Running Hot

[Spider]

Got a link for the temp transmitter you've ordered?

[smithyrc30]

Not sure what the reason for not getting an infra red thermometer is. They are relatively inexpensive now.
http://www.ebay.co.uk/itm/Digital-Infra ... 3f498a39d3

http://www.ebay.co.uk/itm/Handheld-Digi ... 541b129492

If you want to look at how the radiator is actually working: (I have one of these and it is very good. Was able to see where the problem was and then fix my under floor heating with it!!!)
http://www.ebay.co.uk/itm/IR-INFRARED-T ... 19fdb4a738

[Tim]

An old fashioned thermometer in the top tank of the radiator will work too, but not as convenient.

Tim

[Sully2908]

Not sure what the reason for not getting an infra red thermometer is. They are relatively inexpensive now.
http://www.ebay.co.uk/itm/Digital-Infra ... 3f498a39d3

http://www.ebay.co.uk/itm/Handheld-Digi ... 541b129492


If you want to look at how the radiator is actually working: (I have one of these and it is very good. Was able to see where the problem was and then fix my under floor heating with it!!!)
http://www.ebay.co.uk/itm/IR-INFRARED-T ... 19fdb4a738

fair point, I ordered a thermal thermometer from eBay this morning along with a new sender and top hose, now I just need to find the correct running temperatures for a 850 engine.

Sully

[carbon]

Sully,

Would be worth checking the temperature rating of the thermostat, should be stamped on the body:
- original thermostat likely to be 82C
- replacement thermostats likely to be 88C

If you have a working 82C thermostat I would put this in and try it.

[ianh1968]

- replacement thermostats likely to be 88C

"Off the shelf" or at least easily available, you can get
74, 82, 88 degrees and I once bought a 92 degree one...
... (from Halfords).

http://www.minispares.com/search/classi ... ostat.aspx

Strangely, on MS, the 74 degree version has morphed into a "75".
(Or is this just another of the hundreds of typo's on their site?)

Ian

[618AOG]

It may be worth saying, but both of the 1275 engines (a GT and an S) ran good and hot whilst they were still new, but once run it were okay. I found four core rads to be utterly useless, but a Mini Spares two core rad was much better. A couple of 3mm holes drilled in the stat outer ring will help in the short term.

[Sully2908]

Sully,

Would be worth checking the temperature rating of the thermostat, should be stamped on the body:
- original thermostat likely to be 82C
- replacement thermostats likely to be 88C

If you have a working 82C thermostat I would put this in and try it.

The thermostat is stamped 88 on the bottom.

[Sully2908]

- replacement thermostats likely to be 88C

"Off the shelf" or at least easily available, you can get
74, 82, 88 degrees and I once bought a 92 degree one...
... (from Halfords).

http://www.minispares.com/search/classi ... ostat.aspx

Strangely, on MS, the 74 degree version has morphed into a "75".
(Or is this just another of the hundreds of typo's on their site?)

Ian

Ian the one I took out is a 88 should I fit a 74 type or go higher??

[Sully2908]

It may be worth saying, but both of the 1275 engines (a GT and an S) ran good and hot whilst they were still new, but once run it were okay. I found four core rads to be utterly useless, but a Mini Spares two core rad was much better. A couple of 3mm holes drilled in the stat outer ring will help in the short term.

The original 850 engine was professionally rebuilt to just under race standard with new Pistons,rings, valves converted to unleaded head skimmed and all parts replaced. It's pretty much a new engine so your point is valid. Oil pressure is spot on. It's no where near run in so maybe I need to let it bed in.
My next step was to get it set up on a rolling road it seems to be pinking slightly and running a tad lean. I am aware this will add to the problem but I'm so worried about blowing the engine up it's driving me insane.

Sully

[ianh1968]

Ian the one I took out is a 88 should I fit a 74 type or go higher??

I'd agree with Carbon - Try an "82"...

I tend to swap mine about dependent on the time of year:
In the winter, an 88 or more
In the summer, an 82 or less

I either decide that the heater is getting a bit "poor" and put in a warmer stat,
or else I decide the engine's getting too hot and put in a cooler one...

