Question about 2004 Hyundai Sonata

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I've got a 2004 sonata v.6 I'm having over heating issue with it I replaced thermostat and at one time put some barrs stop leak in radiator. How do I check radiator to see if I plugged it up with it?

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Unlikely a Barrs leak will clog a radiator.

Almost no one flow tests a radiator these days, which is the only reliable method of testing. The equipment needed for this is fairly basic but takes up a lot of space. Radiators are generally so cheap and plentiful it isn't cost effective any more to take them apart and fit new tubes or rod them out and then reassemble them.

If I am in doubt about a radiator I can usually peer through one of the inlets and see the top of one or two tubes. If the tubes near the top hose inlet that can be seen are clear it is very likely the others will be clear too.
I am not a supporter of patent radiator flushes and if one is needed a cheap caustic soda solution is as good as anything (off the car). Mostly I flush using water with compressed air and find it fairly successful.

Bedford and Vauxhall, incidentally, are both GM owned and both recommended placing GM Stopleak pellets (very similar to Barrs pellets) whenever building an engine or carrying out repairs that required the cooling system to be drained. GM would hardly do that if it would clog the radiator.

With overheating or problems seeming to be overheating it is important to determine which. A faulty cylinder head gasket blowing excessive combustion gas into the cooling system will displace coolant and probably disrupt the thermostat operation and lead to overheating but the root problem is in no way a cooling system fault as a faulty cooling fan or switch or a blocked radiator or blocked degassing vent is.

I suggest you determine what sort of fault you have as a first step. I could write reams of stuff about this but...

Posted on Apr 19, 2015

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  • Hyundai Master
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Very doubtful that would effect radiator but a blown head gasket will cause overheating as well as a bad water pump are you blowing water out the overflow or seeing steam out the exhaust often. smell exhaust while running if it smells sweet the head is probably the problem

Posted on Apr 19, 2015

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  • Kory Harris
    Kory Harris Apr 19, 2015

    No sir no steam and oil not milky and no oil in my water. Exhaust smells fine. It's like it is overheating way before the thermostat should even have time to open and I've had to wire cooking fans directly to the battery for them to come on so I manually am turning the fans on and off. Could that also be a problem as well?

  • ray gallant Apr 19, 2015

    YES it diffenately could be

  • Kory Harris
    Kory Harris Apr 19, 2015

    Ok on the wiring harness I've got 4 wires and when I unplug the fan only have one wire that's hot. I plug it in all for have power is that normal or have I wiring problems as well?



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SOURCE: 1966 Ford Mustang overheating

try to run the water pump without hoses, and add water in the 'in' side, if is powers out the other side, then it's fine. how is your water/coolant mix?

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SOURCE: 2004 hyundai sante fe is making coolant boil back

I take it this only happens when the vehicle is stopped & idling? If not, check radiator & hoses for blockage (since you've already replaced the thermostat & top hose) - repair/replace as needed. Next, check the coolant temperature sensor's operation (there are two sensors - one for the temp gauge on the instrument panel, the other is used by the ECM (PCM). If that one is malfunctioning (i.e., telling the computer that the engine coolant temperature is less than it actually is, The ECM (PCM) it won't turn on the cooling fans.
Since you didn't specify which engine you have (i.e., 2.4, 2.6 or 3.5), Photo locations of all three are included here.

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Hope this helps.

Posted on Sep 07, 2009

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SOURCE: 2004 Honda CRV Check Engine light

the check engine lamp is not affected by things like tyres, brakes etc. It shows that the vehicles engine management system had detected a fault with the engine or engine sensors. Check the engine for broken or disconnected wiring (maybe it was disconnected during the replacing of the hoses but not reconnected). If you fail to locate anything, check the manual for the correct fault code retrieval procedure or take the vehicle to a professional. Tyres may affect your ABS system or Airbag systems but they usually have their own warning lamp and are unrelated to the check engine lamp..

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SOURCE: 1995 BMW 525I over heating issue. I repaired head

Hi, Sounds like you have tried about everything. Ok the aux. coolant switch is for the electric pump for the heater core will not cause an over heating condition just a longer warm up of the heater core. Has the cooling system been bleed properly if there is a trapped air pocket it will not let coolant circulate. Was the new thermostat installed correctly? They have a vent that needs to be towards the top or they trap air on the back side and cant take an accurate reading to open and close. Other areas to look at would be proper operation of the fan clutch, if they fail they can cause the fan to not lock up properly and supply enough air movement through the radiator. The aux. electric fans and their temp switches do you hear them coming on are they coming on at the right temp.

Posted on Aug 26, 2010

  • 4803 Answers

SOURCE: 2004 Ford Explorer Sports Trac

Did the engine overheat before the water pump was replaced? If so, you may have a warped cylinder head and/or blown head gasket.

Was the radiator full of rusty-colored liquid before you flushed it? If so, your radiator is probably restricted with rust deposits in the cooling tubes. Flushing WILL NOT get this stuff out. The radiator MUST be replaced if this is the case. Your heater core is probably not in real good shape either, so you should be expecting some heating problems this winter.

If the above is not the correct answer, then you should check to make sure the temperature gauge is not "LYING" to you. This could be caused by a defective gauge, a bad temperature sending unit, or faulty wiring.

The way to check this is with a scan tool that can read engine data and an infrared thermometer. While reading the coolant temperature data from the computer, check the cylinder head temperature with the infrared thermomometer. The readings you get should be within 5 degrees (F) of each other. If the computer data does not match the thermometer within the 5 degrees, then the sending unit for the computer should be replaced.

Then look at the gauge to see if the gauge reading is appropriate to the temperature readings that you took. Normal operating temperature is between 190 and 230 degrees. This should place the gauge at slightly to the right of center to about 5/8ths of the way to HOT. If the readings you took are OK and the gauge is reading higher than this, then you should try replacing the temperature sending unit for the gauge and see if that fixes the problem.

Please note that there are TWO temp sending units: One for the gauge and one for the computer.

Posted on Aug 30, 2011

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Boy you have done everything I'd suggest to try,the only thing I can think of when you installed the thermostat did the housing holding it craft maybe a hairline just big enough to cause pressure problems, only other thing else is maybe you have a clog in a hose or in the radiator sorry that's all I got,other then the thermostat they sold you was junk one thing I'd try returning it and get a new one you never said it it was used or new

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