1997 Buick Century gets too hot intermittently

DMG9885

MEMBER
1997 BUICK CENTURY
3.1L
V6
FWD
AUTOMATIC
179,000 MILES

Just got this vehicle a few weeks ago. With a/c on temp gauge usually 1 mark under half. No ac gauge cycles between half and 1 mark over half most of the time but when in the mountains or stop and go it occasionally raises to over 3/4 then I pull over and let her cool off. I've checked coolant level, coolant looks like new, added a hose in overflow reservoir that was missing, bleed coolant, both fans came on when bleeding. These are two speed fans (i've read) I don't know what temp they came on but they didn't go off or seem to change speed while bleeding. Could this be the fans not coming on high when needed and what could cause that. Any advise would be appreciated.

3 Replies

HMAC300

MECHANIC
48,601 POSTS

Yes have the fans checked there are either two or three relays in underhood fuse box and one could be bad.

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Monday, August 4th, 2014 AT 5:42 AM

DMG9885

MEMBER
3 POSTS

Thanks for your reply. I checked fan operation and can see it comes on in low with ac then switches to high. With ac off it comes on in low cools as it should but never switched to high during visual test. Same relays are used so I don't think its a relay issue. Temp gauge runs smoothly before it reaches half way but seems to jump up 1 click at a time over 1/2 way but comes down smoothly. Could engine temp switch stick intermittently? No codes on obd. Where on guage should high fans kick in?