A bit hot under the collar...

[olly22n]

Temperature has started to climb a little too high for my liking in this hot weather, creeping up to just under 100C in traffic (luckily had to wait no longer, so couldn't see if it would carry on rising)

This is normal Elan behaviour or may I have an issue with the cooling system (which i have checked, no leaks or air locks)

Hope it isn't as i ruiles out driving in hot weather, as traffic is unavoidable!

[rocket]

I think you will receive various answers on this one.My car runs ok in even the current high temps never too hot.I also think guages vary somewhat but different cars run diff temps.Obvious things to check like water leaks you have,also what type fan you running?

Ian.

[GrUmPyBoDgEr]

Sounds a bit high to me but it depends on how long the Car was standing in Traffic..
Were there any signs of Coolant loss?
First & cheapest thing to check is the Thermostat.
Remove it, chuck it in a Pan of Water together with a Thermometer & heat it up on the Cooker.
Keep an Eye on it to see when or if it opens.
Quite a few other things to check after that if the Thermostat's OK but let's see.

Good Luck
John

[olly22n]

it has an electric fan on it, haven't checked when its cutting in.

Car gets hot when it has been in town and then sitting in traffic. I think it is lack of airflow as there are no leaks and fan seems pretty good!

[billwill]

If you are having trouble with the thermo switch that turns the fan on, wire up a bypass switch or just short the two wires of the switch together for hot weather, so that the fan runs all the time that the ignition is on.

The problem in summer heat is that you are blowing hot air through the rad, which doesn't help a lot to cool it.



Ducting the fan properly and putting a dam at the bottom of the radiator so that air doesn't bypass the rad underneath is said to help.


In emergency in a traffic jam, turn the heater on, set it's fan on full blast & open the windows if yours is a coupe. You broil your knees but keep the engine temp withing limits.

[Bob]

On our trip last year I was caught in traffic on the Brussells ring road, the temp got really scarey, like well its under pressure so it really wont be boiling at 212 degrees, will it?

What I found was as soon as I could get 40/50 yards of clear road enought to replace the air under the bonnet the temp dropped dramtically. Although I did not try it at the time if I get into traffic like that again I shall pull the bonnet catch I think the problem is in stationary traffic the electric fan cannot pull in cold air only re circulate the air under the bonnet and that gets to a point were it can no long transfer heat from the coolant. I have a Kenlow Fan fitted to a 56 core rad and a new thermostat it normally runs about 150 degrees OK in traffic but after awhile it seems to reach a critical temp and climbs very quickly. Hence I think its air circulation not water or fan. I thought of louvers in the bonnet might help. But at the risk of putting up the costs of spare/surplus bonnets, getting a second bonnet and cut air vents in it just for sunny day motoring. Still thats all going to have to wait things got much worse on this years trip but thats another story to be told when the engine comes out and I know what has really happened. Either flywheel or crank or both.

[m750rider]

My experience is that a proper cooling system should be able to stay below 100 C, even in traffic. I have been in the same situation you described and found there are ways to improve the cooling capability of the system. I now never approach 100 even in the hottest part of the summer.

Efficient ducting of air flow from the grill ensuring it goes through the radiator can do a lot for high speed cooling. There is a large gap under the radiator just behind the steering rack. Plug it up with foam. I've also added foam to the bonnet right over the radiator so that no air flow can go over the top. There are also holes on either side of the radiator in the side mount frames that can be plugged. Force air through the radiator so you are water cooling, not air cooling.

Use the electric fan with the thermal switch, or put a manual over ride switch to turn it on when needed.

Run the coolest available thermostat in the summer. A 10 minute job at most - 75 C thermostats are available.

Of course, good water flow is dependent on a good running water pump, one with fairly tight clearance between the impeller and case. If you rebuild, follow the shop manual very closely. It's also not a job you look forward to doing unless you have replaced yours with a cassette type. Do everything else first.

I live in the southeast US and summer air temperatures for me can be as hot as 95 -105F and even then, coolant temps will not exceed 95C in traffic. I do have a fairly new water pump that I installed when I rebuilt the head. Normal operating temperature is 85 -90 C, and I do not have to run an electric fan.

The aluminum head is easily damaged by high temperature - it can warp, distort, all kinds of bad things. Stop the car before it gets too hot. I think anything over 100 C means you have to find some way to cool it down - turn on the heater full blast or shut it down ultimately if it keeps going. 100 for a short time is acceptable, long term, or heading towards 105 would make me stop.

