Coolant loss

[SurreyPaul]

Coolant is leaking from my Elise S1, especially under pressure. I can see the dripping under the offside rear wheel arch (image attached). Oil seems fine (no discolouration), there are no misfires, smoke from the exhaust or lack of acceleration. I can fill the header tank to the maximum, drive the car and 30 minutes later it is below the minimum level. If I continue to drive then the coolant disappears altogether so I’m loath to use the car. The coolant header tank and cap are new as of July 2021. The radiator and re-conditioned engine were new in 2016.

 

For what it’s worth, I’ve wrapped kitchen towel round pipes and joints for tell-tale signs of coloured coolant but no joy although this is not conclusive. Does anyone have any suggestions?  I read that HGF failure does not necessarily result in oil like mayonnaise.

[jep]

A coolant rubber hose is probably split but may not be noticeable until under pressure. There is one near the manifold by the bulkhead that can weaken due to heat.

Or a lose jubilee connection. 

Justin 

[DH2]

Sill hose (or clip thereon) likely culprit in that area.

Dave

[ADF]

I concure, most likely a pipe or clip from position although it's impossible to tell properly from the pic.  It sounds very unlikely to be HGF from symptoms. But just for information I have suffered coolant loss from waterpump failure (water pissing out of bottom of timing cover) and Inlet manifold gasket (water on back of undertray after running down back of engine).  The jubilee clips do go, I regularly check mine but found some quite loose when I got the car (fully serviced by specialists).

I don't fill my header tank to full, it just empties itself as it is designed to have a certain volume. Just about the min mark is were mine seems happiest.

Best of luck and keep us posted as to what you find

[SurreyPaul]

Thank you everyone for your responses.

When the header tank self-regulates and discharges excess coolant does it do so from the pressure cap?

Previous coolant loss has been due to: HGF, ruptured heater feed pipe in the sill and a cracked expansion tank (twice).

Unfortunately the Lotus garage I have used extensively in the past rarely acknowledge telephone calls or emails these days so I’m taking my ageing car to a local garage on the 13^th June who are not Lotus specialists - just a standard outfit. I’m really hoping it is a question of jubilee clips or, in the case of a split hose, they are able to identify the required part and order from Elise Parts. Whatever, I'll report back.

After 25 years and 115,000 miles I can’t help feeling – and have done for some years - that she is a financial liability but can never find it in my heart to let the dear old girl go.

Leak6.tif

[DH2]

At the age (and your mileage) of these cars - these sorts of issues are becoming more common as the hoses and clips get perished and tired.

A look up the back end of the chassis where that sill hose joins the pipe should determine if that is the problem.  If not, it will be tracking down from somewhere. The aluminium pipe across the rear bulkhead (unless you have the earlier up-and-over) is another culprit, as it corrodes against the bulkhead heatshield.

Minimum in the coolant tank when cold is perfect and normal.

Dave

[jep]

I wouldn't take it to a generic garage. If you are Surrey based, Max500, Lakeside Engineering or Bell and Colvill to name three. Max is very experienced on Elise S1, he's just done my C service.

Justin 

[SurreyPaul]

I've always used Bell and Colvill but have become increasingly frustrated at never being able to speak to front man Phil Marking who has ignored my calls and email this week. Such a shame as the work they do is generally good, but I'm forced to look elsewhere. The generic garage I'm taking the car to on Monday fitted a new cat and starter motor last year so I hope that they can solve the coolant leak problem. Failing that I'll try Max500 which is new to me.

[Bibs]

Jez @ Back on Track is ex-B&C and excellent too, he's worked on my cars in the past. 

http://www.backontrackmotorsport.co.uk/

[philcool]

Give back on track a ring jez and Sam are superb 

They've looked after me for the least 7 years 

[SurreyPaul]

UPDATE - Collected the car this morning. A pressure test found no leaks. The garage said they also made a visual inspection but found no fault with pipes or clips. I'll have to take their word for that as a visual inspection is not included on the invoice. After collection I ran the car, bringing up the temperature and sure enough everywhere is bone dry. The only thing I've done since the original post is to replace last year's pressure cap with a brand new one. But the vexing question is IF the pressure cap was faulty then why was the drip appearing on the rear offside and not the nearside under the reservoir?

I got through to Phil Marking at B&C - always knowledgeable and helpful but difficult to contact - and I'm getting a second opinion this Friday.

As an afterthought: Diagnostics are not foolproof. For months my battery was being drained but extensive (and expensive) diagnostics found no fault and a new battery and starter-motor made no difference. The solution was using the spare car key, replacing the  badly worn one I'd used for 25 years. I'd read that due to a worn key points inside the ignition lock housing can still be closing the circuit, which in turn will leave current flowing, draining the battery. Since changing the key the car fires up perfectly - which leads to the next question: I'd like another key cut as a spare but nowhere I've tried will do it. Where can one obtain a new key? Any suggestions would be appreciated.

Edited June 13, 2022 by SurreyPaul

[exeterjeep]

Some new pressure caps are not well rated . see this bit from MG Rover mobile mechanics,

https://www.facebook.com/MGRoverMobileMechanics/photos/a.544594102280997/7313783095362030/?__cft__[0]=AZWUk0_O9VjG-OkKUWdYxfEv3HPL1liDOobnyR_F1uEwRzoTcWZSBuYYu5BFcv9dhK9lXusgOz6ZJ-QnyRr6fLThXgcOHN5xIviCJpT3rvB3Y3e8gu_eHS1fS6haY9O3ib5qzTUrAgkjqsH3Nvm0Plyaba6G7FkKmeujsSF6OajY-hyp9VLumo5o9SM8N7ZMZh8&__tn__=EH-R

[SurreyPaul]

This is the one I bought from Elise Parts -

S1 / S2 Coolant Pressure Cap A111K6001F

and fitted on Saturday last:

https://www.eliseparts.com/shop/cooling/s1-s2-coolant-pressure-cap-a111k6001f/

Last year I bought the same cap with a new expansion tank as the old one was ruptured. (Even I was able to swiftly identify and rectify that problem). The blub on the above link recommends that a new cap is fitted with each service interval.

I gave the car a good run this evening and still no drip but I just can't fathom how, if the old cap was leaking, coolant found its way to the opposite side of the engine on level ground. Perhaps I should pour cold water over the expansion tank and see where it comes out.

[Bibs]

Stranger things have happened...

[ADF]

Hi Paul glad to hear it's probably sorted, just to chuck my tuppence worth in. The chassis has a horizontal ledge running transversely below the expansion tank, it could easily run onto this, across the car and out the otherside.