Hello Grant and thanks for the continued flow of information, very helpful indeed.

For the vent hole, I installed it as you described, assumed through common sence that it should be so.
But I suffered with the triangular side . The square side installed in no time but the triangle side three times installed and was leaking water and when I would take it off would find that the stat had slipped down thus stopping the gasket from sealing. Luckily I did not damage the unit and made sure to inspect it well and the last time used a helper so I could poke my finger to hold it in position whilst tightening the bolts, I really felt silly !!

With regards to the thermostat photo I posted, I had actually heated it with a high heat gun and it expanded even more than that.
I just waited for it to cool down to 43 mm at which time I took the photo. I guess it is not very clear but it is reading 43, so I guess your concerns are addressed here?

As for the gauge and sender, I am still a bit lost and believe the sender may still be the original.
So, as mentioned above in response to Paul's comments, I am still lost as what to expect to see on the gauge with certain temperatures.
If when in the middle the temp is in the 80's then I assume it is correct to go close to the red line when above 90, but it still makes me feel very uncomfortable.

But if you say that is wrong, i.e. should not be so close to the red line, then when it is in the 80's it will probably read in the quarter range of the gauge, if you know what I mean.

I would like to get a straight view on this to know what to be comfortable with, and also hopefully I will get to sort out the fan issue as well.
I guess I will soon be reading from one or more of you gents telling me to sort out the fan then we talk gauge

Thx again buddy for your input.
Cheers

 

I was aiming for an original fan because as I understand it, it comes 2 speed and requires a 3 wire sensor to activate the higher speed at a higher temp.
I will check out the brand you mention and see if I can get something powerful enough to fit in the little space originally provided for the electric fan. Thx.
My car is wired in a way that the electric fan does come on with the AC.

As for the original fan & clutch, I did go for it and found what was being used by BMW's and Range Rovers to fit exactly in the space. Photos below.
However, after installing it and driving it for a day, I was checking the temperatures at which the clutch engages, and when I thought it did, revved the engine up a bit and a piece of the blade shot out I was revving from the engine bay and luckily it missed. So I took it of and returned the old one which seems to work well (by the amount of noise it makes when hot). But I do need to replace it as signs of old age on the fan are very obvious.
Cheers

 

Farouk,

Don't run that original yellow fan. They are notorious for cracking, letting go of a blade which can punch a hole through your bonnet and make a mess of your engine!

Change it for a newer original-type black ones.

Paul

 

Farouk
Th electric fan is NOT a two speed setup. It is either on or off.

 

Stat trick.

A SMALL dob of RTV on the stat outer disc rear face, insert into groove, and press lightly with Left hand, whilst drinking a beer with the Right hand. When the beer is gone, the RTV should have set enough to keep the stat in place. If not, 2nd beer and hold some more.

Works every time.

I now have more info on what you have done, good job.

As Paul has stated., get RID of that Yellow fan, mine went through the bonnet at highway speed, OOPS. NO stocks anywhere, so Efans took over, and I have never looked back.

 

Not correct

Center of the gauge typically corresponds to thermostat rating, roughly. About 88º for most cars.

And, typically, the Hot or Red area of the gauge represent something just short of boil over....122º or so.

These cars were built with 88º thermostats. In most driving conditions the coolant temp will hover ....plus-minus a few degrees.....at whatever the thermostat rating is and this will be indicated by the temp needle being roughly at the middle of the gauge.

In some driving conditions the coolant temp might increase a few degrees and the temp needle will rise a bit. The 95º you mention would show as one or two needle width's above the center of the gauge, IMO. In your case the needle is nearly at the red and this suggests something wrong with the gauge or sender.

Cheers
DD

 

Thanks Paul, yes for sure replacing it but got very unlucky with the black replacement which broke off, luckily not causing any damage.
Now awaiting a second one of better quality hopefully.
The yellow fan's clutch os also done as it rolls quite freely when hot, i.e. doing nothing.
Praying to find a good one locally otherwise will go for an import.

Cheers

 

Thank you Grant, and thanks to all of you that I ma doing something right
Yes your recommendation is well appreciated, would have been much more fun the beer way
Now I am that more wiser

Cheers

 

Thank you Doug for the explanations.
Today I was driving my 1990 500 SL and observed with more attention the numbers shown, and indeed it goes to 120 before going up again to the red line.
Photo below when still a

bit cold, but just to show the numbers.
As such what you and everyone are saying, the 95 or even a bit above can occur without presenting a danger situation.
My stats are rated 82 and when the needle is around the middle, I measured the temp which was around that level, hence my conclusion from what you are saying is that at the higher temperatures, the reading becomes wrong.
What if I do what a friend here is suggesting. He is a current owner of a handful of E-Types and helped a few other friends restore theirs.
He said he owned a couple of V12 E-Types and was having the same (apparent) overheating issue.
I say apparent because you all are saying such temperatures can be normal with these engines.
He sold both of them, and the new owner, after having given up on trying to keep the temp down, ended up adding an extra electric fan in front of the radiator and managed to keep the "needle" in a happy position.
Should I do the same and stick an extra fan, connect to say a 90 degree sensor ? Any comments against that?

