can't keep my C4 cool ....

[dfuller]

I've got a C4 with a L98. I've replaced the entire cooling assembly, but still it get's hot. While "running" it's nice and cool, but while waiting at a traffic light it'll get 20 degrees hotter ?????

Anyone with a cure to this problem, please help !!!!!!!

[mga]

bad fan clutch?

[mike2004tct]

Originally Posted by dfuller

I've got a C4 with a L98. I've replaced the entire cooling assembly, but still it get's hot. While "running" it's nice and cool, but while waiting at a traffic light it'll get 20 degrees hotter ?????

Anyone with a cure to this problem, please help !!!!!!!

Only 20 degrees?.
My '85 L98 with a 185 themostat will get up to 230 degrees when driving in stop & go traffic. Out on the highway, it rarely goes above 195.

You didn't mention a specific temp, but as long as your under 235, it sounds quite normal to only increase 20 degrees when no cool air is being forced into the minmal openings these cars have.

[mfrank2470]

Mine does the same thing. When I turn on the AC it cools down fine as it kicks on the fan. Did you try this?

[Chevyracincamaro]

the vette, camaro, firebird, and a number of other GM cars do this cause they have a cooling system that draws air from underneath the front of the car with a chin spoiler. they dont get as much air flow sitting in traffic as a conventional system that has air flowing through a grill, straight into the radiator...

[vetteguy1]

I have an 85 that did the same exact thing. I put in a hypertech thermomaster stage 2 chip and a 160 degree thermostat and it now runs at 180 all the time. I did not see it over 200 the entire summer and i raced it quite a bit. It keeps everything cool and it gives you a small gain in horsepower also

[trwong]

I had this same problem in my 1990 with L98. I noticed that only one of the radiator fans comes on when the radiator gets hot. The second radiator fan only comes on when the freon pressure gets fairly high in the a/c system. So if your a/c is off, or if the freon pressure is low because of low freon, or inefficient a/c compressor or low outside temperature then the second fan won't come on.

I solved this problem by wiring the two radiator fans together so that they both come on when the radiator temperature gets hot enough. I just used one of those "T" splice wire things on the wires somewhere near the fan relays near the drivers side radiator fan. It only takes five minutes to do. I can post more specific information if any one is interested.
Terry

[mike 1985]

you can switch to a 160 stat and also get a fan switch from painless wiring for $32 to turn the fan on eariler.

BTW the area between the radiator and A/C condensor gets full of road debris and really hinders stop and go temps.

Mike

[DVS LT1]

I know this all too well. My Z was so awful in stop and go - even if it was cold outside like on a fall night, as soon as the engine was stopped it would get right up to around 230 even 240 (110 celcius anyways), the the fans would kick in and bring it back down to about 100c (210), but it would shoot right back up after that. Problem was once it got that hot it stayed hot - driving at decent speed it would take a long time to get the coolant down to between 75-100c (190f) which was normal operating temp with a 180 stat (would never get bellow that nomatter what), but the motor would still be HOT. You try touching the manifold or TB with your hand and it would get instantly scortched. I'd sit in my car after turning it off with the power still on and watch the thermo slowly climb back past 100, even more.

Its like this: I start it up and get right on the highway so it doesn't ever get past 190f then park it - the motor is not too hot to touch. I start it and let if get to 230f+ and into/off the fans even once then immediately get it down to 190f on the highway and park - the engine is like lava (even though I killed it at 190f).

By all means get the 160 degree stat. I'm not positive about the L98 stat but the LT1 stat is a spring which basically opens up when the temp gets above 180, then recoils, so you get very inconsistant levels of coolant. The 160 stat not only opens sooner but it has a little hole in it where a small amount of coolant is ALWAYS going through (at least thats my understanding). At any rate, I installed the 160 stat in addition to using a Hypertech unit to set fans (instead of 230 or 240on/220 or 230off its now 195on/185off) and I can tell you the engine runs so cool - it has NEVER got above 180 even in traffic. The craziest thing is I can be out for hours in traffic, get home, and plant both palms anywhere on the manifold and its warm to the touch. This is something I should have done years ago.

[mga]

http://www.stewartcomponents.com/

stewart carries a large selection of "hi-flo" thermostats that are designed to constantly allow water to flow thru them, even when closed.

they do make a difference when installed.

[VaVette87]

Originally Posted by mike 1985

you can switch to a 160 stat and also get a fan switch from painless wiring for $32 to turn the fan on eariler.

BTW the area between the radiator and A/C condensor gets full of road debris and really hinders stop and go temps.

Mike

Mike 1985's suggestion is the best solution for you. You can also pick up a fan switch/wiring from Ecklers or Mid-America Corvette.