Category Archives: Caterham

Further issues

It has been a pretty decent summer in terms of use of the car.  Things running generally pretty well, and a decent number of both miles and trips to enjoy.

There was, however, one little concern which became more worrisome in the warm temperatures of late August and early September.  While running at speed, all was fine, but after a long run, if the car was then sitting in traffic, the indicated temperature started to climb, and despite the rad fan kicking in when it should, once the engine was at a certain temperature, it just couldn’t keep cool.  On a couple of occasions over this period I saw indicated water temperatures of 115 degrees (I’m pretty confident that the gauge reads a bit high, but these are worry levels).  And, of course, turning the car off only made things worse in the short term, as the coolant isn’t then circulating, and the fan’s not running.

This all came to a head in early September when, after a day of meetings in the West Country (including a very soggy drive from Hereford to Worcester), I was skirting Cheltenham on the way home and was forced to stop for fuel.  At that point the temps were showing a bit high, but not worryingly so.  However, as had happened a few times, the car then wouldn’t start.  “Ah”, I thought, “it’s just a bit hot”, so once it’s cooled a little all will be fine.  I jiggled a few fuses (as that had helped before) and sat on the forecourt with the bonnet open to let it cool a bit.  However, no joy.  For 3 hours.  The breakdown van was also delayed and delayed, and after waiting for ages, and sitting on a now darkened forecourt (the Petrol station had closed), it finally started.  Having cancelled the breakdown truck, the run home was straightforward.

With other things going on, the car sat in the garage for a few weeks after that before I finally managed to investigate, and get the guys at Spy Motorsport in Berinsfield (who came highly recommended) lined up to take a look.  However, the car wouldn’t start.  The starter was not turning the engine at all – just silence.  It reminded me distinctly of the symptoms of k-click on my old Seven, just without the click ….  So Spy came out with their trailer and took the car away, eventually diagnosing a battery issue (very odd, since the battery that was in the car was brand new in April – warranty claim to come on that, I feel).  They then set about trying to replicate the overheating issue – and failing.  (It’s a bit trickier to do in ambient temperatures in single figures!).

So, it’s not clear what the issue might be, or even whether it is a real issue.  At least I have the car back now, and I have a much more local garage.  Roll on the winter mods …..


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In Car Audio

After almost a year of thinking about how best to do this, I’ve finally implemented my plan.  The ideal requirements were:

  • Allow charging of handset while driving without wires everywhere
  • Mount phone in a visible position to allow it to be used as Sat Nav, ideally avoiding a windscreen suction mount
  • Provide means of listening to phone (whether Sat Nav audio or music/audio books etc) using headphones, in a safe manner – i.e. without too many trailing wires

In the Seven, I managed this by affixing a magnetic phone mount onto the dash, and running a power cable from the knee panel mounted 12v socket (cable tied underneath), plus a headphone wire extension which ran underneath the edge of the transmission tunnel cover to a socket in between the seats.

After much fiddling and deliberation, and trying of various phone positions, I eventually settled on using another magnetic mount, affixed to the flat front of the glove box.  This allowed me to wire in a switchable hardwired charger mounted in the glovebox, with a little channel in the door to accept the wire.


This is wired with an inline fuse taking the power feed from the (now pretty much redundant) 12v socket which is mounted above the instrument pod, in front of the windscreen.  Looks nice and neat from the front too, and with the additional magnet inside the phone case, holds things very securely.


With the automatic brightness adjustment on the phone turned off, visibility is pretty decent too except in very bright sunshine.

Now for the clever bit.  In order to avoid unsightly/unsafe wires going all around the cabin, I’ve gone down the bluetooth route, with a clever little headphone amplifier from Creative – the Sound Blaster E3.  This clips onto the little storage pouch on my Soft Bits wind deflector, and pairs to the phone via bluetooth, streaming any audio across to the headphones wirelessly.  And (as long as the E3 has battery!) it works really well.  It gets over the fact that some audio books in particular are recorded a little quiet for the rather noisier environment of the car, and as a bonus actually has two headphone jacks, do both driver and passenger can listen at the same time.  The E3 will charge from the 12v socket (there is one just underneath the pouch, mounted on the bulkhead between the seats).


As non-invasive and working solutions go, I’m pretty pleased with it, and it will still work as and when the phone gets upgraded.  A lot easier than trying to look at where hardwired speakers might be installed, and what sort of head unit would work.

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Minor niggles

The past week or so has been marked by various minor issues, all of which have been resolved, but each one of which has been a separate issue.

First, on getting the car out to go to the airport last week, it wouldn’t start.  The battery was fully charged (it had been on the trickle overnight), but the starter wasn’t managing to even turn the engine over.  With some time on the plane to think about it, I wondered if it could be a bad earth, which turned out to be correct.  The main engine earth from the block to the chassis (which bolts onto the passenger side engine mount) was loose, and as soon as that was cleaned and tightened all was fine again.  An annoying one, but pleased that I worked it out.

