Still trying to diagnose a cooling issue... upper hose hot, but lower hose cooler?
08-02-2010, 10:05 AM
#1
Still trying to diagnose a cooling issue... upper hose hot, but lower hose cooler? I've made a couple posts about this and was under the impression I was getting a false reading. My temp gauge in my 00' Camaro will occasionally shoot into the red, rather quickly, but just jump right back down to normal operating temperature. I replaced both the sender, the t-stat, and inspected the grounds and I haven't fixed it.
I'm trying to figure out what's causing this... after some looking around I've noticed that the upper radiator hose is pretty hot, but the lower is drastically cooler (maybe slightly warm to the touch but it's 100 degrees here). I know I replaced the t-stat but isn't this a sign of a faulty one? Is it possible I got yet another faulty T-stat?
What about the water pump, is there any way to tell if it's functioning properly?
Also I've been told a T-stat wont open if air pockets are in the system, that being the case, how am I supposed to get the air pockets out of the motor? I've had the radiator cap off, let the car run, and topped off with coolant as I'm supposed to, but I never see much movement in there to show that it's moving aside from when I was filling it when it would bubble up, which to my knowledge is the air leaving the system.
I'm trying to figure out what's causing this... after some looking around I've noticed that the upper radiator hose is pretty hot, but the lower is drastically cooler (maybe slightly warm to the touch but it's 100 degrees here). I know I replaced the t-stat but isn't this a sign of a faulty one? Is it possible I got yet another faulty T-stat?
What about the water pump, is there any way to tell if it's functioning properly?
Also I've been told a T-stat wont open if air pockets are in the system, that being the case, how am I supposed to get the air pockets out of the motor? I've had the radiator cap off, let the car run, and topped off with coolant as I'm supposed to, but I never see much movement in there to show that it's moving aside from when I was filling it when it would bubble up, which to my knowledge is the air leaving the system.
08-02-2010, 10:13 AM
#2
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I've made a couple posts about this and was under the impression I was getting a false reading. My temp gauge in my 00' Camaro will occasionally shoot into the red, rather quickly, but just jump right back down to normal operating temperature. I replaced both the sender, the t-stat, and inspected the grounds and I haven't fixed it.
I'm trying to figure out what's causing this... after some looking around I've noticed that the upper radiator hose is pretty hot, but the lower is drastically cooler (maybe slightly warm to the touch but it's 100 degrees here). I know I replaced the t-stat but isn't this a sign of a faulty one? Is it possible I got yet another faulty T-stat?
What about the water pump, is there any way to tell if it's functioning properly?
Also I've been told a T-stat wont open if air pockets are in the system, that being the case, how am I supposed to get the air pockets out of the motor? I've had the radiator cap off, let the car run, and topped off with coolant as I'm supposed to, but I never see much movement in there to show that it's moving aside from when I was filling it when it would bubble up, which to my knowledge is the air leaving the system.
I'm trying to figure out what's causing this... after some looking around I've noticed that the upper radiator hose is pretty hot, but the lower is drastically cooler (maybe slightly warm to the touch but it's 100 degrees here). I know I replaced the t-stat but isn't this a sign of a faulty one? Is it possible I got yet another faulty T-stat?
What about the water pump, is there any way to tell if it's functioning properly?
Also I've been told a T-stat wont open if air pockets are in the system, that being the case, how am I supposed to get the air pockets out of the motor? I've had the radiator cap off, let the car run, and topped off with coolant as I'm supposed to, but I never see much movement in there to show that it's moving aside from when I was filling it when it would bubble up, which to my knowledge is the air leaving the system.
Edit: Maybe this is obvious, but some temperature difference between the radiator in/out is normal.
08-02-2010, 04:05 PM
#4
Heater puts out hot air...
radiator is clean as far as I can tell
A/C condensor, yes I believe its clean.
The temp gauge just shoots from 210 to 240-260 randomly and sporadically every 30 seconds or so and then returns to normal.
