Heat Wave in SW U.S. No Match for an X 1/9

[LarryC]

We are having a bit of high heat here in the Southwest this week. Today it was 100 F. Of course, the wife and I had to drive around town for one reason or another.

Just to show that it is not impossible, today on the way home, I idled with the AC on while the wife picked up something. The temperature gauge stayed at 185. Then we stopped and did grocery shopping with the X getting a good hot soak for well over a half hour in a parking lot well over the ambient temperature. It started right up using he half throttle technique. Then we crawled in traffic and drove on the freeway in 100F heat with the AC at full blast. At no point did the gauge get past 190 and only reached 190 briefly, even after exiting the freeway. Even idling at lights with the AC didn't have an appreciable effect.

So, as I have reported before, the X 1/9 cooling system is not inherently one that will overheat. The thing that really solved all tendency to get hot was (a) an aluminum radiator (Vics) and (b) a 180 degree Stant SuperStat, which seems to hold the engine temperature at a remarkably stable temperature. Stock engine, stock timing, and all emission controls functioning.

Moral of the story: If you are having overheating problems, then something is probably just not right. The radiator and SuperStat did the trick for me.

 

[Red Bull 78]

. . . Moral of the story: If you are having overheating problems, then something is probably just not right. The radiator and SuperStat did the trick for me.

Almost toasted "Ruby's" Engine last month. 3 hour cruise to hit Nashville, rush hour traffic. 55-60 mph to 1 mph. 3/4 Mile to my exit took 45 mins. Stuck in a center lane, just watching the Temp Gauge rising, I can't even pull over to the Safety Lane and shut it off. When is that Low Temp Sender going to kick on the NEW Dual Fans. Made the exit, then stuck, stoplight to stoplight to stoplight, barely moving. Finally pulled into the first restaurant I saw, to let it cool down while I had dinner. Made it home that night without issues. Upon investigation, all my Mods were fine, but the OEM wire to the Sender had broken.(Or Burned in too). Jumped the wires to make sure fans were working. Added an over ride switch while I was at it. Then, while searching for a Winking Headlight problem,(a loose Fuse) another 16 Amp Fuse almost burned my finger. It was the Rad Fan circuit. I hadn't accounted for the Extra Amps drawn by the 2nd Fan. The Old wire must have burned thru before the fuse blew. Replaced it with a 30 Amp. I'm only running a 20 Amp in my BWM supply line, until I'm sure the OEM wiring can handle the extra load.

 

[rocco79/138]

Replaced it with a 30 Amp.

If you have a 16amp almost burning you installing a higher amp fuse does nothing but almost guarantee burned wires somewhere else.
This is just a suggestion but if things are heating that way you might want to run one fan off the sensor and run additional wire to manually operate the second fan. If you are using factory fans my guess would be that they are protected (fused) to 130/150% so trying to power two fans would exceed design load.
If you are using the new after market fans two on the factory circuit should not be a problem.
I redid my entire cooling system, including the thermoswitch and could not get the switch to kick on... I have a manual override but I wanted the auto mode to work. Finally had it kick on at around two ticks past the center mark in temp gauge. Problem being that my sphincter switch clicks on at one tick over center. My guage runs two ticks below center or as cool as I have ever seen one run if I am moving at all.
Good luck with it! Stay cool!
Regards

 

[rocco79/138]

It started right up using he half throttle technique.

Great to hear your X copes with the heat so well!
I missed it so what is the "half throttle technique?"
I also may have missed this detail but are you running stock cleaned radiator or new aluminum?
Years ago I had a stock one refurbished and it helped keep heat way down. I now have an aluminum one and it does even better!
Regards

 

[sjmst]

Nice! What year is your X? Did the A/C actually keep you cool?
Thanks

 

[aarpcard]

All these comments about the aluminum radiator working so well are encouraging.