Bob

69 S4

[1964 S1]

I've got an electric fan on the +2 which was thermostatically operated but the car would run a little hot shortly after I bought it. I took that switch out and put in a manual toggle so I could anticipate a situation before things warmed up. Haven't had a problem since.
Eric

[terryp]

I think also an occasional rev to (3 - 4000rpm) helps to get more water circulating as on tick over the pump is hardly turning.

Terry

[SpeedModel]

I was concerned that the water temp gauge on my old MG was too high until I realized that the gauge wasn't calibrated properly.

[65 Lotus]

Speaking of thermostats, be sure to fit one of the old, normal styles.

Some of the new "high performance" units will fit in the thermostat well just fine, but upon opening will hit the bottom of the well and not allow the unit to open fully, restricting flow dramatically.

Something to consider if recently replaced.

[GrUmPyBoDgEr]

Speaking of thermostats, be sure to fit one of the old, normal styles.

Some of the new "high performance" units will fit in the thermostat well just fine, but upon opening will hit the bottom of the well and not allow the unit to open fully, restricting flow dramatically.

Something to consider if recently replaced.

That's interesting!
Any chance of a side by side Photo for comparison please?

Cheers
John

[69S4]

My S4 has always run hot and at times I've sat in traffic and watched the needle go well past the 110c mark but I've never had it actually boil over. The Stromberg engined cars are supposed to run hotter anyway which just makes it worse. For my sanity though I've tried to do what I could to keep the temperature down and found a few things that have helped (and some that haven't). I've got the narrow std radiator and found a substantial difference after having it rebuilt with a three row core. Whether it was just the rebuild or the three row core I'm not sure but it probably added ten mins to my traffic jam comfort zone. That's a fair bit of peace of mind. I've used all the various thermostats over the years but not noticed any difference on the overheating rate. Once it's fully open I don't suppose it really matters what the temp rating is.

The std Lotus electric fan doesn't really shift a lot of air. It's better than nothing but to be effective really needs to be working before the engine temp starts to rise. A manual over-ride switch is really the only way of doing this. Cleaning up the wiring connections to the fan, making sure it had a good earth etc probably doubled the fan's speed when I did it last year and improved the cooling. The temperature still gradually increases but at a slower rate.

Popping the bonnet has a huge effect on the cooling. On my drive the car will sit there and idle seemingly for ever with bonnet raised about six inches and the fan going. The temp seems to stabilise around 95- 97c. and you can feel waves of heat coming through the gap. Not very practical in stop - go traffic but it does show where the problem lies.
I've cut various holes in the inner wing which haven't made any difference but have wondered whether fitting them with an extractor fan would! Next "upgrade" for me is to fit a modern fan that will push a lot more air through the rad and see what difference that makes. I have an oil cooler fitted to the car (previous plan to try and split the cooling between the water and the oil) and have thought about fitting a small fan (or two) to the oil cooler. Just need to find something suitable.

I've not really noticed any difference between an old leaky waterpump and a shiny new one but that's probably because the impellers have all been in good nick, it's just the seals and bearings that have packed up. Using Radweld in the engine was the kiss of death though. It fixed the leak I put it in for but severe overheating and a blown head gasket led me to find a lot of the narrow water passages blocked with some sort of deposit. Maybe a bit unfair to blame radweld but you have to look at cause and effect. Anyhow, I won't use it now. When I flushed the rad and the block out last summer loads of rusty gunge came out. That stuff would have been circulating and then blocking various bits of the rad. Interestingly there was a substantial amount of it sitting in a concreted form in the bottom hose.

Getting the engine set up properly - carbs, timing etc hasn't made much, if any, difference to the overheating rate. It makes the car more pleasant to drive but it heats up at much the same rate. On the open road the various bits of card, foam etc used to direct air through the rad do work to bring the temp down more rapidly and in my car at least make about 2-3c difference in the steady state temp (down from 90c to 87c in UK summer) but of course have minimal influence when the car is stationary.

Filling the rad with the front of the car raised to remove trapped air hasn't affected the cooling but I haven't had to add any water in a year. Previously I used to have to top it up regularly. The effect is to ease worries that the reason the temp needle is climbing is because it's run out of water so probably worth doing for that alone.

[gjz30075]

Next "upgrade" for me is to fit a modern fan that will push a lot more air through the rad and see what difference that makes.

Stuart, I have a Hayden 10" electric fan fitted as a pusher, on the left side of the radiator, ie, pushing air over the exhaust. When it kicks on, I can feel the hot air come around my ankles if I happen to be standing on that side of the car at that time. Yes, it'll move some air!

Absolutely no problems with cooling, but I"m also using a full width S3 radiator.
Greg Z

[smo17003]

http://www.pacet.co.uk/BONNET.HTM

Won't improve the looks, but this might do the trick?