Then later in the week, on the way to Aylesbury, the speedo stopped working.  Completely.  I still had a backlight, but no needle or odometer movement.  Investigation behind the dash revealed nothing untoward – everything was still connected (except the trip reset, which I never use anyway because it’s manual).  So a bit of research needed.  The standard Caterham speedo works on an angle drive cable that connects into a flange on the rear part of the gearbox, so jacking up the car was needed.  Once located, it was very clear what the problem was – the cable was simple hanging loose.  Reconnecting was fairly simple, though getting the thread to bite was tricky initially as there’s quite a bit of lateral movement in the angle drive socket (I need to keep an eye on this).  Once on though and tightened up, all seems back to normal.  Once to watch, and check whenever I’m under the car, I think.

Last night, on starting the car – no tacho.  Some wire tracing this morning and a bit of unplugging and replugging revealed simply a bad connection to the main tacho feed from the ECU, so a pretty simple fix this time.

An instrument upgrade is in my mind at some point, either to SPA gauges, or more likely to the cheaper (and matching) Racetech ones.  It would be nice to have a speedo which reads somewhere close to reality, rather than under-reading by over 10% (according to my test GPS runs), and integrated shift lights on a replacement tacho sound an attractive proposition.  However, this would not be a cheap upgrade, or a straightforward one, given the configuration involved, and indeed the legal issues about the odometer.  It would be pretty odd to have a brand new tacho showing a few hundred miles on a 20 year old car, but it seems slightly questionable to ‘clock’ a new speedo to show the accurate mileage (though of course, given the time running with no speedo connection last week, those miles aren’t counted anyway!).  Not sure on the real rights and wrongs of this – some people say that as long as its all documented in the history of the car, then it’s fine – so I probably won’t be doing this anytime soon, and particularly not without some rather better advice.

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SPA gauges

After a really nice short run on Friday giving my Mum her first ride in the car, Saturday morning yielded an issue with the SPA oil pressure/oil temperature gauge:


A constant 16 bar of oil pressure at 162 degrees C on startup first thing in the morning?  I don’t think so somehow.  Given that it’s both readings, I suspect either a failed gauge or crashed software in the gauge.  Not a major problem, but not ideal to be running without any metrics.

To be fair to SPA, so far their customer service has been excellent – very quick response to emails and eager to assist.

So, after much investigation with the multimeter (primarily checking continuity of wiring, as the initial diagnosis was potentially a dropped earth feed), the gauge and both sensors (pressure and temperature) have been sent off to SPA for them to investigate.  I’ve sent them the other gauge too, which had a failed backlight.  Fingers crossed that we can get to the bottom of this one quickly.

Update 1

So, SPA have fixed the backlight on the lower guage, and have checked both the oil pressure/temp gauge and the oil pressure/temp sensors, which all seem to be OK.  So it looks to be a wiring issue, and given the minimal cost of a new wiring harness (£35) it seems sensible to just replace the harness.  It wasn’t the easiest job in the world (getting the oil pressure plug through the bulkhead was a bit of a pain), but it’s nice and neatly done now.  And all seems to be working again.

Update 2

Or at least it seemed so.  Same problem has reoccurred, and with an extra paid of hands to watch the dial, I finally managed to recreate both working and non-working conditions by manipulating the connector.  As the connector itself, and the wiring is brand new, this indicates that the fault is in the electrical part of the sensor (all SPA did was test the sensor and plug a wire in to get a reading).  In very close examination having removed the old sensor, there does look to be a bit of corrosion around the base of the earth post, to it looks as if water has got into that area and caused the problem.  So, new sensor fitted, and all working properly again.

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New ECU loom

I have the car back, thanks to David Wedge at DTM Power and his work on installing the new ECU loom from Emerald.  This is what he took out of the car, some of which looks just about OK, and some of which looks pretty agricultural:

Old ECU wiring loom

Old ECU wiring loom

The new loom looks much neater and smarter, and should also mean that the ECU to engine is much more reliable.  There’s also an ECU fan controller that we could wire in should we wish.  It’s still unclear why the wiring was done the way it was, or indeed why the silver box burnt out, but given that it’s not in the signal path any more, that can only be a good thing.  The engine certainly ran nice and smoothly on the way back home from Burcot, not that that was a very long run.  Proper update to come, when I next take the car out for a decent journey.

One more significant job out of the way, and hopefully soon an opportunity to enjoy the car and its new engine map!

Update:  slightly longer journey yesterday, where the car was definitely smoother running, both in the lower reaches of the rev range, and revving out towards the red line.

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