My X has had cooling problems since I got it back in March. If ambient temperature gets above 70 degrees, then the gauge will just go up and up and up. I end up having to coast in nuetral to build up cooler coolant in the radiator and then rev it to send that cold coolant back to the engine. This drops the gauge, and I'm good for another couple miles. I have the fans wired to be on all the time.

I've replaced the waterpump, thermostat, all gaskets, waterpump belt, and radiator cap. I've also flushed the system forwards and backwards with a decently powerful garden hose.

The stock radiator isn't leaking and visually looks to be in good condition, but there was nothing else to replace, so I bought one of the new aluminum ones and a a full set of new coolant hoses.

After reading this thread I'm getting more optimistic that I didn't just throw $350 at a solution that won't fix the problem.

 

[sdlsaginaw]

If you have a wire to the sensor in the radiator burning then you have a serious wiring problem. By design the sensor is only triggering a relay, it should never be used to switch the fans directly. Doing so will destroy the sensor rapidly.

 

[Rupunzell]

Over heating is more often than not due to cooling system degradation over time. Keep in mind none of these exxes are young anymore. Most thane suffered and endured clogged cooling passages, porous coolant tubes (bottom of the chassis), sub-standard coolant pumps with excessive impeller to housing clearance and tolerances, small leaks, clogged radiators and more.

These cars had NO cooling problems when new in any 100+ degrees F hot weather even when the power train was pushed to it's absolute limits. Even with a uprated power train, there are still few if any problems with cooling.

It was over 100 degrees F in the south west last weekend and the 74' had zero cooling issues even when stuck in traffic.

What makes the exxe cooling system a problem is the complexity compared to a front engined car. There are simply a lot more plumbing and stuff that can go wrong. All it takes is one tiny seeping leak and the system can be a problem.


Bernice

 

[aarpcard]

Over heating is more often than not due to cooling system degradation over time. Keep in mind none of these exxes are young anymore. Most thane suffered and endured clogged cooling passages, porous coolant tubes (bottom of the chassis), sub-standard coolant pumps with excessive impeller to housing clearance and tolerances, small leaks, clogged radiators and more.

These cars had NO cooling problems when new in any 100+ degrees F hot weather even when the power train was pushed to it's absolute limits. Even with a uprated power train, there are still few if any problems with cooling.

It was over 100 degrees F in the south west last weekend and the 74' had zero cooling issues even when stuck in traffic.

What makes the exxe cooling system a problem is the complexity compared to a front engined car. There are simply a lot more plumbing and stuff that can go wrong. All it takes is one tiny seeping leak and the system can be a problem.


Bernice

Do you think cooling issues are more prevalent on 1.5L cars than they are on 1.3L cars due to the bigger engine?

I've used a '91 MR2 for the last 5 years as my daily driver. It has a very similar cooling layout when compared to the X1/9. Granted the MR2 is newer than my X, but it's still over 26 years old. I've never had an overheating issue - including driving it through Death Vally in 120 degree heat.

One major difference I've noticed between the cooling systems in both cars is airflow into the engine bay. The side vents in the MR2 are large, and unrestricted allowing a lot of airflow into the bay when compared to the X1/9. Additionally, there is ducting on the underbody of the MR2 which picks up air traveling under the car and funnels it unto the engine bay - there's nothing like this on my X. Also the vents on the MR2's engine cover are much larger allowing for much more airflow . . .

Would we benefit from figuring out a way to increase airflow into (and out of) the engine bay in the X or is the only factor the liquid cooling system?

