Engine Cooling and Heater

[Rob C 8]

Ok if your an avid V8 owner new or old, this tip may give you at least peace of mind.

I'e run V8 Lotus Esprit's, longer than most I guess, 1998 and running.

I wonder how many owners, Know there is an Electric Water pump on the car ! its mounted N/S Rear outside the chassis main frame, its purpose is to cool the engine, if for any reason at Rest the car has been parked Red Hot. It's to protect this very special 918 Flat Plane Crank Engine from Damage.  Note the Engine Temp will rise even Higher after it's switched off With latent Heat....(ALL ENGINES)..... before they cool down.

How this system works is not why I'm writing this ( my back ground was an Auto Electrician) But this pump may never have run or has not had to run, the problem is How do You the "Owner" know its in working Order ?

Note IGN Key not in the Socket

 INFO Workshop Manual (or hand book ) section ML pages 14/15.    Rear Relay box. Remove cover and the "A" relay......will easy just pull Out.

 Look at the Relay drawing on its side. it shows 5 contact's, Noting Terminal's 30 and 87 !

On the relay Pin base note where the spade 30 *&87 terminals are.

 Now Looking at the Cars Main Relay Base and that relay you have in your hand, you should be able to Note the 5 Pin slots..... make a note of the positions of No 30 & 87 in the Relay Base.

What you need is about 5cm piece of wire, the actual wire thickness about  3-4mm thick for safety,   Fit on Two Spade Terminals.(halfords) ( To attach you could just squash the crimped end on with a pair of plies, No Bare Wire )  showing !!!)

Take the wire and push one end into the relay base Slot at 30 or 87, gently  contact, with other pin onto the  other terminal Slot.  if your pump is ok it will run smooth and not very Loud. fit the pin in properly let it run maybe 30 seconds, if the pump does not run. check the fuse, the data is on same page, retest. If its very noisy or does not work, you should consider who needs to look at the pump to fix it.

(then remove the test wire, refit relay and the cover) I've owned my SPT 350 for 17 Years, the test was normal ran like a watch. Those looking below will note my battery Isolation Switch.

Also the inline 10A fuse, that is the protection fuse for the Power Socket inside the Unused Fuel Filler Door. For Trickle charging.

    Very Important advice....... Make sure you have good clean Anti Freeze in the system, Have a good Look at Yours ?

     Please Note Only do this if you feel competent , if not ask some one, who Is.         I've been working on cars all my my working life

      All these words of wisdom came about from my Heating fault and having a conversation with Peter from PNM,  Good friend for many years. Very Gifted man.

 

 

[LotuStuart 91]

Thanks for that-its always good to be proactive on things like this..

I checked mine last night and the pump is working, and the relay is too (it had a 5 pin instead of a four but that's fine-the 87a pin was wired as the alternate state rather than the linked (same) state.)

Next I would like to check that the sensor is OK but that can wait for a dry day.

[Rob C 8]

Think you will find that its normal sensor that brings in the Cooling fans. On that subject My car has an override switch to manually switch the fans on with a warning light.

Note the take off point in the wiring is an negative Wire not a live.. look at the AirCon Drawings

tip 2

use the unused Fuel Filler flap to trickle charge the battery

[Rob C 8]

On 09/12/2018 at 14:19, Rob C said:

Think you will find that its normal sensor that brings in the Cooling fans. On that subject My car has an override switch to manually switch the fans on with a warning light.

Note the take off point in the wiring is an negative Wire not a live.. look at the AirCon Drawings

tip 2

use the unused Fuel Filler flap to trickle charge the battery

I now wonder How many V8 owners have had or do have any problems with there cars Heater,  The info about that Water Pump was brought about because my heater had stopped working.

I spent a lot of time looking at my car, that meant removing each seat in turn and actually lying on the floor with a torch and finding out where all the Parts were located, NOT EASY.

So having done all of that and noting where the Vacuum operated Recirc Valve, was, which I removed and tested, because I could. and inside the boot behind the Power Steering Reservoir the Vacuum Tank and ONE Solenoid Valve ( Which was DUFF) replaced with  one from a Vauxhall Astra 1.7turbo Diesel (boost controller). So Note Guys, I have all the data now in my PC on the Heater, which is Not in the manual.

[Steve V8 1,311]

Interesting stuff @Rob C,  I may be picking your brains later on with regards to my non existent heater.

My car is early '96 and the recirculation pump has operated just once after a rather spirited run on a hot summers day, frightening the shit out of me coming on a good few minutes after shutdown, and loud too, which is something I may need to look at, but at least it works.

The other issue, my recirculation valve was in the early reversed orientation, (working the flow against spring pressure) this can cause heater bypass issues, I've now changed its orientation but still need to rework the relay to solenoid wiring, but also noticed a small stone dent on the valve body which may have also restricted valve operation. I haven't had the chance to test anything yet.