Hello everyone!

to make a long story short:
I have repetitive overheat problem (water + oil) so I had everything cleaned and installed an oil radiator.
since then oil temp never (or juste a little) exceeds 120°, it rather sticks around second mark.
But, from time to time I had water overheat. So once again I had oil + coolant emptied and new. My car mecanic was not so convinced about a HGF.
Since then water temp is rock steady 1.5 mark bellow middle. However.... in about a week the level in the water tank dropped by about 3-4cm and I have some oil floatting in there.
OK, tank is damn dirty and it could, in some part, be a reason. Or from the rest of the circuit due to previous overheats. The car already had a HGF before I bought it.
There is absolutely no grey or white smoke at the exhaust.

so my questions:
- where can the oil come from?
- where can the water disapear?

it would be a pain to have the engine taken appart for.... nothing except $$$

any advice or help welcome
cheers
Philippe

If you just won't belive in a HGF... I won't tell you anything about it.

Water could disappear at the plastic screw in the front radiator, thats where my TF loses some water from time to time. Can smell it everytime it does...
Or the cap of the expansion tank is damaged, get a new one.

Regards,
Sven

I ordered a new water tank at B&G with level sensor (so at least I can see through lol and will have new cap coming with it) as well as the 2 stainless steel tubes under the car going from back to front.
I will mention the plastic screw to the mecanic...

any explanation where oil in the water can come from?

thx

If you really won't belive in HGF... it COULD be from the last HGF, if the system wheren't cleaned properly. No other explanation, besides new HGF.

gasp..... ok... well, need to prepare myself from what it seems...

thx
Phil

Hi Phil,

here is a quite interesting explanation about coolant overheating issues on a Lotus Elise due to the returning liquid from the radiator being actually too cold. Scroll down to the "the bis one" headline.

Mykel

thx Mykel!

in fact I had a look already on this page.
I can only agree about the missconception issues regarding the cooling of the K engine.

I tought the "drilled thermostat" or the 82° could be an easy thing to try if overheating comes back.

Thing is that my temp is for the moment really VERY stable... it actually is not very hot (as mentionned, 1.5 mark under mid).
I'm affraid that implementing the "drilled" or the 82° could prevent the engine from reaching it's proper working temp?!

I have the feeling that in most cases, in my case, overheating were caused by low coolant level.
(that's why I ordered the B&G water tank with level sensor)
which means that if I figure out where is my coolant disapearing, it could solve my problem... make also sens to you?
and also figure out why there is oil in my coolant... and if both problems are linked...

Hi Phil,

the water temp gauge will always rest at one line below middle, no matter what the actual coolant temp is. This position means that you are in a range from roughly 86 to 104°C. When the pointer goes up, it's usually kaboom.
Oil in the coolant definitely is a hint to more serious problems, so better prepare for the worst. When the coolant was drained, has the system been properly flushed, as some stains from the previous HGF could indeed be left in the tubes and hoses and the rad/heater as well.

Mykel

uhmmmm.... sounds like lots of good news to come.

regarding water temp gauge, I do not completely agree.
prior to install the oil radiator, I had it perfectly at the middle once warmed up.
it is only with the oil radiator that it is lower than middle.

I agree, oil in water smells like dead rat...
last hope, as you mention, would be that it comes from previous HGF and not properly flushed coolant circuit.

when installing new water tank and under car pipes, my mecanic told me he would try to "high-pressure" wash the circuit.
once this done, if I get back oil in the coolant... I'll know I need to sign up for the big show

How old is your car and what condition are pipes, hoses and radiator in? Just as applying "high pressure" might lead to more problems when the pressure is too high.

btw: a little more info about you, your location and your car in your profile might come handy at times ...

MGF Trophy Oct2001, 95K Kms roughly

I'll update the profile.... now...
Thx

Hi Phil

Go to "Autobritt SA, Geneva" and let's check the matter.
They know, what they do!

Regards
Andy

So what was the failure ?

The K-Series HGF (inside in every original 1.8 K-Series after 80 tkm, original K-series with SLS and old oilrail, without PRRT and oil/water cooler) ?

regards
Uli