Overheating, running after switched off ! - Paranoid Owner ?

[Stopher-Walker]

Can anyone, please, give me a little bit of advice. I am having a few problems with my '97, 1.6 K-series Supersport (with a high, 30,000 miles).

Being new to Caterhams and a mechanical novice/idiot, I have absolutely no idea what I'm doing.

The problems began a few days ago when I started the car, there was a rattle/knocking noise from the engine. This soon disappeared as I set off. This noise is now intermittent when starting and this morning there was no sign of it.

Secondly, when actually running the temperature gauge used to just hover around mid-point (except in traffic of course) but now even on the most gentle run, the needle hovers between 100 and 120 degrees.

Thirdly, when I switch off the engine, it carries on running for up to 5 seconds.

HELP ! What's wrong ?

I have only had the car two and a half months and it has been nothing but trouble. Is this something serious ?

It is still under warranty (well just 9 days left of it). But I have already had several minor problems with it and the 'AGENT' already thinks I'm a pain. Thus, he hasn't exactly 'bent over backwards' to try and help with the other matters (although his mechanic has been excellent). This, and the fact that the agent is 200 miles away, and you will see my reluctance to 'bother' him again - unless it is serious. Has anyone any idea what could be the matter ?

Am I just being paranoid ? I thought when I bought a three year old car, built and owned by Caterham, from an official agent, with a warranty for just under £15,000 that I would have no problems with it - WRONG !

 

[Casbar]

You might want to give Roger King (Roger King Engines) a call. He builds and tunes engines for 7's. He has always freely given me advice when I have had problems.

 

His number is 01992 421111

 

Good luck, Robert

[Alex Wong1697456877]

Check the simple things first :

Oil Level

Coolant (you could have an air trap causing the high temperature reading)

Bolt check - make sure any visible bolts are tight. 7's rattle loose!

 

What petrol are you using - Should be Super unleaded only

 

Beyond that, you could have a temperature sensor problem causing the engine to run a bit lean when cold which can cause pinking which sounds like a pebble in a tin rattling away.

 

The diff always rattles a bit especially when the car is cold.

 

Don't panic. These rattles and quirks are part of 7 ownership. Check the basic things first. The temperature shouldn't get that high.

 

It's amazing how many of these noises disappear when the weather is better!

 

 

 

Alex Wong

alex.wong@lotus7club.co.uk

www.alexwong.net

Home : 44-(0)121-440 6972

Fax : 44-(0)121-440 4601

[Graham Sewell]

Probably totally in the wrong direction, check your alternator mounting bolts. If this is loose, the the drive belt will be too. This is under more strain when cold because the thermostat hasn't opened - hence noise moves away when warming up. Also, if the belt is slipping slightly, the engine will be prone to overheat. The knocking may be that the alternator is physically moving relative to the engine.

 

A dead give away would be a screaching noise when cold as well (particularly when accelerating).

 

Hope it is that simple.....

 

Cheers,

 

Graham

[Simos]

 

I suppose the fan is actually running when it's hot ? You should hear it cut in with a loud whirr at around 98oC. If not check the connections to the fan and the sensor (in the side of the block ? I don't know Rovers).

 

Is there an air bubble in your water ways (the car's). On my BDR, before I added a header tank I could unscrew the pressure cap (when cold) on the top hose running to the top of the radiator and check to see if any water was missing (usually) and top it up with water and 30% antifreeze mixture. on occasion I would need to release an air lock by unscrewing the bleed bolt on the top of my rad until water came out, and then screw it back in really really quickly :-) and then add more water in the pressure cap. Fire it up for a few secs and do it again if necessary.

 

If the engine has been getting well hot for whatever reason and you don't have a header tank, this could be a distinct possiblity as the water expands and spills into the expansion tank but doesn't necessarily, as it's supposed to, return when it cools, it drags air in instead leaving a big air bubble which collects in the cooling jacket and melts a piston when you thrash it next...

 

Now I have a header tank and Roger's latest sealing techniques mean it doesn't leak oil or water anymore.

[Red SLR]

probibably wrong but I would get the hydraulic tappets looked at. Also maybe an engine flush. Then SLICK 50.

 

Simon

 

X777CAT

[Tony Martyr]

The noise of ticking on start up that soon disappears sounds like the hydraulic tappets not yet being filled. I used to get the noise when I used Mobil 1, now I use Halfords synthetic it has gone.

I suggest you check that the fan is switching in at 90-92 degrees by letting the car idle. I can't remember if the device in the radiator header that switches the fan is also the sender for the guage I am going to change mine as I have also developed a high indication of water temp.

[Red SLR]

The tappets (if thats what it is) can sometimes get a build up on them which makes them "stick" when cold...(common problem on hard worked 16v lumps) as the oil is not up to temperature. Using a thicker oil will help but you could really do with getting someone to have a look at it. I would say you should not be getting any major problems with hydro tappets before 60 - 70,000 miles.

