Radiator blowing

[SmokinDiesel]

Ok my friend has a 84 6.2 liter full size van and it keeps blowing the radiator. He has flushed the system and replaced the thurmostate and doesn't know what is wrong. I have a fealing it might just be the radiator cap, but he says it is a head gasket. I would think if the head gasket was blow it would be leaking out or mix with the oil and neither has happened. He says it blowing because it has too much air pressure in the radiator, but the radiator cap is suppose to realive the pressure when it gets above the certain amout of pressure right? What is your guys thoughts? He says the motor is rebuilt and will sell me it for $86 so if I can steal it from him it will help me out alot because my diesel is going to [censored]. thanks for the help!

Bryan Neu

 

[Tybee]

What do you mean by blowing the radiator? I had antifreeze flowing into the over flow bottle right after start up, and since the 6.2 is known for cracked heads I replaced both. Problem fixed. But I never had oil in the water just compression. Hope this helps

1984 GMC Jimmy 379 diesel, 700R4, 3.73s, 31x10.50 x 15

 

[DieselDan]

Easy enough, put a radiator pressure tester on and start it up. A leaky head/gasket will be obvious as pressure will rise fast and high (stop before you blow the radiator up as there in no pressure relief with a tester). Any decent garage/mechanic will have a radiator/cap tester kit.

Real trucks don't have spark plugs!