Engine Heat problems
#1
Burning Oil-Grinding 3rd
![](https://www.rx7club.com/images/misc/10_year_icon.png)
Thread Starter
Engine Heat problems
My temp guage has been running at half or a little more for the last several weeks So far I have done the following
Bubble Check to see if an internal seal was bad> no bubbles.
Pulled all the air conditioning parts>thought it might be blocking air to the Rad.
Flushed the Rad with CLR> Flues look good and clean.
Cleaned the Rad outside> All the fins were very clean.
Changed the Coolent > replaced with distilled water and Water Wetter, and some antifreeze.
Double Alt Pully
16 Inch Electric Fan inside of the fan shroud.
Installed an aftermarked temp guage in the water pump housing.
180 degree thermostat, with a bypass hole drilled in it.
I took the car out last night and the temp guage got up to 210, This was in less then 5 miles and sitting at one stop light.
The water pump is not leaking but could it still be bad in some way?
The car is a 79 with a SP 12a, Webber 48 carb, and RB muffler.
Could I be running the car to lean? Should I adjust the carb to more rich?
Thanks for any help.
Bubble Check to see if an internal seal was bad> no bubbles.
Pulled all the air conditioning parts>thought it might be blocking air to the Rad.
Flushed the Rad with CLR> Flues look good and clean.
Cleaned the Rad outside> All the fins were very clean.
Changed the Coolent > replaced with distilled water and Water Wetter, and some antifreeze.
Double Alt Pully
16 Inch Electric Fan inside of the fan shroud.
Installed an aftermarked temp guage in the water pump housing.
180 degree thermostat, with a bypass hole drilled in it.
I took the car out last night and the temp guage got up to 210, This was in less then 5 miles and sitting at one stop light.
The water pump is not leaking but could it still be bad in some way?
The car is a 79 with a SP 12a, Webber 48 carb, and RB muffler.
Could I be running the car to lean? Should I adjust the carb to more rich?
Thanks for any help.
Last edited by Hades12; 05-20-04 at 10:53 AM.
#2
sounds like the flow rate of the rad isn't enough. no matter how much U flush it out, if the tubes in it r clogged up, u'll never get those cleaned out. a rad repair shop uses a solution that they soak the rad in that will desolve and loosen some of that stuff up, and sometimes it's neccesary to remove one of the tanks and rod it out to remove the more stubburn(sp) clogs. a rad might look clean, but that doesn't mean that it is clean. the more gallons per hour of water a rad can flow, the better it can cool the engine.
#4
Burning Oil-Grinding 3rd
![](https://www.rx7club.com/images/misc/10_year_icon.png)
Thread Starter
Originally posted by nevarmore
Are you sure its not the guage or the sender?
Are you sure its not the guage or the sender?
#5
Burning Oil-Grinding 3rd
![](https://www.rx7club.com/images/misc/10_year_icon.png)
Thread Starter
Originally posted by rxtasy3
sounds like the flow rate of the rad isn't enough. no matter how much U flush it out, if the tubes in it r clogged up, u'll never get those cleaned out. a rad repair shop uses a solution that they soak the rad in that will desolve and loosen some of that stuff up, and sometimes it's neccesary to remove one of the tanks and rod it out to remove the more stubburn(sp) clogs. a rad might look clean, but that doesn't mean that it is clean. the more gallons per hour of water a rad can flow, the better it can cool the engine.
sounds like the flow rate of the rad isn't enough. no matter how much U flush it out, if the tubes in it r clogged up, u'll never get those cleaned out. a rad repair shop uses a solution that they soak the rad in that will desolve and loosen some of that stuff up, and sometimes it's neccesary to remove one of the tanks and rod it out to remove the more stubburn(sp) clogs. a rad might look clean, but that doesn't mean that it is clean. the more gallons per hour of water a rad can flow, the better it can cool the engine.
I put the water hose in the rad top and it seamed to flow real well. My outside water hose at the house gets pressure direct from the meter without going through the Regulator in the house, so it flows a lot of water. With the hose in the top of the rad the water was flowing thrught just as fast as the hose was putting it out.
A new Rad is 114 online so that may be my next step. But I would have thought that cleaning it would have helped at least a little.
#7
How are your radiator hoses? Are they new, if not they may be collapsing.
Replace your radiator cap. If it vents too soon things don't work right.
Does the t-stat work? I know its new, but ya can't expect aquality control on a $6 part to be that good. Dunk it in a pot of water and boil it. When it opens put a thermometer on it and make sure its opening at 180 degrees. '
Is your fan kicking on? Instead of relying on its temperature sensor, wire it to a switch and kick it on yourself.
