So I put an 086 (head machined to block) on an ld9 with felpro bolts, cosmetic head gasket, lsj injectors, and got it tuned. I only run 93 octane and lately have been using an octane booster with no change. Everything was fine seemed like it was running and good temp. was at 195 always, but it didn't seem like all the power was there.
Then randomly one day it started overheating and hasn't stop. Driving on interstate, no issues but idling or around town will go straight up to 260 if I let it. I have to shut it off at red lights. Even was pushing coolant out off mls gasket.
I thought head, so I took it off, had it checked for straight and pressure tested. Less then .003 and no cracks, put a felpro gasket ARP studs and had the radiator cleaned and tested.. put it all back together and it ran great again. Had hot heat and wouldn't overheat at idle. when I drove it home (2.5 hours) it was running warm, 230 but that's as far as it would go. Today it's doing the same thing as before. I'm sure there is air in the system because I had heat this morning and now it's ice cold, but I can't figure out how or what's going on. Any help would be much appreciated.
OK. So i have an update. The top radiator hose is luke warm and the bottom is ice cold. I have the thermostat in the bottom and its stock temp. Now I know i probably want something cooler, but at any rate, 230 on the gauge, any temp should have been opened up by then and especially after a short drive. This is the second thermostat i put in and i tested it before i put it in. I know this is bring up a Huge controversy, but how would a 180 in the head with adjusted coolant fan temperatures be worse then a stock location and a tstat that wont open up?
Check thermostat and cooling fan. Does ur ac work? Gm was a big fan of having the cooling fan system on the single fan cars like the cavalier sunfire malibu and saturns, the oldsmobiles and whatnot run through a condensor fan circuit. and if ur ac doesnt have freon in it the fans tend not to turn on.
Had a similar issue on my 96 sunfire, turned out to be my fan motor, (replaced it 60$ at autozone) now temps are fine.
