Author Topic: whirring noise for 10sec then bang  (Read 2995 times)

Offline JoeH

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whirring noise for 10sec then bang
« on: February 19, 2016, 07:16:19 pm »
And engine dies and I freewheel down the hardshoulder. Won't even do more than half a turnover on the starter.
Plenty of oil petrol n coolant.

Any ideas?

Offline JoeH

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Re: whirring noise for 10sec then bang
« Reply #1 on: February 19, 2016, 07:23:38 pm »
Note I was doing 60mph.
Engine n charger all been rebuilt 350 miles ago currently being run in. I.e yet to take it above 3k

V belts n cambelt at first glance appear intact

Offline runforrestrun

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Re: whirring noise for 10sec then bang
« Reply #2 on: February 22, 2016, 01:40:51 pm »
So is the engine seized? It could be a valve that's lost its head (collet end) and pinged into the cylinder stopping the position from coming up.

Have you tired turning the engine over by hand i.e with a ratchet and socket on the crank pulley?

Offline JoeH

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Re: whirring noise for 10sec then bang
« Reply #3 on: February 23, 2016, 05:30:38 pm »
Car is back with engine shop / garage so not entirely sure. They mentioned something nylon the found in boost pipes.
Thanks for your reply engine appeared seized when tried with starter...

Offline JoeH

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Re: whirring noise for 10sec then bang
« Reply #4 on: February 24, 2016, 01:05:08 pm »
I'm gonna need some help on this one.

Charger has blown up.

I'm running stock 77mm pulley (for it's entire life 130k) and it's all been rebuilt with a full charger rebuild kit by JNL racing. And I've done 350miles at no higher than 3k since rebuild.
Plus new feed and return oil pipes.

Tipton Garage have found the long brown boost seals and others all caught in the intercooler mesh/gauze and charger has locked solid!

JNL!

Apparently the back force on the V - belts was enough to stop the crank pulley / stop the engine - which now runs fine without charger attached

« Last Edit: February 29, 2016, 09:15:22 pm by JoeH »

Offline PeteG40

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Re: whirring noise for 10sec then bang
« Reply #5 on: February 24, 2016, 02:35:55 pm »
Hi Joe,

Will try to ring you to discuss but likely to be tomorrow night.

Pete

Offline JoeH

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Re: whirring noise for 10sec then bang
« Reply #6 on: February 27, 2016, 07:16:18 pm »
Thanks Pete, I'll get in touch with you at some point hopefully.

I'll let the photo's do the talking (and partly because I don't know what to say, other than I'm convinced it's spat out apex seals and bits of metal)
Tipton Garage will post it to JNL who will open it up then we can take it from there.














































Offline JoeH

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Re: whirring noise for 10sec then bang
« Reply #7 on: February 28, 2016, 04:48:19 pm »
Can moderaters/admin move this to the supercharger sub-forum as this is not strictly engine and transmission any more.
Thanks
Joe

Offline JoeH

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Re: whirring noise for 10sec then bang
« Reply #8 on: February 28, 2016, 04:59:32 pm »
Zoomed in detail of a piece of ejected metal. Not sure what it's from though:




Offline PeteG40

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Re: whirring noise for 10sec then bang
« Reply #9 on: February 29, 2016, 10:17:30 am »
Tried to ring u again mate.


That metal is scroll part.  I'd say the charger is probably toast unfortunately.

Offline JoeH

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Re: whirring noise for 10sec then bang
« Reply #10 on: March 04, 2016, 04:12:43 pm »
JNL have received the charger in the post and have stripped the G40 down and taken lots of high res photo's which I will share with you.


Hi Joe
Not good. Charger is completely foobarred
See attached pictures. Feel free to share on forum for other opinions on possible cause. I've never seen a failure like this before so would only be guessing as to the cause of the failure.
I can only point out some findings made during disassembly.
1. Displacer bearing has exploded and has shifted upwards.
2. Exhaust casing has minor damage and is potentially salvageable.
3. No other bearings in the charger are damaged.
4. Displacer and intake housing are completely annihilated.
5. No shaft seals have any damage.
6. The charger bracket is cracked heavily around the bolt holes that connect to the charger.
7. Pulley and gear bolts are all tight.
8. The main shaft and the idler are no longer correctly timed, out by 90 degrees.
9. The belt considering its new appears to have a lot of play in it.

