Thought I'd ask the car buffs here a question.

If you have a good car message board please link me!

Alright... today driving in my '96 Blazer my engine overheated for the first time. I was not running the A/C. I let up on the gas and coasted and the temp dropped fast to about a quarter of the way on the temp gauge.

What would make my engine heat so damn fast!?! It was all the way in the red and the "Check Gauges" light came on.

I'm thinking Because it is a 96 and it is the year 2001 that the Dexcool anti-freeze/coolant is due for a change (they say it lasts 5 years).

Right now I'm kinda strapped for cash... to have the dealer drain and fill, it will cost $49.99

Ouch.

To have a full flush... $129.99

Double ouch.

I have changed normal green stuff with no problems in cars I have owned in the past. But they tell me Dexcool is a whole new beast and you have to get the mix just right and it's not like the green stuff where you can get it sorta right...

I'm hearin horror stories.

What should I do?!? Try to drain and fill myself and get the full flush when I get cash?

Let it overheat and crack the engine block and say "oh well!" and have a very nice looking lawn ornament?

FYI: all the fluids are topped and I just had the oil changed yesterday.

Think it could be old Dexcool?

This is all I need....

So i'm driving my lil camoed 91 Ford Ranger. 4 Cyl-
And for some reason, IT WON'T GO INTO REVERSE!!!!
Just like a "grrrrrrrrrrrruuuuuuuuuddddddddggg" sound whenever I go 2 shift in2 reverse.
Every other gear is fine.

Someone today told me it was just fluid...

God, I hope so.

Slipping belt?
Stuck thermostat?
Blocked or plugged radiator?
Worn-out water pump impellers?  Don't laugh, it happened to my son on a 96 Chevy.  96 was not a good year for Gen. Motors.


See if it is still full of fluid.  It can build up an air bubble causing water pump to "lose its prime. It may need topping off again  I think there is a drain thing near the lower radiator hose.   That caused my sons 96 Chevy to overheat.
marsh

If you do not have any coolant leaks, then I'll bet that your thermostat is to blame.  I'd check that, and replace it if necessary.

As far as the coolant, a "flush" will supposedly pressure clean the block, radiator and hoses.  You can do a simple "drain and fill" yourself, but I'd check that thermostat first.

Your waterpump may be next, but start simple and go from there.

When your car overheats, you can get more than just a cracked head. The waffer thin gaskets between the head and block disintergrate fairly quickly with extreme heat. Prestone will start to seep into your block either way.

Actually, you are supposed to change the anti-freeze once a year unless you add a nuetralizer/lubricant to the mix. Acids build up in the fluid and corrosion builds very quickly.

There is a anti-freeze called Sierra that is biodegradable and is supposed to be close to Prestone in protective ability. There are many flush solutions out there. Empty out the old stuff. Fill with water and flush solution. Run the engine for a while. Replace with Anti-freeze and water. You are supposed to use distilled water in the cooling system, it doesn't leave mineral deposits and such.

Thanks for the advice guys.

I don't wanna mess with it since it is still under warranty.

I found a place that will do a full flush for $50

He said depends on how bad it is... I've read some bad stories about Dexcool, like it turns to apple sauce and plugs EVERYTHING. Search for Dexcool and sludge and you will find a lot of info on it.

Damn American cars... if that damn Toyota 4-Runner had just a little bit more room... or I was built like a 4 foot asian man I woulda got that instead of this nightmare. I got it 6 months ago and in the first week I had it in the shop 5 times. Replaced the master brake cylinder, the 4X4 servo, had the computer upgraded, various recall fixes on the anti-lock brakes...

ugh...

I had a thermostat go out once, but it wasn't sudden, but a gradual occurance. The engine temp would reach a higher point everytime I drove. I even tried to delay the inevitable by running the heater full blast when it was 90 degrees outside. This lasted for about 2 weeks before the gauge started going into the red zone and I had to finally take the car in to get fixed.

Yeah it could be that.... makes sense huh?

