Ruined weekend

[Fernando Gonzalez]

(2001 ST 4x2 4.0l V6): Changed a punctured upper radiator hose; apparently it was rubbing against a metal clamp from the AC system. Installed the new one, made sure nothing was rubbing against it, turn the motor on and everything seemed fine until I went for a ride. On the next stop light the temperature started rising and then I turned into a gas station to check it out. The hose I have just installed was now very stiff and the coolant reservoir is now filled with what looks like a cappuccino blend.

I have checked the engine oil but it's fine, no water there. Any ideas on what might had gone bad and why? Thanks.

 

[Tom Schindler]

What does the coolant look like that is in the radiator?



When you say the hose is stiff, is it from pressure or is the hose stiff?





Tom

 

[Fernando Gonzalez]

The coolant in the radiator looks the same brownish color.

The hose was stiff from pressure; it became flexible again after I opened the radiator cap; this after the engine cooled down obviously.

When the hose got punctured, the temperature went up but not onto overheating and the coolant looked fine at that time.

 

[Rodger Tellefson]

Change the thermostat and the water pump (which I am going to do soon). As far as the coolant being a murky color, I will defer to others to answer that for you. While you are at it you might as well change the serpentine belt, idler & tensioner pulleys.

 

[Kevin Palmer]

You may not have had the coolant level topped off. If you filled it while the t-stat was closed, then there were areas that had no or little coolant.



Once the t-stat opened,,,, the coolant went to those areas but you did not have enough to fill those areas as well as cool the engine.



I suggest letting it run for some time with the cap off and seeing if you can get some more coolant into the system.



It would not be a bad idea to replace the t-stat as they seem to fail more often once you have a coolant issue such as the blown hose..

 

[EddieS'04]

Air in the system, not toped off. Also sounds as if it stired up some junk. Time for a flush and refill..

 

[Jimmy Lavoie]

Sounds like a head gasket break.



Same thing happened to me many years ago on a Mazda pickup.

 

[Bill Barber]

As above, head gasket.

 

[Ray McIntireJr]

If it was a head gasket wouldn't the ST be running rough and smoking from the burning coolant?

 

[Tom Schindler]

If it was a head gasket wouldn't the ST be running rough and smoking from the burning coolant?

Actually no. Head gaskets failures can sometime be difficult to diagnose. Sometimes a car can run perfect with a blown head gasket. Other time, the car will not run at all.





Tom

 

[Richard L]

Don't worry about a blown head gasket just yet. There are plenty of things that cause the kind of overheating you are experiencing that are much easier to diagnose and fix.



One of the quickest fixes is to replace the theromostate. It sounds like the thermostat and all the hoses, as well as the coolant are all original, so they are all very old and prone to failure. Replace them all !! Radiator hoses, heater hoses, radiator pressure cap, etc, the coolant and the thermostat. Be sure to purge all the air out of the system by going for a short ride and adding more coolant to the overflow reservoir. After a few test runs replacing the fluikd in the overflow tank your system will have purged the air out of the cooling system. You can easily do all thins in one evening or over a weekend.



step-2. Since the fluid is brownish (custy) you might consider having the radiator professionally flushed and pressure tested for leaks.



Then if you still have overheating problems you need to start looking at doing a compression test and/or having your coolant tested for combustion byproducts which would indicate a blown head gasket. Head gaskets can blow and not show any real simptoms except overheating. They will eventually get worse to include steam coming out the exhaust and the excess pressure pushing coolant out the overflow tanks, etc.



...Rich

 

[Fernando Gonzalez]

Thanks for all your help guys!



I took the ST to an independent shop this morning (a couple of blocks from home); oil in the engine is still OK, no signs of coolant in there or rough idling whatsoever. Did noticed that the gears are not engaging as usual, they stay in neutral for a few seconds and then engage. Does the transmision uses the same cooling system as the engine?



Thanks again!

 

[Tom Schindler]

Does the transmision uses the same cooling system as the engine?

Kinda.



If the radiator split between the water and tranny fluid, the result would be a pepto-bismal mix. Check the tranny fluid. If it is a pink color (I mean bright pink) then it is a possibility the radiator needs replaced. If it looks red, the radiator is fine.





Tom