 

[rocco79/138]

I would think that might help marginally. There are no fins or other devices to effect a heat transfer to air. I am curious though about the design of the air box for the radiator... The MR does not have the same frunk capacity correct? Could this be due to a larger more efficient radiator surround?
Sorry, not wanting to take the thread off topic...
+1 to Bernice. Properly sorted the cooling system is enough for both 1300 and 1500cc.
Regards

 

[aarpcard]

I would think that might help marginally. There are no fins or other devices to effect a heat transfer to air. I am curious though about the design of the air box for the radiator... The MR does not have the same frunk capacity correct? Could this be due to a larger more efficient radiator surround?
Sorry, not wanting to take the thread off topic...
+1 to Bernice. Properly sorted the cooling system is enough for both 1300 and 1500cc.
Regards

The frunk is smaller - but not by a huge amount. In the MR2, you have the spare tire, clutch master cylinder, brake master cylinder and booster, power steering pump and resevoir, all in the frunk - so the actual volume is a little decieving.

The fan layouts and ducting behind the radiators on both cars are basically the same. The X1/9 seems to have a significantly freer flowing grill though, while I believe the MR2 does have a slightly bigger radiator - but it also has a significantly bigger engine.

The MR2 radiator is aluminum with copper fins, while the X1/9 radiator is all steel. Maybe that's the key difference.

 

[rocco79/138]

The MR2 radiator is aluminum with copper fins, while the X1/9 radiator is all steel. Maybe that's key difference.

That made a huge difference in my car.
A good radiator, like a propeller on a single engine aircraft, helps keep the pilot/driver cool... Doubt this? watch either when the prop stop swinging or the temp gauge on the X gets north of 190 and doesn't look like it might stop...

 

[LarryC]

Mine is a '79.( I just went into the signature info to find out why it was not posting my signature. I think I fixed that. As wonderful as Xweb3 is, it has afew quirks and gotchas.)
As I noted, this is with a Vicks aluminum radiator installed a couple of years ago. The AC of course is the one I utterly and completely rebuilt a few years ago (https://xwebforums.com/forum/index....d-upgrade-what-the-wife-wants-she-gets.21920/). Yes, the AC was plenty cool. At least as cool as theoretically possible when the ambient is 100 F. More important, we have not been sweating at all. More important still, the coolant temperatures don't appear to care if it is sitting still or cruising on the freeway. The Stant SuperStat was the real improvement though, if I must specify one thing. Did I mention that the Stant SuperStat was the real key to stable temperatures?

The half throttle technique: It's the inverse of the choke in a way. You slowly -so as not to squirt the accelerator pump -the throttle down half way. Then turn the key on ( I have an electric pump). Then start. It fires right up, hot or even hotter. Hot start problems appear to be fuel that has boiled out of the carb and into the intake. Half throttle gives it more air to help burn the excessively rich mixture. The cause: Pretty much widely accepted now that it is modern highly volatile fuels that are no longer correct for carbs in hot weather. Gotta "inverse choke" them now.

 

[rocco79/138]

Thanks! I had missed that. I have been trying to figure out what would make mine start hot. It will start but it needs full throttle and a pretty long crank period to do so. I look forward to testing this out.
Regards

 

[Red Bull 78]

If you have a wire to the sensor in the radiator burning then you have a serious wiring problem. By design the sensor is only triggering a relay, it should never be used to switch the fans directly. Doing so will destroy the sensor rapidly.

It blew a hose in a funeral home parking lot, 3 years ago. I figure all the activity to add the second fan only stressed the old wires a bit too much and of course, as Mussolini wanted, they betrayed me at the worst possible time.

 

[Red Bull 78]

Thanks! I had missed that. I have been trying to figure out what would make mine start hot. It will start but it needs full throttle and a pretty long crank period to do so. I look forward to testing this out.
Regards

You have Electrical or Mechanical Pump? Makes a difference. Modern Ethanol Fuel blends were designed for Closed, Fuel Injection Systems. They evaporate quickly, specially from Hot Carbs. They knew this back in 73. That's why the Carb Cooling Fan is there and runs even after you stop the Motor. Look at the total design of these cars. Large Cooling System, Side Vents, Top Vents, Vented Hood. Everything is about keeping the Engine Cool.
This system was designed to save your $4.00/Gal, "REAL" Gasoline they knew was coming, Not the $2.00 stuff we're trying to run these cars on today.