https://honda-tech.com/zerothread?id=205457

if anyone has any ideas please help

 

need more info dude. what kind of honda , when does it overheat, in traffic,on the highway does the fans run? is there coolant in the radiator? give me something to work with.

 

91 civic hatch dx auto, d15b2 (stock block) with a p&p d16y8 head milled approx .040" (mini me). it overheats about 5-10minutes of really getting on it, it hasnt overheated on the fwy yet (while driving). although when i come off the fwy the temp will go up, then i keep driving and itll go past 3/4 on the temp gauge then all of the sudden just drop back down to normal, and slowly climb from there, but will still drop back down, and rise back up (really weird) just driving on the normal streets it wont overheat, only if i get on it really hard itll do it after maybe 5 minutes. when it does i pull over and the overflow tank level is almost at the top and it seems to be boiling?/bubbling.. then the coolant will be a bit low after it cools down...

 

have you checked your head gasket ,good place to start from what your telling me .check the obvious first t-stat, fans ect.

 

Sounds like a head gasket problem to me. Mine is doing the same thing. Sending coolant to the overflow tank, and it is definately bubbling from the coolant being pressurized.