Possible overheating?

[jreacock]

So - Beta Spyder 2L 1981 - just had a full engine rebuild and has Evans waterless coolant and new (nos) radiator, coolant pump, hoses - and it appears to be getting a tad hot when it really shouldn't be.

It's still being run-in, and has Pistoneze oil in it which might be a bit on the thin side. I fitted a new fan thermoswitch (from Vickauto) during the rebuild and assume that it switches at the correct temperature, but after an easy drive in 16C temperatures, the fan is coming on when I pull up. I've just had to re-shim the head (don't ever use this person http://www.cylinderheaddevelopments.co.uk/ - he claims to have worked on these cylinder heads but has no idea what he's doing). 4 out of 8 of the cam gaps were way out of spec - like double what they should have been.

I think the thermostat is working fine. All of the pipes and rad are getting hot - and I would think that if the stat wasn't opening, then only a subset of the cooling circuit would be used and getting hot.

The temperature gauge needle is staying at the low end (around the left-most mark), but does flick slightly every so often. The coolant pipes don't seem to be boiling hot - so I'm wondering whether the fan switching on is misleading. I guess that I need to measure the actual temperature instead of relying on the thermoswitch as a guide - but does anyone have any ideas or suggestions of things I should check?

Thanks.

[peteracs]

Hi

A tip from one of the LMC guys was to buy one of the infra red temp gauges widely available on Ebay etc to check the temp without having to 'insert' anything into the coolant circuit. I would start there and see what temp it switches on at.

Peter

[lanciamad]

I take it the cooling system was bled with the heater set to hot to allow it to flow through the heater matrix as well? Really like you say, you could do with knowing what temp the fan is being operated. My money would be on the fan switch, mine runs about a constant 79-80 degrees while on the move, and I believe the switch cut's in around 90-92 so it should be a good couple of minutes before it kicks in

[jreacock]

Hi Peter. That's a good idea. I was wondering how to probe the flow, as the expansion tank is the most convenient place to get to the coolant, but the liquid in there isn't flowing (I assume?).

Marcus - I think you could be right. As mentioned - the needle isn't anywhere near the center of the gauge - in fact, hardly off the left-most region when the fan cuts in. When I had the engine out, I blew air through the heater matrix to get all of the old water-based coolant out, and last night when I took it out for a test drive, I made sure the heater was on the hot setting.

I'll get a temperature probe and see what's going on.

Thanks for the advice.

[jreacock]

I measured the temperature at various places the other day. After running for about 10 to 12 mins, the fan came on. To be honest - I wasn't quite sure where best to point the probe. You'd think that the sensor would be the best place - but it's difficult to get to, so I measured lots of different places (hoses and radiator) and got between 70 and 90C. The temperature gauge is always around the minimum mark - slightly over when the fan comes on. If I push the test button - the gauge goes to max and the over-temperature light comes on. I'm not sure why the movement seems to be greatly reduced under normal conditions.

What I've decided to do, is to drain the Evans waterless coolant, and to go with Paraflu - as Guy Croft recommends.

I can't see what else to do with this, as I would have thought that a brand new radiator, new hoses, new coolant pump clean engine, good timing, cool weather - is all as good as it's ever going to get, so if it's over heating now, then it's only going to get worse with time. I think the Evans coolant just makes an engine run hotter. It may not boil over - but that is a necessary requirement for something that doesn't shift as much heat as regular coolant/water mix does.

I've got some Paraflu coming soon - so I'll update when it's in and tested. If I can go for a normal easy drive, come up the drive and pull up for 30 seconds without the fan coming on, then it will be an improvement.

[rossocorsa]

As regards the temp guage the sender might be defective as it is separate from the fan sensor. These sensors do drift over time becoming less accurate. I'm intrigued by that Evans coolant in theory running a tad hotter without the associated risk of boiling over isn't such a bad thing as surely it will aid combustion efficiency? The fan would however cut in rather more quickly when stationery I'm not sure that's too disastrous , I'm intrigued what others think.

[Neil-yaj396]

Did you check the temperature in the region of the sensor on the top of the cylinder head? This might confirm if the gauge and sensor are accurate.

Also, as per my posts under '1300 Coupes' I've got through three NOS fan thermostats recently. My trust in them then failed sufficiently to fit an aftermarket remote adjustable thermostat.

[peteracs]

I think it would be worth putting some numbers to the situation and then we can establish what is not conforming

So.....

Temps required for

1) when thermostat turns on (both ideal and actual)
2) when fan sensor turns on (both ideal and actual)
3) temp range for coolant exiting head/entering rad (both normal and in this case)

With this info I would suggest you can decide where the problem lies.

One thought I had was a poorly functioning water pump if it is shown the temp at 3 is excessive or of course a blockage in the head maybe?

Peter

[rossocorsa]

One thing to remember the Evans coolant doesn't boil until a much higher temperature, this means you can run on tighter margins for overall engine temp without issues the standard running temp is compromised a bit by the characteristics of water. You will also find that internal pressures will be lower so I suppose less chance of a blown head gasket I think I'd run it as is and see how it goes maybe change the gauge sensor though

[rossocorsa]

 From Evans website
'Q. Will Evans Waterless Coolant cause my engine to run at a higher temperature?