08-02-2010, 07:33 PM
#5
TECH Senior Member
Bleed air out of block by disconnecting the hose from the crossover pipe, and rev engine 2000 rpm every minute or so...
air gets trapped behind the bypass valve on the end of the thermostat, by revving engine the bypass valve gets pulled open which allows the air to pass thru and get pumped into the block where it travels to the heads, and from here you bleed it out of the crossover tube...
air also gets trapped in the heater core, by revving engine the pump pulls air from the heater core;
for some reason the air can't flow from the crossover tube thru the hose to the radiator neck, so it has to be relieved at the crossover tube.
air gets trapped behind the bypass valve on the end of the thermostat, by revving engine the bypass valve gets pulled open which allows the air to pass thru and get pumped into the block where it travels to the heads, and from here you bleed it out of the crossover tube...
air also gets trapped in the heater core, by revving engine the pump pulls air from the heater core;
for some reason the air can't flow from the crossover tube thru the hose to the radiator neck, so it has to be relieved at the crossover tube.
08-02-2010, 07:35 PM
#6
TECH Senior Member
Then on a daily basis, check cold level and hot level... those two levels should not change daily, if they do you have a leak or a faulty cap (cap has pressure valve and vacuum valve).
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08-05-2010, 10:57 PM
#9
TECH Senior Member
Yes, the one and same crossover steam tube.
08-06-2010, 11:44 AM
#10
Also, should the radiator cap be off and I add coolant as I see it's needed? What should I do if I have a full radiator (With the car running to operating temp) but no coolant coming from the crossover?
Thanks for the help thus far!
08-06-2010, 02:07 PM
#11
How many miles are on the car? Is it the original radiator? It may be clogged. One way of telling is if you have cool spots in the radiator itself. That may be another thing to look into. When your car is at operating temp does the lower hose feel like it has any pressure behind it or can you squeeze it pretty easily?
08-06-2010, 02:44 PM
#12
this happens everytime we put a heads/cam car back together. we usually crack open the driver side crossover tube with the car idleing, and coolant will eventually come out. and usualy we squeeze the coolant tube rapidly, because like already said, its usually cold. and im not sure what it does but it always works, havent had a car go over 210* in the last 8-10 cars
08-08-2010, 12:01 PM
#13
TECH Senior Member
Also, should the radiator cap be off and I add coolant as I see it's needed?
What should I do if I have a full radiator (With the car running to operating temp) but no coolant coming from the crossover?
leave rad cap off until these conditions all coexist:
- coolant exits from crossover tube,
- coolant in radiator is hot,
- both heater hoses are hot,
then reconnect crossover hose, add coolant to rad and install a new cap.
Last edited by joecar; 08-08-2010 at 12:12 PM.
08-08-2010, 12:15 PM
#15
TECH Senior Member
If the crossover tube is clogged with Dexcool gel, remove the crossover tube, blow it out with compressed air, reinstall it, and blow compressed air into it (in an attempt to clear any blockage at vent holes in the heads).
If you have Dexcool gel forming, then the cooling system (block, heads, radiator, hoses, pump, thermostat housing) has an air leak someplace... hopefully that's not it, and your block was just empty.
If you have Dexcool gel forming, then the cooling system (block, heads, radiator, hoses, pump, thermostat housing) has an air leak someplace... hopefully that's not it, and your block was just empty.
Last edited by joecar; 08-08-2010 at 12:20 PM.
08-09-2010, 12:21 AM
#17
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If the outlet is way cooler than the inlet, be happy. The radiator
is doing its job.
I've dealt with a loose ECT sensor connector that acted flaky
like that. Real temperature won't "flicker" or spike instantaneously.
But readings can.
is doing its job.
I've dealt with a loose ECT sensor connector that acted flaky
like that. Real temperature won't "flicker" or spike instantaneously.
But readings can.
08-14-2010, 12:50 PM
#19
Just got around to getting some work done on this today... I'm not overly pleased with the results...
First I removed the upper radiator hose and with the car off I added some coolant, it kept taking a little when I kinda worked the hose and attempted to burp it. Good sign I thought.
Once the upper wouldn't accept anymore coolant I reconnected it, and removed the radiator cap... A little was lost during this process so I topped it off. Everything looked good, nice and bright green (Previous owner switched it off the dexcool crap). At this point I disconnected the hose going into the crossover tube (btw throttlebody bypass is done if that makes a difference) and connected a clear piece of hose to it and watched for coolant, none came out. At this point I started the car watching three things... the radiator cap, which was open; the clear hose hooked to the crossover, and my factory temp gauge.
