Lost belt tensioner on I-75; now temp fluctuates wildly!

[jsimpson]

I've got no bubbles in the overflow tank, so i don't think I cracked a head, but I'm slowly losing coolant (can find no leaks). No boilover; no steam. Does the 5. 9 require air bleeding after a total coolant loos, like some jap engines do?

 

[LSMITH]

When I drained mine to change the coolant I used low pressure air to force out all that I could and did not need to bleed it at all to get it refilled. I did refill the block with coolant through the thermostat housing though and continued until the radiator was full to the same level as the Tstat housing. I got just shy of 5 gallons out, so I was very close to complete evacuation. It did need about a quart and a half to bring the overflow bottle up to the full a day or two later, I am guessing that the coolant went to the heater core. Hope this helps.

 

[mwilson]

Probably nothing, but just a thought--- Did they get the belt routed on the pulleys correctly? I have seen that happen before.

 

[Rob Thomas]

Hey,

when you get the coolant thing fixed,you can get a heavy duty pully at, www.psdieselproducts.com



Rob

 

[Un-Hemi]

As mwilson said, I would check VERY carefully that the belt is on correctly. Cost me a radiator and heater core (and the HOURS of installation ) on a 3. 3 Dodge Dynasty (die nasty) just to find that the belt was driving the water pump backwards.

 

[jsimpson]

I did the repair; couldn't wait on the dealer. I installed the belt; it's on right. But I DIDN'T bleed the cooling system. I'm pretty much without tools. I'll try to do that when i get down to Florence! I already spent $200 on a used idler; I can't afford to buy a stronger one now! The idler was strong enough; the bolt is what sheared!!!

 

[Rob Thomas]

jsimpson,



You mean $20, I hope you didn't spend $200!



Rob

 

[Cooker]

Practical solutions is just an idler pully. If you needed the entire tensioner this wouldn't have helped you. $200 is a bit steep for a used unit. I thought they were only (only ) around $150 new.



You do not need to bleed the air out of the coolant system after a coolant flush, but you may find the coolant a little lower after a few miles of driving than when you originally filled it.



-Ryan

 

[Rob Thomas]

ooooops,



My fault , I didn't know he needed the entire thing.



Rob

 

[jsimpson]

I've added quite few times. It stays full now, but the temp guage still fluctuates wildly between 140 and 180.

 

[Jetson]

It might be a bad electrical connection?

 

[Extreme1]

The fluctuation is (was) normal on mine until I replaced the t-stat. It was normal on all the other earlt 2nd gen trucks too.



It will heat up to 180 then the stat opens and it drops to 140, builds heat, stat opens (you may see a pattern forming here), etc



The system is self bleeding also. There is a "jiggle valve" located above the t-stat in the head. It is what the small bypass hose attaches to that goes from the head to the t-stat cap. This is supposed to remove the air from the engine and send it to the radiator where it will go out through the overflow bottle after a few heat cycles.



Did you replace the t-stat? If so, where did you get the replacement?

 

[jsimpson]

Didn't replace the T-stat, and the gusage didn't fluctuate before the brakdown. Is the jiggle valve manually operated and external?

 

[jsimpson]

jiggle valve???

jiggle valve?

 

[Cooker]

It is not manually operated, but it is external. It is near the thermostat housing. It is connected to a small line (1/8"?) that runs from one side of the stat to the other.



Does this help?

Ryan