A.The operating temperature of the engine and coolant may increase slightly, by approximately 3-7 degrees. However the temperature inside the engine will be consistent and steam vapour will not be produced. i.e engines often run cooler with Evans Waterless Coolants.'

I think your situation is exactly what would be expected and safer than normal coolant.

[jreacock]

Yes. Thanks to all for the thoughts and suggestions.

I read up on the Evans coolant both before I got it, and since I've been running with it. Other write ups (not from the Evans site), suggest that because it's more viscous than a water/coolant mix, the pump can't flow it around as efficiently, and it also doesn't get through the radiator as quickly. Given that it also doesn't have the heat transfer capacity of water (about 30% less), it does have the effect of making everything hotter - all other things being equal. It might not boil at as low a temperature as conventional coolant, but given its other properties, it's a good job that it doesn't. It just doesn't feel right to me, so it's coming out. It's probably best to run this in cold climates if it makes an engine run hotter - but I'm certainly not going to be driving in the winter.

Before I drain it out though, I'll measure the temperature sensor and see if it reflects what's really going on. Does anyone know the approximate temperature values that the min and max lines on the gauge (one that's reading correctly) correspond to by any chance?

This is from another coolant manufacturer's web site. I take all these claims with a pinch of salt, both this site and the Evans site:
http://www.norosion.com/evanstest.htm

[rossocorsa]

I don't know the temp guage real figures but it's probably very approximate anyway and many manufacturers build in an area around typical engine temperatures that is less sensitive to damp down the variations in normal running.

[rossocorsa]

I had a look through several owners manuals the berlinas are actually marked but coupe's not, it looks like the red sector starts at about 110c needle should sit roughly in the middle but these things aren't all that accurate and I honestly think your sender is probably too old. I forgot that these cars have oil temp as well is that staying well in the good sector? A good indication of overall engine temp if combined with the coolant reading

[jreacock]

The oil temp does slowly rise during a drive, but not so much that it looks like there's a problem. One thing that I've noticed, is that the oil pressure starts off fine (center of the gauge) but this gradually lowers its position on the gauge into the journey when it all heats up. Tick-over when started from cold - it's in the central position, and when I get back from a 30 min drive, it's hovering around the min line (at tick-over), although I've not seen the warning light come on.

It still has the running-in oil in there - so I guess that it might be a bit thinner when it's hot compared to regular oil.

[rossocorsa]

If the oil pressure sensor hasn't been changed it may be out of calibration like all the 30+ year old sensors on these cars! I think that's the more likely explanation

[rossocorsa]

The oil temp does slowly rise during a drive, but not so much that it looks like there's a problem. One thing that I've noticed, is that the oil pressure starts off fine (center of the gauge) but this gradually lowers its position on the gauge into the journey when it all heats up. Tick-over when started from cold - it's in the central position, and when I get back from a 30 min drive, it's hovering around the min line (at tick-over), although I've not seen the warning light come on.

It still has the running-in oil in there - so I guess that it might be a bit thinner when it's hot compared to regular oil.

I checked some tech bulletins that I have, oil pressure on cold start up should be in the right hand sector, but not quite as high as fully across its travel,I think this suggests that your pressure sensor is most likely past it's prime I'd either get a garage to check with a test gauge or replace the sender (assuming you haven't already)

[jreacock]

As you say - maybe best to replace this and the other sensors as they are getting old. It has been stood for a good few years in the 26 that I've owned her, and everything has a life expectancy.

[rossocorsa]

As you say - maybe best to replace this and the other sensors as they are getting old. It has been stood for a good few years in the 26 that I've owned her, and everything has a life expectancy.

It all gets a bit never ending if you are aiming for perfection! And with old cars a certain sense of paranoia seems normal. I suspect the Evans coolant is ok but it's set you watching all the gauges like a hawk. It will be interesting to see the final outcome though. My engine is rebuilt so a prime candidate for water less coolant so I'm quite interested in what you decide in the end.

[rossocorsa]

Just to make everyone more confused Evans sent me this document that was their response to the link earlier in this thread, I've uploaded to the link below
https://www.dropbox.com/s/amrswp9rzbyeito/Evans%20UK%20response%20to%20No%20Rosion%20for%20Dealers.pdf?dl=0

[jreacock]

Yes - I saw that also, and then decided that you can't really trust any of them to give an unbiased set of results or opinion - where there's a vested interest. I could be persuaded to believe either of them. All I can say is that my engine appears to be running much hotter than it did before, and this stuff is the only thing that is actually different. I don't want the fan coming on every time the car stops moving for 30 seconds - and that's not how it would have been off the line (rusting maybe, but not overheating). The other things have been renewed and should be working like they would have when the car was new, but this coolant represents a change, and I'm seeing a big difference in behavior. It may be fine to run hot, but I prefer it running cooler.
I'll leave it in until the new temperature sensor comes - only going to change one thing at a time.

I'll keep you updated on what happens with this.