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Dears .. thanks for accepting me as a member in your forum

My story is not too long .. I have impala 96 I swapped the engine to 6.0 small block and since that day the engine is overheated I replaced the radiator but still the same .. my friend told me to change the fans but I'm not sure if that's going to work

I live in Dubai (middle east) and the temperature in summer reach 50 Celsius

Is there anything I can add to the car which will make it cooler

I attached the pictures to let you know how the engine look like

Please I need your suggestions to make my car better … this is my dream car since I was 8 years old and now I'm thinking to sell the car after 4 months of work
 

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I'm not an expert on this, but I do believe your fans are on the wrong side of the radiator. I see too that you have 2 different types of fan blades. You might want to look at some new fans. I may be wrong on this though. I do know about summer in that part of the world, Been there done that, 50C is about what Oklahoma is in the summer. One last thing. DON"T let your dream get away from you.

Mark: Snowman-33
 

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Fans on both sides of radiator are definitely blocking air flow. Especially if working against each other. Stock GM fans are highly effective,and what I recommend. Along with replacing that busted top support. Damaged/missing airdam(s) under the core support also contribute to overheating issues. Last,but not least. Install a 160 degree thermostat,along with re-programmming fan turn on temps. Along with a manual fan switch for added confidence/insurance..
 

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I would consider getting a 4 core radiator. The 4 vans may be a little much at speed, because if they are not turning fast enough, they will block the air going through the radiator. Get a good pair of high CFM fans, and a shroud with pressure relief flaps.
 

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I have a question about your car. I know it's not about your cooling problem but I'm curious. You had said that it was an Impala, but being a middle east car is it really a Caprice SS? They just interest me a bunch. BTW, I did miss the stock fans in the pics. I just looked and was dumbfounded with the mis-matched front fans. Look closely to what you are being advised here. Lots of good information.

Mark: Snowman-33
 

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.......You had said that it was an Impala, but being a middle east car is it really a Caprice SS?......
Mark,

Not uncommon for an Impala SS to end up in the Gulf states.

On one of my tours (Kuwait) I came across four of them.....all brought over by American contractors who said they would sell them when they came back home.

KW
 

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KW
Hey Bud, thanks for the info. All of the Caprices I saw there were the box's. But then most of them were burnt up destroyed hulks on the Highway of Death. Although they are the same, that Caprice SS is different. I don't know why maybe the unavailability here and the T84s.
Dubai, Keep us posted on what you find.

Mark: Snowman-33
 

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I see a few things going on.

You are using the LT1 surge tank as an overfull which will not return spent coolant to the system.

I don't see a bleed line from the heads going anywhere.

Personally I would connect the bottom of the LT1 surge tank to the heater hose return so the water pump is "pulling" on it.
Then connect the head bleeds to the top line on the surge tank.

Drill about a 1/16 hole through the rad cap on the rad so it it just a restrictor.

Tee the rad over flow line to the surge tank too.

All the above is basically putting the surge tank back in the system like it was.


I can't see the rad well enough to make a comment on number of cores.

Many 2 core aluminum rads have just as much heat rejection as old school 4 cores
 

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Yeah,and block airflow the rest of the time. They gotta go...
 

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First of all get rid of the front fans. They are doing absolutely nothing. Except blocking your radiator.

The rear fans are your important ones. In the stock configuration whenever the AC is on one of the fans run. The other fan runs when the temps are above whatever the setpoint is. The "AC" fan will also come on at a set temperature as well.

Since you are not running in a stock configuration you may want to just have both fans come on with the AC and on when the temp is above a certain point. Also make sure all of the shroud is in place as it forces the air to go through the fan instead of around the fan. (No shroud means your just moving air around the fans instead of pulling air through the fan.) If you need a better vision.. Think of a wet dry vac. It has the top part which has the blower/vacuum in it and the bottom half that holds whatever you sucked up. Running your fans without shrouds would be like running the top of the unit without the bottom. It sure sucks but doesn't really do anything useful as the vacuum is not directed properly. Put the bottom back on and you have great suction at the end of the hose. If you put holes in the hose along the way less suction at the hose... Same thing with your fans and shroud.

