we drove the same 50 miles or so home with no problems. Ran a couple errands and then drove a few miles home and when I got home, the engine temp was once again starting to climb.

Any suggestions on what could be causing the engine to run fine for a good distance, get hot, cool off, then drive fine again? I'm wondering if it's the thermostat, but would that cause it to over heat faster than 50 miles down the road?

Thanks

id replace the thermostat and do a block/radiator flush.

Brakelate · Aug 3, 2014

!)

I'm having the exact same problem on a little Suzuki Samurai with a Tracker 1600cc "big block" swap I did.

Could be a sticky Thermostat, quick, cheap and easy to do.

Could be a Water Pump. See if it is circulating fluid in the Radiator (*Remove cap BEFORE it gets warm!), and see if things start moving around once the Thermostat opens and you rev it a couple times.

Unfortunately, it could also be a cracked head or bad head gasket, especially at those miles. Those seem to be more 'hit and miss' in terms of when and how long it may go for in between overheating episodes.

This is the step where I am on my little project, but see no other signs of it being a head gasket issue, like water in the exhaust, condensation in the valve cover cap or any steam or moisture out the tail pipe. The plugs look fine.

So, good luck and I hope it is one of the quick, cheap and easy fixes before it comes to pulling the heads off. For both of us!

Jaeger62 · Aug 3, 2014

Thanks for the tips. A little more backgroud.... when I got the truck it was running REALLY rough. It was throwing codes for the crankshaft and throttle position sensors. We swapped them out and it still ran rough and it threw the code for the random/multiple cyclinder misfires. Checked the plugs and they looked just fine and when we went to mess with the plug wires on the distributor cap, a couple of them snapped down more, as if they weren't popped on right. Ran the truck right after that, and it ran MUCH better, no misfiring at all like it had been.

It still doesn't mis-fire but hesitates quite a bit and recently through the codes for 2 cyclinders mis-firing (can't remember which) and a "too lean" code.

And then this last trip where it started over-heating .... .when it had never done that after putting on the fan, fan clutch, shroud.

Plugs look good, oil looked good, and I haven't noticed water out of the exhaust.

2000 5.9 Over heating

Jaeger62

Junior Member

jbmobbs

Senior Member

Brakelate

Senior Member

Jaeger62

Junior Member

Similar threads

Latest posts

Members online

Forum statistics

Share this page