Well it's time for it to be changed anyways... so I wanna replace any fluid and then go for major parts. I'll have to pay a $200 deductible for any warranty service.... :(

Tomorrow I think I'm gonan take it to that one place and have it flushed for $50

I have always found that its a good idea to change the thermostat whenever you flush the system.  Seems like the stat goes bad soon after the flushing if you dont.Probably your themostat stuck briefly causing the overheating to begin with

Ditto the above on changing the thermostat! They cost like $5.00. You should change out the radiator hoses now also.(they're 5 years old)When these things decide to "let go" it's always when you are in the fastlane going 75 in rush hour when it's 105 out and trust me, you will loose the motor! (don't ask how I know this to be true)

You can always just take the thermostat out if you don't need the heater.  It's pretty easy on most cars.  Or at least it used to be.

I used to have overheating problems on a firebird with the original 305sb radiator
when I put in a 383 chevy, it would run about 210 with even the lowest temp thermo, took the thermo out and put in the smallest restrictor plate I could find and it never went above 150, HAVE BEEN TOLD NUMEROUS TIMES HOWEVER by a buncha folks that running a motor under 180 will shorten it's lifetime almost surely. a cool temp can give you a better charge and horsepower which was worth it in my case anyway and hell the thought of it wearing out faster just meant I got to build a new one for it that much sooner (entertainment to me back then) but I sure would be afraid to even replace spark plugs on a 96 blazer all those wires and tubes and little boxes with bundles of wires coming out just frighten me. Plus running at a too low temp on one of them would probably play tricks with the cpu and cause it to go full rich or retard on the timing or some other stupid crap.

I flushed a moonfish today.

Yeah man...

I did a lot of work on 1980 Toyota pickup truck.

My new Blazer?

Shit... I don't even know where the damn spark plugs are, hell do they even use spark plugs?!? Everything is jammed together and looks like the inside of a Sun UltraSPARC server.

And my current problem is the coolant isn't even green anymore. Weird ass orange.

The temop readings is weird... At idle it gets halfway... I stop and go and it almost peaks at red. Crusing on the freeway it stays at a cool quarter of the way.

I think the coolant is just bad, what do you all think? I know theses newer cars have eletric fans and when they reach a certain temp it turns on. But it should NOT be getting anywhere close to red. It's warm out but not hot.

Like I said before... it's due for a flush so I'm gonna start there and see what happens.

Hope I start my new job soon... :(

Good points although I didn't mean to leave it out forever.  If it's 90 degrees you'll probably be OK.

Then again I quit working on my own cars the first time a saw a wire connected to the carb.  

You mean people actually drain and flush cooling systems? I've been driving for 26 years and have owned God only knows how many cars, vans and trucks, and I never purposefully drained and flushed a system. Never. And I've never had a single problem that could be traced to lack of cooling system maintenance.

It always sounded like an anti-freeze mfg's way of selling more product.

Frankie, DexCool is SUPPOSED to be orange. That's it's normal color and it is supposed to last for 100,000 miles. My wife's 96 Pontiac made it to 81,000 on the original antifreeze before the water pump developed a leak and the DexCool was still just fine. Unless your coolant level itself is too low, I very much doubt that your overheating problems are related to the antifreeze. If you are loosing coolant I would check the water pump very carefully. GM designs them so that they start to leak a small amount of coolant through a weep hole and the leak gets bigger as the condition of the pump worsens. The thermostat or the water pump are the most likely culprits. The $50 for a flush will probably just be wasted money. If the vehicle is still under warranty, I would take it back to the dealer and have them fix it.

And DO NOT run this vehicle without a thermostat. You can get away with it on an older non-computer controlled vehicle, but the ECM in newer electronically fuel injected vehicles monitor engine operating temperature and use to information to help determine the fuel mixture that is injected into the intake manifold. Running too cold can cause your EFI system to run in closed loop mode, which will make it run too rich and use excessive amounts of fuel. Performance and economy will definitely suffer.

I personally would do this sort of coolant sytem work myself, but if you are unfamiliar or uncomfortable with basic mechanics and these ECM/EFI systems, take it to someone who is. If it were my vehicle and still under warranty, I would take advantage of that warranty.

