12a Blew a belt, now running more hot?
05-05-15, 12:25 AM
#1
Full Member
Thread Starter
12a Blew a belt, now running more hot?
Yes, I did replace the belt before anyone comments on that. It is an 84 12a with only the alternator and water pump.
So I was cruising with a friend and decided to do a quite lengthy pull to about 90. I let off at the top of 3rd right before I shifted into 4th. Right as I let out the clutch in 4th I heard a loud pop. Looked in the rear view to make sure I didn't lose anything important, all good. Came up to a stop light and my radio shut off while I had the brakes pressed. Pulled over and found my belt across the engine bay split in half. I would have loved to see it go
Anyways, I always had to adjust that belt like it was stretching or wearing ungodly fast. This was a new belt from autozone. It also always made a low volume squeal, like it was slipping? So I made a pit stop at auto zone and the only belt they had was the wrong size of course. So now I have the previous belt, which is shorter in length but bigger in width and I think I see why it was on there now. But now my engine is running way more hot than it ever has, almost to the "oh crap" line before overheating. Runs steady there too. And the incident blew my horn switch, but no fuses.
So I'm wondering if anybody has had a similar experience. Could this be the thermostat or something else in the cooling? Everything is as it was before, no leaks, clutch fan is fine, etc. Or could the temp sender have taken a crap along with my horn switch during this event?
So I was cruising with a friend and decided to do a quite lengthy pull to about 90. I let off at the top of 3rd right before I shifted into 4th. Right as I let out the clutch in 4th I heard a loud pop. Looked in the rear view to make sure I didn't lose anything important, all good. Came up to a stop light and my radio shut off while I had the brakes pressed. Pulled over and found my belt across the engine bay split in half. I would have loved to see it go
Anyways, I always had to adjust that belt like it was stretching or wearing ungodly fast. This was a new belt from autozone. It also always made a low volume squeal, like it was slipping? So I made a pit stop at auto zone and the only belt they had was the wrong size of course. So now I have the previous belt, which is shorter in length but bigger in width and I think I see why it was on there now. But now my engine is running way more hot than it ever has, almost to the "oh crap" line before overheating. Runs steady there too. And the incident blew my horn switch, but no fuses.
So I'm wondering if anybody has had a similar experience. Could this be the thermostat or something else in the cooling? Everything is as it was before, no leaks, clutch fan is fine, etc. Or could the temp sender have taken a crap along with my horn switch during this event?
05-05-15, 01:50 AM
#2
84SE-EGI helpy-helperton
You're trying to attribute your overheating to too many extraneous events. The event here is that you have the wrong size belt on your water pump which is slipping and moving less coolant than it needs to remain cool.
Disregard everything else you THINK it is, and replace the belt with the correct size and width. Also, know that the belts were designed to pull even tension on the main shaft pulley, and when you start removing stuff like A/C, Air Pump, etc. the loads aren't balanced and subsequently it pulls unevenly on the water pump bearing.
Also, you probably know this, but at 46 posts here - maybe not - but it's critical that your engine NEVER be allowed to overheat. One time is enough to toast your seals and then you're looking at a rebuild.
Disregard everything else you THINK it is, and replace the belt with the correct size and width. Also, know that the belts were designed to pull even tension on the main shaft pulley, and when you start removing stuff like A/C, Air Pump, etc. the loads aren't balanced and subsequently it pulls unevenly on the water pump bearing.
Also, you probably know this, but at 46 posts here - maybe not - but it's critical that your engine NEVER be allowed to overheat. One time is enough to toast your seals and then you're looking at a rebuild.
05-05-15, 06:20 AM
#3
Full Member
Thread Starter
You're trying to attribute your overheating to too many extraneous events. The event here is that you have the wrong size belt on your water pump which is slipping and moving less coolant than it needs to remain cool.
Disregard everything else you THINK it is, and replace the belt with the correct size and width. Also, know that the belts were designed to pull even tension on the main shaft pulley, and when you start removing stuff like A/C, Air Pump, etc. the loads aren't balanced and subsequently it pulls unevenly on the water pump bearing.
Also, you probably know this, but at 46 posts here - maybe not - but it's critical that your engine NEVER be allowed to overheat. One time is enough to toast your seals and then you're looking at a rebuild.
