Anyone know or have the same problem as my: Every time I stop my after drive , I can see the coolant in expansion tank is boiling ! I checked the level ; even it below the mark or same level as the mark . It still boiling after the car park ! The coolant boiling and sometime even coming off from the expansion tank ! Anyone know why it happen like that ? Quang
Coolant boiling after car stop
Nov 02, 2005
15 Replies
It helps to identify the vehicle, but a bad thermal radiator fan clutch is a likely culprit. On some types of vehicle, it would be an electric radiator fan that is the problem.
Earle
Or a bad radiator cap. The boiling is because the superheated coolant is flowing from the radiator to the expansion tank
I am for the clutch, because he said "every time I stop". This would of course be a good time to check out all the cooling system components.
Earle
Possibilty of too much water in the mix. Get an antifreeze tester at the local autoparts store, and check your mixture. Also, how old is the coolant?
Eric
Thanks for the tips. What is the thermal radiator fan clutch ? Where is it location and what it does ? It is 1994 jeep grand cherokee !
Radiator cap have been changed new . The old one, for some reason it got a litle cut on it so I got new one . Thanks!
It is bolted to the engine-driven fan, behind the radiator. Besides causing problems like this, its main function is to delay fan operation until the engine reaches operating temperature. Some (maybe a lot of) manual dexterity is required to replace it. If you have an additional, electric, radiator fan, the control circuitry for that may have problems too.
Earle
Radiator cap have been changed new . The old one, for some reason it got a litle cut on it so I got new one . Thanks!
Do you still have the boil-over problem now that the radiator cap has been replaced?
Does it have the V8 or the inline 6? My 93 has the I6 and it only has the engine driven fan installed (the XJ had the two fans, engine and electric). I would be looking at the mix ratio of coolant and water. What does the temp gauge on the dash say?
Snow...
It is behind the mechanical fan. To test it, heat up the engine fully and have someone shut it off while you watch the fan. If the fan keeps on spinning, the clutch is dead. A good fan clutch will stop a hot fan almost instantly.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail >New radiator cap . coolant about 2years old . V6 engine driven fan ! Thanks!
Have you checked your thermostat?
KJK
If you just installed a new cap the problem may be solved then.
On another note if your coolant is two years old and is the old style 'American Green" it might be time to flush and refill. Be sure to use distilled water when you refill with coolant and stay away from DexCool and its clones.
Just a side note.. you have and inline 6 not a v6.. :) Snow...
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