My 89' formula 305 overheats if i get stuck in traffic. With both fans on and the heat on high i can get the needle to stop rising but not cool down. I have a new radiator and stat and i have no air pockets in the system. Does this happen to anyone else?

 

What do you mean by "stop Rising" ? If you mean at 220 or so you're O.K. These motors always ran a little hot. Are you running coolant or straight water? Are your fans stock? or did you install them? I ask because I've seen fans installed with reverse polarity (wires crossed) This makes the fans push instead of pull. You could also try a search on this topic. Probably find an answer there.

 

Hi,

Funnily I had this the other week when I ended up in a 45 min jam near to where I live! I found the temp guage would rise past centre (straight down on mine) and then I presume the fan cut in but it didn't bring the temp down entirely to normal... it then just gradually cycled between overheat and cooler until I got out of the jam. I'm guessing it's normal

Thanks,

Ian

 

I am running coolant and the fans are spinning the right way, but ya it sits right at 220 and thats way to hot for me but if its normal i guess im going to have to live with it,
thanks guys

 

220 is normal operating temperature for almost every V8 ever made. It's not considered running hot at 220 by any means. If your engine is running consistant at 220 then consider yourself lucky. Anything lower, your engine does not run efficiently.

 

What temp do you have your fans set to turn on at? Are you sure they're on?

 

It runs alot cooler then 220 but once i stop moving it jumps up right away. I had an on going going problem with the fans not turning on. I just got fed up and just wired them to a toggle switch so whenever i start to sit in traffic i turn em on and when i get moving past 25 miles an hour i turn em off, would an oil cooler be over kill? i only drive the car in the summer months

 

Completely stock, these cars run at like 180ish when moving around (ie: highway, country roads...no stop and go) but when you get stuck in traffic or in a lot of stop and go they tend to heat up to 220ish+.

I had an LO3 car and I put in a 180* t-stat and it kept the car cool all the time.
My LB9 car I have a 180* t-stat and a Hypertech Fan switch and it never really goes about 180* even in the hottest of days. If running at stock temperatures was "normal" I would think that there wouldn't be such a market for lower degree thermostats and fan switches...

 

Because not everybody's cars run between 180 and 220. Alot of times they're jumping up to 250-260. I'm curious, do you think that 220 is not normal operating temperature? You run a 180* thermostat but your car doesn't usually reach 180*? Shouldn't you match the thermostat with the normal operating temperature of your engine? Aren't you concerned about the lack of water flow? Why not a 160 or 170? Then you'ed have positive water flow through your block. Usually when you need to boost your temperature you'ed put in a higher degree thermostat.

 

Ok this has set me wondering. My 91 V6 here in the UK will run all day at about 180-190 with what I believe is a stock thermostat but in traffic it will rise to easily 220 and then the fan must cut in. Kevin you said about about the lack of water flow, does this occur when the engine temperature is less than the fitted thermostat? Should I be worried?

 

I just don't like the idea of an engine running for extended lengths of time without water flowing through it. If you have a 180* thermostat but the engine never meets that then that would be my concern. It would be appropriate to run a 160* or 170* thermostat. Then you would have positive water flow. There can be hotspots in the motor that raise above 220* that aren't picked up or monitored on the temperature gauge. If you are running a stock thermostat then you probably do have positive water flow. Isn't stock 160* to 170*? Sounds like your system is working fine. Your engine warms up to 170*, the thermostat opens up, the engine raises to 180*-190* When it reached 220* the fan kicks on...I run a 170* thermostat and drilled 5 small holes around the base so that it will assist the engine in warming up but also keep positive water flow.

 

I thought the stock thermostat was 195, I got that from:

http://www.gmtips.com/3rd-degree/dox/tips/cool/cool.htm

My temp guage sticks at 6 marks past the 100 mark, which I worked out to be 180 at 13.33 per mark! This makes me think I've either got a problem, thermostat not opening or it has a 180 thermostat fitted. I guess the only way to really know is connect up a ADLD cable and use RT Tuner to read the temp sensor

 

Well the way that I've looked at it is that when the car is just driving around it stays at approximately 170-190ish (can't tell exactly because as you all know, our temp. gauges arn't the most accurate). So when I used to pull up to a stop light or get stuck in traffic and it would heat up to 220+ and it just seemed to idle a little weird. Not to mention the type of heatsoak you get when you shut off your car and it's already at 220*. You turn the car on 10 minutes later and the temperature gauge is pinned.

With my 180* t-stat and Fan switch the car runs much cooler and even in traffic wont creep up past the 220* mark. Even with heatsoak it won't go over 220-225*. I'm not saying the way I have my cooling system set up is ideal, but I'm just a proponent of cooler engine temps. As far as water flowing through, like I said, the gauges aren't completely accurate but I would assume it hits 180* most times I drive it and it does have coolant circulating through it...

 

try a new radiator cap. mine was doing the same thing andi replaced 2 thermostats only to find out it was the radiator cap because of a suggestion from my dad...

 

Funny enough, these motors have different cooling issues. They can easily spike over 220* in stop and go traffic but in the winter on the highway they don't always heat up enough to be able to use the actual heater. That must be why they use a 195* thermostat, the motor can heat up in winter driving and then in the summer it opens before it reaches 220* I have hot summers and mild winters, so I'm able to get away with running a 170* thermostat.