3S-GTE USDM Turbo Engine Sanity check for overheating 3sgte

skeptic · 03-20-2010, 06:33 PM

'77 Celica with JDM 3sgte.

I've done a lot of searching here, but nobody has described the exact symptoms I am having. My SWAG from reading the other overheating threads is air in the cooling system, but I'm not really sure. Here are the symptoms:

*It over heats (duh!), but only at idle or driving easy.
*Heater blows cold air while overheating.
*Right at 3k rpms it will start to cool down and slightly warmer air from the heater.
*If I rev it up to 4k or higher, the temps drop quickly and much warmer air blows from the heater.
*These are true whether I'm driving around or parked.

I've had my mechanic do a bunch of things, both to fix the issue and for peace of mind (JDM engine of unknown miles):
*Replaced t-stat (on the 3rd one now, original had a hole drilled in it, second two have jiggle pin, current one is cooler than stock temp).
*Replaced water pump (and timing belt - would have done this anyway not knowing the miles on the existing belt, orig looked fine)
*Replaced radiator (only one side was getting warm)
*Flushed coolant lines/block - apparently lots of gunk came out. Flushed several times with running the engine in between until water flowed crystal clear.
*Fixed leak in bottom of overflow bottle (didn't notice right away, maybe this was the original cause?)
*Replaced radiator cap (twice)

I drove it infrequently enough, and hard enough when I did, that I cannot say for sure if it had this problem or not the day I got it from the mechanics. I suspect it did not have this issue because I didn't notice it right away, but the shop doing the work claimed to have road tested it a lot including the owner using it as his daily driver "for testing purposed" for a month or more. I cannot take it back to them because I now live in UT and the shop that did the work is in South Florida.

Does this sound like air in the system to you guys? The engine is north-south and no mr2 bleed valves that I know of, how would you suggest I bleed the system? Is there something else I should check?

Big Thurs · 03-21-2010, 06:43 PM

Quote:

*Heater blows cold air while overheating.
*Right at 3k rpms it will start to cool down and slightly warmer air from the heater.
*If I rev it up to 4k or higher, the temps drop quickly and much warmer air blows from the heater.

These symptoms almost always indicate that air is in the system. If there are no bleed valves, hold at around 4-5k for a minute, after getting it warm enough for the thermostat to open. This will force the air out of the smaller passages in the engine and heater core and into the radiator, will it should purge out of the cap. Of course, if it begins to overheat, stop the engine and check the coolant level in the radiator. (release the pressure slowly and don't burn yourself)
Also the "one side of the radiator is warm" issue was more than likely caused buy the original thermostat with the hole drilled in it.

rhino · 03-21-2010, 07:13 PM

ThisThmusis is a bit off topic but your celica is so sexy!!! Just thought I would throw that out there.

skeptic · 03-21-2010, 07:50 PM

Quote:

Originally Posted by Big Thurs

These symptoms almost always indicate that air is in the system. If there are no bleed valves, hold at around 4-5k for a minute, after getting it warm enough for the thermostat to open. This will force the air out of the smaller passages in the engine and heater core and into the radiator, will it should purge out of the cap. Of course, if it begins to overheat, stop the engine and check the coolant level in the radiator. (release the pressure slowly and don't burn yourself)
Also the "one side of the radiator is warm" issue was more than likely caused buy the original thermostat with the hole drilled in it.

Thanks - just wanted to make sure I'm on the right track. I've tried warming it up then briefly reving it up, back to idle, rev up, back to idle a few times, but never just held it at 4k+ for any period of time. I'll give it a shot.

As for the radiator, it had a bunch of gunk in it so I didn't mind just replacing it. I don't want to just throw money away, but if I'm replacing something questionable with something new and/or better I'm ok with it.

Quote:

Originally Posted by rhino

ThisThmusis is a bit off topic but your celica is so sexy!!! Just thought I would throw that out there.

Thanks, I always appreciate the compliments. Now if I could just get it on the road reliably I'd be set.

BTW, has anyone here ever tried one of these? You can find them online for about $70. I've considered picking one up if I can't get this resolved.
UView: Product Detail

skeptic · 09-20-2010, 01:16 PM

Bringing this topic back from the dead!!!

Since a lot of the history is already here I thought I'd continue with my overheating saga instead of starting a new thread.

So... While the head gasket was being replaced (psi was a bit low and not consistent), it was determined that the coolant lines off the rear outlet were wrong. No bypass straight to the t-stat and the heater lines were basically in a loop.