Check your coolant for any rust colored gunk
that would most likely be present in the recovery jar or the fill neck of the radiator. If the thermostat is working properly and no apparent engine damage has occured your system could be degraded or plugged with the residue from dexcool. GM has issued a service bulletin basically stating that some years and engines are prone to this dexcool breakdown condition .
It occurs when the engine is shut off and air pockets are present in the system, the dexcool reacts and turns "grainy" ,this has the effect of oveheating the engine and reduced heater performance when the vehicle is running. Since the design of the engine allows for this to happen it can reoccur over time . The fix is to flush the coolant and use a two part prestone flush kit one part of the kit is run in the engine to "boil " out the gunk but it is very
corrosive and has to be neutralized by the second part which is run through the system to remove and neutralize the acid. The radiator cap and probably the thermostat will have to be replaced as well. In some cases the heater core will not clean up and require replacement. If you have a local GM dealer in the area and would like them to help have them reference GM bulletin 99-06-02-012B for further instructions.
It may be covered by them for this condition . This all assumes that the waterpump etc and other things are not contributing to the problem. Dexcool seems to work well but also seems to be overated by the industry. Hope this helps.  Dustdevil out....

My money is on a clogged radiator.  Here's the scoop on Dex-Cool straight from GM:

Forget 5 years, 50,000 miles.  How long it will last depends on where the vehicle was assembled.  Blazers/S10s are assembled in Shreveport, LA.  The water there sucks leading to clogged radiators.  Took GM a couple of years to figure it out.  

Here's how to tell: Run the engine until the thermostat opens; feel the top of the radiator and then the bottom.  Betcha the botton is about 40 degrees cooler.  

Odds are a normal flush won't get it all out.  I've pulled three S10 radiators in the last five months; all had to be flushed by a radiator shop.  If I recall correctly, an S10 radiator should flow about 18 GPM.  The last one I did ('96 Blazer) flowed nine.  

Make certain you replace with Dex Cool.  the green stuff has silicates which will destroy the cooling system in a matter of months.

Another trick: Check the voltage in your coolant.  Place the positive lead of a volt meter in the coolant and the negative on a known good ground (- on the battery if you can reach it).  If it's more than .003 volts it will lead to corrosion.

Good luck,

Eddie

As Boomer said "Dexcool is supposed to be Orange" and for those who say you are suppose to change it every year, wrong "5 years 100,000 miles.  Itried to have mine changed and they refused to do it because it didn't have 100,000 miles on it.

Frank
Look for the easy stuff first
All of the above is good info but no one said a thing about a collapsed hose.  
Shadowjack1

Betcha it heats up normal and then shoots up towards the danger zone.  As long as you keep moving at 45 or so it will stay out of the danger zone, but still higher than normal.

Eddie

Now [i][b]that[/b][/i] sounds familiar! [B)]

frank,this is a commom concern with 95-96 blazer and bravada vehicles with the 4.3 engine.G M has issued a long service publication on this subject.it involves a very detailed flushing procedure that in my experiance is only about 60% effective. contact your local GM dealer for a copy of this publication. not to be negative but do not be suprised if a new radiator and heater core are in your future.

It sounds like a bad thermostat to me, if the temp dropped suddenly. There was all that cool liquid in the radiator just waiting to rush into the engine once the thing finally opened.

It's bad to run any car without a thermostat, except a thermosiphon Model T. It will run way too cool, and combustion conditions won't be right. Power and gas mileage will suffer. Worse yet, water and other nasties from burning hydrocarbons will condense in your oil and never steam out. This makes your oil corrosive and maybe even foamy. Foamy oil doesn't pump well.

I never flush my coolant unless I'm just working on the engine or it really, really looks brown and nasty.

One thing to watch out for when having your temp spike and then go back down is that it goes back down when all the coolant leaves if you had a rupture.  This happened to a friend of mine and he kept driving as the temp guage started to drop.  Except he had no coolant left. So he warped the head and cracked his block.  This was on a Honda Civic.  If you see a temp spike, pull over and check it out.

Thank you all for your help.

I know Dexcool is supposed to be orange, I was saying how my Blazer is all alien to me compared to my 1980 truck.

I have found the problem [:(]

Doing some research on the web... MANY and I mean MANY MANY MANY people have had sludge in their radiators due in part by the Dexcool. With Blazers it seems the cap is also contributing to the problem and should be replaced.

