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mine was an 85 just did it,
not sure if we share cooling systems but here is what i did:
get a new thermostat for 7$.
check all hoses for tight clamps.
fix your drip at the heater valve.
and when u buy the thermostat put two holes here: these were drilled.
then follow shop manual procedure for filling coolant.
notice the 1/8 inch holes drilled on the flange of the tstat. do this.
mine was an 85 just did it,
not sure if we share cooling systems but here is what i did:
get a new thermostat for 7$.
check all hoses for tight clamps.
fix your drip at the heater valve.
and when u buy the thermostat put two holes here: these were drilled.
then follow shop manual procedure for filling coolant.
notice the 1/8 inch holes drilled on the flange of the tstat. do this.
Is there any concern about drillings getting in there?
Also I just spoke with someone at a shop here and he tried to tell me all thermostats are designed to stick open if they fail and they learn that during their certification. Is he just full of it?
Is there any concern about drillings getting in there?
Also I just spoke with someone at a shop here and he tried to tell me all thermostats are designed to stick open if they fail and they learn that during their certification. Is he just full of it?
before you start pulling your hair out, Start off with the basics.
1) is the radiator clear of debris, look under the by the front license plate look at were the air enters Radiator/A/C. would be surprised what you will find. also look between Radiator and A/C, you do this from Right Front wheel area from under the hood. just follow lines there and look in..
2) is the coolant worn out / or weak, clean properly mixed coolant with a working thermostat is a must.
if the basics are good well then things get a bit more costly, like professional radiator cleaning or replacement and so. hopefully its one of those simple stupid problems with simple fix.
Is there any concern about drillings getting in there?
Also I just spoke with someone at a shop here and he tried to tell me all thermostats are designed to stick open if they fail and they learn that during their certification. Is he just full of it?
drill those holes before you install the gasket and place in the tstat housing.
look between Radiator and A/C, you do this from Right Front wheel area from under the hood. just follow lines there and look in..
Toni's car is an '84. That gap does not exist before 1990. You have to take the top of the radiator shroud off to see the area between the AC condenser and the radiator.
Since I just posted this in another thread I have a link in my clipboard:
I have foam rubber weatherstripping under my condenser so I get much less trash than otherwise.
The basics above are a good start. The open/close function can be tested on a stovetop, with a thermometer reading water temp when the thermo opens.
I prefer Robert Shaw brand to Stant thermostats; run a 180 in mine. I found no need to drill any holes. The Stant's orifice is a fair bit smaller when fully open.
A huge clue is the "moving" temp drop. Sounds like the cooling system is okay IF there's adequate airflow, which apparently there is, when moving.
I'd check the fan running at full speed. They're neither expensive nor hard to change out.
Many threads here explain how to fully flush the system, including the block.
Last edited by whalepirot; 12-17-2014 at 01:04 AM.
The basics above are a good start. The open/close function can be tested on a stovetop, with a thermometer reading water temp when the thermo opens.
I prefer Robert Shaw brand to Stant thermostats; run a 180 in mine. I found no need to drill any holes. The Stant's orifice is a fair bit smaller when fully open.
A huge clue is the "moving" temp drop. Sounds like the cooling system is okay IF there's adequate airflow, which apparently there is, when moving.
I'd check the fan running at full speed. They're neither expensive nor hard to change out.
Many threads here explain how to fully flush the system, including the block.
I just had the fan replaced a couple moths ago and its spinning as it was the day it went in.
I think what made it begin to start dropping was hitting a bump and the thermostat maybe jarring open finally? It seemed like thats wht happened a few times whn it was sticking before too,a few months ago.
I cleaned out the radiator, new coolant, changed to a 180 therm and a 195 on/180 off fan switch (from corvette central) .. coolant temp stays around 185 now..
I would recommend you (or your mechanic) do the following:
1. Full flush of engine block and heater core as per the FSM;
2. replace thermostat - drill holes per VikingTrad3r;
3. pull out radiator, flush it out and clean fins of debris;
3. clean ac condenser fins;
4. if hoses are more than a few years old - replace them;
5. if drive belt is more than a few years old - replace it;
6. check water pump for bearing wear and movement. If it is more than five years old you may want to think about replacing it;
7. refill with 50/50 mixture of antifreeze and distilled water - do not use tap water.
If you have not pulled and cleaned the radiator before, you may be surprised by the amount of debris, leaves, etc. that can be clogging up the fins. The same goes for the ac condenser.
The heater control valve looks pricey from a quick search I did. Me, I would replace it - but it's up to you to make that decision.
If you don't already have the Factory Service Manual (FSM) for your car - get one. Usually available on Ebay.
Regular maintenance is key for every car and especially for older cars like these. If I had what I believed to be a sticking thermostat, I would have fixed it (and done all of the above) before I drove the car again. If you seriously overheat one of these engines you might as well just open up your wallet to watch the money fly out.
Last edited by Silver96ce; 12-17-2014 at 01:20 PM.
