I have a 1989 Geo Tracker LSI 8v 4X4. and when its cold and starts to warm up to operating tempture it starts to go past the point it is seposta be at the it will go back down then a bit later it will do it again. it also pushes the coolant out and some times will sucke it back up from the over flow canester. but i dont know if its the head gasket or the intake gasket its just driving me nuts right now and i cant do any thing till it warms up because its cool and i have no place to work on it. i live in manchester nh



                                                 thanks joe

it sounds like you have a malfunctioning thermostat. thats an easy and cheap fix. its a good place to start anyway.

well i did replace the stat about 2 months ago and thats when it started acting up. so i did the water pump and timing belt at the same time it was a stat from discount auto parts not sure what kind it was it was cheep its a 195 i also put a 180 in there for a wile but it did the same thing just at a lower temeture

Have you tried replacing your radiator cap?  It might be causing a pressure issue.

on my 93 16 valve when it was cold the thermostat would not open until it was like 3/4 to the over head and then it would always stay right at about 1/2. point being I don't think it is bad if it goes high the first time, but I don't know why it would do it again. the only thing that controlls temp. is the thermostat and fan. let it warm up, open the hood and see if you can see steam coming out. if it was a head gasket it would have to be running weired, loss of fluids, mixing of fluids, exhaust smell in the oil,etc. it could be a bad radiator cap like drone637 said. try this: take the cap off, then set it back on the the top of the neck. before screwing it on push down on it. there should be some tension pushing against the cap. in other words make sure the rubber ring on the tip of the cap should have pressure on the seat of the neck.

ok sorry guys i for got to tell you that ive replaced the water pump rad cap and stat and fan the only thing left is the head gasket im just hoping that its not that but if it is i will just half to replace it. thanks for all the help guys

I just did a head gasket on one and it wasn't that bad. the head was rebuilt sometime in its life, so I never took the manifolds off. I bought the whole head set with out bolts for $75, but I only used the head gasket and the exhaust flange gasket, but if you buy just the head gasket it was $48-$70 and about $3 for the flange gasket, for only a couple dollar more you get all the gaskets. my advice is if you change the head gasket mark the cam, crank and belt before disassemble. also mark the distributor. I bought my trackick with a bad gasket, so I didn't know the condition. I would say for you to at least replace the intake and head gasket. BUT make sure it is head gasket first.

ok will do im going to do a compression test tomarow and see how that checks out. as far as i know the truck only has 52000 miles on it but i will make sure bufore i do that. thanks joe 

ok guys i did the head gasket set and every thing is good so far wasent 2 bad and it runs like a champ now. thanks for all the help. joe