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okay so I have a stupid question.. if you read my coolant temps above the upper hose is cooler than the lower by a substantial amount. I thought I remembered reading about cooling flow direction so I looked it up again.. Heres the picture I found. Are we overlooking something so simple or is this diagram wrong?
okay so I have a stupid question.. if you read my coolant temps above the upper hose is cooler than the lower by a substantial amount. I thought I remembered reading about cooling flow direction so I looked it up again.. Heres the picture I found. Are we overlooking something so simple or is this diagram wrong?
Okay so i let my 2013 silverado run through a complete heat cycle while monitoring everything. I used those numbers to compare to my camaro..
Okay so lets start with lsx motors being reverse flow. To those who may not know what this means, it means the the coolant flows into the motor from the lower hose and out the upper hose. Now with that, my truck when temped throughout a full heat cycle would show 215 upper rad hose and 99 low rad hose. From what i gather my truck has a 195 thermostat.
So now onto the camaro. First 5 minutes, lower rad hose was cooler than the upper. Okay, cool. After that, they ramained very similar in temp. I think i have it figured out and ill run i by you guys and see what your opinion is.
If you notice in the picture below, my downpipe ( 4") is only an inch away from the rad hose. Now i temped it with the car running and even though the downpipe is wrapped its still seeing 300+ degree temps.
So now im thinking the downpipr is heating up the what should be " cool " coolant going into the motor. If im thinking right with my theory, my car is reacting as if the thermostat is " stuck open". Reason im saying this is because the downpipe i believe is reheating the already "cool" coolant and making sure the thermostat never has a chance to close and regain a lower temp.
Some pretty good logic there! Can't help that's for sure. Check the temp of the lower hose right at the radiator and then right over the down pipe. That'll tell you if it's hearing it up. Worse case, unwrap the down pipe, make a heat shield an rewrap it. Any deflector will make a big difference. Take a piece of steel and hold it a quarter inch from your downpipe while the car is running. Bet you won't feel any radiant heat from the pipe.
ok that steam vent is a by pass for water meaning it can circulate without going thru the radiator. I dump mine into the upper waterpump neck so it goes thru the radiator.
my hot side is unwrapped and a lot closer than yours and I have no issue so that should work good it looks very good.
where is the timing when driving easy. ?
get it running and check the heat at the tanks see if that rad/fan setup is removing heat . I can tell you if you don't have a ton of airflow on that turbo it will radiate heat into the rear core of the radiator and reheat that water. so make sure there is a good temp drop from driver to pass side tanks. that should be very accurate being there aluminum.
you might try removing the rear hood seal to help get heat out of the engine compartment. if you close the hood and the heat is trapped it will just circulate and keep getting hotter.
its a good idea to close the hood and try to block off any area where under hood heat can get from the engine compartment back to the fans . make sure it has to suck cool air and push it thru the radiator.
you will need good fans on that car as it looks like you will not get much help from road speeds with the intercooler up there. hope you get it cooler. good luck.
okay so to answer your questions. i have removed the hood gasket ( awhile back) and it didnt help ( or if it did, it wasnt noticable). Now, the next thing is airflow, i built an airdam and like previously stated im not overheating yet but its going to happen. At idle, once it hits into the 215's, itll start sowly creeping up until i shut it off. My truck, does not do that, so this isnt right. ( obviously).
According to charts i read, i have plenty of fan for my setup being a small block. They claim you need 4000 cfm. I have 5200 cfm as pushers ( 80% efficiency) . So, in theory that should not be my issue.
From what i know now about cooling steam vents and reverse flow patterns, my steam tubes should of vented to the upper hose not the thermostat housing. I do not however think that would solve all my cooling problems but it may help them.
As stated previously i think the downpipe is heat soaking the rad hose and causing the fluid to reheat and allow the thermostat to stay open all the time.
Now, as you can i have the downpipe wrapped. ( 1 layer).. Can i mulilayerthe heat wrap on the downpipe to achieve more cooling efficiency?