Disregard everything else you THINK it is, and replace the belt with the correct size and width. Also, know that the belts were designed to pull even tension on the main shaft pulley, and when you start removing stuff like A/C, Air Pump, etc. the loads aren't balanced and subsequently it pulls unevenly on the water pump bearing.
Also, you probably know this, but at 46 posts here - maybe not - but it's critical that your engine NEVER be allowed to overheat. One time is enough to toast your seals and then you're looking at a rebuild.
05-05-15, 08:52 AM
#4
Waffles - hmmm good
iTrader: (1)
You may also want to invest in a dual belt pulley for the alternator. Running 2 belts is the easiest
way to fix the issues caused by removing the air pump and other stuff.
Like duck says, fix the belt then worry about the overheating. You are trying to solve a problem
with too many unknowns right now.
way to fix the issues caused by removing the air pump and other stuff.
Like duck says, fix the belt then worry about the overheating. You are trying to solve a problem
with too many unknowns right now.
05-05-15, 09:48 AM
#5
Full Member
Thread Starter
You may also want to invest in a dual belt pulley for the alternator. Running 2 belts is the easiest
way to fix the issues caused by removing the air pump and other stuff.
Like duck says, fix the belt then worry about the overheating. You are trying to solve a problem
with too many unknowns right now.
way to fix the issues caused by removing the air pump and other stuff.
Like duck says, fix the belt then worry about the overheating. You are trying to solve a problem
with too many unknowns right now.
05-05-15, 04:03 PM
#7
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Thread Starter
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05-05-15, 04:13 PM
#8
84SE-EGI helpy-helperton
Still cheaper than rebuilding an engine due to overheating, am I right?
Might also want to throw in a new thermostat (Mazda Factory, with the 'jiggle pin' facing up) for good measure. When was the last time you had your radiator rodded-out?
Might also want to throw in a new thermostat (Mazda Factory, with the 'jiggle pin' facing up) for good measure. When was the last time you had your radiator rodded-out?
05-05-15, 04:58 PM
#9
05-06-15, 09:30 AM
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05-06-15, 11:31 AM
#12
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Thread Starter
And what exactly does the bracket do? It looks similar to the stock one.
And I'm not really seeing how the gilmer can cause extra wear as long as you don't over tighten it. Plus it doesn't need to be nearly as tight as the stock belt setup, and I love the sound
05-06-15, 01:12 PM
#14
Waffles - hmmm good
iTrader: (1)
You know what, your right lmao. Im not sure why I always thought the water pump was a single pulley. I'll probably go ahead and order that then.
And what exactly does the bracket do? It looks similar to the stock one.
And I'm not really seeing how the gilmer can cause extra wear as long as you don't over tighten it. Plus it doesn't need to be nearly as tight as the stock belt setup, and I love the sound
And what exactly does the bracket do? It looks similar to the stock one.
And I'm not really seeing how the gilmer can cause extra wear as long as you don't over tighten it. Plus it doesn't need to be nearly as tight as the stock belt setup, and I love the sound
forward from the eshaft putting a greater load at an angle than a thin belt which puts
the load at about 90% to the shaft. Also because its looser, it slaps around more
at the increased angle and causes even higher dynamic loads than just the width
would alone.
05-07-15, 04:13 PM
#17
Full Member
Thread Starter
Ok, so I started my car today to tune the carb. I let it idle till it got at running temp. The new, right size belt is on it btw. It still got hot as before and it almost gets to the thin line after the middle on the gauge but then goes back down to right after the middle which is hot for my car, not sure what others run at.
There's no slipping because it was just idling, but there was a low volume squeaky ticking coming from the front of the engine. Kinda hard to explain. The coolant overflow was still at the max line which isn't normal right? It should be a bit lower since some is flowing through the engine? I'm thinking the waterpump, because of the noise or a stuck thermostat. The temp did fluctuate from middle to that thin line when I was driving it a few days ago though, but it was hardly noticeable on the gauge.
05-07-15, 05:16 PM
#18
84SE-EGI helpy-helperton
Thermostat is next - when you're grabbing at straws, replace parts in order from cheapest to most expensive!