New head gasket and fixed the cooling flow - heater now works as it should and the overheating issue is better. Also higher and more consistent compression test. I also now have a bleeder valve at the highest point which has been really handy.

Bad news, the thing still overheats, but slower. It no longer overheats while idling or holding rpms up while sitting in the driveway. Well, eventually it might, but certainly not like before. My test loop has been around 15 to 20 miles one way. By the time I get there, it's starting to run warmer than it should. By the time I get back it's running hot. Not into the red hot, but coolant boiling hot. I've only driven it far enough to run hot twice. First time I didn't realize I still had an issue so I was running A/C on the return trip. When I saw the temp well above normal I used the heater to get it temps back down to a reasonable range (still warmer than normal). Second time was a test run, A/C off, heater on cold (no coolant flow through core) on the way there, then heater on hot (A/C and heater fans off) on the way back. Still running hot by the time I got home. After shorter drives where the engine warms up but doesn't get hot I don't see any air in the system. Bleeder valve just lets fluid out, cracking open the radiator cap is just fluid. When cold the radiator is full. Clearly after running hot enough to boil the coolant, there is "air" in the system.

Electric fan comes on and is pulling through as it should. Cooling system had a vacuum test with an airlift which easily surpassed the ok/not ok mark. Switched to a 16psi radiator cap. New coolant (50/50 mix).

I'm nearly out of ideas and patience. Any suggestions are welcome.

arber0214 · 09-20-2010, 01:26 PM

you could have damaged the engine to the point that it will keep overheating until you rebuild it. Or the head gasket is not sitting right in place. Did the mechanic send the head to be resurfaced and tested for cracks?

skeptic · 09-20-2010, 01:40 PM

Yes - head was taken to a machine shop to be resurfaced and inspected. New valve guides were also installed (should be unrelated).

What kind of engine damage are you referring to, and how can this be tested? A full leak down test was suggested on a another forum, so I'll probably have that done.

WrenchswingeR · 09-22-2010, 12:35 AM

If turning the heater on instantly makes the temp drop thats 99 times outta 100 a thermostat issue. Stupid questions but is the t-stat installed properly? The jiggle valve has to be in the right position or it wont work right. 2nd dumb question-are u sure the t-stat is opening before you finish the bleeding process? I just got done doing my water pump and while attempting to bleed system it took almost 20min of revving car to get t-stat hot enough to open to get coolant up to the radiator and heater core bleeders. Last suggestion, try running it with no thermostat at all-it will take longer to heat up but will take a possible problem out of the system. PS-love your STINGRAY!!

skeptic · 09-22-2010, 10:55 AM

I wouldn't say heater on instantly makes the temp drop, it's more like the little extra cooling it needs. Another test run last night: The engine warms up to a specific point on the temp gauge and holds there for a while. After about 10 miles of mixed city/hwy the temp very slowly started to rise. Running the heater kept the temp down at that specific temp and I was able to toggle the heater on and off to keep the temp where it should be.

I'm certain the t-stat is opening, but it's possible the t-stat isn't aligned correct. Where should the jiggle valve be? I didn't install the t-stat but I can check with the person who did. I wouldn't imagine it makes any difference in flow, only a question of trapped air (possibly leading to not opening correct). Assuming no trapped air, it shouldn't make any difference, correct?

My bleeding procedure is different. I have exactly one bleeder valve, it's on the hose going into the radiator, which happens to be the highest point. With everything under the hood, I don't have long coolant runs so my bleed procedure should be more typical. At least that's the way I'm approaching it. I've been bleeding it when it's fully warmed up, both with the engine running and after it's been shut off. As far as I can tell, there is no air in the system.

I did pay close attention to the A/F gauge as well, it seems to be running a bit lean. I'm running a stand alone SDS for engine management so I should be able to tune it. I wonder if this is the issue, running a bit lean so the engine is running hotter than it should, and the cooling system just can't keep up once the engine is fully heat soaked.

PS - Thanks for the compliment, but I'll be selling the Vette in the spring. Love the car, lots of fun to drive, but I hardly ever drive it. Based on one of those "next oil change due" stickers on the window, I've driven ~1,700 miles since Nov. 2004. Less than 300 miles a year average. About 300 of those miles came a couple months ago when the wife was taking it to work and back - it failed smog because of old gas and too much sitting. After a few hundred miles of driving on fresh gas it passed with flying colors. Before anyone asks - I work from home and most of my driving is going to get my kids, dropping off my kids, or driving on the weekends (usually with the kids). Three car garage, 4 vehicles, and the wife wants a summer car of her own, but doesn't like the Corvette (front end is too long for her comfort zone).

