620s - Engine cutting out in very heavy rain

[Benton]

May be a total red herring but .... the early 620Rs didn't have a thermostat fitted, subsequently Caterham offered owners a retrofit solution around 2016, see Mark Ws write up https://6100ef74-38c4-4cc4-b213-902faf3c744c.filesusr.com/ugd/a3e364_2ffc471a99f8410fb2c7868da09405a5.pdf?index=true

Obviously don't know the history of your car, apart from your introduction you said it was the "first" 620S 2015 maybe (?), does it have a thermostat fitted? Strange that you as the new owner are encountering these problems, you would have thought they'd be sorted.

If the car is running anytime below 60 using the standard 620 map (although my understanding is that the ECU has a different temp sensor to the gauge one so one can't 100% rely on the temp gauge reading ) then it'll be running the cold start set up, ie running rich, and if doing so for any prolonged time will coke up the lambda/plugs etc.  More seriously if it's happening a lot you risk bore wash/dilution of the oil on the cylinder walls which could lead to worn bores in the engine, which apparently has happened to at least one 620 owner.

 

 

[7 wonders of the world]

Even the 620's with thermostats fitted don't function correctly as CC plumbed them incorrectly as I explained to Mark in a previous long thread.

 

[Phillip Meyer]

Mine is a 620s and yes, the first 's' built so not sure if it will have a thermostat or not, possibly it will if this was an 'r' problem? Any way to easily tell? 

[Mark w]

The solution to 620 cold running is available , i helped co develop it and IT WORKS. 

It was all written up by me in Low Flying earlier this year and any competent Caterham owner could implement the same.https://6100ef74-38c4-4cc4-b213-902faf3c744c.filesusr.com/ugd/a3e364_2ffc471a99f8410fb2c7868da09405a5.pdf?index=true

Andy at PGM is selling that solution ( with my agreement ) if one doesnt feel able to DIY .

No Caterham 620 ( R or S -Factory thermostat or not ) has a properly regulated cooling system unless the modification set out in Low Flying is undertaken. 

Philip , if yours is a 2015 car it wouldnt have had a thermostat fitted from new , if it had the Caterham mod retrofitted ( post 2017 ) then whilst it may have a thermostat the housing the thermostat sits in will have a big bypass cut out machined in it which is why cold water rushes into the engine as per your post no 25.

[John Vine]

Re #25:

I think long term I will go down the PGM solution but this will obviously invalidate my warranty so I will wait until that has expired.

I'm wondering whether there might be mileage in talking this over with CC.  Mark W's excellent LF article notes that they're "looking at introducing something along the same lines".  If their upgrade looks to be months away, perhaps they would be willing to modify their warranty to include PGM's proven upgrade, or even fit the upgrade themselves?  (This assumes, of course, that the not-invented-here syndrome doesn't apply!)  Their alternative seems to be having to deal with regularly failing lambda sensors, and possibly engine damage due to bore-wash etc.

JV

 

[Phillip Meyer]

I did speak to CC, their response was that they had looked into this and that they felt that the cooling issue would have 'no impact on longevity' and therefore they would not take any action. Perhaps my 2 lambda sensors in 4 weeks suggest different.

[Phillip Meyer]

Thanks, I have spoken to PGM and I will probably get this done when my warranty with CC expires but doing it sooner would obviously invalidate my warranty. In the mean time I will try covering a portion of the radiator and will ask CC about the thermostat, I think that is a minimum requirement.

[OldAndrewE]

Ref #31 To paraphrase Mandy Rice Davies (if you are old enough to know who that was) "They would say that wouldn't they"

[David aka Blue7]

Profumo, Mandy Rice and Christine Keeler, what a scandal but actually quite sad and I do indeed remember the "affair".

Speaking about being old enough to remember certain things, with regard to the radiator blanking does anyone remember the system which was like a miniature roller blind installed in front of the radiator, you could raise it and lower it by means of a choke type cable fitted to the dashboard.  Blanking radiators during winter months was a fuel saving ploy there were some very fancy styles, the best being leather attached to the outside of the radiator grill with two opening options, bog standard cloth cap peasant options were a sheet of cardboard.  They went out of fashion when the fly wheel f/ water pump an was replaced with an electric fan that only operated when the engine reached optimum temperature.  I remember many occasions driving down the road and seeing steam coming from below the bonnet and suddenly remembering that the radiator was still blanked off

Pretty sad that in 2021 a £60k car has to have the radiator blanked to operate normally ... get the finger out CC!

 

[Jonathan Kay]

There's a Seven out there with a radiator blind that's adjustable from the cockpit...

Jonathan

[7 wonders of the world]

FFS.... 

Are they running on crossplys with drums brakes all round too, may with tungsten lights and a starting handle up front.....

There's a reason all these were left in the 1950 / 60's......

[ECR]

A couple of strips of gaffer tape across the bottom of the rad worked for me when I needed it. Easy to fit and remove

[Phillip Meyer]

Car is currently with Caterham cars to fix another problem while I am on holiday. However, I will try masking the radiator when I get back 

However, I did ask if my car has a thermostat and did ask if one can be retrofitted if not. Still not totally clear how I can easily check if it already has one though

[pgm]

Hi Phillip

If you can manage to see the thermostat housing it is possible to tell whether it has an early type housing which didn't have a thermostat. If you call the workshop they will be able to explain. We have had several in with the early type of housing (without a thermostat) usually on the early models. You do need the later housing though to modify to correct the over cooling issues, so even if you eventually have to do that at least you are starting with the correct housing.

Kind regards PGM

[CtrMint]

This thread makes for familiar reading 

 

[ScottR400D]

#40. It does, but as Tom Jones might say, it's not unusual....... 

[HendrixsWhiteStratReturns]

#41

why, why, why'd he drive 'er ...

[ScottR400D]

#42  

[CtrMint]

With a bit of luck, crossed fingers and fair weather, CC will be fixing mine in September.  It might actually get driven at that point, 

[ScottR400D]

What does 'fixing it' entail? 

[CtrMint]

Installation of the revised cooling solution. 

 

[7 wonders of the world]

Cooling system - not so much fixing but doing what should have done in the first place and have a correctly functioning cooling system......  

wonder if they are going to add a thermostat to the oil system too or are they still committed to the 'remove the front number plate when the oil gets too hot' approach......  

[Benton]

#46

Are they using you a "test bed" or is it now a tried and approved solution that they are going to offer to other owners?

[CtrMint]

Well if I'm at least able to start using it, then its a step forward.

[David aka Blue7]

I assume that "factory recall" for all 620 owners is errr, two dirty words not to be mentioned but just whispered quickly in Latin

currum revocare