Well... I asked about this a long time ago and the dealer shop said they check for it and mine was fine.

I took off my radiator cap a few minutes ago...

[img]http://www.imcool.com/images/Cap1.jpg[/img]

[img]http://www.imcool.com/images/FillerNeck1.jpg[/img]

A spittin image.

And I always saw this: [img]http://www.imcool.com/images/bottle.jpg[/img] and the dealer said it was normal.

heh...

It looks like brownie mix was poured in my radiator. Yep... I am one of the millions with the Dexcool nightmare.

Read about it here: [url]http://www.imcool.com/articles/anitfreeze-coolant/dexcool-macs2001.htm[/url]

And do a search for Blazers and Dexcool and see all the complaints from people.

for now I poured in some Dexcool straight into the radiator. It was low for some reason. The reservoir is full, but the radiator had the brown gunk powder on the top...

Some say a full chemical flush to fix this.

Some say new radiator, new heater core and a week on the flush machine plus more parts replaced.

It is still under warranty..

I have a $200 deductible and right now I'm between jobs... I will probably start work 2 weeks from now...

I'm gonna try the $50 flush first thing in the morning, maybe a new cap.

When I start working again I'll have them do a super duper flush or I might have them replace everything.

This couldn't have come at a worse time... fuckin American cars... this damn thing is a fucking lemon. I need to sell it fast and get something Japanese.

Check the Thermostat.

Flushing the Dexcool isn't that bad, I've done it many times.  Flush and change the fluid, don't forget the engine block.

When you replenish, make sure you use distilled water and NOT tap.

good luck.

I put that stuff in my Mom's  '92 Volvo (235k miles)about 4 years ago.  I guess I better find some time to flush it out again.

This is going to get technical....Your cap is fucked...your radiator is screwed...your resivoir needs major cleaning and your heater core is proabaly shit.

Take this POS into the dealer and have all those parts replaced.  And bitch like a mo fo until you get it.  Thats what the warranty is for.  If they do not, complain to GM direct and/or the BBB.

Flusshing ain't gonna do shit. don't waste your money-you can't polish a turd.

My POS car did the same thing (same year)  I replaced/flushed the old crap out and refilled with new orange crap-now its brown again-here I come Nissan!

From all the boards I've read it says a major chemical flush fixes everything.

And yep my cap is gone.

Know why it was overheating?

There was so much sledge on it that it was not working properly, so that's why I was getting weird boiling points and then fast cool downs.

And the radiator was dry...... ugh... it was not sucking from the reservoir which I was told by my manual to only use to check the water level and not the radiator itself.

I poured in pure Dexcool and scrubbed the cap clean and cleaned out the radiator nose of all the crud. Went for a test drive last night down the freeway and some stop and go and the temp never got past a quarter of the way.

Ya know this fuckin pisses me off... I am on a first name basis with the people at my GM Goodwrench service place, that is how often I am in there with so many damn problems I've had, and they always say "we will check everything, we will do a full inspection blah blah blah"

Yeah... I guess they didn't think of checking for sludge in my radiator, a problem that EVERYONE with mid 90's Blazers seem to have...

Well it seems to cycle, I was also running the heater an it gets VERY got. A way to know if your heater core is not clogged.

Well... I can't spare any money... $200 for my deductible is money I can't spend right now, I can't spend $50... but I think I'll have to just as a temp fix to get me to my job interviews to Sacramento and for the first two weeks of the job I start.

After that I'll take a whole Saturday with printed out pages and pictures of my sludge system and what needs to be replaced and they WILL take care of it.

I already know what they will say, a flush. Well I will make them sign something saying if I pay their $150 for a flush and I do need to replace parts that I will only pay $50 more for my warranty deductible.

Think I'm askin for a lot?

I can't believe my water was low... I cannot... believe it..

O keep my fluids topped off like it is my fucking religion!!!!!!!!!! I change my oil WAY before it is due for a change. I don't hotrod my cars either, I baby the hell out of them.

And this is what I get.. a dry radiator that overheats... I feel sick...

I always keep my fluids topped.... damnit.

That's what I get for following the manual.