WrenchswingeR · 09-23-2010, 12:07 AM

cant remember off the top where the jiggle valve on the thermostat points, but i know its not straight up as most japanese motors are. U can try checking the BGB for info on that. And it is a possibility that your system cant keep up with the demands, if thats the case some water-wetter and a higher PSI radiator cap may help you out.

03-20-2010, 06:33 PM	#1 (permalink)
skeptic No Skills Join Date: Aug 2006 Posts: 66 Thanks: 0 Thanked 3 Times in 3 Posts iTrader Rating: (0/0% )	Sanity check for overheating 3sgte '77 Celica with JDM 3sgte. I've done a lot of searching here, but nobody has described the exact symptoms I am having. My SWAG from reading the other overheating threads is air in the cooling system, but I'm not really sure. Here are the symptoms: It over heats (duh!), but only at idle or driving easy. Heater blows cold air while overheating. Right at 3k rpms it will start to cool down and slightly warmer air from the heater. If I rev it up to 4k or higher, the temps drop quickly and much warmer air blows from the heater. These are true whether I'm driving around or parked. I've had my mechanic do a bunch of things, both to fix the issue and for peace of mind (JDM engine of unknown miles): Replaced t-stat (on the 3rd one now, original had a hole drilled in it, second two have jiggle pin, current one is cooler than stock temp). Replaced water pump (and timing belt - would have done this anyway not knowing the miles on the existing belt, orig looked fine) Replaced radiator (only one side was getting warm) Flushed coolant lines/block - apparently lots of gunk came out. Flushed several times with running the engine in between until water flowed crystal clear. Fixed leak in bottom of overflow bottle (didn't notice right away, maybe this was the original cause?) Replaced radiator cap (twice) I drove it infrequently enough, and hard enough when I did, that I cannot say for sure if it had this problem or not the day I got it from the mechanics. I suspect it did not have this issue because I didn't notice it right away, but the shop doing the work claimed to have road tested it a lot including the owner using it as his daily driver "for testing purposed" for a month or more. I cannot take it back to them because I now live in UT and the shop that did the work is in South Florida. Does this sound like air in the system to you guys? The engine is north-south and no mr2 bleed valves that I know of, how would you suggest I bleed the system? Is there something else I should check? Last edited by skeptic; 03-20-2010 at 06:39 PM..*

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03-21-2010, 07:13 PM	#3 (permalink)
rhino mk2 tyte booste yo!!! Join Date: Feb 2010 Location: Kansas Posts: 117 Thanks: 8 Thanked 2 Times in 2 Posts iTrader Rating: (0/0% )	ThisThmusis is a bit off topic but your celica is so sexy!!! Just thought I would throw that out there.

09-20-2010, 01:16 PM	#5 (permalink)
skeptic No Skills Join Date: Aug 2006 Posts: 66 Thanks: 0 Thanked 3 Times in 3 Posts iTrader Rating: (0/0% )	Bringing this topic back from the dead!!! Since a lot of the history is already here I thought I'd continue with my overheating saga instead of starting a new thread. So... While the head gasket was being replaced (psi was a bit low and not consistent), it was determined that the coolant lines off the rear outlet were wrong. No bypass straight to the t-stat and the heater lines were basically in a loop. New head gasket and fixed the cooling flow - heater now works as it should and the overheating issue is better. Also higher and more consistent compression test. I also now have a bleeder valve at the highest point which has been really handy. Bad news, the thing still overheats, but slower. It no longer overheats while idling or holding rpms up while sitting in the driveway. Well, eventually it might, but certainly not like before. My test loop has been around 15 to 20 miles one way. By the time I get there, it's starting to run warmer than it should. By the time I get back it's running hot. Not into the red hot, but coolant boiling hot. I've only driven it far enough to run hot twice. First time I didn't realize I still had an issue so I was running A/C on the return trip. When I saw the temp well above normal I used the heater to get it temps back down to a reasonable range (still warmer than normal). Second time was a test run, A/C off, heater on cold (no coolant flow through core) on the way there, then heater on hot (A/C and heater fans off) on the way back. Still running hot by the time I got home. After shorter drives where the engine warms up but doesn't get hot I don't see any air in the system. Bleeder valve just lets fluid out, cracking open the radiator cap is just fluid. When cold the radiator is full. Clearly after running hot enough to boil the coolant, there is "air" in the system. Electric fan comes on and is pulling through as it should. Cooling system had a vacuum test with an airlift which easily surpassed the ok/not ok mark. Switched to a 16psi radiator cap. New coolant (50/50 mix). I'm nearly out of ideas and patience. Any suggestions are welcome.