Here are some other common causes of overheating:
1) Radiator needs to be rodded-out - sediment and scale build up and prevent good coolant flow.
2) Fan Clutch slipping - the silicone oil in your fan clutch is gone, causing the fan to freewheel and not pull air through the radiator (be sure your shroud is on and sealed at the edges)
3) Radiator Cap - letting pressure out through the overflow bottle. You'll notice this as steam coming out of the overflow bottle.
4) Timing - too advanced and you're getting a lot of excess heat.
5) Lean running - too lean and more heat, rich is actuall cooler, as the excess A/F mix takes heat energy out of the system through the exhaust.
6) Leak somewhere in the system - heater core, heater hoses (that one under the oil filter pedestal is common to blow out), lets out pressure.
7) Coolant mix - you want 50/50 water and antifreeze, as the antifreeze (for aluminum blocks) also raises the boiling point of the coolant.
Here are some other common causes of overheating:
1) Radiator needs to be rodded-out - sediment and scale build up and prevent good coolant flow.
2) Fan Clutch slipping - the silicone oil in your fan clutch is gone, causing the fan to freewheel and not pull air through the radiator (be sure your shroud is on and sealed at the edges)
3) Radiator Cap - letting pressure out through the overflow bottle. You'll notice this as steam coming out of the overflow bottle.
4) Timing - too advanced and you're getting a lot of excess heat.
5) Lean running - too lean and more heat, rich is actuall cooler, as the excess A/F mix takes heat energy out of the system through the exhaust.
6) Leak somewhere in the system - heater core, heater hoses (that one under the oil filter pedestal is common to blow out), lets out pressure.
7) Coolant mix - you want 50/50 water and antifreeze, as the antifreeze (for aluminum blocks) also raises the boiling point of the coolant.
Last edited by LongDuck; 05-07-15 at 05:20 PM. Reason: All great lists have 7 items!
05-07-15, 06:07 PM
#19
Full Member
Thread Starter
Thermostat is next - when you're grabbing at straws, replace parts in order from cheapest to most expensive!
Here are some other common causes of overheating:
1) Radiator needs to be rodded-out - sediment and scale build up and prevent good coolant flow.
2) Fan Clutch slipping - the silicone oil in your fan clutch is gone, causing the fan to freewheel and not pull air through the radiator (be sure your shroud is on and sealed at the edges)
3) Radiator Cap - letting pressure out through the overflow bottle. You'll notice this as steam coming out of the overflow bottle.
4) Timing - too advanced and you're getting a lot of excess heat.
5) Lean running - too lean and more heat, rich is actuall cooler, as the excess A/F mix takes heat energy out of the system through the exhaust.
6) Leak somewhere in the system - heater core, heater hoses (that one under the oil filter pedestal is common to blow out), lets out pressure.
7) Coolant mix - you want 50/50 water and antifreeze, as the antifreeze (for aluminum blocks) also raises the boiling point of the coolant.
Here are some other common causes of overheating:
1) Radiator needs to be rodded-out - sediment and scale build up and prevent good coolant flow.
2) Fan Clutch slipping - the silicone oil in your fan clutch is gone, causing the fan to freewheel and not pull air through the radiator (be sure your shroud is on and sealed at the edges)
3) Radiator Cap - letting pressure out through the overflow bottle. You'll notice this as steam coming out of the overflow bottle.
4) Timing - too advanced and you're getting a lot of excess heat.
5) Lean running - too lean and more heat, rich is actuall cooler, as the excess A/F mix takes heat energy out of the system through the exhaust.
6) Leak somewhere in the system - heater core, heater hoses (that one under the oil filter pedestal is common to blow out), lets out pressure.
7) Coolant mix - you want 50/50 water and antifreeze, as the antifreeze (for aluminum blocks) also raises the boiling point of the coolant.
05-08-15, 02:17 AM
#20
84SE-EGI helpy-helperton
Well, the O-rings which seal the oil filter pedestal get hard or crack, which allows oil to seep out around the edge of the pedestal. When it drips, it drips right onto the heater hose return to the engine block. When that hose gets oil saturated, it breaks down the rubber, causing it to swell and weaken. Over time, the coolant system pressure is enough to burst that hose, and then you have no coolant pressure, all your coolant gets pumped out on the ground, and the engine will overheat. I doubt that's your problem, but it's good preventative maintenance to check it every once in awhile.
