md21722

Typically the head cracks in such a way that exhaust gasses leak into the coolant system. In minor cases it can lead to over pressurization of the cooling system and erratic coolant temperature issues such as high coolant temperatures climbing grade in cold weather. In major cases you have coolant "explusions". Ask anyone who has ever owned a MB OM603 with a cracked "14" head which were known to crack or have head gasket problem, or both Bad heads out there across a large range of vehicles.

djb383

Excess coolant/pressure should be expelled to the recovery bottle, not outside the cooling system.

johnson8769

well after i replaced the cap it was still leaking ...so i took it to a mechanic and he said i had a cracked head he replaced it and now its not doing it

djb383

Maybe your mechanic did what Robert suggested. No way a cracked head/blown head gasket will cause coolant to leak at the rad cap or neck of the rad. Pressure/coolant will/should escape to the bottle.....not to the outside of the rad.

johnson8769

maybe he did ...i wasnt there when he worked on it but did a google on this also and sure enough other vehicles do this same thing and i did install a 16lb. cap

johnson8769

maybe ill put the old 1 back on and see if does it again as i havent bent the tabs on it.

djb383

Coolant leaking at the rad cap/rad neck area is due to a bad cap, or bad cap to rad neck seal, or cracked rad neck, or some combo of those. It's that simple and nothing to do with a cracked head/bad head gasket. Coolant should never be seen on the outside of the rad cap/rad neck area.....it should always pass to the recovery bottle and always will pass to the bottle if the rad cap/rad neck r functioning correctly. Those Googled leaks in that area of the rad cap/rad neck r simply leaks for the exact reasons I described.

Radi

Yes.
A cracked head or blown gasket can pressurize the cooling system, but it will expel into the overflow tank and eventually spill from there, not the radiator cap. (unless the cap seal is bad) Often you'll hear gurgling in the overflow tank.

djb383

I guess his mechanic didn't explain it to him.

johnson8769

well hopefully i didnt get took for my money on this and ill definately be on here a little more in the future...had this been in the summer instead of winter i might have tried doing this myself but dont have a garage big enough to tackle this on my own .have a weld shop in my garage now.mechanic i took it to does know what he is doing 30yrs plus experience but i am no mechanic so i did listen to him on this .

johnson8769

the head that was pulled from this was the 0331 head.not the tupy head

Kalali

Whether or not a cracked head directly caused the leak from the cap, you did the right thing by replacing the 0331 head, even proactively. The question you should ask your mechanic is what did he replace it with. Hopefully not with another rebuilt 0331.

johnson8769

no i purchased it and it is not an 0331 head ....it is a new manufactured head.