94 Z28 overheating....................
08-19-2008, 12:03 AM
#1
TECH Regular
Thread Starter
iTrader: (9)
Join Date: Dec 2006
Location: Bremen, Ky
Posts: 429
Likes: 0
Received 0 Likes
on
0 Posts
94 Z28 overheating.................... I have replaced everything but the rad and heater core. The only thing that help was the rad cap. It quit gurgling with it on. I turned the heater on and left the cap off. It still went into the orange. I noticed that the hose from the rear of the engine was blowing air and sometimes coolant. can anyone help me? if its at the 160 temp then its take about 3-4 min to get to the orange.
08-19-2008, 12:58 AM
#4
TECH Enthusiast
Join Date: Feb 2006
Posts: 517
Likes: 0
Received 0 Likes
on
0 Posts
did you replace the water pump? i know you said everything. Did you bleed the system of all the air that could cause it to overheat.
08-19-2008, 01:17 AM
#6
TECH Fanatic
iTrader: (5)
Join Date: Mar 2004
Location: Melrose, MA
Posts: 1,196
Likes: 0
Received 0 Likes
on
0 Posts
Yeah, my next question was going to be have you heard any odd noises (or new) from your water pump? When you pop the radiator cap whenn the car is running, can you see coolant circulating? (with the car cold, of course!)
Last edited by Fixxer99TA; 08-19-2008 at 01:36 AM.
Trending Topics
08-19-2008, 01:38 AM
#8
TECH Fanatic
iTrader: (5)
Join Date: Mar 2004
Location: Melrose, MA
Posts: 1,196
Likes: 0
Received 0 Likes
on
0 Posts
Couldent tell if the coolant was circulating? If not, then it more than likely wasnt (when it IS circulating, the coolant in the neck of the radiator will be churning like its flowing). If the coolant isnt circulating, it could be other things but its more than likely the waterpump.
08-19-2008, 01:57 AM
#10
TECH Fanatic
iTrader: (5)
Join Date: Mar 2004
Location: Melrose, MA
Posts: 1,196
Likes: 0
Received 0 Likes
on
0 Posts
The reverse cooling takes awhile to bleed, your more than likely going to have to get it to where its not overheating and drive it to get all the air out (If thats actually whats causing you to overheat).
08-19-2008, 02:12 AM
#12
TECH Fanatic
iTrader: (5)
Join Date: Mar 2004
Location: Melrose, MA
Posts: 1,196
Likes: 0
Received 0 Likes
on
0 Posts
The reverse cooling is to help with the higher compression, so the coolant straight from the radiator goes to the heads first to lower cylinder temps. This allows for the 10.4/1 CR.
08-19-2008, 05:57 PM
#17
TECH Enthusiast
iTrader: (9)
Join Date: Feb 2007
Location: Stank Cloud, FL
Posts: 744
Likes: 0
Received 0 Likes
on
0 Posts
This may be a dumb question but you did remember to put the drive coupler back in behind the waterpump right? I know people who get excited about putting things back together and forget it. Just a thought. But I would say a new radiator would be the next thing to do. Also, make sure you dont have a shitload of trash against the condensor and radiator. You'd be amazed at what you'll find if you haven't cleaned it in a long time.
08-19-2008, 07:17 PM
#18
TECH Regular
Thread Starter
iTrader: (9)
Join Date: Dec 2006
Location: Bremen, Ky
Posts: 429
Likes: 0
Received 0 Likes
on
0 Posts
yeah it was all put back together right. I drain the radiator and it was a blittle nasty at first. I flushed it for about 5 min. did the same with the engine. Its all clear water now. I pulled the thermostat out and brought it in to check it. The damn thing dont start to open until 220 then it opens really slow. its suppose to be a 180 
08-19-2008, 07:18 PM
#19
I've Got Warranty On A Radiator And I Would've Hooked You Up But I Live In Fort Worth. I Could Of Took Yours And Cored It In And Got A New One. Sorry. But I Have A 94 Z28 And I Changed Everything From The Cooling System And What It Came Down To Was That I Wasn't Bleeding The Air Out All The Way. I Actually Put My Mouth On The Radiator And Blew In It And Kept Putting Water In It Till I Got All The Air Out. It's Crazy But It Did Work. I Also Got Mad At Gm For This Coolant Setup But I Do Love My Lt1!
08-19-2008, 08:04 PM
#20
Registered User
Join Date: Jul 2008
Posts: 9
Likes: 0
Received 0 Likes
on
0 Posts
ok i had the same problem.. pisses u off alot... did everything. lastly i looked at the thermostat and it wasnt working.. it overheated a few times. pritty high. put a new one in,.. didnt go above 180. got excited ran the car to about 5,000 rpm shifting good and blew a head gasket.. so watch out overheating kills if u have aluminum heads!!