Horrible engine noise

[ChriS7ven]

I'm sorry for the bad google translation, I'll try to be more careful.
I searched but I couldn't find a translation for the con rod problem "couler une bielle in french".

The garagist removed the crankcase, the second cylinder is dry, it has warmed up and indeed some bit off alloy have moved in the oil.
I drove for about a kilometre with the noise.

[alan.barker]

There have been problems recently with replacement Oil Pumps. Where the Bypass Valves have not been staked into Pump Body correctly. This causes the Bypass Valve to fall down into the Canister Filter = unfiltered Oil supply to Bearings
Alan
n.b. complet strip of Engine required and flushing out of all Oil Galleries

[nmauduit]

I'm sorry for the bad google translation, I'll try to be more careful.
I searched but I couldn't find a translation for the con rod problem "couler une bielle in french".

The garagist removed the crankcase, the second cylinder is dry, it has warmed up and indeed some bit off alloy have moved in the oil.
I drove for about a kilometre with the noise.

good thing that the garage removed the crankcase.
did you have oil pressure while driving with the noise ?

I'm not sure how to take the "second cylinder dry" symptom at this point (heat marks without clear signs of metal friction yet?) in any case the metal in the oil call for an engine removal, bearing inspections and crank measurement against specs, then the bores can be fully checked to find out if a rebore has to be performed (rebore is not expensive, in itself, say 40 per cylinder, but a set of oversize pistons will be needed).
In case the crank needs a regrind, I would be careful to pick the right machine shop, this is more delicate than a road engine rebore.

[2cams70]

Virtually guaranteed that if you drove the car for one kilometre with what sounds like some kind of lubrication problem the damage done throughout the engine will be severe. It can now only be assessed through a complete strip down. The engine has to be shut down immediately if there’s a sudden loss in oil pressure.

That’s the problem with cars fitted with these Lotus engines. They are fitted with an oil pressure gauge and no warning light. People especially those with limited technical knowledge will respond quicker to a warning light than a reading on a gauge which requires knowledge to interpret.

When it’s fully dismantled I’d be interested in hearing about what the root cause of the failure was.

[HCA]

Totally agree on the warning light comment. I have on one or two customisations - especially when I have had the cranks tuftrided, gone further and fitted a little piezo sounder to the oil light and will be doing so on the +2 I am playing with now. Gauges, and lots of them, were popular back in the day and stood as a symbol of potency with the likes of the Sunbeam Rapier and Humber Sceptre taking them on to sell the saloon car to sporty men, and as you say, most would not know what each gauge actually told them whereas a red light in their face makes them think twice! The other thing about instuments is that they are placed badly so that one does not naturally look at them often.

I quite fancy making my dashboard using Auto Meter's combo thus:

https://www.autometer.com/5-quad-gauge- ... tw-ii.html

[alan.barker]

The minute there's no Oil pressure you hear the Big Ends knocking (alarm bells):cry:
Switch off at once.
Alan

[h20hamelan]

.
I quite fancy making my dashboard using Auto Meter's combo thus:

Wonder when an app will be developed to ring your phone if something is a miss?

[Billmack]

Thought I'd check in with you. How is the engine removal and tear down going?

[alan.barker]

Bonjour ChriS7ven,
How are things going no news for a while. We can help you.
Amicalement
Alan

[ChriS7ven]

Thank you for your help, it's a very cool forum.

Now the engine is completely disassembled, there is no damage in the engine block.
I'm making the list of parts to order with the garage.
I need a new crankshaft and four connecting rods.

(the engine is original, the pistons are 83.5 and the connecting rods are 125E)

I think I'll order from QED:
- LOTUS TWIN CAM STEEL CRANKSHAFT, STANDARD PATTERN, EN19, 6BDD:
https://qedmotorsport.co.uk/product/ste ... 4b4d-6bdd/

- LOTUS TWIN CAM CON RODS, FORGED STEEL, WIDE/NARROW PINE,4.8 "
https://qedmotorsport.co.uk/product/con ... ous-sizes/

What do you think about it?

[alan.barker]

Why do you need a new Crankshaft and new Con Rods that is very drastic measures.
I think you need to go to a different Garage.
Alan

[2cams70]

What do you think about it?

I think you need to post some pictures for us to properly assess. As they say - a picture tells a thousand words!

[Billmack]

I think you are on the right track now!

[ChriS7ven]

I didn't take pictures of the parts in the garage.
I saw the problematic connecting rod which is well damaged on the part that rotates on the crankshaft.

For the QED references I am not mistaken for an original engine?

[2cams70]

The important question here is not about replacing components but rather why did it fail in the first place. Bearings don’t fail like this in normal use
Was the oil level low?
Was there a failure within the oil pump?
Was there an air leak through the oil pickup?
Is there evidence of failure on the other bearings?
These are the type of questions that you need to find answers to before embarking on a corrective action plan