Uphill over heating

Driving home tonight going up a long steep hill(Stone Quarry Rd. Ithaca, NY), my temp guage pegged out. I pull over it starts dropping. I shut it off then back on, but not running, and the needle is right back at 1/4 where it usually is. I pop the hood and look around and nothing seems out of place and the rad cap is hardly warm. Give it a few minutes and start it back up and head home with the heater on Hi, driving it easy. Temps stay normal till i get to the next decent uphill section. Then temps starts climbing again, fortunatly I'm over this smaller hill before it goes over 1/2.

In my 2 years with this car, this is the first time it has ran hotter than usual. I flushed the coolant last fall, and topped it off recently. However, I didn't replace either the rad cap or t-stat last fall. When I get a chance I will look it over in daylight.

Any sugestions on why it suddenly overheats only going uphill?

Sounds like the radiator is starting to clog up. Try flushing it. Sometimes you can feel varying degrees of hotness on the rad depending on how well the coolant is flowing thru the tubes. Going up hill requires the engine to do more work. More work means more heat to get rid of.

Also, I forgot to mention, I havn't driven it since wensday and I don't have any big hills to go UP on my commute in, so it wouldn't happen going to work.

First thing I'd do is question the temp guage. Is it a factory piece of crap or is it a real guage with actual temp numbers on it. My first step would be to check the accuracy of the temp guage and see if the thermostat opens when it's supposed to. The rad cap being barely warm is a bit odd. If the engine was running hot and it's full of coolant, that cap should be too hot to touch. Replace the thermostat and the cap, flush, and see how things work out.

Either you've got a blockage as suggested, or the water pump isn't doing its job. Something is preventing proper coolant flow through the radiator.

I suspect the factory temp guage is the problem, but it happening again going up the next hill has me doubtfull. Fortunatly I am borrowing my mom's car till things get sorted but I wont have time to look into it till friday and by then it may be in the shop getting a new rear struts.

I'd be tempted to think the thermostat is stuck open and it never gets up to proper temp. Going up the hill allowed it to get to correct temp.

edit This was at night, in the rain, with a week flashlight after working late.

So I finally have a chance to look at things(I have been borrowing my mother's car) and now there is no visible coolant when I open the pressure cap, and the radiator feels empty. And I topped it off less than 2 weeks ago.

I don't work till later tomarrow so I will have a real chance to look deeper at this in the morning.

well, that sounds like a BIG airblockage. Time to find out where the coolant went

New T-stat and rad cap along with a COMPLEAT flush tomarrow. No signs of an external leak, but no signs of it in the crank case, which is my main concern.

Check if the w/pump is leaking, that coolant tends to evaporate quickly and may or may not leave some residue.

I guess you have a leak somewhere but it's obviously a case of finding it...

Neon.... head gasket?

I really hope it isn't either the HG or water pump. Both where done appox. 30K miles ago. Although the HG could explain my 1qt/700 mile oil consumption.

Love/Hate relationships...

I just finished my flush-n-fill and installed the new t-stat and rad cap and took it out.

On my first drive out I noticed some coolant steam comming from the back of the block. When I went out a bit later it seemed fine. So it has me thinking it was just some spilt coolant boiling off.

crossing fingers for you

Could it be something as simple as a hose that's leaking?

Thanks, the hoses look good. I'm going to keep a closer eye on my coolant levals. But the only driving it is going to do in the next week is to the shop. My rear suspension has been in bad shape and now it is spitting out parts of the rear upper strut mount.

FOUND IT!!!! It has finally choses to show itself to me. And it is the radiator. Unfortunatly, the shop gets to deal with it as I have no time to work on it, and pulling the radiator is a PITA on this car.

Once again, I hate closing shifts.

still, pulling the radiator should not take more than a couple of hours at most. I remember doing that job on my Father's old 300zx.. and that radiator lays down inside the bumper