95 Sc300 radiator bubbling issues
09-03-14, 02:59 PM
#1
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95 Sc300 radiator bubbling issues
Please Help? I have a 95 sc300 #PreppyOne and i have just come into a lot of problems and i have been looking for weeks/months for real answers online:
#2 My car keeps getting really hot on top i have been constantly replacing dried out and rotted plugs all over the cars engine. but it never over heats. i have flushed and burped the system, replaced the thermostat, radiator hoses and yes im using Toyota red coolant. Today i tried removing the thermostat because my bottom radiator hose never felt like fluid was going in it and was always ice cold. after today i found out a little more about how the system works with the thermostat on the bottom hose. The problem is replacing all the plastics cause it gets too hot on top and if the car sits running or i drive awhile when i stop the reservoir bubbles.
#2 My car keeps getting really hot on top i have been constantly replacing dried out and rotted plugs all over the cars engine. but it never over heats. i have flushed and burped the system, replaced the thermostat, radiator hoses and yes im using Toyota red coolant. Today i tried removing the thermostat because my bottom radiator hose never felt like fluid was going in it and was always ice cold. after today i found out a little more about how the system works with the thermostat on the bottom hose. The problem is replacing all the plastics cause it gets too hot on top and if the car sits running or i drive awhile when i stop the reservoir bubbles.
- Noticed anything in the coolant other than coolant?
09-04-14, 09:19 AM
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09-04-14, 09:29 AM
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I thought the same thing so i went down to Autozone and rented their head gasket leak tester and fluid and it came up negative. So i dismissed it and bought one of those big funnels to properly burp the system but I have noticed a little bit of a sludge like substance in the fluid around the radiator cap. the main thing is she never overheats its just when i drive her for awhile and then shut her off she makes that embarrassing gargling sound in the reservoir... makes me afraid to drive her more then just around town. Let me know if your still thinking head gasket please? 
09-04-14, 10:14 AM
#7
I thought the same thing so i went down to Autozone and rented their head gasket leak tester and fluid and it came up negative. So i dismissed it and bought one of those big funnels to properly burp the system but I have noticed a little bit of a sludge like substance in the fluid around the radiator cap. the main thing is she never overheats its just when i drive her for awhile and then shut her off she makes that embarrassing gargling sound in the reservoir... makes me afraid to drive her more then just around town. Let me know if your still thinking head gasket please?
If you want to upgrade to a GTE gasket I have one for sale in my link below
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09-04-14, 10:16 AM
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Sounds like i have to tear it all down again, i just did the head covers last year it sucked especially working around the EGR with no room. My only problem now is i wont have a place to work on it till March. So i guess its deal with the way it is till then. I was hoping it was a bad water pump or something.
09-04-14, 10:19 AM
#9
If there is any milky "chocolate milk" type foam substance on the bottom of the oil cap, oil dipstick or you can see that the coolant is milky then it's 100% blown HG.
The easiest way to determine if there is a BHG is to cold start the car with full coolant. If there any bubbles there is a blown headgasket. There should not be any bubbles or pressure in the system. If you've recently replaced hoses, thermostat, and are refilling the system then you will initially have bubbles and you will have to let it "burp" a few times. Fill the coolant on a incline hill so that the radiator fill cap is the highest point in the system. After a couple top offs and the operating temp at 200deg plus a few times this should go away. Mine would bubble constantly at idle!
I also started noticing coolant mysteriously disappearing, the radiator top hose would be empty and I'd have to keep topping it off. The car would occasionally smoke and it got worse the more I drove it. There was a noticeable "hiccup" at idle in the exhaust note. Also it started overheating even though it was completely full, fans functioning fine. My guess is depending on where you have the blown head gasket the exhaust gases are leaking into the coolant system and heating up the coolant / coolant sensor which makes the gauge needle start to climb.