Cheers

 

Oh, I thought I read it somewhere on this Forum in previous posts.
OK so mine is wired like this but for sure not the original fan and looking to replace it.
As it will be practically impossible to find the original one, and maybe I should look for an updated one, probably more efficient, is there a sort of rating CFM of air to be blown for it to do the job?
How can I tell which is correct.
Without any scientific guide lines, I will keep looking to find the one that blows most and fits in the space provided

 

Farouk,

I don't mean an aftermarket black one, but the genuine replacement black one that Jaguar introduced to replace the yellow ones.

Paul

 

That's my experience and my opinion, yes.

Some people believe that ANY increase over thermostat rating is actually overheating. I don't.

For 20+ years I've read god-knows-how-many accounts of people pulling their hair out and spending gobs of money.....sometimes thousands....in an effortto achieve the nirvana of a cooling system that holds temps at thermostat rating at all times and under all conditions. Some have succeeded, others not. Money and effort wasted, IMO. Not to mention the driving experience being ruined by constant worry that the needle is gonna tick up a bit.

If you're running 95º in mild weather then I'd say there's a fault to to found and corrected. If you're running 95º driving in Las Vegas in August, I'd say you're doin' just fine.

Just my two cents!

Cheers
DD

 

AMEN!! The truth that people don't recognize is that thermostats set the MINIMUM warmed up engine temperature. They cannot control the maximum temperature. Temperature does not remain rock steady once the engine is warmed up; the temp gauge SHOULD move. And if all modern engines should run below 100°C/212°F, we wouldn't need pressurized cooling systems, coolant recovery systems, etc all designed to help raise the boiling point. 225F/107C is not a cause of concern. We are talking a 35F safe swing if using 190°F thermostats.
Jon

 

If you have the fan shroud in position, a 10 inch SPAL will go in nicely. Measure the size of the hole and buy the largest that will fit in.
Here is a pdf link to SPAL fans and the 10 and 11 inch ones are in there on page three.
https://indd.adobe.com/view/dd4d901e...1-2fcb4ff0b3ba

Here is another guide to their models where you select the diameters required in cm.
https://www.spalautomotive.com/en/axial-fans

These fans will be vastly more effective than the OEM four bladed fan.

 

Thanks Paul well understood but unfortunately I have no access to that here and in my case I need to change the clutch too as that has gone.
Hence my option to get one for Range Rover or BMW which fits perfectly well.
I have no experience with these cars and for sure must assume that the blade I was given is a cheap aftermarket one, and thats why it snapped.
I am now looking for a genuine blade and I should be able to get it here. The new clutch seems good and adjusts to temperatures as need be, as observed when testing it before the fan snapped.

Cheers

 

WIth the stats sorted out and now waiting for the main fan to be replaced as well as the electric fan, will get to the bottom of things and see if the temp acts as you say.
Otherwise will have to look again for the possible culprit
Keeping fingers crossed
Cheers

 

Hi Greg, an answer for every problem

Many thanks for pointing out SPAL.
I just took some screen shots of the various size details of the fans 10-14" and will check them out on my car.
I just hope we have an agent for them here, otherwise I may have to import them.
If a reliable make is available here where SPAL is not, I will mention it here to see if anyone can recommend, otherwise will go for the import.

Thx again buddy

 

Hello. Had to read through all this to get caught up. Was this engine overheating before the work? Have you had it long enough to have a history with it? I have heard of piston rings being installed without having the proper ring end gap checked and essentially being too tight in the cylinder causing a lot of heat and drag. Just thinking out loud. Also could be something blocking a cooling channel in the block if the engine was opened.

 

Hi there and thank you for getting involved and spending time going through the previous posts as well as for your comments.
When I purchased the car it was behaving in the same way but with a difference source of worry, the engine oil pressure was always going down considerably when the car gets hot even at normal temperatures, and much worse when the heat scrolls up.
During motion, the car would maintain a fair amount of pressure but as soon as the RPM drops when standing idle, the needle would drop down to very close to Zero and the low oil pressure red light would come on.
As such, I decided to have the engine opened and change the bearings but ended up doing that as well as the piston rings etc and all the suspension, hoses etc, almost a full restoration job for the engine and under.
I would say that the car is still behaving pretty much as it was before but in a better way now as to start with the correct type of thermostats have now been installed, thanks to the group's advice. If I drive the car now without AC, ne needle barely goes beyond the middle range a state that was not so before, as the engine would continue to rise in temp even without the AC.
As for the overheating issue, knowing the facts more now, what I describe as overheating is apparently normal on this 12 Cyl engine as the temperatures I measured during the supposedly overheating range is normal (95 - 97 C).
However, I am still unable to put the car to a full test now and finish the running in period due to a faulty radiator fan/clutch and also an inadequate AC cooling fan both of which I will be sorting out soon.
So, please follow up on this interesting post and see what is next after fixing the above

Thanks again for chipping in.
Cheers