Bit of a chicken or egg scenario.
Did the idler slip on the belt causing the displacer to hit the casing causing the seizure and damage to the displacer bearing.
Personally i feel that it is very unlikely to be the cause or sequence of events as the charger would've stopped dead instantly.

I personally think the sequence was the displacer bearing let go causing the idler not having a correctly timed control of the displacer causing them to hit causing the idler to seize and skip teeth on the belt.

The only item of concern is that the bearing was allowed to shift upwards which due to the design just doesn't seem plausible. I noticed that the thrust stop in the exh housing had been smoothed down by whoever done the original porting. Other than that can only assume the bearing was not of the same quality as the genuine one.

JP (JNL Racing)




































The Money Shot Below:














Port work done by PeteG40 a few years ago (below):








Offline PeteG40

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Re: whirring noise for 10sec then bang
« Reply #11 on: March 04, 2016, 04:46:52 pm »
I didn't port it -it looks like a psd ported jobby.

Did JNL just rebuild it then or port it?

I've seen this happen a couple of times - the damage on bearings /belt/bolt holes etc i suggest would've happened after it had gone pop when it kept rotating.  Causes I know about are would suggest are.

1. Apex seals not in correctly - if not quite rightly seated, its a ticking time bomb.  I;ve seen a few serviced chargers where the end of the apex seal has popped up and not been in its groove on assembly.  when its by 2mm they last - a few more and it'll last a bit and then come out and BOOM.  (in my early days i wrecked an outlet side of mine with this!!!)  If the charger is long in the tooth - high miles - the apex seal grooves can be too deep and then apex seal can pop out and cause the damage.
2. oil ways blocked - that would cause one of the bearings to go (displacer) and then seize, leading to the above damage.  However, often an oil seal would blow because of this before it got to this stage.
3. Incorrectly timed charger - the nicks in the pulleys can shift, if timed up with these and they are a tooth off - it may run for a while?  doubtful tho.
4.  No grease in the top scroll bearing - this will get hot then seize causing the timing issue. - leading to displacer hitting casing.
5. Overrevving - this will cause the two countershaft bearings to get hot, expand and seize -leading to displacer hitting casing. (doesnt sound like this was the cause)

as for bearings - all are either oem - or higher spec -  so shouldn't have been an issue -did you replace the top scroll bearing - or was it regreased??

Pete

Offline PeteG40

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Re: whirring noise for 10sec then bang
« Reply #12 on: March 04, 2016, 04:50:03 pm »
there's also that debris could get in to it.

I know of 3 where a copper washer/plastic bag/pen lid (don't ask) have gone in and had similar consequences - promotes displacer to casing contact.

Offline JoeH

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Re: whirring noise for 10sec then bang
« Reply #13 on: March 04, 2016, 05:03:48 pm »
Thanks pete you sent me this message a long time ago.

if i remember it (the GLader) had a full blend which had all the bearings and seals replaced - full service pretty much. was over a year ago though - at a guess.

Pete

dated 02/11/2012


Previous owner told me you did rebuild back in 2011..anyway it doesn't matter who did what, it ran perfectly for 40k from then until now.

Yes I did replace the top scroll bearing - everything you sell pretty much charger related
I bought this package of bits of you last autumn

185 kit with belt and bolts
5 kluber
42 bearing
35 pair of hubs.
shipping is £11.58 insured up to £250 (should be ok - replacement value wise)
£273.58


Thanks for you help and analysis - you clearly know as much if not more than JNL themselves.
I feel a little out of my depth. I'm sure i'll get a solution - new charger I guess.

One problem is - right from mile 1 after rebuild I never put my foot down - so never know if it was a problem from the start...because I was running my engine block in carefully.

Offline JoeH

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Re: whirring noise for 10sec then bang
« Reply #14 on: March 05, 2016, 09:51:15 am »
JNL just did a rebuild with your bearings Pete, no porting. Does that then mean JNL don't take responsibility ...
Jabba offer 6month warranty etc, have to see what JNL offer.