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Intermittent cut out at startup

DrJimBone

Well-known member
Joined
12 Oct 2017
Messages
314
Hi all,

I've got an issue where every now and again I have trouble restarting the car (987.1) if I've parked for a short period - such as to run into the shops.

I will turn over and fire for a couple of seconds, then just cut out. The rev needle drops instantly to zero and it doesn't sound like it's struggling or anything like that so I'm leaning towards electrical.

I'll turn off the ignition then try again - it will struggle to turn over for a second then fire, then cut out again. I can even rev it up to 3-4k before it cuts straight to zero again.

Rinse and repeat two or three times, then just as suddenly as the problem appeared it goes and the car runs perfectly. No power issues, no bogging, nothing.

It's embarrassing more than anything, but I would like to sort it!

Any ideas?

Cheers,

Jimbo.
 
If you see the needle drop to zero even if you are reving it then its the crank position sensor imho thats the problem .

A short stop is building the extra heat thats causeing it to fail .. its the early symptoms of a cps failure .

EDIT ..

Just to say this effects every car out there , even my wifes Kia .. but unlike Porsche that actually gives a fault code for it !!
 
Update on progress:

Monday - finally got round to fitting a new camshaft position sensor. Only did the passenger side as that was the first one I found and I wanted to see if the fault went, or if I'd need to try the other side too.

Tuesday - Made it out for some test driving! Yay! A few shorter runs then a blast up the motorway (right into a sodding camera van but that's a different story). Behaved beautifully and started on the button every time.

Wednesday - Short drive of about 30 mins through heavy traffic then parked up for five minutes. Went to restart and .... hesitation... then klank klank klank klank klank and a *massive* cloud of white smoke. Recovered to OPC Brooklands where is is currently sat in a puddle of it's own coolant waiting to be looked at. Bumsocks.
 
From your description then it sounds like the water pump has let go :(

If the fault is fixed by replaceing the cam shaft sensor on 1 bank then thats good .. im a little dubious as theres one on each bank and a single failure would just drop the car to defaults ( it looks at the other and the crank sensor ) ..

But hey a fix is a fix and not something i would have guessed at being the fault :)
 
OPC Brooklands have been extremely accommodating, considering I dumped the car then jumped on a flight. Kudos for great customer service.

They've said no external leaks from pipes etc so the coolant leak is internal. Their opinion is too much for just a head gasket. Ive been asked if i want to approve £1,500 ish to drop the engine to see if they can find something like a cracked head. Obviously this would mean plus parts and labour if they do find something and another 10 hr £1,500 bill for putting it back together...

Not sure which way to go from here.
 
Ouch .. thats not good at all , coolant must be coming out of the exhaust i would guess hence the puddle ..


Not running , noise and if coolant in the exhaust then im guessing D chunk / headgasket has allowed coolant into a cylinder .. thats bad.

D chunk is what we call a hydrauliced cylinder that has split a piston liner , the bit of the liner that breaks always looks like a D .

A cracked head usually allows oil to get into the coolant system , it doesnt cause a noise or a non start .

If it is that then it will be an expensive repair .. my only suggestion would be a second hand engine , and i would suggest getting an indy to do it .. cheaper labour rate i would think .

Sorry young man .. i hate posting bad news :(
 
Cheers Demort; that's pretty much what the tech at OPC Brooklands told me.

I'm shipping it home so I can borescope it and see if I can see any damage but with the knocking I'm leaning towards chunking rather than just the gasket. They also said it was way too much coolant in the system to be the gasket in their opinion.

So... now I start the research on what engine will fit in the hole! Powwweeeeeeeeeerrr!!! :chin:
 
Quick update to this very old thread!

The engine has now been dropped out of the car and sent to Hartech to see if any parts are salvageable.

The diagnosis is that it dropped a valve seat, which mashed the piston and head and cracked the cylinder, so just as terminal as we thought.

They have now taken it off my hands to be added to their spare used parts bin.

*** Public thanks to Baz and Grant at Hartech for being brilliant to deal with throughout ***

:thumb:
 
Im sorry young man .. that is a pretty rare fault .. ive only ever seen a handfull of cars that have done this but it is pretty dam destructive .. there wont be a lot left thats of any use :(


Its good of you to post the outcome but to be honest i feel bad just reading your post left alone trying to answer it .
 
Nothing to be sorry about - I had always planned on the car being a donor for a project.

The failure just cut out a few months of fun driving it around and a bit of budget from selling a working engine.

I'm now happily on my way to a ludicrous conversion... A thread will appear once complete! (I might need to go into hiding from the purists though)

:thumb: :bandit:
 
deMort said:
Sounds good and if you need any info / help you know were to find me :thumb:

Good to know you're on standby! :thumb:
 

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Stuff me .. a V 8 ??

Cayenne or what ?

Clearence .. the mind boggles atm !!

Cayenne and im in !! .. ill do some searching on the manuals if needed :D but it dont look Cayenne to me so im lost lol .

Looked at picture .. looked again .. how the hell is that going to fit !

How close to the bulkhead is it ?

If ok then height .. custom cover .. side ways .. you can cut a certain amount .. should clear the chassis .. move air filter / coolant tank .. dam tight though !
 
Last teaser....

Oh, and clearance issues have been fixed with a plasma cutter and some tin snips.
 

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Not an engine i recognise .. but my hat off sir .. this is a first that i have ever herd of .. not a small improvement thats for sure ..

Not sure i can be of much use but feel free to pm me if you think i can be of assistance .

Im loveing it :thumb:
 

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