Before I had my auxiliary rad, I was running a "74", or sometimes a "blanking sleeve/plate"...
http://www.minispares.com/product/Class ... o%20search

Running a lean mixture and having it pinking sounds like a recipe for disaster:
In the interim, I would definitely sort this out, even if it's just by using the
"finger-up-the-backside" method... I would either richen up the mixture,
or back off the timing, or both. A lean mixture does require more advance,
but not so much that it causes the engine to pink.

This lean mixture is not helping your temperature issues, and it might cause
your exhaust valves to burn out!

Ian

[Spider]

The original 850 engine was professionally rebuilt

Sully

Have you spoken with the Professional Re-builder man? Best you do so as to not void any warranty before you do anything.

[Sully2908]

The original 850 engine was professionally rebuilt

Sully

Have you spoken with the Professional Re-builder man? Best you do so as to not void any warranty before you do anything.

Yep I nag him to death, he's happy with the process of elimination I am following.

Sully

[Sully2908]

Quick update:

I replaced the sender and top hose, put the the 88 thermostat back in. The temperature garage is now going to the H point before the thermostat is opening as the radiator is so cool I can stick my finger in it. The new sender seems to push the needle to H quicker. i don't think the engine is as hot as the gauge is showing.

So as far as I call tell here are my possible solutions.

1. The water temperature gauge is having a bad day and no longer works.
2. The wiring to the temperature gauge is Incorrect.
3. The engine is getting hot very quickly and i have a serious engine rebuild problem. Possible water pump issue?

The IR Gun will arrive tomorrow or Thursday so I can confirm the actual engine temp at running. Fingers crossed it's a 1or 2 issue.

Sully

[Sully2908]

First thing to do is actually confirm 100% what the temps are, the sender you have for example may well be wrong (all the new ones I've bought over the past 3 or so years are). If it is right, then I'd suggest finding the root cause, not masking it with a bigger radiator. When everything is right, they don't run hot.

Noted.. Where should I get a new sender from ?

OK, again, as many of us have said, best to measure the temp with a known means. Some of the guys have mentioned the IR type temp gun, they are pretty handy sure (I have one and love it) but these more than one way to skin a cat!

I had a reliable and known capillary type gauge that I used to use many moons ago for example. You could have your gauge and sender tested but I think these days an IR gun would be cheaper. You could try test it yourself in a pot of water that you can fairly finely adjust the temp on over the 75 to 95 C range and measure with one them old fashioned (but highly reliable!) Mercury Gauge. I'm sure a few of the other guys would have some suggestions here.

Also, have a look on ebay and other places for an IR gun, they were expensive years ago, but these days, you can pick up one that is quite suitable for around 50 bucks.

Once you've established the running temp of the engine, then that will show you if it really is overheating or if the gauge is telling you porky pies. You can then do what's needed to correct it or live with it.

As 360gts said above ^ the original gauge would have been a full voltage type and these have a matching sender. New ones from what I understand are NLA (and have been for a while), however is that the type of gauge you are running or has the car been changed over to a later set up that uses the voltage stabaliser?

This may be the issue ^ the gauge maybe telling porky pies. The full voltage/ NLA comment might be the key to this. The IR gun should answer a few question. I have fitted a new mini spares sender unit, if I am presuming that a new mini spares water gauge would be NLA and work with the sender provided it's not overheating and wired correctly?

Cheers

Sully

[Spider]

Until you measure the true engine temp, it's only guesses at best.

[NotNormal]

I had water temp issues after the restoration of my Mini which sound exactly like yours. After trying all sorts of things relating to the temp gauge/sender/stat etc etc I eventually found the issue.

Result was a multitude of tubes in the rad were blocked meaning hardly any water was passing through the rad itself. The car had sat for years and although it flushed through all ok and I believed it was fine to use it wasn't!!