I let the car run for probably 10-15 minutes and it was showing no signs of overheating, the intake was fairly cool to the touch in fact. During this whole process the gauge showed no signs of overheating at all. The highest it got was probably 205~. I continued to let the car run watching for coolant from the clear hose that never came, and watching to see if I needed to add coolant to the cap. Nothing... Again, the gauge was showing normal. Eventually, some steam started to slowly come out of the coolant cap and it was bubbling slightly, I thought that maybe the thermostat had finally opened. I tested it with my finger and while it was cool just seconds ago, it was now pretty hot. I thought it seemed odd, but the gauge was, for once, appearing to read correctly. Finally, after several minutes running and nothing coming from the crossover, I decided to try and take it for a drive. After I shut the car down, I observed where I was filling the coolant in the radiator again and noticed there were little grey specs in it that weren't there before... fantastic.
I took the car for a quick drive around the block, the gauge is acting up again, just the same as it did before. No change at all. I came back and shut it down and now I'm typing this.
Did I blow a head gasket somehow now? What could these small grey specs be? They look like a liquid of some sort, but not exactly like oil... I have no clue. I'm at the end of my rope with this thing, I have no idea what to do.
First I removed the upper radiator hose and with the car off I added some coolant, it kept taking a little when I kinda worked the hose and attempted to burp it. Good sign I thought.
Once the upper wouldn't accept anymore coolant I reconnected it, and removed the radiator cap... A little was lost during this process so I topped it off. Everything looked good, nice and bright green (Previous owner switched it off the dexcool crap). At this point I disconnected the hose going into the crossover tube (btw throttlebody bypass is done if that makes a difference) and connected a clear piece of hose to it and watched for coolant, none came out. At this point I started the car watching three things... the radiator cap, which was open; the clear hose hooked to the crossover, and my factory temp gauge.
I let the car run for probably 10-15 minutes and it was showing no signs of overheating, the intake was fairly cool to the touch in fact. During this whole process the gauge showed no signs of overheating at all. The highest it got was probably 205~. I continued to let the car run watching for coolant from the clear hose that never came, and watching to see if I needed to add coolant to the cap. Nothing... Again, the gauge was showing normal. Eventually, some steam started to slowly come out of the coolant cap and it was bubbling slightly, I thought that maybe the thermostat had finally opened. I tested it with my finger and while it was cool just seconds ago, it was now pretty hot. I thought it seemed odd, but the gauge was, for once, appearing to read correctly. Finally, after several minutes running and nothing coming from the crossover, I decided to try and take it for a drive. After I shut the car down, I observed where I was filling the coolant in the radiator again and noticed there were little grey specs in it that weren't there before... fantastic.
I took the car for a quick drive around the block, the gauge is acting up again, just the same as it did before. No change at all. I came back and shut it down and now I'm typing this.
Did I blow a head gasket somehow now? What could these small grey specs be? They look like a liquid of some sort, but not exactly like oil... I have no clue. I'm at the end of my rope with this thing, I have no idea what to do.
08-14-2010, 01:12 PM
#20
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Take a deep breath and calm down mate, all is not lost. Grey debris can't be the head gasket unless someone has changed them to graphite style which is just stoopid. Can do a TK leak down test to verify. Just like a pregnancy checker if it turns blue your screwed
Firstly how old is the t/stat.
Second get a powerade bottle cut the base of and use it to fill the rad with the bypass x/over off. Leaving the top hose off just leaves your system open so make sure it's on.
Thirdly, get a digi thermometer can help diagnose a bad guage.
Four, borrow or buy a ECT sensor.
Five, to do a awesome on car coolant flush 5l of table white vinegar and water. Won't hurt anything unlike some proclaimed radiator flushes.
If you follow these steps and it still Seems like it is genuinely overheating I'd be looking at a blocked radiator or something severley blocked in the block.
Firstly how old is the t/stat.
Second get a powerade bottle cut the base of and use it to fill the rad with the bypass x/over off. Leaving the top hose off just leaves your system open so make sure it's on.
Thirdly, get a digi thermometer can help diagnose a bad guage.
Four, borrow or buy a ECT sensor.
Five, to do a awesome on car coolant flush 5l of table white vinegar and water. Won't hurt anything unlike some proclaimed radiator flushes.
If you follow these steps and it still Seems like it is genuinely overheating I'd be looking at a blocked radiator or something severley blocked in the block.