What i can tell you about the end tanks is the rad isnt hot. When the temp of the vehicle is 225 the radiator ( this is a full idle heat cycle so now air has hit the rad) Is only 143 degrees.
If you measure from the radiator side of the lower hose then measure it on the thermostat housing side, it has substantially raised once its passed by the downpipe.
Although it's just simantics, an LS cooling system is not a reverse flow system. In a reverse flow system, the coolant enters the head first, then goes through the block. Not the case here. Either which way, when the engine is 225, you shouldn't be able to touch the radiator without burning your hand (above the fan that is). Below the fan is another story. How much timing at idle? Low timing will affect exhaust/engine temp tremendously. Don't believe the whole "the coolant is going too fast through the radiator" BS. The engine temp should definitely stay in check while sitting idling. If that's not straight, typically your problems will only become worse when driving. I'd still mount some sort of heat shield between the DP and the radiator hose if you think that's a problem. Bend up some cheap thin wall aluminum and metal zip tie it temporarily to the DP as it sits right now. Easy enough to try, just be sure you have an air gap between the pipe and the heat shield. Otherwise you'll conduct heat from the pipe to the shield rendering the shield useless.
I will have to see what mine does when idling but you should not be overheating at idle
whats the chance you have a bad thurmostate or the wrong one?
whats your timing table like.
I will post my hot side and you will laugh at how tight it is and I run it unwrapped. mine runs 195 all the time in 90* heat.
I whould think you whould be cooler at the pass tank than 143* id think more like 100.
my timing is sitting at 18 to 19 degrees at idle. it was previously at 34 degrees at idle and did the exact same heating issue.
one thing I can add to this is I went and checked the part number on my thermostat and its actually a 160 degree not a 180. I can post a part number if that helps the situation at all.
Originally Posted by yenkomike
here is mine .
I run it thru that opening then down about 6" to radiator to tell you the truth I expected issues but it has been fine 2 years now.
yours does look extremely close. Cant believe you have no overheating issues. If your car is done, get some hose temps so we have something to go off of on a car that doesn't overheat.
Originally Posted by 3 window
Although it's just simantics, an LS cooling system is not a reverse flow system. In a reverse flow system, the coolant enters the head first, then goes through the block. Not the case here. Either which way, when the engine is 225, you shouldn't be able to touch the radiator without burning your hand (above the fan that is). Below the fan is another story. How much timing at idle? Low timing will affect exhaust/engine temp tremendously. Don't believe the whole "the coolant is going too fast through the radiator" BS. The engine temp should definitely stay in check while sitting idling. If that's not straight, typically your problems will only become worse when driving. I'd still mount some sort of heat shield between the DP and the radiator hose if you think that's a problem. Bend up some cheap thin wall aluminum and metal zip tie it temporarily to the DP as it sits right now. Easy enough to try, just be sure you have an air gap between the pipe and the heat shield. Otherwise you'll conduct heat from the pipe to the shield rendering the shield useless.
19 at idle now was 34 before and still acted the same way.
im going to start with a heat shield after work and see what that does. does anybody know if I double wrap the downpipe if thatll lower the downpipe temp?
Is the DP that hot? What wrap did you use? I've heard of some wraps allowing you to be able to touch the pipe when it's running. I think it's lava wrap or something like that. I'd say eventually it's goin to heat soak and stay whatever temp it gets up to an matter how thick you wrap it. It'll just take longer to get up to temp on the outside. Make sense? Just for an example, I have another car that the steel fuel line runs about 1/2 from the header just before the collector. I made a small shield and split the difference and I can sit with my hand behind the shield and feel no heat at all on my fuel lines.