 

I beleive that if you replace the tappets then it will solve the problem, but they are about £10 ea I think. X 16 = £160. Probibably atleast 3 hours labour.(£400 in total I would say). But your problem could basically be a lack of lubrication, check the oil pump. I would not jump straight to conclusions straight away with this but get the rocker cover off and have a look. What part of the country do you live in???

 

Hope this is of help.

 

Simon.

 

 

 

 

X777CAT

[Simos]

 

I wouldn't put an oil additive in your oil, especially a synthetic. No claim by slick or anyone else has ever been indepentently substantiated, usually quite the reverse. Mobil etc spend a great deal of money researching the product with the engine builders. Engine manufacturers build engines with clearences designed to be lubricated by oil only. Adding complex chemicals with dubious properties is asking for trouble.

[Rory McLeod]

Oooh Errr, I am a 'new' 7 owner also, I bought a S/H 1.4 K series SS in March from Caterham in Caterham.

 

My 7 started to sound like a tin full of nails after 3 weeks, and used to 'after-chug' like crazy, I took it in for a 12000 mile service (at 15000 miles) in a paranoid frenzy at Caterham in Dartford (Luckily I work close by) The noise went, the 'after-chug' went and I got hit for a £225 bill for a new sump cover!

 

However after that I was as happy as a pig in the organic matter.

 

I suspect that I had had a 'sprint' tune rather than a general tune as I believe the supersport Engine Management System is modifiable.

 

Next para is extract from...

http://members.aol.com/_ht_a/DVAndrews/kengine.htm

which is a damn good site from my point of view.

 

>>>>>>There is the Caterham Supersport kit which is a revised MEMS ECU and cam upgrade and includes an airfilter and plugs, the cams retain the standard hydraulic followers which in turn limits both duration and lift of which those sad carniverous gits without windscreens delight in supplementing their protein diet with, you will hear the fan cut in at 98 with no mistake so I assume it is working OK.

 

I was REAL paranoid and scared for a while by the various noises that come and go but now realise the bloody things are very tough and quite frankly my bottle goes waaaaaay before the car/engine will break.

 

Remember: You have to work at a good love affair!!! smile.gif

[Northern Banana]

Hi,

 

I've just done my first track day at Brands.....what a fantastic experience. Many thanks to all the Club Members there who gave up their time to organise a really well run day.

 

With regards to original topic, my car a 1.6k Superlight suffered similar problems at the track. Firstly after switching off the ignition the engine continued to run for around 5 secs. Also the oil temp (I'm using Mobil 1) was running at nearly 130 degrees (almost into the red zone) after each 15 minute session.

I kept checking the levels, but any comments on whether this is normal or if I should check it out I'd be grateful. Oil pressure also hovered, at hot idle, just above the red zone.

 

Anyway followng a couple of spins, but no trips into the gravel traps, I can't wait for Cadwell Park on the 6th October.

 

Regards,

Paul.

 

 

 

[CHRIS CLARK]

If you have read any of the previous article on this site you'll see I've had a problem with cooling but a suspected overcooling!

I changed to using a 'kenlowe' adjustable fan thermostat/switch in place of the std.rad mounted unit. It cost about twenty five pounds and gives me the ability to swich the fan in as low as 45* & as high as 120* (& anything in between! Put me at ease & is another thing to fiddle with! (These guys with 40 DCOE's can't have all the fun at our 'injections' expense?). Another thought is that your thermostat may be stuck closed? I had one jammed by solder (I think it came from the rad manufacturer when they fitted the top/bottom inlet/outlet). It had gone around (or stayed in the rad) until I fitted a new top hose & flushed the system. It actually jammed the stat tight!

Mike B's says that his his ecu reads eng temp as 10* higher than his gauge reads so beware of the 120* temp--- that would explain the run on!!!

[Robbie J]

I used to have a 1.6K SS and was continually troubled in the early days by the temp of the water and also the oil temperature being driven up by the water temp.

 

One thing that no one else has mentioned...... on the water rail on the head of the engine - there is a brass outlet, inside this outlet(return pipe) is a ball bearing. If this ball bearing gets stuck the only movement of heat away from the engine is by thermal movement in the water and not by water flow, as the water doesn't - flow that is :) It might worth your while getting this checked. AFter i had this done it certainly cured the problem.

 

However I went over to the large Aluminium racing radiator, mainly as I did track days and also runs down to the South of France during summer when the ambient temp was considerably warmer than the UK, plus the car was being driven quite hard. The only problems I had after that was on some evenings it ran a little cold!!!!!

 

Edited by - Robbie J on 19 Aug 2000 09:31:38

[aideen]

It's common for K-series engines to continue running for several seconds after switching off IF the cooling fan has been on.

Quite strange to have the keys in your hand and be listening to the engine still running!

 

Aideen

 

[Pierre Gillet]

Well I have a normal 1.6 K and it happens to me quite often without the fan being on.

