First Questions - Cooling etc.

[92Typhoon]

If you've read my intro in the General Forum you'll know I've only had my car for a few days. I'm no stranger to the search button on forums, and am not afraid to work on my own car. I'm almost a certified mechanic in some areas after owning a Typhoon. I've read pretty much all the info on the main W-Body.com main page. I've searched and read most of the threads pertaining to cooling on these cars. I know how my 4.3L should run temp wise, cruising, idleing in traffic, etc.

 

On to the questions:

 

1. Do most all 3.4's tend to run warm? I have the standard symptoms for bad cooling fan motors. Runs cool down the highway, but heats up in town. Actually had the car die on me twice. Once while waiting to get my emissions tested, second at a stoplight on the way back to work. I've checked all the fuses, they are all good, unless there's a hidden one I missed. Coolant levels are just where they should be, cold and hot. I let the car idle in the parking lot when I got home, it got hot, first mark past middle, and the cooling fan did kick on, so I know it works. A/C also brings the fan on, so I don't think it's bad motors. Is it possible to run a 160* or even 180* thermostat on the 3.4? I have to run a 160 in the Typhoon to keep it running nice and cool. I thought I would replace that as my next step. If that doesn't get it, I'll have the radiator flushed and refilled, to make sure there's no air in the system, etc.

 

Sorry for the long question. I'm new to the 3.4 and want to make sure I cover all my bases.

 

2. When checking the ECM trouble codes, is the cooling fan supposed to run when the key is turned on? It doesn't on my Typhoon, and didn't know if it was supposed to on my Lumina. The dealership replaced the EGR and forgot to reset the ECM, so I was throwing a 32 with a new EGR valve. Go figure.

 

Thanks for reading my long winded post. I'd certainly like to keep the Z34 alive and well.

[pwmin]

I would start with a thermostat like you said and go with a 180 to start. mine has a 195 and runs a little below that but i wouldnt go down to a 160 but it might be okay since its supposed to be warmer from now on except for the usual june snow shower and days like tomorrow (here on the front range CO anyway). does the coolant look okay? have you checked it with a hydrometer? thats more for the antifreeze properties but still can tell you if the coolant is "going bad" or however you say it. when filling it make sure you open the little valve on top of the water outlet housing to bleed the air out (sorry if you knew that already). run it until a steady stream of coolant comes out. also if you can find an ir temp ga. and measure the radiator to see if its cooling the antifreeze correctly.

 

if your car is still hot the fan will have power with the ignition switch in the run position and will turn on. otherwise it shouldn't

 

does that help? sorry if i missed something or said something obvious you knew already. i am only about a half hour from you so feel free to ask for anything.

[Daggar]

From my expirence the 3.4 DOHC Tends to run warm. Some owners have even put a fan bypass switch in to keep them cooler at idle. The fans on the 3.4 Tend to wear out on the drivers side thats your primary cooling fan. if your car is running hot like you decribed check that fan out cause the berrings are probably shot.

 

As for checking ECM codes. The fans turning on is normal in diagnostic mode. it's just part of the test to see if they are operational.

[THe_DeTAiL3R]

I don't know much about the 3.4, but my 2.8 and 3100 run around 1/4 on the guage normally, and not quite half during slow city driving, sitting idling not quite 2/3rds and the fan kicks in bringing it back down to about half (and it goes back down to 1/4 once you get moving).

 

Coolant flush and t-stat were among the first things I did to my 95 when I got it and it ran cooler... that's something I'd do with any new vehicle is change ALL the fluids.

[92Typhoon]

Thanks for the quick replys! I'll be buying a new thermostat today, and my wife will get the radiator flushed and thermostat installed on Thursday cause I just don't have time. and ladies day saves 10% . Hopefully that will take care of it. I know the fan works, comes on when it's supposed to, just runs too warm in traffic is all.

 

I'll also check the fan bearings. Just because the motors were replaced doesn't mean the fans were.

[5speedz34]

Thanks for the quick replys! I'll be buying a new thermostat today, and my wife will get the radiator flushed and thermostat installed on Thursday cause I just don't have time. and ladies day saves 10% . Hopefully that will take care of it. I know the fan works, comes on when it's supposed to, just runs too warm in traffic is all.

 

I'll also check the fan bearings. Just because the motors were replaced doesn't mean the fans were.

 

Ladies day?!

 

And usually from what I've always thought is the fans are replaced as a unit...

[92Typhoon]

Ladies day?!

And usually from what I've always thought is the fans are replaced as a unit...

 

Yeah, the quick lube place has specials for ladies. As far as the fans are concerned, all I was told was cooling fan motors. The whole unit could have been replaced. Electric fans is a new concept to me. My Typhoon has the good old fashioned fan clutch/cooling fan.