I got tired of changing that hose, and having hot coolant squirt out on my right foot when I'd hit the gas due to a bad heater valve, and so I had the radiator shop pinch off and braze the feed off the lower radiator hose, and then built a plug on the block for the return line mentioned above - so I have no heater hoses running anywhere, and no heat in my car. I live in the desert and I don't miss having heat, and my A/C works tons better now that it's not fighting the heater core!
I got tired of changing that hose, and having hot coolant squirt out on my right foot when I'd hit the gas due to a bad heater valve, and so I had the radiator shop pinch off and braze the feed off the lower radiator hose, and then built a plug on the block for the return line mentioned above - so I have no heater hoses running anywhere, and no heat in my car. I live in the desert and I don't miss having heat, and my A/C works tons better now that it's not fighting the heater core!
05-08-15, 07:08 AM
#21
Waffles - hmmm good
iTrader: (1)
One thing LD skipped, the hose from the front of the engine to the beehive may be restricting
the flow of oil which will cause higher temps as well.
On cars with FMOC, the old hoses swell internally and eventually cause the same issue.
Remember, most of the cooling for a rotary is via the oil. Beehives are more sensitive to any
cooling issues because the oil only gets cooled down to the temp of the water that runs
through it. So you have a cooling issue to solve but its a matter of elimination to finally get
it resolved.
Heres another one: make sure you have the lower engine pan on ( the one that sits between
the crossmember and the lower part of the radiator). If thats not on with the stock setup air
will not flow through the radiator and will bypass it.
the flow of oil which will cause higher temps as well.
On cars with FMOC, the old hoses swell internally and eventually cause the same issue.
Remember, most of the cooling for a rotary is via the oil. Beehives are more sensitive to any
cooling issues because the oil only gets cooled down to the temp of the water that runs
through it. So you have a cooling issue to solve but its a matter of elimination to finally get
it resolved.
Heres another one: make sure you have the lower engine pan on ( the one that sits between
the crossmember and the lower part of the radiator). If thats not on with the stock setup air
will not flow through the radiator and will bypass it.
05-08-15, 10:58 AM
#22
84SE-EGI helpy-helperton
Good point, Mr, Farrell. I have an -SE, so I don't tend to think about beehive coolers.
Your comment about the lower pan is solid, as well. I have the Mariah Mode4 airdam on my car, which channels the air directly into the radiator and FMOC, so no issues with leaving the lower pan off my car, but stock front ends definitely benefit from the lower splash panel being in place. I've also toyed with the idea of building a bent sheetmetal 'ramp' which would connect the lower portion of the airdam to the lower portion of the FMOC to ensure 100% of the air goes through a cooling appliance. Here's what it looks like;
Maybe a future project after the rear axle bearing replacement, and rear brake caliper rebuild, and... the list goes on.
Your comment about the lower pan is solid, as well. I have the Mariah Mode4 airdam on my car, which channels the air directly into the radiator and FMOC, so no issues with leaving the lower pan off my car, but stock front ends definitely benefit from the lower splash panel being in place. I've also toyed with the idea of building a bent sheetmetal 'ramp' which would connect the lower portion of the airdam to the lower portion of the FMOC to ensure 100% of the air goes through a cooling appliance. Here's what it looks like;
Maybe a future project after the rear axle bearing replacement, and rear brake caliper rebuild, and... the list goes on.
05-08-15, 02:50 PM
#23
Full Member
Thread Starter
The factory splash pan is installed, but it does not have the factory air dam just the grille. Even though they still look decent (but old) I'll replace the hoses under the beehive asap. Airflow really isn't a big concern right now because it was fine before. Leaning towards the cooling/oil system.
I just can't figure out why the belt blew, and then and only then did my car start running hotter.
I just can't figure out why the belt blew, and then and only then did my car start running hotter.
05-08-15, 10:49 PM
#25
Full Member
Thread Starter
Well, the belt that blew was only about 2 months old. The damage done to it was rather violent with multiple teeth worn down near the break, I can post a picture if it helps. And I don't hear or see any slippage with the new belt, but I suppose it could just not be making a noise?