Overheating issue....tried everything !!!!!!!

[sieng123]

Hello everyone. I have a 1999 safari with 300,000 km on it. I have an overheating issue. I'll start my story from a long time ago. I'm in Canada and I only drive this van in the winter, I put about 5000 km on in the winter and then it sits all summer. About five years ago I noticed it wasn't blowing as much heat as it use to so I changed the heater core, it didn't help. So over the past 4 winters I've noticed it giving less heat every winter, not heating up to operating temp when I start it in the morning to let it warm up, even when the air temp here in Calgary is around the freezing mark, it just would not come up to operating temp. The only way to get the temp up was to take it out on the highway. Just this last winter the running too cold problem turned into a overheating issue where I couldn't even drive it down the street without it overheating, also at this time it blows no warm air out the vents at all, only cold. Over these past 4 years I have changed the heater core, heater control valve, thermostat 3 times thinking the first 2 were faulty I finally put in an AC delco, changed the water pump, just did the head gaskets thinking it was pressurizing the system, and also just put in a new rad when the head gaskets didn't help. There's nothing in the system left to replace. Does anyone have any ideas what the issue could be? Thanks.

[MountainManJoe]

Hi welcome to the forum.
Does the fan run when the temp gets hot?

[sieng123]

Thank You for the welcome. I've never noticed if it ran when hot. I don't think so, I mean the van now idles in my driveway for 5 minutes and the temp guage is already in the red zone and I don't think the fan clutch kicks in. I did also replace the fan clutch about 10,000 km ago.

[MountainManJoe]

It should be coming on full blast.
Try the troubleshooting here: https://charm.li/Chevy%20Truck/1999/Ast ... erheating/