Pierre

 

 

[Pierre Gillet]

Can anybody tell me where is located the thermostat for the water radiator (not the fan) of a 1.6 K ? I tried to find it but was not successful with the Caterham Owner manual. Sorry to bother with this basic question.

Cheers,

Pierre

 

 

[Glen]

Water temperature sender is on the left side of the K engine at the top - it screws into a short metal section of water pipe and is very easy to get at. Going by my own, limited, experience it is well worth unscrewing the sender and then winding it back in to ensure a decent earth and therefore circuit back to the gauge. The whole set-up is pretty inaccurate I reckon. I like to pay attention to the whole picture rather than rely on the gauge - an overheating engine smells and sounds hot.

 

To get back to the original enquiry - although every bit of advice on the topic is undoubtedly invaluable if the car is under warranty then I'd take it back and insist that it's put right. Why should we tolerate machinery that patently does not perform as designed? It's not as if the cars are cheap - and using a standard, mass-manufactured, engine ought to at least bring the benefit of low maintenance and peace of mind.

[Pierre Gillet]

Glen, thank you for the indication.I would like to locate too the ..., well I cannot find the word in English! You know a kind of valve that's open up to let the water going to the radiator...

Cheers,

Pierre

 

 

[CHRIS CLARK]

Pierre,

Your English is OK. It's 'our' interpretation that is adrift!

 

The engine thermostat can be found on the right hand side of the engine in the housing that comes off the back of the water pump. This is under the injection unit and low down (just behind cam cover). It can be identified by having the lower radiator flexible 50mm pipe doing a 180* turn to connect onto the back of it.Three bolts (with 8mm heads I think) have to be removed to get at it. Best to drain water from bottom rad point before doing this!!!

 

Hope this helps.

[Pierre Gillet]

Chris,

it certainly helps very much. This damned thing is well hidden!Thank you very much for the very precise description, I had been trying to locate it for quite a long time.

Cheers,

Pierre

[Stopher-Walker]

Thanks for all your replies.

 

Still haven't sorted the problem out yet.

 

But thankfully, it is still under warranty and Derek Moore has very kindly said that he will sort it out for me. But I've got to trailer it down to them, hence the plea for any infomation on the hiring of suitable trailers.

 

I'll keep you all posted of what they find !!!

 

Thanks again

Philip Stopher-Walker

 

 

[Stopher-Walker]

Thanks again for all the suggestions.

 

I've now got the diagnosis back from Andy/Derek at Classic Carriage:

 

It appears to have been "a rubber seal on the inlet manifold allowing water to enter the number 4 cylinder." !

 

Is this a common thing ?

 

PSW

[Peter Carmichael]

A water leak into the cylinder from the inlet manifold would not cause high coolant temperature. I therefore suspect that matters are more serious than others have suspected, but Derek Moore is likely to find this out soon enough.

 

I had a rather dramatic case of 'water in the cylinder' caused by undermining of the head gasket by cavitation erosion of the head, with similar symptoms. eek! Let me explain.

 

The head is aluminium alloy. It sandwiches the steel head gasket on top of the cast iron liners. The seal contains the combustion gasses and keeps coolant out of the cylinders. Aluminium is a reactive metal which readily forms aluminium oxide when in contact with oxygen. A thin skin of aluminium oxide typically forms on all aluminium surfaces. This skin is brittle.

 

When the coolant gets hot, small localised boiling occurs at the hottest points in the cooling system - the trapped layer of coolant just outside the compression ring of the head gasket. These bubbles tend to form and collapse as the surrounding cooling flow carries the heat away. The bubbles collapse under the action of the surface tension in the coolant, sending a shock wave into any metal surface they are in contact with - in this case the head. The shock wave breaks the brittle surface skin of aluminium oxide on the head, which floats off with the coolant. A new skin forms on the exposed aluminium. Gradually the head erodes until it breaches the head gasket.

 

A way of diagnosing this is to remove one of the coolant hoses, especially the ones around the submarine tube for some reason and look for a dusting of white aluminium oxide. Best of all is a leakdown test and looking for excess pressurisation of the cooling system. If you don't go looking for the pressurisation, it will usually come and find you. I run with aeroscreens, so I am now acquainted with the taste of antifreeze.

 

Cures? You have to disassemble the head and get it skimmed to remove the damage. This is quite easy to do with guidance. Reassembly needs you to take account of the change in timing from skimming and it can be an idea to get the combustion chamber reshaped to maintain compression ratio.

 

Prevention? Coolant choice on the k-series is quite important although there is no definitive answer. Rover 2-year coolant, mixed 30-50% with de-ionised water is commonly quoted. Redline Water Wetter reduces surface tension, decreasing the shock wave strength. Rover 4-year coolant is a premixed propylene glycol (i.e. not ethylene glycol) coolant which has superior properties.

 

My engine has been running fine since re-assembly this time last year.