I also had "wet" spark plugs. I'd pull the spark plugs due to the car refusing to start and they would be noticeably wet looking. At the time I thought it was my tune, I was on AEM V2 at the time tuning the car myself and I assumed it was wet from possibly being too rich, and wasn't starting due to the tune being "off". What was happening is when I would cut the car off the system would leak coolant into the cylinders and the water / coolant in the cyl will kill any chance of starting the car. The AEM wasn't the culprit of my cold start woes, it was the HG slowly giving out. During cold cranking you could hear the car turn over slower than normal like it had ignition issues or all the cylinders weren't healthy.
With all these symptoms I still had good compression believe it or not, but it was high numbers which could be the liquid in the cylinders causing the reading to higher than normal. Compression testing doesn't tell the whole story.
On a more positive note though, now you can lower the compression slightly with a new GTE HG and do ARP head studs and be boost ready! That's a big step to adding a safety margin tune wise when going NA-T on pump gas 93 oct, unless you are able to run E85 then most would suggest keeping the stock 10:1 compression.
The easiest way to determine if there is a BHG is to cold start the car with full coolant. If there any bubbles there is a blown headgasket. There should not be any bubbles or pressure in the system. If you've recently replaced hoses, thermostat, and are refilling the system then you will initially have bubbles and you will have to let it "burp" a few times. Fill the coolant on a incline hill so that the radiator fill cap is the highest point in the system. After a couple top offs and the operating temp at 200deg plus a few times this should go away. Mine would bubble constantly at idle!
I also started noticing coolant mysteriously disappearing, the radiator top hose would be empty and I'd have to keep topping it off. The car would occasionally smoke and it got worse the more I drove it. There was a noticeable "hiccup" at idle in the exhaust note. Also it started overheating even though it was completely full, fans functioning fine. My guess is depending on where you have the blown head gasket the exhaust gases are leaking into the coolant system and heating up the coolant / coolant sensor which makes the gauge needle start to climb.
I also had "wet" spark plugs. I'd pull the spark plugs due to the car refusing to start and they would be noticeably wet looking. At the time I thought it was my tune, I was on AEM V2 at the time tuning the car myself and I assumed it was wet from possibly being too rich, and wasn't starting due to the tune being "off". What was happening is when I would cut the car off the system would leak coolant into the cylinders and the water / coolant in the cyl will kill any chance of starting the car. The AEM wasn't the culprit of my cold start woes, it was the HG slowly giving out. During cold cranking you could hear the car turn over slower than normal like it had ignition issues or all the cylinders weren't healthy.
With all these symptoms I still had good compression believe it or not, but it was high numbers which could be the liquid in the cylinders causing the reading to higher than normal. Compression testing doesn't tell the whole story.
On a more positive note though, now you can lower the compression slightly with a new GTE HG and do ARP head studs and be boost ready! That's a big step to adding a safety margin tune wise when going NA-T on pump gas 93 oct, unless you are able to run E85 then most would suggest keeping the stock 10:1 compression.
Last edited by HiPSI; 09-04-14 at 10:23 AM.
09-04-14, 12:29 PM
#10
On a more positive note though, now you can lower the compression slightly with a new GTE HG and do ARP head studs and be boost ready! That's a big step to adding a safety margin tune wise when going NA-T on pump gas 93 oct, unless you are able to run E85 then most would suggest keeping the stock 10:1 compression.
09-04-14, 09:58 PM
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Cause the Gasket Sizes are:
2JZ GE : .015" or .30mm - The 2JZ GE has 10:1 - 10.5:1
2JZ GTE: .051" or 1.295mm - The 2JZ GTE has recessed piston tops and a thicker Head Gasket to lower its compression to about 8.5:1
Would this benefit me if i wasn't able to boost it for awhile? Ive just started to research this subject and in no way am a expert, Im just asking...
09-04-14, 10:29 PM
#12
The reality is that the sc300 is dog slow without boost 
.
The GTE HG on the GE bottom end and head lowers total compression to appx 9.2:1, it's not going to make a huge difference in how your NA setup "feels". I drove mine completely stock with exception of the GTE HG and ARP head studs and it drove great.
I did notice a slight loss in torque being NA when I switched from the stock GE intake manifold to a forward facing intake manifold. This is expected when shortening the intake volume and runners, the powerband is shifted to upper RPMs. However when you add the turbo setup you realize it doesn't matter anymore
.