As already stated you will want to use a 160 degree thermostat and have the car programmed accordingly.

Also as stated you want to incorporate the overflow tank into the system. The biggest issue is the over flow tank is the highest point in your system. This will allow air to come out of the system which is not possible without it. If you have air in your system you will never cool properly. The old LT1's came with an air bleed valve on the water pump. The LSx engines require the over flow tank coming off the "steam vents" to vent all the air off. If you look at the front of the engine there is a pipe or hose that goes from the front of one head to the front of the other head. That pipe/hose also goes through the throttle body. You certainly don't need this hose going through the throttle body but this hose also feeds back to the coolant loop allowing air to be vented from the engine as it runs. if you do not have those steam lines connected somewhere to allow them to vent you will certainly over heat. Since the heads are reversible you will notice the rear of the heads have the same ports on them although they are plugged off. To make the best usage of those steam lines you can take all four and run them to a location to vent.

My truck has the same style engine in it and the steam lines go to the radiator in a spot higher than the engine. The over flow tank in my truck is tied into the top coolant line which is higher than the steam line to the radiator. Since the LT1 radiator does not contain this extra line for the steam lines you may want to tie those into the top hose as well.

If you still have issues you need a different radiator.

So in short... As already mentioned... Get rid of front fans, make sure rear fans are working correctly and properly sealed.
160 degree stat and programming to act accordingly. (Needs programming otherwise car will run poorly and burn WAY too much fuel and plug any catalytic convertors still on the car)
Tie over flow tank into system return (top hose) and also tie steam lines into this line to get rid of air from the heads. You can use the original setup which only vents the front steam vents or do all 4.
Then lastly if this all does not work, get a better radiator. It is possible the 6.0 just produces too much heat for that Lt1 radiator and needs to be replaced but this is your last option. I suspect you didn't reconnect the steam lines and if so that is your biggest issue.
 

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First of all get rid of the front fans. They are doing absolutely nothing. Except blocking your radiator.

The rear fans are your important ones. In the stock configuration whenever the AC is on one of the fans run. The other fan runs when the temps are above whatever the setpoint is. The "AC" fan will also come on at a set ....

Thanks a lot rodney

This is a good plan I will keep you updated
 

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Thanks for the reply

the two fans on the front are for the AC ... they work on high speed when I turn on the AC
when I saw fans on both sides of radiator I did think the ones on the condenser are for AC...
ac is on most all the time at your location ...

since this over heating occurred after engine change maybe a leak or air trapped in system..

run engine with pressure cap off do this on a cold start allow engine to get to temp and rev engine several times pressure tank cap off.. this should remove air on the 6 L engine..

check that the coolant system has pressure if it not having pressure the coolant will boil @212 and then water pump cannot pump air bubbles..

another reason bad head gasket .. if not finding the cause ..compression check .
 

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I believe there is an air bleed at the thermostat cover on top of the intake manifold with the heater hose attached to it.
 

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For the 4.8, 5.3 and 6.0 LSx engines found in 2003-2006 trucks as well as other vehicles probably other years, this is the air vent system.

I have included 3 pictures to demonstrate.

First picture shows the actual steam/air vent where it goes in the engine. The second shows the plugs installed at the rear of the engine. The last one is a blow up of the vent line. The rubber line goes to the TB, then another rubber line goes from the Throttle Body to the Radiator.

Note, some racing shops notice hot spots at the rear of the engine too so you will see a configuration like this installed on the rear as well instead of the plugs with the output from them all going back to the radiator. The intention of these "steam" lines is to allow trapped air and steam to vent back into the system and not over heat your engine.

This is totally different from an LT1 engine.

My understanding is that an LSx engine flows coolant like a standard engine. Through the block first, then through the heads. Where as an LT1 flows through the heads first, then through the engine. So each engine style will have air in different locations thus the different methods of removing air from the system. Note the pictures are straight from the GM service manual for my 2003 Avalanche with 5.3.
 

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.So each engine style will have air in different locations thus the different methods of removing air from the system. ..
Yes but they both have bleeds from the top of the heads where air gets trapped ( regardless of direction of fluid flow)

The best place to to route this to is the highest point in the system.
On a "B" body, it is the surge tank, regardless of where the bleed went when the engine was in something else.

