Overheating Problem - Serious !!!

[RichieL]

Guys,

Took my S2 out for a spin last night and saw after 5 mins of driving
that the temp gauge was off the scale nearly !!! Pulled over over
quickly back at home and got the AA out. He looked around and
diagnosed the thermostat was knackered (stuck closed) and the car was boiling over as water wasn't getting round the engine. He then told me
he couldn't do anything as the radiator and pipes all seemed ok.

He diagnosed internal problem or head gasket possibly gone !!!

Before i take it to the garage can anyone else help ?? The car
has full lotus history and only 50 k on the clock.

When the car runs warm normally the engine fan comes on but
not this time..

HELP !!!

[Enright]

Just change the thermostat (you're going to need to do that anyway and it's a readily available part from Halfords) and then get it sniff tested for hydrocarbons in the coolant - you may be lucky if you caught it in time.

Unfortunately the fan switch is on the wrong side of the thermostat, so if the stat fails then the fans don't cut in because the switch is still taking the temperature of cold water. If you've got A/C then you have the option of turning the fans on manually, but it's still a bit scary.

[RichieL]

Thanks ever so much for your advise.

Popping down to Halfords now..

I bet my bottom dollar the head gasket has gone !!!

£££££££££££££££££££££

L.ots Of Trouble Usually Serious
LOTUS !!

Oh, well, we shall see..

[Enright]

The part number is HTK602 if my feeble old brain remembers correctly - Edit: It does!

And a thermostat can fail on any car, usually with similar consequences.

Let's see how many K-Series engined cars get to 15 years without going through bendy head syndrome!

[muley]

Rchie,

Exactly the same thing happened to me. I assumed the head gasket had failed and did a sniffer test - luckily I had a negative result

It was just the thermostat. Car is running fine, now.

Hopefully your will be the same.

Cheers

Jim

[GeoffSmith]

Fingers crossed that it's only the thermostat Richie.

It strikes me that shed loads of thermostats have failed in the 18 months or so I've been around, causing anything from rough running to possibly head damage.
I'm beginning to think that thermostat replacement should be added to the regular service list. Also, does anyone know if there is anywhere convenient to put the fan thermal switch on the hot side of the thermostat?

Geoff

[RichieL]

Thanks for the part no, just popping down there now
for the part which is in stock.

I am praying the head is ok and not gone !!

Will keep you posted !

[RichieL]

Ok, new part fitted, fan is now cutting in and it seems ok ! I think,
I am going to put some K seal through it, just incase !!

I think Geoff has a good point, all Elans should be checked for
thermostat problems, that can occur with the cars.

Thanks for all your advice it is much appreciated.

Regards

[quiksilva]

Agreed.. a fiver or so for the part and one of the easiest DIY jobs to do on the car, Id recommend doing the interior matrix heater valve while your down there as that will probably be shot as well

[Enright]

Ok, new part fitted, fan is now cutting in and it seems ok ! I think,
I am going to put some K seal through it, just incase !!

I think Geoff has a good point, all Elans should be checked for
thermostat problems, that can occur with the cars.

Thanks for all your advice it is much appreciated.

Regards

Just a couple of things:

I've never heard of K seal - what is it? I didn't know you could treat the engine with anything that would protect against head-gasket failure.

Don't forget to get your coolant sniff tested for hydrocarbons.
If the overheating has weakened the head-gasket, it will give you a heads-up. You don't want to allow it the chance to let go on you and leave you stranded somewhere.

Incidentally, how many miles has your car done? As an S2 I wouldn't expect it to be that many, so perhaps we could work out a lower limit above which we could recommend to change the stat as a matter of routine.

[GeoffSmith]

The car has full lotus history and only 50 k on the clock.

Incidentally, how many miles has your car done?

Keep up Neil.

[Jon]

It actually mentions right here:

http://www.lotuselancentral.com/repair/thermostat.htm

"Thermostats usually last about 60-70,000 miles. They usually fail in the closed position which traps the coolant within the engine with no way to circulate to the radiator."


My S2 failed just before 70,000 - you would think that it would be included in the B+C service, but I guess they just wanted to save the £7 odd!

[GeoffSmith]

There have also been a couple of failures where thermostat operation appeared to be erratic rather than stuck.

[muley]

Drifting off topic - it's so easy and cheap to replace I'd recommend replacing the thermostat every year.

The Elan does seem to be plagued with thermostat problems - perhaps because they are not used daily?

Cheers

Jim

[GeoffSmith]

perhaps because they are not used daily?

Good point Jim.

[RichieL]

OK Guys, the sniff test was carried out and all seems ok.

K seal is added to your coolant and I was informed by the AA
that it can protect against 1-2mm cracks but not if you have
a K series engine ! His remarks was to an Elise.

My car has 50k just on the clock and on replacement it had
literally just corroded away. So I would be inclined to go with
the age of deteriotation as opposed to higher mileage cars.
Although it cold be indicative of both. For the sake of £6 quid
it really is replacing on any Elan of any age or mileage.

My main concern now is that cracks could appear or the engine
could be weakened as a result of the overheating so I will
keep my fingers crossed.

As regards to the heater matrix, mine was bypassed by by
the Lotus dealership last year ! Ridiculous as I have only just
got the car and on the service schedule it reads that Lotus
cannot get the part anymore !!!

Any ideas before the cold weather sets in ?

Thanks

[quiksilva]

I bought an XJ40 heater valve from SK Jaguar an independant specialist for about £35, Undo the in/out hoses refix the vacumn tube and your done - even simpler than the thermostat

[discovery]

I must be one of the lucky ones , my thermostat stuck open. Discovered it during first autumn i had the car . Not much heat from heater . I would also recommend checking/changing heater valve . I pushed against mine when changing gear cables ,it just broke off on one of the hose connections due to corrosion ,again i was so lucky.

[muley]

OK Guys, the sniff test was carried out and all seems ok.
... ...
it had
literally just corroded away....

Any ideas before the cold weather sets in ?

Thanks

Good to hear all is OK. I would suggest that you ensure you have a 50% mix of coolant and (distilled) water as the coolant is a rust inhibitor as well as a coolant. A while back a LEC-er had a cylinder head fail almost certainly due to coolant not being used.

Bye for now

Jim