Low Airflow Thru Radiator
 

Hello,

I am new to being a Cobra owner and new to the forum. But I thought it would be a good idea to get some expert opinions on this.

My Cobra had a blown header gasket so I took it to a mechanic to get it fixed. While he was revving the engine to test the fixed gasket he overheated the car. I've got a manual switch for engaging the fan and he didn't check for this. It wasn't until he heard popping from the radiator that he realized the temperature problem and cooled it down.

Ever since this incident the gasket is fixed, but the car temperature shoots right up when I try to drive it. I took it back to this same mechanic since the overheating started with his repair job.

After trying the obvious replacement of the thermostat and verifying the accuracy of the temperature sensor with infrared, he came to the following conclusion. He believes that the overheating incident has caused the radiator tubes to expand to the point of blocking all airflow through the radiator. He verified that with a fan right against the radiator he could barely feel the airflow on the engine side.

Does this seem plausible to you guys? This is a 2.5 in Mustang II Griffin radiator. I am finding it hard to believe that a heavy duty radiator like this could be damaged so easily.

yes it can happen. try to look through the radiator and see if the cooling tubes are round instead of flat. i had a radiator with every tube blown out to almost round. when the car over heats and loses coolant the cylinders get hot, then what water is left comes in contact and produces steam which can damage the radiator. if you have no other problems like a blown head gasket you are lucky.

Dump the dope to start
 

mjanczura Dump the dope to start. Lets start with simple things
Radiator cap has a pressure rating, said on top from 12 to 17 psi. At this point to releases pressure to over fill tank or on the ground. Griffen radiators will take 25-32 psi. No way this happened.
Does you car have side pipes and the motor have a little lope at idle? if yes, again another BS story of hearing the radiator pop. You should have blow a radiator hose before a core.
Sounds like you dope blew an head gasket and not wanting to eat the repair point the blame at a failure of a part.
Start with a home test. Check the oil level and color of it. Should be clear and golden color. If at full level Start the motor and let it run at idle. If the motor is overfilled and the oil is cloudy, DON'T run the motor, you could have coolant or water in the motor. This will wipe out the bearings. This means blow gasket. Stop here and have car towed to another garage and have checked. Sue the dope later for screwing up your car, keep all bills. Make sure the level is full, Put a drain pan under the car. If you have a coolant pressure tester this would be big. Let the motor get to operating temp and check for high pressure or bubbles coming into the top of the radiator. GUESSING he blew a head gasket if the car had no problems before the exhaust gasket was replaced. Guessing, you need to replace gaskets and that the damage is little, couple of oil changes "should clean out the rest of the water/coolant" Don't beat on the car. Check your oil pressures, they should be within 5 psi before you had the repair if they are more, than a motor rebuild would be the right way to go. Good luck. Rick Ps You live if CA, find some local cobra guys and see where they go for repairs. Pss you didn't say what kind of motor you are running but my all aluminum motor heats up in about 2 minutes to 198F and then drops about 30 degrees once the thermostat is open and balances out to 180-185f when racing. At the end my temps are about 195-198f. Rick

:rolleyes:

the radiator i blew was a racing radiator, when i talked to whoever made it they explained the reason why the tubes blow out, the steam goes through the system so fast and hits a wall then blows the tubes out. yes it does happen, i had a radiator to prove it, only worth about $18 scrap.

Thank you both for the information. I feel better armed now to have another conversation with the mechanic and figure out what really happened.

What exactly do you mean by "shoots right up"? Like, within a mile or two? Or before you get out of the driveway?

Start the engine and let it idle for just a few minutes. As the temperature rtises, does the upper radiater hose get hot, and then very hard? Does it fill up the overflow bottle?

If those things are happening, it could be a blown head gasket.

Talked to Griffin techs
 

mjanczura M I had a 20 minute talk with Griffin tech on Wed's. This is what he said" A Griffin raditor, street or race will take 35 pounds of pressure "WITHOUT" and damage to core of tanks". If you can blow the core channels apart or balloon them the system. Very old radiator of aluminum becomes weak. Would need 1,000's of heat cycles. The system caped with out a pressure cap and a major engine failures of compression gases get into the coolant system in quick time. Motor would be overheating and you would have all the pre tell signs. Pressure could go to 60-100 psi and this will damage a radiator. This wouldn't be a parts failure.
I agree with Bob C. and think he blew your head gasket or gaskets. A leak down test should tell you what cylinder is blown, compression test too. It is possible that 2 cylinders blew out the seperator gasket between the cylinders and cause this pressure to go into coolant system. Any white smoke coming from exhaust?? White,white?? How about a sweet smell if the car has coolant in the system?? All good signs of a failure, sorry. Good luck. Don't be afraid to take a court action with him for damage to your cars motor. Judges are real understanding about poor repair work. Rick L. ps seeing the money or repair done for free will be another story.%/