Is the DP that hot? What wrap did you use? I've heard of some wraps allowing you to be able to touch the pipe when it's running. I think it's lava wrap or something like that. I'd say eventually it's goin to heat soak and stay whatever temp it gets up to an matter how thick you wrap it. It'll just take longer to get up to temp on the outside. Make sense? Just for an example, I have another car that the steel fuel line runs about 1/2 from the header just before the collector. I made a small shield and split the difference and I can sit with my hand behind the shield and feel no heat at all on my fuel lines.
the wrap your referring to is lava wrap. The turbo blanket I have is made from that. ( pulverized lava rock) . My turbo never sees temps over 150 degrees.
The wrap I used on my downpipe I only did 1 single layer of it, and its thermal zeros high heat wrap. Its supposed to withstand like 1500 degrees or something like that so I figured its plenty.
I considering trying a heat shield just for peace of mind and see how that effects it.
The heat shield can't hurt. Not to open a powder keg, but are the heater hoses used, capped or looped? As far as the tstat staying open, it's going to no matter what. Tstas only stay closed to allow the car to heat up. After that it's just a restriction. Rarely is a system going to cool enough for a tstat to close again. Unless of course we're talking winter driving. Pull the stat and put it in a pot of water with a thermometer and verify when it opens. Wouldn't be the first time I've seen a brand new part bad. The curve ball is that the radiator is 140 degrees when the engine is 225. That means no coolant flow. Or is it 140 with the fans running? If that's the case, maybe you pushed a head gasket and youre pumping some compression into the cooling system causing excessive temps. You wouldn't necessarily be losing coolant either if you pumping compression into the system. They make testers to see if you're blowing exhaust into the coolant system. Might be worth a check too.
The heat shield can't hurt. Not to open a powder keg, but are the heater hoses used, capped or looped? As far as the tstat staying open, it's going to no matter what. Tstas only stay closed to allow the car to heat up. After that it's just a restriction. Rarely is a system going to cool enough for a tstat to close again. Unless of course we're talking winter driving. Pull the stat and put it in a pot of water with a thermometer and verify when it opens. Wouldn't be the first time I've seen a brand new part bad. The curve ball is that the radiator is 140 degrees when the engine is 225. That means no coolant flow. Or is it 140 with the fans running? If that's the case, maybe you pushed a head gasket and youre pumping some compression into the cooling system causing excessive temps. You wouldn't necessarily be losing coolant either if you pumping compression into the system. They make testers to see if you're blowing exhaust into the coolant system. Might be worth a check too.
the heater ports are capped off. To add something else I just thought of, im using a standard coolant overflow tank not a pressurized one like a normal everyday ls would. Not sure where thatd play into the factor of this..
I honestly think that im right with saying the thermostat opens and closes. If you read the system on my truck, the temp of the housing and the lower hose are around 100 and the thermostat is a 195 degree. Meaning it should technically be closed at that point. I ran it for a half hour that way in 90 degree weather and it continuously stayed like that. Temp never went over 105 on the lower hose of my truck.
The motor is a brand new oem longblock that now currently has about 5 miles on it or so and has never seen any sort of boost. So the chances of it being head or gasket related are not too likely. Bad thermostat, maybe.
I have my fans on constantly because if I don't the car will overheat.
Let's think about this. Your upper hose should always be hotter than your bottom hose once up to temp correct because the radiator cools the coolant, right? Yep, if not, that means the coolant isn't flowing through the upper hose. Why would the coolant not flow through the upper hose? Only a bad pump or a restriction not letting the coolant out of the radiator. Notice on an LS engine the tstat is after the lower hose. The tstat extends into the water pump and is exposed to the recirculating coolant from the water pump. After the tstat, The coolant goes from the block to the heads to the pump, recirculates down to the tstat and back into the block. Once the stat gets to temp, it opens and allows the coolant from the radiator into the block. This is really simple. I'm not being demeaning at all, so please don't be offended. Maybe your stat isn't opening fully?