Is the fan pulling air just from the radiator? If theres a hole or seam in the shroud it'll suck through that instead.
I know I sound like a smartass here, but sometimes the little stuff gets you. It's worth checking on.
Aside from the small stuff, is your carb tuned correctly? I've heard of some cases where a bad mixture (too rich IIRC) led to excessive engine heat.
Replace your radiator cap. If it vents too soon things don't work right.
Does the t-stat work? I know its new, but ya can't expect aquality control on a $6 part to be that good. Dunk it in a pot of water and boil it. When it opens put a thermometer on it and make sure its opening at 180 degrees. '
Is your fan kicking on? Instead of relying on its temperature sensor, wire it to a switch and kick it on yourself.
Is the fan pulling air just from the radiator? If theres a hole or seam in the shroud it'll suck through that instead.
I know I sound like a smartass here, but sometimes the little stuff gets you. It's worth checking on.
Aside from the small stuff, is your carb tuned correctly? I've heard of some cases where a bad mixture (too rich IIRC) led to excessive engine heat.
Trending Topics
#8
Burning Oil-Grinding 3rd
![](https://www.rx7club.com/images/misc/10_year_icon.png)
Thread Starter
Originally posted by nevarmore
How are your radiator hoses? Are they new, if not they may be collapsing.
How are your radiator hoses? Are they new, if not they may be collapsing.
Originally posted by nevarmore
Replace your radiator cap. If it vents too soon things don't work right.
Replace your radiator cap. If it vents too soon things don't work right.
Originally posted by nevarmore
Does the t-stat work? I know its new, but ya can't expect aquality control on a $6 part to be that good. Dunk it in a pot of water and boil it. When it opens put a thermometer on it and make sure its opening at 180 degrees. '
Does the t-stat work? I know its new, but ya can't expect aquality control on a $6 part to be that good. Dunk it in a pot of water and boil it. When it opens put a thermometer on it and make sure its opening at 180 degrees. '
Originally posted by nevarmore
Is your fan kicking on? Instead of relying on its temperature sensor, wire it to a switch and kick it on yourself.
Is your fan kicking on? Instead of relying on its temperature sensor, wire it to a switch and kick it on yourself.
Originally posted by nevarmore
Is the fan pulling air just from the radiator? If theres a hole or seam in the shroud it'll suck through that instead.
Is the fan pulling air just from the radiator? If theres a hole or seam in the shroud it'll suck through that instead.
Originally posted by nevarmore
I know I sound like a smartass here, but sometimes the little stuff gets you. It's worth checking on.
Aside from the small stuff, is your carb tuned correctly? I've heard of some cases where a bad mixture (too rich IIRC) led to excessive engine heat.
I know I sound like a smartass here, but sometimes the little stuff gets you. It's worth checking on.
Aside from the small stuff, is your carb tuned correctly? I've heard of some cases where a bad mixture (too rich IIRC) led to excessive engine heat.
It could be to rich, I know that in a piston engine that rich runs cooler, Guess I need to read some more about tuning a rotor.
#11
Burning Oil-Grinding 3rd
![](https://www.rx7club.com/images/misc/10_year_icon.png)
Thread Starter
Originally posted by rxtasy3
sounds like the flow rate of the rad isn't enough. no matter how much U flush it out, if the tubes in it r clogged up, u'll never get those cleaned out. a rad repair shop uses a solution that they soak the rad in that will desolve and loosen some of that stuff up, and sometimes it's neccesary to remove one of the tanks and rod it out to remove the more stubburn(sp) clogs. a rad might look clean, but that doesn't mean that it is clean. the more gallons per hour of water a rad can flow, the better it can cool the engine.
sounds like the flow rate of the rad isn't enough. no matter how much U flush it out, if the tubes in it r clogged up, u'll never get those cleaned out. a rad repair shop uses a solution that they soak the rad in that will desolve and loosen some of that stuff up, and sometimes it's neccesary to remove one of the tanks and rod it out to remove the more stubburn(sp) clogs. a rad might look clean, but that doesn't mean that it is clean. the more gallons per hour of water a rad can flow, the better it can cool the engine.
From a previous post you said you did Rad Repair at one time. Can you tell me how to "Rod out the rad"?
I would guess that I would desolder the top and bottom tank and then use a rod to clean out the flues. I know the shops use a Propane/Oxy mix to keep the temps down. Would it be OK to use a Oxy/act with a small brasing tip to do the desolder and soldering? Small tip like a 000 or 0?
