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Inlet Camshaft

PostPosted: Sat Nov 17, 2018 8:59 am
by GHill
Morning All

I would appreciate your advice/thoughts/inputs on what to do next...

So my Lotus Elan +2S130 which has been in storage for 3 months since I moved to Toronto was sent to the local car garage for a service & MOT. All was fine until they tried to drive the car back to the storage location. There they have informed me that 100 yards from the garage the inlet exhaust camshaft has broken.

Questions:

- I assume that they mean one of the inlet exhaust camshaft has broken (only received email last night and Garage not open at the moment)?
- Is this failure feasible, will an exhaust camshaft simply break? What is the likely cause of a failure? Timing chain too tight perhaps?
- What is the liability for a garage when a failure happens in their possession (I assume zero)?
- Assuming its a camshaft and with a failure of this type what is the natural remedy (I assume head off and full rebuild - but very hoping it isn’t)?
- Assuming that I need an engine rebuild and based on the fact that for the next 2 years & most likely 4 years I will be in Toronto then what would you suggest I do, rebuild now or rebuild when I’m back?
- Assuming an engine rebuild then what other tasks would you suggest be carried out at the same time?
- Is there anything else that I should be considering also?

Huge thanks as always.

Regards
Gareth

Re: Inlet Camshaft

PostPosted: Sat Nov 17, 2018 9:40 am
by rgh0
It is probably the exhaust cam that has broken as this cam has more load than the inlet due to the chain drive arrangement. While it is possible for a cam to fail it is extremely rare on a standard road engine being driven at normal revs. i would be asking the garage for details of what they did to the engine and in particular did they tighten the timing chain ( perhaps to much).

If the cam broke then the pistons will have hit the valves and its time for a full rebuild of the head at least and probably the bottom end also depending on how much piston damage was done.

Unfortunately your chances of getting the garage to admit they screwed up something during the service are remote. However get pictures of the broken components as they may show something. Hopefully you can find a good location in Toronto to do a good quality rebuild

cheers
Rohan

Re: Inlet Camshaft

PostPosted: Sat Nov 17, 2018 10:03 am
by richardcox_lotus
That sounds very....odd. How do they know what’s broken - have they taken the cam cover off to check the actual cams in the head ?

I can’t see how it can just...break, did they warm the car up or just gun it straight from cold ?

I feel your pain but you need to be asking some questions.

Regards
Richard

Re: Inlet Camshaft

PostPosted: Sun Nov 18, 2018 12:15 am
by GHill
Thanks Gents

So I spoke to the garage today and they said that the time chain was very tight, however I checked this (in the summer) about two years ago, surely it shouldn’t make too much difference between summer and autumn in the UK?

Fortunately I am in the UK currently from Toronto (the car is stored in Wales) and they have stated that the valves are bent and I have asked for photos and will be seeing the car next week. What should I be looking for/asking for when i see the garage & the mechanics and what is a likely cost to be? Should I get the head checked that it is unleaded at the same time?

Cheers
G

Re: Inlet Camshaft

PostPosted: Sun Nov 18, 2018 8:08 am
by promotor
GHill wrote:Thanks Gents

So I spoke to the garage today and they said that the time chain was very tight, however I checked this (in the summer) about two years ago, surely it shouldn’t make too much difference between summer and autumn in the UK?

Fortunately I am in the UK currently from Toronto (the car is stored in Wales) and they have stated that the valves are bent and I have asked for photos and will be seeing the car next week. What should I be looking for/asking for when i see the garage & the mechanics and what is a likely cost to be? Should I get the head checked that it is unleaded at the same time?

Cheers
G


I would be asking why they ran the engine if they had checked and knew that the timing chain was very tight.

Re: Inlet Camshaft

PostPosted: Sun Nov 18, 2018 2:26 pm
by Elan45
G,

One thing. Don't let your local garage repair your car. They obviously are not knowledgeable w/ twincams.

Even if the pistons don't look that bad, if the valves have hit the pistons, I'd be concerned that the impact may have closed up the ring grooves, pinched the rings and might not show up right away, but a few hundred miles later, when the rings can't rotate, you'll have problems that will require another tear down.

Roger

Re: Inlet Camshaft

PostPosted: Sun Nov 18, 2018 6:56 pm
by alan.barker
I would imagine they checked and adjusted the Valve Shims. THEN they DID NOT set the Timing correctly IMHO Tell they NOT TO TOUCH ANYTHING :evil:
First give them the option to pay a different PROFESSIONAL Garage of your choice to do the Job.
If they refuse to pay name and shame them :wink:
I wish you good luck and try to stay zen :wink:
Alan

Re: Inlet Camshaft

PostPosted: Sat Dec 22, 2018 1:21 pm
by GHill
Hi Chaps

So the engine has been rebuilt with QED cams, two valves replaced and the car is running very well...

However...

At 2500 revs both stationary and driving there is an audible engine rattle? The garage are scratching their heads as to what it may be!

So give me an early Christmas pressie and help me diagnose.

Regards
G

PS have a happy lotus Xmas and an awesome new year

Re: Inlet Camshaft

PostPosted: Sat Dec 22, 2018 5:46 pm
by alanr
Without hearing the noise it obviously is pure guesswork but knowing the cylinder head has been off with the work you have had done my thoughts would centre around a badly adjusted timing chain.
The Timing Chain is too loose and hitting the cam cover?

Alan.