Let's think about this. Your upper hose should always be hotter than your bottom hose once up to temp correct because the radiator cools the coolant, right? Yep, if not, that means the coolant isn't flowing through the upper hose. Why would the coolant not flow through the upper hose? Only a bad pump or a restriction not letting the coolant out of the radiator. Notice on an LS engine the tstat is after the lower hose. The tstat extends into the water pump and is exposed to the recirculating coolant from the water pump. After the tstat, The coolant goes from the block to the heads to the pump, recirculates down to the tstat and back into the block. Once the stat gets to temp, it opens and allows the coolant from the radiator into the block. This is really simple. I'm not being demeaning at all, so please don't be offended. Maybe your stat isn't opening fully?
Well heres another question to go along with this. Would the front steam tubes being plummed into the lower waterneck behind the thermostat ( engine side) cause any issues like this? I mean in theory im putting hot coolant back into the already hot motor.
How often do new thermostats go bad in these? Not too up on them.
The steam lines being pumped back into the back side if the pump may not be the best bet. As I understand, they should be on the radiator return side or in the upper hose. Which makes sense, you want ALL of the coolant to go through the radiator. Otherwise, it's just recirculating some hot coolant. The water pump does that until the stat opens then the coolant goes to the radiator for cooling after the stat opens allowing the coolant from the radiator to the engine. The fact that the upper hose is cooler than the lower is still stuck in my head. The upper is the "hot coolant" return. Id pull the stat and check it then just leave it out for a test and just see what happens without it. Could it be defective from the factory? Hell yah! Very possible. At least you'd know if it made a difference. Really without it, all your temps should be close until the fans come on. That upper hose should be scorching. I'd try it. What's it on a hurt? I know antifreeze is a pain in the ***, but it's worth it to me. Hell, if it finds the problem, you could be out in a few hours enjoying your car and not worrying about it anymore.
The steam lines being pumped back into the back side if the pump may not be the best bet. As I understand, they should be on the radiator return side or in the upper hose. Which makes sense, you want ALL of the coolant to go through the radiator. Otherwise, it's just recirculating some hot coolant. The water pump does that until the stat opens then the coolant goes to the radiator for cooling after the stat opens allowing the coolant from the radiator to the engine. The fact that the upper hose is cooler than the lower is still stuck in my head. The upper is the "hot coolant" return. Id pull the stat and check it then just leave it out for a test and just see what happens without it. Could it be defective from the factory? Hell yah! Very possible. At least you'd know if it made a difference. Really without it, all your temps should be close until the fans come on. That upper hose should be scorching. I'd try it. What's it on a hurt? I know antifreeze is a pain in the ***, but it's worth it to me. Hell, if it finds the problem, you could be out in a few hours enjoying your car and not worrying about it anymore.
Heres what i just tested.
At 220 laptop temp
Lower rad hose before dp 192
Low after dp at therm housing 212
Dp 330
Upper hose 195
Not sure if i posted above or not, but i was wrong. It has a 160 thermostat.
Did/can you calibrate the sensor? Does it seems accurate at ambient air temps? You might have to scale the gauge/sender through the ecu tuning software. If you're reading those temps you posted, go drive it and enjoy. 190s-210 sitting still is fine. Look at it this way, the sender could be off 10 degrees. So it's reading 218 and you're not even 210.
Did/can you calibrate the sensor? Does it seems accurate at ambient air temps? You might have to scale the gauge/sender through the ecu tuning software. If you're reading those temps you posted, go drive it and enjoy. 190s-210 sitting still is fine. Look at it this way, the sender could be off 10 degrees. So it's reading 218 and you're not even 210.
The problem is, thats in 75 degree weather not 100. Thats also with me not beating on it. If i even get on it a little temps go up. I cant take it more than 5 miles without it getting up in temp.
Im thinking about swapping the t stat out for a 180 and move the steam port to the upper hose.
Didn't realize that you weren't able to drive it. I'd try moving the steam lines. Not sure the stat is going to make that big of a difference, but it's easy enough to try. I'm out of ideas right now. lol.
08-14-2015, 05:48 PM