.The GTE HG on the GE bottom end and head lowers total compression to appx 9.2:1, it's not going to make a huge difference in how your NA setup "feels". I drove mine completely stock with exception of the GTE HG and ARP head studs and it drove great.
I did notice a slight loss in torque being NA when I switched from the stock GE intake manifold to a forward facing intake manifold. This is expected when shortening the intake volume and runners, the powerband is shifted to upper RPMs. However when you add the turbo setup you realize it doesn't matter anymore
.
09-04-14, 10:31 PM
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The reality is that the sc300 is dog slow without boost .
The GTE HG on the GE bottom end and head lowers total compression to appx 9.2:1, it's not going to make a huge difference in how your NA setup "feels". I drove mine completely stock with exception of the GTE HG and ARP head studs and it drove great.
I did notice a slight loss in torque being NA when I switched from the stock GE intake manifold to a forward facing intake manifold. This is expected when shortening the intake volume and runners, the powerband is shifted to upper RPMs. However when you add the turbo setup you realize it doesn't matter anymore.
.The GTE HG on the GE bottom end and head lowers total compression to appx 9.2:1, it's not going to make a huge difference in how your NA setup "feels". I drove mine completely stock with exception of the GTE HG and ARP head studs and it drove great.
I did notice a slight loss in torque being NA when I switched from the stock GE intake manifold to a forward facing intake manifold. This is expected when shortening the intake volume and runners, the powerband is shifted to upper RPMs. However when you add the turbo setup you realize it doesn't matter anymore
.
09-04-14, 10:37 PM
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Ok, I have checked all the other signs, no milkiness under the oil cap or radiator just this orange sludge, which i am using Toyota red coolant. i just flushed the system a few months ago cause that was my first impression. Should i try to do it a few more times or is it possible someone put like a head gasket sealer or something in my system before and because im flushing it, it is clogging my system? i will attach pictures as soon as i get a chance.
09-05-14, 07:34 AM
#15
Cold start the car, see if there is any bubbling with the radiator cap off. There is no heat or pressure during a cold start / idle so it won't hurt anything. If there is no milk shaked oil and there is no bubbling at idle / mysteriously missing coolant then you can rule out the blown head gasket.
Try flushing the radiator out separately, remove it from the car and put a strong cleaner / gas and shake it out upside down. These cars are 20 years old there is no telling what a previous owner has put in there. Mine had alot of sediment come out that would not come out while flushing it on the car. I wouldn't even use the silly drain plug to drain it / flush it. I drained all the coolant and once that was done I removed the lower radiator hose into a bucket and attached a hose to the car and let it go for awhile. I removed the thermostat prior to allow for it to flow.
After my head gasket blew and the oil mixed with the coolant I wanted to make sure it was cleaned thoroughly. You should use distilled water anytime when adding water to the system but I didn't have 20 gallons of distilled water on hand. Definitely drain it as best as you can and then mix your toyota coolant with distilled water.
I would look at the cooling system components and start replacing them one by one.
Thermostat
Clutch fan
Radiator
Radiator cap
Water Pump
Try flushing the radiator out separately, remove it from the car and put a strong cleaner / gas and shake it out upside down. These cars are 20 years old there is no telling what a previous owner has put in there. Mine had alot of sediment come out that would not come out while flushing it on the car. I wouldn't even use the silly drain plug to drain it / flush it. I drained all the coolant and once that was done I removed the lower radiator hose into a bucket and attached a hose to the car and let it go for awhile. I removed the thermostat prior to allow for it to flow.
After my head gasket blew and the oil mixed with the coolant I wanted to make sure it was cleaned thoroughly. You should use distilled water anytime when adding water to the system but I didn't have 20 gallons of distilled water on hand. Definitely drain it as best as you can and then mix your toyota coolant with distilled water.
I would look at the cooling system components and start replacing them one by one.
Thermostat
Clutch fan
Radiator
Radiator cap
Water Pump
Last edited by HiPSI; 09-05-14 at 07:37 AM.