Earlier "F" bodies ran 4 corner bleeds as well but the factory kind of gave up in it .

Yes some builders swear by them.
Depending on engine angle in chassis, I question their requirement

Interesting note, one of our cars is a (name drop warning) Pratt&Miller build with a Katech built LS. They did not feel it necessary to bleed the back of the engine.
While it is not some 1400 hp drag race engine, it is 600+ and runs for hours at a time

I have done more than one build with unique cooling systems.
As long has you get the surge tank as high in the car as you can and run bleeds ( small as #3 is fine ) from areas that are trapped high points . the system will self bleed any air it generates.

Odd ball setups that are hard to bleed because of packaging ( we have one car that traps air in heads till it is running at high speed)
a person would be wise to invest in a vacuum bleeder.

https://www.uview.com/index.cfm?dsp=productdetail&id=45700&productid=5120
 

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For the 4.8, 5.3 and 6.0 LSx engines found in 2003-2006 trucks as well as other vehicles probably other years, this is the air vent system.

I have included 3 pictures to demonstrate.

First picture shows the actual steam/air vent where it goes in the engine. The second shows the plugs installed at the rear of the engine. The last one is a blow up of the vent line. The rubber line goes to the TB, then another rubber line goes from the Throttle Body to the Radiator.

Note, some racing shops notice hot spots at the rear of the engine too so you will see a configuration like this installed on the rear as well instead of the plugs with the output from them all going back to the radiator. The intention of these "steam" lines is to allow trapped air and steam to vent back into the system and not over heat your engine.

This is totally different from an LT1 engine.

My understanding is that an LSx engine flows coolant like a standard engine. Through the block first, then through the heads. Where as an LT1 flows through the heads first, then through the engine. So each engine style will have air in different locations thus the different methods of removing air from the system. Note the pictures are straight from the GM service manual for my 2003 Avalanche with 5.3.
on my 5.3L engine if air is in the coolant system then no heat ... heater hoses warm not hot ..many have had this issue with the 5.3L engines ... start cold pressure cap off idle it until up to temp and then rev it , then the pressure tank coolant level will drop down .. common question in the early winter ... IMO the heater is never used where he operates ..
ac on all the time so the condenser will require max air flow .. probably has a 200amp alternator on this engine ..with 4 fans ...
4 fans on and it runs hot then its a coolant flow problem .. water pump only pumps water so air in the system poor flow and the fans will only cool the block not the coolant ..
 

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So in my truck with a 5.3, there is no other way to bleed the air out of the system than through the steam vents on the top of the heads. The water pump is pretty low on my 5.3. After having the heads replaced on mine (If you have the 706 caltech heads they are prone to cracking. Mine did and was noticeable by the 260k mile mark. ) the heat seemed to work ok and was not over heating but I still lost a half gallon of coolant in my system as the air worked its way out. The steam vents are very small lines but the air did eventually work its way out. But again, those vents go back to the radiator and the radiator t's into the over flow bottle which allows air to get out of the radiator so it all works.

So realistically it gets down to three issues.

#1, have to get the air out of the system. If your engine has steam vents, vent those to the line going to your over flow bottle somehow. Should get the air out even if it takes a little while.

#2, Water needs to be moving around. If the thermostat is working properly and everything else is going well then the size of your radiator may not be big enough.

#3, Air movement. The front fans are doing very little due to the fact there is no shroud to direct the flow. They are likely blocking more flow than they are creating. Rear fans are more than enough. Nothing wrong with running both rear fans all the time when your car is running other than they may burn out faster and may take a little more power. So if you want to just connect them to an ignition source you can. As mentioned before. OEM in those with the electric fans were to have one of the fans come on with the AC and the other come on by temp. (Maybe both fans come on at a higher temp) Since your running the LSx PCM I would have to imagine they have the same turn on/ turn off possibilities as well? You may be able to use those instead but still. As already mentioned. It is imperative to have the shroud in place in the rear to allow the best efficiency of the fans. If the shroud is not all the way in place air can get around it instead of through the radiator.

Also all of this is assuming the radiator is not plugged up either internally or externally.
 
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