Hey guys, I've been having this wierd issue with my 95 sixxer lately. I wouldn't say the car is fully overheating, but it does get to around the M in Normal sometimes. The wierd thing is, the heater will blow cold air sometimes, sometimes I have heat. The thing that concerns me is I could come up to a stop light, rev it to around 2k for about 10 20 seconds, the guage will go down, and i'll have heat for a little while. I figured I'd ask you 3.8 guru's, also, if I run the car hard, the heat will stay pretty consistent, and the gauge will be around the N in Normal. If I just run the car normal, say 55mph, at a constant speed and low RPM, i lose the heat, and the guage goes up a bit, not scary overheating or anything. I'm hoping maybe waterpump, but I have a feeling it could be a headgasket. Any help at this point would be AWESOME! Oh, and the car runs fine, no cel's or anything, but I like my heater in the winter.

P.S I have changed the top rad hose, new thermostat, radiator and cap, temp sensor, bled the system, etc... I've been running plain water lately, because of all the issues I've had, I will put in some anti-freeze.

 

bump!!

 

The water might be an issue, or it could be a headgasket stating to go. Have you seen any water leaking out of the exhaust pipe? See a milky sustance in the oil? Air bubbles in the rad while the car is running? You might want to check those for signes of the headgasket problem. You can also do a compretion test of each of the cylinders to see if any of the cylinders are showing a diffrent number, I would try this first as it is not that hard to do.

Good luck,
Matthew

 

No, I haven't seen any water out of the exhaust, I did that check already. No water in the oil, I've seen the mocha colored stuff before with older cars. I have seen a little bit of air bubbles which concerns me. Yeah, a compression test will be done, I'll have to find the damn thing in my dirty *** garage. LoL Thanks for the advice, I think I'm screwed, but I'd rather expect the worst and hope for the best. Thanks again.

JK

 

bump, no other suggestions, comments, etc...

 

So I drove it to the bay area last night, heat working sporatically, guage going up a little bit. On the way home, needle didn't move at all until I was almost home, heat was still working now and then. This issue is ridiculous, the car is running fine too, turned it off, no bubbling over, no noises, hoses not that hot(fan never kicked on once and I have tested the fan, it works fine), so I'm up in arms. I can't believe all these 3.8 owners and no other suggestions or experiences with this, other than matt's suggestion which is appreciated. Come on, I know you gurus are all about the 3.8's, help a fellow stanger out.

 

thats quite a weird problem, my guess would be head gasket starting to go like said above too.

 

Yeah, it's a trip man, I think it's starting to go to, water pumps usually tell you when they need to be changed, I've done quite a few in my day. I guess I'll just drive it til' the wheels fall off!

 

Most likely a bad or clogged heater core. The gauge going down when revving it is normal, since the water pump pumps the coolant quicker than when just idling.

The reason you have heat when reving is because the pump is pumping the coolant faster and harder, and allowing it to flow through the clogged heater core.

Here's what you do to confirm this. Let the car warm up, then grab both heater core hoses (the ones going into the firewall), and see what the temp is. If one is hot, and one is a good deal cooler, then you're heater core is clogged with a bunch of ****.

Before replacing the heater core (which sucks ***), try this: Disconnect both hoses off the firewall fittings. Then take a garden hose, preferably with one of those trigger handles for more pressure, and put it up to either fitting. Then you're basically going to flush the heater core. If a bunch of dirt and other **** comes out the other fitting, your heater core was clogged. Keep flushing until clean water is coming out, then re connect everything (top off the coolant cause you'll have lost some taking the hoses off), and see if you have heat.

That's my best guess. A car at work came into work with everything you're describing, and it needed the heater core replaced.

 

I actually had to do that to a car a few days ago. Seems to have work quite well too...^^