I would recommend you (or your mechanic) do the following:
1. Full flush of engine block and heater core as per the FSM;
2. replace thermostat - drill holes per VikingTrad3r;
3. pull out radiator, flush it out and clean fins of debris;
3. clean ac condenser fins;
4. if hoses are more than a few years old - replace them;
5. if drive belt is more than a few years old - replace it;
6. check water pump for bearing wear and movement. If it is more than five years old you may want to think about replacing it;
7. refill with 50/50 mixture of antifreeze and distilled water - do not use tap water.
If you have not pulled and cleaned the radiator before, you may be surprised by the amount of debris, leaves, etc. that can be clogging up the fins. The same goes for the ac condenser.
The heater control valve looks pricey from a quick search I did. Me, I would replace it - but it's up to you to make that decision.
If you don't already have the Factory Service Manual (FSM) for your car - get one. Usually available on Ebay.
Regular maintenance is key for every car and especially for older cars like these. If I had what I believed to be a sticking thermostat, I would have fixed it (and done all of the above) before I drove the car again. If you seriously overheat one of these engines you might as well just open up your wallet to watch the money fly out.
Thanks, hoses are about 1.6 years old, fan motor a few months old, drive belt less than a year ago.
Im not concerned right now about flushing the radiator or about debris since once I hit a bump or something, temp drops from 230 to 195 in a few blocks. And stays around 190-195 even at stops and long idle.
Going for the thermostat if I feel comfortable doing it myself.
Does the 84 use a gasket or o ring?
Any type of gasket people prefer on here for an 84? Paper composite rubber etc.
I was thinking about the Murray ultra stat maybe 180.
Should I get a plastic scraper? Probably cant fit my plastic window scraper in there?
I think I remember hearing the 84 has iron heads so hitting 230 probably didnt hurt it for a few minutes.
I used the gasket that came with the stat.. A razor scraper got the old stuff out of there then I used some emery cloth to finish....
I read several threads where the bolts holding the housing broke or were stuck and hard to remove.. Mine is not a daily driver so I have the time to soak the bolts several times with PB blaster.. don't try to force them out.. Good luck!!
230° is normal temperature for these cars. Start worrying if it goes over 250°.
It will though if it doesnt drop when I switch my fan on over 220 I know somethings wrong
Tonight I let it idle fan on it went up to 229 230 then back down to 210 for a minute and back up. It usually would stay around 190. Fan off it went up to 230 shut engine off it went to 233 right away, so I feel some coolant s circulating but not enough.
I hope you used the correct coolant when you refilled after the last thermo change. Look at your coolant.. hope it isn't brown.
what he means is that we are supposed to use the oldschool coolant that looks like lemonade.
Regarding 230deg temps and no heat from heater core,
i had similar after i drained the coolant.
My heat was working before i did the drain and refill, was yours??
because mine was working fine before, it seemed like a low probability that it somehow blocked during a drain and refill.
So then i figured "air lock".
I wasnt able to build pressure in my upper rad hose, meaning that my tstat was closed or my water pump want working. it was making no noise and worked fine before the drain and refill sooooo....
so i installed the new tstat, drilled two holes in the flange which is there to release air trapped under the tstat (u get air in system when u drain and refill)
THEN I RAISED THE FRONT END ON JACK STANDS.
to encourage any air that was trapped in my heatercore to "rise up"
turn heater on max and fan on max.
filled reservoir to cold line (with the lemonade coloured coolant, not brown)
filled rad to top of cap.
leave cap of rad.
start car
watch the level in the rad its going to suddenly drop.
this means your tstat just opened
keep filling the rad to keep it full
when it stops taking fluid, wait for a bit.....i saw bunbles start to bubble in my rad for a short time then they stopped.
dont run it for more than a minute without the cap on after its been filled and u r looking for bubbles.
close cap.
check upper rad hose that is leaving tstat, should be warm and be filled with pressure
check lower hose, same deal.
check to and from hose at heater core, should be warm.
that should do it unless your waterpump is broke.
if this doesnt work, check back here and post results.
does your fan automatically come on or is it broke?
also, i wouldnt accept a 230 number either. both of mine (85&87) are capable of 180 degrees in the hottest summer day stuck in traffic).
after rereading your post, i would conduct a second drain and refill, pulling the knock sensor which is also a block plug and also pull the oil cooler line if u have one of those. and drain your rad and reservoir.
refill per above directions with the 2 holes in the tstat for air to escape.
if your rad was clogged, i would think u should still have hear from heatercore. unless that is clogged as well. my bet is on air lock.
Last edited by VikingTrad3r; 12-18-2014 at 11:48 AM.
The fan doesnt come on by itself when I got the car a little over a year ago it had a switch to turn on the fan.
I usually switch it on around 210 or somewhere near that,and it goes back to 190-195.
It had only water in the engine then, I drained it and put that green stuff in. There was some brown stuff at the top of the radiator I wiped it off the cap.
Someone said it could be rust that the new antifreeze is taking up.
12-16-2014, 03:22 PM
84 overheating help please
