Overheating problem

[magnus]

Hello all,

My engine (in an Elan +2 1968, rebuilt about ten years ago) gets to hot. The problems started on a hot day last summer. The temperature rises to about 90-95 degrees c when its cold outside, when the weather is warmer, the gauge is touching the red. I?ve checked the thermostat, the waterpump seems to be working all right, the fan belt is tight and the radiator is ok. When revs go down, the temp falls. Seems like classic symptoms of a blown head gasket?.

However, I can se no traces of oil in the water or water in the oil. It seems like it?s a "light" problem if it?s the head gasket and of course, avoiding to take the cylinder head of would be a relief.

Is there any possibility that it?s the head bolts that?s become loose and needs tightening? I?ve discovered that other bolts on the engine (or the car for that matter) has been badly tightened by the previous owner.

Is it a good or a bad idea to try tightening the head bolts to correct torque?

Greatful for advice

Magnus

[M100]

There might be nothing mechanically wrong, it could be an electrical/gauge problem.

Sort out an independent means of checking the engine temperature. Either an infra red thermometer (usually equipped with a laser sight) or a thermocouple probe.

I'd leave the head bolts for now. If you really feel the need to retorque them do it with the engine fully cold. Remove them one by one, oil the threads and under the washer. Take them up to the final torque setting in two stages. Oh and get a new head gasket just in case!

[1964 S1]

If you're not needing to add coolant or oil then it's not your headgasket. After reading your line about revs and temp it sounds like a thermostat problem to me. How did you check your radiator to make sure it's ok?

[john.p.clegg]

Sounds electrical,to prove it do the two other gauges ( oil and petrol) move as the engine revs increase/decrease (bearing in mind they are dampened....
John

P.S. try ebay 4627964921

[simonriley11]

My father has just started running his 68 Plus 2 after a 12 month rebuild, the temp gauge reads high as does the fuel gauge and the oil pressure gauge reads low. We know for definite that the fuel gauge is reading high as we emptied the tank and have only added 2 gallons so we suspect the voltage stabiliser which appears to feed all 3 gauges. The temp gauge will just go in to the red yet there are no signs of overheating and the Kenlowe fan (which worked correctly previously) doesn't cut in until the gauge goes futher. This could be your problem too or perhaps a sticking thermostat.

[richardcox_lotus]

I'm having a similar issue with my '72 Sprint. Not really losing any more fluids than normal, no mayonnaise in Sump/Rad BUT it did get v. hot last summer - without overheating - , & now I notice that No1 (Or No4 ? - bulkhead end) cylinder is starting to look remarkably clean - Getting steam cleaned ?

So in my case I think it may well be the dreaded HG. Have to get the leak/coolant tests as defined in other posts.

Rgds
Richard

[john.p.clegg]

Simon
You dad may be interested in Ebay 4627964921
John

[jkatthehelm]

If it turns out that all gauges are engine (= generator) speed dependent, then I have a natty solid state conversion kit for the voltage stabiliser - (solders inside the existing unit, so looks original but maintains steady 10v at instruments), ?10 plus carriage

[iain.hamlton]

My father has just started running his 68 Plus 2 after a 12 month rebuild, the temp gauge reads high as does the fuel gauge and the oil pressure gauge reads low. We know for definite that the fuel gauge is reading high as we emptied the tank and have only added 2 gallons so we suspect the voltage stabiliser which appears to feed all 3 gauges. The temp gauge will just go in to the red yet there are no signs of overheating and the Kenlowe fan (which worked correctly previously) doesn't cut in until the gauge goes futher. This could be your problem too or perhaps a sticking thermostat.

Simon. You are right it sounds like the stabilizer. I had the same problem: someone had fitted a negative earth one in my positive earth car with similar results. But I am pretty sure the oil pressure gauge should use battery voltage not stabilized 10V.

You can now get electronic stabilizer rather than the nasty original electromechanical ones.

All: I'd always check the stabilizer and wiring first.

best regards, Iain

[simonriley11]

Iain. Father's car is negative earth and the wiring diagram in the manual does show the oil pressure gauge as well as the other 2 being fed by the voltage stabiliser. I did read somewhere, although I can't remember where, that this set up was short lived in the life of the Plus 2.

[iain.hamlton]

Simon,

a couple of ideas:
I dont necessary mean that the voltage stabilizer is the wrong one. It may be broken, or not earthed. Either would show the effect you describe.

As far as the oil pressure gauge is concerned, perhaps some need 10 volts and some 12 - I dont know.

best regards, Iain

[magnus]

I have had the radiator off the car tested at a specialised workshop. The man there also mesured the temperature under the thermostate housing when the car was running with an infrared instrument (as you suggested Martin) and the gauge in the car unfortunately shows the correct temperature, the engine is to hot.
Probably have to test coolant to find out if theres a leakage.

Thanks for all advice!

[M100]

If you are sure the engine is running hot, test the thermostat opening temperature in a pan of water or run for a short while without one fitted to see if there is any difference. Also check the radiator hoses for internal delamination (particularly the bottom one)

[cdraper]

It could be something simple like a lose fan belt - these should not be too tight - I use a modern belt with "teeth" in the internal V rather than a continous form. These transmit far more trorque at a much lower belt tensionm than the originals.

[Jason1]

Hi guys

I just thought I would put my opinion in; I have just replaced my dash and had all sorts of electrical problems. I agree with the other posts, it is probably the voltage stabiliser, I read somewhere that the stabiliser needs to be mounted not more than 10 degrees off the vertical or it does not work

None of my gauges were working when I took the dash out so I fitted a solid state stabiliser and now they are great. I bought mine from ebay (?6) because I was to lazy the go to Maplins (like Radio Shack in UK), they are much cheaper in Maplins if you have the time to glue it into a small box and solder on three wires, or you could sell them on ebay like many others

I do have another electric problem though; the rev counter works great until I switch on the side lights then it reads zero???? Is this gauge voltage stabilised? I thought it came straight off the coil? I have recently fitted a Luminition so figure it could be this and am prepared to live with it if I must.

Also, I have a dynamo and the amps gauge barely moves, I know the max output is only 22 amps at 2250 RPM but is this gauge reading normal???

Thanks

Jason