09-20-2010, 01:26 PM	#6 (permalink)
arber0214 OT people blew me hard Join Date: May 2006 Location: MA Posts: 2,824 Thanks: 11 Thanked 96 Times in 94 Posts My Google Map iTrader Rating: (5/100% )	you could have damaged the engine to the point that it will keep overheating until you rebuild it. Or the head gasket is not sitting right in place. Did the mechanic send the head to be resurfaced and tested for cracks?

09-20-2010, 01:40 PM	#7 (permalink)
skeptic No Skills Join Date: Aug 2006 Posts: 66 Thanks: 0 Thanked 3 Times in 3 Posts iTrader Rating: (0/0% )	Yes - head was taken to a machine shop to be resurfaced and inspected. New valve guides were also installed (should be unrelated). What kind of engine damage are you referring to, and how can this be tested? A full leak down test was suggested on a another forum, so I'll probably have that done.

09-22-2010, 12:35 AM	#8 (permalink)
WrenchswingeR Cage Fighter Join Date: May 2010 Location: Dirty Jersey Posts: 1,364 Thanks: 5 Thanked 66 Times in 65 Posts iTrader Rating: (11/100% )	If turning the heater on instantly makes the temp drop thats 99 times outta 100 a thermostat issue. Stupid questions but is the t-stat installed properly? The jiggle valve has to be in the right position or it wont work right. 2nd dumb question-are u sure the t-stat is opening before you finish the bleeding process? I just got done doing my water pump and while attempting to bleed system it took almost 20min of revving car to get t-stat hot enough to open to get coolant up to the radiator and heater core bleeders. Last suggestion, try running it with no thermostat at all-it will take longer to heat up but will take a possible problem out of the system. PS-love your STINGRAY!!

09-22-2010, 10:55 AM	#9 (permalink)
skeptic No Skills Join Date: Aug 2006 Posts: 66 Thanks: 0 Thanked 3 Times in 3 Posts iTrader Rating: (0/0% )	I wouldn't say heater on instantly makes the temp drop, it's more like the little extra cooling it needs. Another test run last night: The engine warms up to a specific point on the temp gauge and holds there for a while. After about 10 miles of mixed city/hwy the temp very slowly started to rise. Running the heater kept the temp down at that specific temp and I was able to toggle the heater on and off to keep the temp where it should be. I'm certain the t-stat is opening, but it's possible the t-stat isn't aligned correct. Where should the jiggle valve be? I didn't install the t-stat but I can check with the person who did. I wouldn't imagine it makes any difference in flow, only a question of trapped air (possibly leading to not opening correct). Assuming no trapped air, it shouldn't make any difference, correct? My bleeding procedure is different. I have exactly one bleeder valve, it's on the hose going into the radiator, which happens to be the highest point. With everything under the hood, I don't have long coolant runs so my bleed procedure should be more typical. At least that's the way I'm approaching it. I've been bleeding it when it's fully warmed up, both with the engine running and after it's been shut off. As far as I can tell, there is no air in the system. I did pay close attention to the A/F gauge as well, it seems to be running a bit lean. I'm running a stand alone SDS for engine management so I should be able to tune it. I wonder if this is the issue, running a bit lean so the engine is running hotter than it should, and the cooling system just can't keep up once the engine is fully heat soaked. PS - Thanks for the compliment, but I'll be selling the Vette in the spring. Love the car, lots of fun to drive, but I hardly ever drive it. Based on one of those "next oil change due" stickers on the window, I've driven ~1,700 miles since Nov. 2004. Less than 300 miles a year average. About 300 of those miles came a couple months ago when the wife was taking it to work and back - it failed smog because of old gas and too much sitting. After a few hundred miles of driving on fresh gas it passed with flying colors. Before anyone asks - I work from home and most of my driving is going to get my kids, dropping off my kids, or driving on the weekends (usually with the kids). Three car garage, 4 vehicles, and the wife wants a summer car of her own, but doesn't like the Corvette (front end is too long for her comfort zone).

09-23-2010, 12:07 AM	#10 (permalink)
WrenchswingeR Cage Fighter Join Date: May 2010 Location: Dirty Jersey Posts: 1,364 Thanks: 5 Thanked 66 Times in 65 Posts iTrader Rating: (11/100% )	cant remember off the top where the jiggle valve on the thermostat points, but i know its not straight up as most japanese motors are. U can try checking the BGB for info on that. And it is a possibility that your system cant keep up with the demands, if thats the case some water-wetter and a higher PSI radiator cap may help you out.