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Ian C has major engine probs!!!!


Alex
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I've been asked to post this as Ian is too distraught to type :(

 

Actually I think he'll be ok, as there is light at the end of the tunnel...

 

Anyway, today I get a call from him saying "err...I think my engine totalled my engine"

 

"I've lost boost from the engine after running at 6,000rpm and 1.5 bar down the A11! (the boost was higher than ever becuase the weather is cold and the car was never used in cold weather by its previous owner)

 

So I jump in and say its a hose!!! Problem solved .00001 of a second of smugness!

 

"No its not a hose" ...DOH! "The engine is still runs but making a major mettallic *banging* noise.

 

effin hell have you melted a piston, deformed the crank shaft is the valve train intact?

 

"Can't tell, need to get it to a mechanic to open her up..."

 

Which is were we've left it, Ian is going to arrange transportation to a friendly garage.

 

He's going to get a compression test done...(unless they can tell instantly what the problem is)

 

I'm thinking he's had major detonation and screwed some internals.. the noise is eminating from the back of the block near the bulkhead.

 

..but as we know I'm no expert so I was wondering if the more experienced members of the BBS could put their thinking caps on and have a stab at what could have happened?

 

... the light at the end of the tunnel is mental internal mods!!! Strocker kit replaced internals maybe on the cards...which will make Ian's car quick revving, more torquey and effing insane!!! :)

 

Cheers for an and all help

 

 

 

 

 

 

 

(Edited by Alex Holdroyd at 9:43 pm on Nov. 17, 2001)

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I doubt whether he would have suffered *major* detonation, Alex, as the engine management system will not allow it.

 

What happens is the timing is retarded and a large proportion of the burning mixture is sent out the exhaust pipe. This has the effect of superheating both the exhaust valves and the turbos which, over a fairly short time, severely degrades the valves and seats, cooks the turbos (cracks the casing of No1) and deep-fries the oil.

 

One person's "major metallic banging noise" could be another person's light clunking. So it is difficult to gauge where to start. It could be a severe bearing failure in the big or little-end region. If so then it would be interesting to hear the cause. I'll be putting my money on oil breakdown due to excessive heat coupled with too infrequent oil changes.

 

At 6000 rpm at 1.5 Bar, without provision for significant extra fuel flow, the engine would have been running lean to the point of madness. Especially as the ambient outside air temperature has been much lower of late.

 

Maybe during an attempt to quell repeated detonation, the exhaust valves of one of the cylinders got so hot as to prompt a significant pre-ignition explosion which has melted something. From memory, it is number 6 cylinder that first goes into meltdown due to a sustained lean condition. Don't as me why that is. At a guess it's probably something to do with the design of the intake plenum.      

 

Thinking about it, though, if some kind of massive pre-ignition were the cause then it could have had the effect of presenting an upward-moving piston with a virtual impact load. This could have bent the rod and/or shattered the little-end. In doing so the piston could have also suffered a degree of damage. Hmm, maybe I should start hedging my bets here.

 

Whatever it is, it will be mighty interesting to discover the cause.

 

I'd be grateful, Ian, if you could keep me informed. Especially if the head has to be removed. I'll be hoping you can email some digi-pics of the condition of the valves and seats, and so forth, in order that I may compare with the data I gleaned from Justin's broken engine.  

 

Yours,

J

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Ian does take very good care of the car...regular oil change, serviced by people he trusts (he goes out of the county to get it serviced!) so I don't think the oild would have been that bad.

 

Paul Whaite (not sure if that's spelt correctly) put that car together so it should have been a fairly reliable motor. Ian has never changed the settings on the AVC-R or the S-AFC so he's not meddled with it. Since he bought it of Paul its been hitting 1.45bar fairly consistantly and peaked at just over 1.5 bar when it went a threw a wobbly.

 

Ian said it wasn't the big end failier (as far as he could tell) as he's experienced one of them before with his MKIII.

 

The last couple of paragraphs of Ash's estimation of the situation would sound most plausible...I don't think Ian has an EGT gauge so he wouldn't have seen it coming! Let that be a lesson to us all!

 

Although this may seem odd Ian uses a Ford Garage in Thetford for light servicing as he knows them personally and know's they'll see him right, they are used to dealing with prepped Ford Motors so they must have seen a totaled engine or two by now ;)

 

Also Ian wasn't running any Octane Booster (the one time he doesn't the engine has a problem....lesson No.2!) Because Ian's car is only a weekend car its been used to the expensive Silkolene ProBoost in every tank.

 

Demon, Get that Supra in any way .... I need its ECU please! How much for just the ECU? Mail me off the BBS at mailto:[email protected].

 

Cheers for the suggestions so far...I'll make sure Ian checks the Spark plugs!! ;) (He'll have to for a compression test anyway.)

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