88 supra turbo overheating problems Help!!!!

[suprat]

Hey guys i have the 88 supra turbo and i finally fix the afm and now the car overheats and bubbles coming from the reservoir. I know the whole thing abput the headgasket on these cars but what i can't understand if it was a headgasket would the car smoke or would their be oil in the coolant. My car will not overheat if its just idiling and i can drive it for about maybe 10 miles befor the guage starts to go up but once it goes up it will get right to the red on the hot side and then drop to normal temp reading and as soon as i hit the gas again it will go up and once i let off the gas it will go back down. I have also notice that i have to put coolant in it often. I already replaced the thermostat and the radiator cap i was wondering if you guys think this could be a water pump cuase for it to be a headgasket would the car have to smoke or have oil in the coolant my car dosen't have either of those.

[Sonyps307]

To see if it's the headgasket do a compression test and see what numbers u get or for a fast test take off ur oil filler cap and look at the bottom of it. Look if there is a milky looking stuff there. if so then most like ur HG is blown. But I would still do a compression test. Also I heard off a blown HG and it not smoke

[87hilux7mge]

sounds like the water pump has a hole in the housing somewhere and is recirculating water through itself at idle, but cant flow enough under load or higher rpms.

might be a bhg, but im leaning towards a wp. had the same problem on my buddies dodge dakota 5.2. would idle all day long, but put it on the freeway, itd over heat in 2 min. 1/2 inch hole in the pump housing...gaudamnit..

but like said, do a compression test. check for any coolant hose leaks (small hole can suck air in instead of leaking).

[suprat]

Thanks guys im gonna try that im leaning more towards a bad water pump or clutch fan i think im gonna get both of them new,

[cre]

If the car isn't overheating at highway speeds then check the water pump before the clutch fan... the fan doesn't really move a lot of air that isn't already coming through at those speeds.

[depami]

Originally Posted by cre

If the car isn't overheating at highway speeds then check the water pump before the clutch fan... the fan doesn't really move a lot of air that isn't already coming through at those speeds.

Are you sure your logic isn't inverted?

[cre]

Originally Posted by depami

Are you sure your logic isn't inverted?

Good catch... Just didn't manage to type out what I was thinking. If it IS overheating at highway speeds check the water pump first.

BTW, the temp gauge is logarithmic... 1/4" above center is not the same as 1/8" indicates times 2... it's closer to 1/8" times 3. The red area is so hot that you may be causing engine damage by continuing to operate the vehicle for any period of time.