99 Ford Ranger 3.0L

Tiny
RLEMARR
  • MEMBER
  • 1999 FORD RANGER
  • 6 CYL
  • 4WD
  • AUTOMATIC
  • 154,000 MILES
Cabin blows cold air but thermostat reads hot. A lot of hissing by the radiator. I've replaced the rad cap and no change.
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Tuesday, December 28th, 2010 AT 10:24 PM

10 Replies

Tiny
JACOBANDNICKOLAS
  • EXPERT
When you say it reads hot, do you mean overheat hot? Also, is the hissing coming from the radiator? Is the coolant full and not overflowing?

One last question. With the engine at operating temp, running, and the heater on high, do both heater core hoses get hot?

Let me know.

Joe
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Tuesday, December 28th, 2010 AT 11:37 PM
Tiny
RLEMARR
  • MEMBER
Thermostat gauge reads normal to high. The hissing does sound like it's coming from the radiator. The radiator itself doesn't seem to be getting very hot though.
I think the heater core hoses are the two lines running into the back of the dashboard? If so, they are not hot.
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Tuesday, December 28th, 2010 AT 11:56 PM
Tiny
JACOBANDNICKOLAS
  • EXPERT
You are correct. The heater core hoses run to the firewall (rear of dashboard engine side). If neither is hot, there is no coolant flowing. Either you have a plugged heater core, air pocket, low on coolant, or you could have bad head gasket allowing compressed air to get into the system and blocking it.

I would start simple. First, with the engine cold, remove the radiator cap and make sure coolant is full. If it is, replace the cap and loosten the heater core return hose and start the vehicle. See if air comes out. If it does, make sure the coolant overflow stays full. If that still doesn't help, replace the thermostat and flush the radiator and heater core. It that still doesn't help, you need to check engine compression to make sure there isn't a bad head gasket.

This sounds like a lot of work, but really it isn't. If you want to do it, let me know and I will walk you through it. It isn't as bad as it sounds.

Let me know. I have to admit, the hissing sound you are hearing has me a bit concerned. Are you sure none of the hoses are collapsing causing a restriction and a hissing sound?
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Wednesday, December 29th, 2010 AT 5:59 PM
Tiny
RLEMARR
  • MEMBER
I found where the hissing sound is coming from. There is a pin hole crack on a metal connector coming off the thermostat. It has an orange wire connector at the top of it and a hose attached to the bottom. It's spewing out coolant from just above where the hose connects to the bottom of it. I attached a picture. I couldn't get a good pic of the hole at the bottom so I took a pic of the top. Is this something I can buy?
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Wednesday, December 29th, 2010 AT 7:00 PM
Tiny
RLEMARR
  • MEMBER
Do you think I can use metal epoxy putty to fill this instead of replacing it?
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Wednesday, December 29th, 2010 AT 8:55 PM
Tiny
JACOBANDNICKOLAS
  • EXPERT
That is the temp sending unit. Is the crack in the electrical component or the steel item the sensor screws into? As far as the part, you can get them all. However, the if it is the steel component that the sensor screws into, it will be a dealer part or junk yard part. The sensor, which can go bad a leak, can be purchased at any parts store.

Based on the rust color on the hoses, it has been leaking for some time. Also, I would recommend flushing the entire cooling system. It appears as though there is a lot of rust and dirt in the system.

Let me know if you have other questions. As far as the epoxy, IF it works, it will only be a temporary fix.

Joe
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Wednesday, December 29th, 2010 AT 10:14 PM
Tiny
RLEMARR
  • MEMBER
Yeah it is on the steel part that the sending unit screws into. I have stuff to flush and fill the system as soon as I can get it to stop leaking. Hopefully when I get the crack fixed and system flushed everything will work. Thanks a lot.
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Wednesday, December 29th, 2010 AT 10:28 PM
Tiny
JACOBANDNICKOLAS
  • EXPERT
Glad to help. Let me know how things work out for you, and if I don't hear from you, have a great New Year!

Joe
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Wednesday, December 29th, 2010 AT 10:30 PM
Tiny
RLEMARR
  • MEMBER
Well, I got the hole filled with the steel reinforced epoxy putty and it held. Went to try and flush the system and found a pretty big clog in the radiator. Got most of that taken care of and replaced the thermostat. Filled with new coolant. Running real well now. I think I will take her to the shop anyhow within the next couple weeks and get them to flush out the system with high pressure air or something to make sure the radiator doesn't clog again. I got most of the rust and gunk but not all of it.
Thanks again for your help.
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Thursday, December 30th, 2010 AT 10:34 PM
Tiny
JACOBANDNICKOLAS
  • EXPERT
I'm glad you got it going. The epoxy should hold for some time, but I would be concerned if I took a longer trip. Who knows, it may last longer than the original one did. As far as the flush, it wouldn't be a bad idea. Make sure when they do it, they flush the engine block and heater core too. They will need to remove the thermostat to do it, so keep an eye on them so they do it.

Let me know how things work out for you, and I wish you and your family a Happy New Year!

Thanks for using 2carpros. Com, and let us know if you have questions in the future.

Joe
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Friday, December 31st, 2010 AT 4:20 AM

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