Thanks
#12
oxy/act is just too hot and will burn right thru the thin copper real quick, and the repair shops use propane/compressed air mix, at least the shop i worked at did. as for how to rod a rad, remove the top tank, or in the case of side tanks it would be the one the top hose connects to, connect a supply of water to the other end so water will be running up thru the tubes the opposite direction as normal flow would be while pushing a flat, thin metal strip down each tube. when it comes to flushing out a rad, it's best done in the opposite direction of normal flow, since anything that will clog up the tube goes in from one direction, u flush it out the other way. now, if ur inexperienced in doing this, u can ruin ur rad and end up having to have a shop fix it or buy a new one. copper rads absorb heat really fast and if ur not careful when removing tanks and then resoldering them, u'll pretty much melt the solder around the tubes in the header, which is the flat looking part that the tubes go in to and the tank is soldered to. and then there's the question of how u going to test it for leaks once u get it all back together. how that's done, plug all hose connections, connect compressed air supply regulated at no more than 30 psi, and submerse the rad in water and watch for bubbles. a bathtub would work but ur mom or wife might not like it.
#13
Never satisfied
![](https://www.rx7club.com/images/misc/05_year_icon.png)
Join Date: Aug 2003
Location: San diego, CA
Posts: 305
Likes: 0
Received 0 Likes
on
0 Posts
My 12a running too lean would run way too hot. Richened it up and she runs perfect now. So unfortunately it could be rich or lean. Does the engine itself seem to feel very hot? Mine did when it was running lean.
#14
Burning Oil-Grinding 3rd
![](https://www.rx7club.com/images/misc/10_year_icon.png)
Thread Starter
Originally posted by rxtasy3
oxy/act is just too hot and will burn right thru the thin copper real quick, and the repair shops use propane/compressed air mix, at least the shop i worked at did. as for how to rod a rad, remove the top tank, or in the case of side tanks it would be the one the top hose connects to, connect a supply of water to the other end so water will be running up thru the tubes the opposite direction as normal flow would be while pushing a flat, thin metal strip down each tube. when it comes to flushing out a rad, it's best done in the opposite direction of normal flow, since anything that will clog up the tube goes in from one direction, u flush it out the other way. now, if ur inexperienced in doing this, u can ruin ur rad and end up having to have a shop fix it or buy a new one. copper rads absorb heat really fast and if ur not careful when removing tanks and then resoldering them, u'll pretty much melt the solder around the tubes in the header, which is the flat looking part that the tubes go in to and the tank is soldered to. and then there's the question of how u going to test it for leaks once u get it all back together. how that's done, plug all hose connections, connect compressed air supply regulated at no more than 30 psi, and submerse the rad in water and watch for bubbles. a bathtub would work but ur mom or wife might not like it.
oxy/act is just too hot and will burn right thru the thin copper real quick, and the repair shops use propane/compressed air mix, at least the shop i worked at did. as for how to rod a rad, remove the top tank, or in the case of side tanks it would be the one the top hose connects to, connect a supply of water to the other end so water will be running up thru the tubes the opposite direction as normal flow would be while pushing a flat, thin metal strip down each tube. when it comes to flushing out a rad, it's best done in the opposite direction of normal flow, since anything that will clog up the tube goes in from one direction, u flush it out the other way. now, if ur inexperienced in doing this, u can ruin ur rad and end up having to have a shop fix it or buy a new one. copper rads absorb heat really fast and if ur not careful when removing tanks and then resoldering them, u'll pretty much melt the solder around the tubes in the header, which is the flat looking part that the tubes go in to and the tank is soldered to. and then there's the question of how u going to test it for leaks once u get it all back together. how that's done, plug all hose connections, connect compressed air supply regulated at no more than 30 psi, and submerse the rad in water and watch for bubbles. a bathtub would work but ur mom or wife might not like it.
I am not afraid to ruin the Rad, I have found that I can screw something up just as good as the Pro's can.
![Smilie](https://www.rx7club.com/images/smilies/smile.gif)
#15
i think propane will work ok by itself, i used mapp gas on my last home repair and it's alittle too hot also. i'll use propane the next time. don't use any of the acid or resin core solders, they're for electical/electronic stuff. rad shops use solid core, lead free solder that is near 1/4 in thick so get the thickest u can find. the small stuff would take forever to reseal a tank and alot of it.
Thread
Thread Starter
Forum
Replies
Last Post