I see you've fitted a new rad but was there any crud in the engine that could have got sent round the system and are now blocking the rad tubes? On mine, once I had the rad re-cored with a new element its been perfect ever since. The temp now sits in the middle of the N for most of the time, moving up when on steep inclines or prolonged motorway runs but never going into the red (which it used to do very quickly and all the time with the blocked rad).

Agree with the above comments thought, getting a laser temp reader certainly helps diagnose exact temps the engine is running at.

[Sully2908]

I had water temp issues after the restoration of my Mini which sound exactly like yours. After trying all sorts of things relating to the temp gauge/sender/stat etc etc I eventually found the issue.

Result was a multitude of tubes in the rad were blocked meaning hardly any water was passing through the rad itself. The car had sat for years and although it flushed through all ok and I believed it was fine to use it wasn't!!

I see you've fitted a new rad but was there any crud in the engine that could have got sent round the system and are now blocking the rad tubes? On mine, once I had the rad re-cored with a new element its been perfect ever since. The temp now sits in the middle of the N for most of the time, moving up when on steep inclines or prolonged motorway runs but never going into the red (which it used to do very quickly and all the time with the blocked rad).

Agree with the above comments thought, getting a laser temp reader certainly helps diagnose exact temps the engine is running at.

Still awaiting the arrival of the IR gun, although the engine was stripped and rebuilt, so I am presuming it is clear although the head being blocked somewhere is a viable option, the IR gun should show a hot spot when at running temp, I have flushed the system quite a few times the water is pretty clear, to,the point where I would possibly make a cup of tea with it.

as its only a 850 I would presume some movement of the gauge from normal to the H as I live in Wales?

[Sully2908]

Hello all,

The IR Gun arrived, its not the most well bit piece of equipment but for £18 it did the trick, the engine is running at a constant 80-85 degrees although I have not pushed it over more than a mile. The temperature gauge is indeed not working rather than the engine overheating (phew).

Thank you to all that commented on the thread and helped me on my merry way to finding a solution, a top tip is if you test between the connectors you should get a reading of 60 Ohms on the gauge.

Best wishes and kind thanks

Sully (Shaun)

[dgear1984]

I had a few issues with a "hot" engine after I built up my 1275s.

I was a little worried to start that it might have been an engine build issue as it had been built up from unknown history parts and was not a complete engine before I started, (block from oz, crank from ebay, rods from miniformum etc....)

I tested the standard electric temp gauge out of the car and it seemed to be reading about right so that lead me down the garden path for a while.

In the end as I didn't have a IR gauge to hand I use some temp stickers, they change colour as a temperature is reached, that showed it didn't seem to be running that hot.

In the end I bought a second hand genuine smiths mechanical capillary temp gauge and used that. That was much easier to test, simply by putting it in a cup of boiling water with mums cooking thermometer and watching the two scales as it cooled to check the calibration. It was close within a degree or two.

After fitting the mechanical temp sensor the engine temp was running where I would have expected it to, and I had confidence in what it was telling me. So the way I had tested the electrical sensor was inaccurate and let me down the garden path.

Shortly after that the water pump started to knock. Brand new repro item less than 100 miles old. Luckily next door had a nos cast water pump he gave me so fitted that and at the same time I fitted the old plastic fan rather than the 16 blade metal one. Once again that dropped the temperature a little more. Not sure if it was the pump change or the fan that made the difference..

I would recommend to you getting a mechanical temp sensor, if only to use until your happy you don't have an issue. I think my good condition second hand one was around the £50 mark so not too expensive, and it can be checked for calibration easily and also will tell you a temp in degrees rather than C N H. With a IR gauge you'll have to keep stopping to check the temp, at least with this gauge you can watch the temp as you drive along and know if you need to turn it off when sat in traffic.

Once your happy with your engine temp issues, and if you do find its the gauge reading wrong you can always go back to a electrical gauge once you have fixed the gauge for originality sake if your concerned about that and sell the mechanical one on, i doubt you'll loose much money.

Hope that helps?

I find my car runs very cool now, very very cool, in fact it never gets even warm, mainly due to the face I have not been able to use it for close to a year now that i'ved moved to Australia and the car is still in the UK. Shame the shipping and import costs are so large.