Dexcool

[96_2DRSPORT]

Ok someone told me that dexcool doesnt have to always be used in the hoes????????? i dont believe everything i hear so can someone please tell this guy what the real deal is and he can see my computer so dont hold no punches lol

 

[grnrpr68]

if you flush all the dexcool out you need to put regular antifreeze back n thats what i do on almost all my cars i think dexcool is junk dont like it at all just flushed all out and replaced with green fluid you will be just fine

 

[96_2DRSPORT]

if you flush all the dexcool out you need to put regular antifreeze back n thats what i do on almost all my cars i think dexcool is junk dont like it at all just flushed all out and replaced with green fluid you will be just fine

they said its for gm cars? why u say its junk

 

[nimrodcs]

I'm pretty sure that from late '95 to '04 GM put plastic intake manifold gaskets on the 3.4L V6, 4.3L V6, and the 5.7L V8. This supposed 5-year, no maintenance coolant contains a plasticizer. Over time, usually at about 100,000 miles (if driven hard) the intake manifold gaskets will start to deteriorate because of the extra chemicals in the Dex-Cool. Then after that, many bad things can happen. I've seen missfires, stuck valves, overheating, etc., its a nightmare.

Best thing to do is to flush it ALL out, a complete back flush, then install rubber Fel-Pro or equal intake manifold gaskets, and refill with glycol coolant (green)

 

[96_2DRSPORT]

I'm pretty sure that from late '95 to '04 GM put plastic intake manifold gaskets on the 3.4L V6, 4.3L V6, and the 5.7L V8. This supposed 5-year, no maintenance coolant contains a plasticizer. Over time, usually at about 100,000 miles (if driven hard) the intake manifold gaskets will start to deteriorate because of the extra chemicals in the Dex-Cool. Then after that, many bad things can happen. I've seen missfires, stuck valves, overheating, etc., its a nightmare.

Best thing to do is to flush it ALL out, a complete back flush, then install rubber Fel-Pro or equal intake manifold gaskets, and refill with glycol coolant (green)

damn thats crazy

 

[Da90]

I had that recently happen to me and after replacing the gasket about a month later the motor started knocking really bad and now I'm dealing with putting a new motor in my hoe! So if anyone has a Vortec 350 for sale with low miles or rebuilt let me know. This just happed last week and I need to get her back on the road. I just had a shop quote me $2500 for a turn key motor replacement with a 3yr 100k warranty. IDK what hell I'm going to do yet?

 

[nimrodcs]

I had that recently happen to me and after replacing the gasket about a month later the motor started knocking really bad and now I'm dealing with putting a new motor in my hoe! So if anyone has a Vortec 350 for sale with low miles or rebuilt let me know. This just happed last week and I need to get her back on the road. I just had a shop quote me $2500 for a turn key motor replacement with a 3yr 100k warranty. IDK what hell I'm going to do yet?

It depends on what is knocking, but you might be able to get away with getting your heads redone and replacing lifters/rockers. Might be a little cheaper. But if its something deeper, a crate motor might be a good investment.

 

[haks310]

Yeah, GM ****** up with their Dexcool when they first brought it out and started running it in their vehicles. After some years they discovered the problem and changed the compounds in it. So new Dexcool shouldn't have the same problem, but seeing as how it has left a bad taste in many peoples mouths, they choose to completely flush their engines and replace it with regular old green. I have heard of guys flushing their systems hours after purchasing their vehicle.

I run regular old green. But either way you go, just like anything else, just keep up with the maintenance of your cooling system and you will be fine.

 

[bishop]

Dexcool is the worst thing you can put in your vehicle (truck,car,gm,notgm) doesn’t matter. I am a licensed mechanic, I've been working in the same shop for 9 years now and every gm that comes in with dexcool we recommend to the customer to flush it out and put the green stuff in.

GM knows now that dexcool is crap but they have had, and still have so many lawsuits about it and its detrimental effects on gaskets (especially the plastic intake gaskets in the 3.1L 3.4L 4.3L 5.7L and soon it will show up on the 3.9L in the Montana sv6) that if they admit it is crap or stop using it they will have to pay everyone’s bills for there repairs. Since they've been using it since the mid-late 90's it would cost them hundreds of millions if not billions.

Having said all that if you really want to use it I recommend this, keep it clean! If you flush it out and put new dexcool in it every 6 months to a year you shouldn’t have any problems. Dexcool is crap right out of the bottle but in there "5 year extended life" it becomes very corrosive.

Some of our costumers come to us before there warranty is up so for then we flush out the old and replace it with new dexcool so it doesn’t void their warranty.

 

[Mattjr79]

i have had all mine changed to regular bc my mechanic told me that dexcool is more acidic that regular and eats away at the internals....so i took his advice

 

[hapyspaz]

Couple things to add here. I also have worked on cars, managed shops, etc for 12+ years.

DexCools original design was flawed, the new stuff you buy is not. The chemicals in DexCool is actually designed for your vehicle. Every time I have had a customer come in that has green anti-freeze in it and is supposed to have DexCool, they have a blown waterpump bearing, or clogged thermostat, or clogged heater core, or ...

The parts of your cooling system are designed to work with these chemicals.

 

[Da90]

It depends on what is knocking, but you might be able to get away with getting your heads redone and replacing lifters/rockers. Might be a little cheaper. But if its something deeper, a crate motor might be a good investment.

I'm not sure if you have priced a Vortec crate 350 lately but they are to the tune of about 5k for a long block. If anything I will buy a short block and send my heads to machine shop. I'm going to spend the same amount on a motor as the truck is worth. Once again if anyone knows where to get a motor let me know! I'm not in a huge rush to get it back on the road cause my family has cars for me to drive but I'm going to do it right!

 

[steamroller]

I'm not sure if you have priced a Vortec crate 350 lately but they are to the tune of about 5k for a long block. If anything I will buy a short block and send my heads to machine shop. I'm going to spend the same amount on a motor as the truck is worth. Once again if anyone knows where to get a motor let me know! I'm not in a huge rush to get it back on the road cause my family has cars for me to drive but I'm going to do it right!

No way is a Vortec longblock 350 $5k, unless your talking dealer prices

4 bolt mains:
http://www.summitracing.com/parts/NAL-12530283/

http://paceperformance.com/index.asp?PageAction=VIEWPROD&ProdID=225981

2 bolt mains:

http://paceperformance.com/index.asp?PageAction=VIEWPROD&ProdID=225980

http://www.summitracing.com/parts/NAL-12530282/

 

[destroyer1362]

Da90, if I were you I would just do the 5.3 swap. Just look for a low mileage motor, 5.3s are dime a dozen. When all is said and done you will end up with more for less $$, than a new installed crate 350.

 

[Da90]

No way is a Vortec longblock 350 $5k, unless your talking dealer prices

4 bolt mains:
http://www.summitracing.com/parts/NAL-12530283/

http://paceperformance.com/index.asp?PageAction=VIEWPROD&ProdID=225981

2 bolt mains:

http://paceperformance.com/index.asp?PageAction=VIEWPROD&ProdID=225980

http://www.summitracing.com/parts/NAL-12530282/

Thanks for the links! I have not looked that hard so... I just googled it and came up some prices and I just stopped looking after I saw what they were asking. I have a buddy checking today from GM for a crate motor. He get cost plus 10% so I will see what he says!? Now that I think about it I may have been looking a 383s