over heating

pandrade · 12-01-2011, 04:50 PM

I have a 87 7m-gte whith a new oem radiator, radiator hose, and thermostat. I just did a system flush but in the city i NEVER have a heating problem no matter how hard i drive it , but at highway speeds at 3000rpm in 5th gear i start to over heat.I think its because im missing the front air defuser that guilds air into the intercoller and radiator. any suggestions?

cre · 12-02-2011, 05:27 AM

Test the radiator cap and the new thermostat (You'd be surprised how often new parts are still bad). Check your ignition and mechanical timing as well if the exhaust gasses don't leave until after expected that heat is absorbed by the engine... so retarded valve timing or advanced ignition timing will cause an increase in heat.

Missing the undercover reduces efficiency it doesn't do so much that a car will overheat without it... The fan cowl is more important but even that is more effective at low speed.

pandrade · 12-04-2011, 02:27 PM

I Bought a brand new 13 psi cap. And tested the thermostat all good. I contacted the origonal owner and asked about the radiator that was supposedly new. After talken to the guy an further inspection of the radiator, turns out he took it to a radiator shop and rebuilt it. I replaced the water pump about a year ago. I think the crapy radiator can cool at low speed but just cant keep up at high speed. Probably gona end up buyen a 3 row alinum megan racing radiator. Your thoughts?

oh and i do have the origonal fan shroud on btw, first thing i fixed on the car sadly not the last

cre · 12-06-2011, 02:08 AM

The stock radiator is rebuildable.

I'd be more suspicious of the water pump again. Yes, a shot radiator will not cool sufficiently at higher loads. A radiator shop can test it to see if it's not flowing well enough. I wouldn't just go throwing money at this problem.

Have you checked the timing? Start cheap.

pandrade · 12-06-2011, 12:50 PM

Well i went back and checked ignitin, timimg,looked for exshaust leakes, and took off the water pump. No luck on them, they all seem fine. But like u said ill test the water pump at a shop nothing to lose and alot of saved money to gain.

also went price checking a 3 row megan racing aluminum radiator is running about 220 whithout shipping ( if all else is ok this might be my possible route)

cre · 12-07-2011, 04:32 AM

Nothing wrong with better components.... unless they're hiding bad ones.

Hopefully, it is the radiator or the pump.

pandrade · 12-07-2011, 12:32 PM

Thats tue. I hope the radiator solves it if not the not i see quite a bit of disasembling in the future but the radiator should solve it... hopefully

pandrade · 01-26-2012, 01:24 AM

just an update on this thread. I installed the new megan racing radiator from hoarse power freaks. The install was the simplest thing in the world alone takes maby 30 min 2 people 10. only fabing i had to do was the clamps that hold the radiator down onto the frame which i drilled the hole longer, if any one wants i can post pictures

12-01-2011, 04:50 PM	#1
pandrade 12psi boost Join Date: Mar 2011 Location: fort myers florida Posts: 345	over heating I have a 87 7m-gte whith a new oem radiator, radiator hose, and thermostat. I just did a system flush but in the city i NEVER have a heating problem no matter how hard i drive it , but at highway speeds at 3000rpm in 5th gear i start to over heat.I think its because im missing the front air defuser that guilds air into the intercoller and radiator. any suggestions?

12-02-2011, 05:27 AM	#2
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	Test the radiator cap and the new thermostat (You'd be surprised how often new parts are still bad). Check your ignition and mechanical timing as well if the exhaust gasses don't leave until after expected that heat is absorbed by the engine... so retarded valve timing or advanced ignition timing will cause an increase in heat. Missing the undercover reduces efficiency it doesn't do so much that a car will overheat without it... The fan cowl is more important but even that is more effective at low speed. __________________ If something breaks or you need to contact a member of the administration please post HERE. Unless it's a private or administration matter please post it on the forum. It benefits no one else if car related questions aren't posted for future users and takes away from the time I'm able to spend helping on the rest of the forum. If you're so inclined I'm always more than happy to accept tips via PayPal. Tip Jar --->

12-04-2011, 02:27 PM	#3
pandrade 12psi boost Join Date: Mar 2011 Location: fort myers florida Posts: 345	I Bought a brand new 13 psi cap. And tested the thermostat all good. I contacted the origonal owner and asked about the radiator that was supposedly new. After talken to the guy an further inspection of the radiator, turns out he took it to a radiator shop and rebuilt it. I replaced the water pump about a year ago. I think the crapy radiator can cool at low speed but just cant keep up at high speed. Probably gona end up buyen a 3 row alinum megan racing radiator. Your thoughts? oh and i do have the origonal fan shroud on btw, first thing i fixed on the car sadly not the last Last edited by pandrade; 12-04-2011 at 02:41 PM.

12-06-2011, 02:08 AM	#4
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	The stock radiator is rebuildable. I'd be more suspicious of the water pump again. Yes, a shot radiator will not cool sufficiently at higher loads. A radiator shop can test it to see if it's not flowing well enough. I wouldn't just go throwing money at this problem. Have you checked the timing? Start cheap. __________________ If something breaks or you need to contact a member of the administration please post HERE. Unless it's a private or administration matter please post it on the forum. It benefits no one else if car related questions aren't posted for future users and takes away from the time I'm able to spend helping on the rest of the forum. If you're so inclined I'm always more than happy to accept tips via PayPal. Tip Jar --->

12-06-2011, 12:50 PM	#5
pandrade 12psi boost Join Date: Mar 2011 Location: fort myers florida Posts: 345	Well i went back and checked ignitin, timimg,looked for exshaust leakes, and took off the water pump. No luck on them, they all seem fine. But like u said ill test the water pump at a shop nothing to lose and alot of saved money to gain. also went price checking a 3 row megan racing aluminum radiator is running about 220 whithout shipping ( if all else is ok this might be my possible route) Last edited by pandrade; 12-06-2011 at 01:04 PM.

12-07-2011, 04:32 AM	#6
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	Nothing wrong with better components.... unless they're hiding bad ones. Hopefully, it is the radiator or the pump. __________________ If something breaks or you need to contact a member of the administration please post HERE. Unless it's a private or administration matter please post it on the forum. It benefits no one else if car related questions aren't posted for future users and takes away from the time I'm able to spend helping on the rest of the forum. If you're so inclined I'm always more than happy to accept tips via PayPal. Tip Jar --->

12-07-2011, 12:32 PM	#7
pandrade 12psi boost Join Date: Mar 2011 Location: fort myers florida Posts: 345	Thats tue. I hope the radiator solves it if not the not i see quite a bit of disasembling in the future but the radiator should solve it... hopefully

01-26-2012, 01:24 AM	#8
pandrade 12psi boost Join Date: Mar 2011 Location: fort myers florida Posts: 345	just an update on this thread. I installed the new megan racing radiator from hoarse power freaks. The install was the simplest thing in the world alone takes maby 30 min 2 people 10. only fabing i had to do was the clamps that hold the radiator down onto the frame which i drilled the hole longer, if any one wants i can post pictures

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