Running Too Warm

Results As Of 11-4-13

OK, finally got the car buttoned up after addressing the impeller clearance question as well as a small leak from the stat housing area and replacing the heater control valve and some other tasks like shortening the plug wires and R&R-ing a broken speedo inner cable.

As far as I can tell, adjusting (tightening) the water pump impeller clearance has not made any noticeable difference in the original "issue" which was elevated (but not overheating) cooling temps during extended idle situations.

The car is perfectly driveable and does not overheat in the classic sense, so I will continue to drive and monitor this situation. The next time I plan to do anything to the cooling system is to install the Bob Grasch aluminum radiator once production and shipment has occurred. While the system is open for the new rad I might drop in another thermostat just to eliminate that as a very remote possibility.
 
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I got stuck in a huge traffic jam last week Thursday, long periods of no movement, crawl a few yards, repeat. Temp slowly rose, fan kicked in, I ended up turning on the heat and it did not get dangerously hot, as soon as I broke free and started moving at speed the temp dropped to normal, with in a minute. Just saying, my car doesn't like to stand still, maybe a second fan would help but it's so rare that the car idles for 1/2 hour that I just don't think it's a "problem".
 
Something just isn't "right"?

After monitoring a number of these threads about overheating over the years, including the current one about the Queen, and mulling over the fact that my 79 will not overheat on the hottest day idling indefinitely with the AC on full blast here in the desert Southwest, I am starting to conclude that it is all about either the condition of the radiator or, maybe (and I have no information to go on) the water pump. It does not take much to plug the radiator. I would seriously go after the radiator flushing thing before going with various fixes. It is pretty clear that there are conditions under which the stock arrangement works just fine. I have no idea what I did, but everytime I drain the cooling system the antifreeze-coolant is crystal clear. Maybe it says that the system is debris-free. I do not know.
Just my growing theory.
 
I've been giving this a lot of thought too...

Still mulling over Mark Allison's observation of a 1 degree drop with the auxiliary pump I installed "running", then a significant temperature drop with it "not running".
This leads me to believe the radiator as being totally ineffective at cooling in it's current state.

I think this because that aux. pump I installed has a 0.75 inch ID tube that did all the work of "pushing" the coolant inside an (approx.) 1.3 inch ID tube connected directly to the high side (input) of the radiator.

Looking at the coolant volume alone, there is absolutely no way a coolant pusher like that could force enough fluid across the 2+ foot span of an X1/9 radiator, with all those coolant tubes, and with the radiator fans running, and achieve ONLY a 1 degree drop at the other end... unless there was something else going on inside the radiator itself. There has to be a majority of those tubes blocked at the lower to mid end of the radiator for this to happen.

When I did my tests here, I saw an overheating situation virtually go away when I tested the aux. pump.
The engine was running at idle, the AC was on, the engine coolant pump doing a poor circulation job, and turning on the the aux. pump added just enough push to make it all work.

In the end, I'm betting a Bob Grasch aluminum repro radiator will cure the issue once and for all without the aux. pump.
 
Just my 2 cents...

I have owned 2-82 X1/9's for the past 5 years. One is completely stock and has had overheating issues pretty much since I bought the car. My 2nd 82 has a few modifications such as a header, big valve head, cam, etc and has never so much as gone 1 degree above 190 in any condition, including autoX. This had puzzled me for years since there were absolutely no differences in the cooling systems.

I tried addressing the over heating issue as everyone else has described in this thread as well as many others. Nothing ever made a difference. Both cars are have about 30,000 miles and were well taken car of in there lifetimes. I had changed every part in the chain with no improvements over a 2 year period. Including sending the radiator out to be boiled and pressure tested. When I finally had the prototype aluminum radiator made. Then installed it in the car everything now works as it should. For some reason the old radiator just wasn't doing it's job anymore. I even removed my 2nd original fan I had installed to help the issue, and I am now running just one fan.

I'm not saying this because I'm selling the aluminum radiators. It's just been my experience in trying to fix my overheating issue. Yet my other car with all the stock cooling system parts still works perfectly as well. The only difference is the aluminum radiator gives me a 5-10 degree cooler reading on the stock gauge.

Maybe if I found and bought a brand new stock radiator it would have solved the problem as well. Although using modern materials seems to do a much better job from what I can tell anyway.
 
When I first got my '87 Corsa it would run hot on a long freeway run. I tried various things but what ultimately fixed it was a new stock style radiator from Obert.

Early Fiat 850's had instructions in the owner's manuals to run vinegar through the radiator yearly. Obviously clogging radiators were always an issue. When I obtained a good used replacement radiator for my Scorpion I let it soak with vinegar in it for a few days, partly to clean it and partly to test for leaks. No problems found and it certainly helped clean it.

Looking forward to one of the aluminum jobs for my Scorpion, for piece of mind.
 
Another Theory

Add these factoids up:

1. Steve C. posted a couple of days ago that the X1/9 radiator has an unusually high fin-count, meaning there are a lot of fins per inch as compared to other FIATS and other contemporary cars;

2. Said fins are made of some sort of steel because they rust;

3. "Proper" installation the temp probe that my second fan system uses for activation calls for separating radiator fins and sliding the tem probe into the rad core. When trying to do this on my car, I noticed there was a LOT of rust "fuzz" in between the tightly spaced fins;

Theory: it may not be only the inside of our radiators clog...it could be the outside "clogs" as well, in the form of rust "fuzz" on the closely spaced steel fins that reduces airflow and the dissipation of heat by convection as well as by radiation.

Thoughts?:geek::huh:

And if that's the case, how would you fix it? Would you try to beadblast the rust off the fins, or dunk the whole radiator into an electric de-rusting bath? Google rust removal using electrolysis.
 
First thing I would try...

Dan Sarandrea (Phila) said:
I noticed there was a LOT of rust "fuzz" in between the tightly spaced fins;

Theory: it may not be only the inside of our radiators clog...it could be the outside "clogs" as well, in the form of rust "fuzz" on the closely spaced steel fins that reduces airflow and the dissipation of heat by convection as well as by radiation.

Thoughts?:geek::huh:

And if that's the case, how would you fix it? Would you try to beadblast the rust off the fins, or dunk the whole radiator into an electric de-rusting bath? Google rust removal using electrolysis.
Click to expand...

would be an external bath of CLR or similar. How long that would stave off the external rust might be questionable though. Eastwood does make a very thin black paint (laquer I think) specifically for radiator cores, so I might try that provided it did not bridge between the fins.

I have tried numerous things to prevent overheating in my car, both when it had the stock engine and after the K20 conversion. In stock format, switching to a Sirocco radiator was the biggest help.

Not really applicable to most, but after the K20, a Bob Brown style helper pump up by the radiator made no discernible difference. But this was probably due to the fact that water was not flowing well onto the radiator circuit in the first place, so there was not much for the helper pump to help. Switching thermostat styles (single action to dual action) corrected all cooling problems and I have since removed the helper pump. Car now runs between 190 and 205, being well regulated on the low end by the thermostat, and well controlled on the high end by the fans. As it should be.

Pete
 
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