Engine Blown

[Chris Hebden]

Driving home from work on Tuesday the engine went bang! Went to overtake some one on the M40 and a big bang and a very big cloud of white smoke occurred until I clutched it and the engine cut out.

The boost pressure was slightly less than what it was set at, which was 17.4lb the oil pressure was fine at 45psi, the coolant temp was great at 76° and the charge temps were fine at 20°!

Well started the strip down last night and first had the turbo off the car, its seized solid! Well chuffed at this point!

Started taking everything off to remove the head, got to the sparks, removed them and noticed the spark plug in number four cylinder was mullered, the electrode was pushed right into the plug. See pick. Really happy at this point!



Good working practice I thought I’d time the engine up so started turning it over to get it into position and it would just lock! Really really happy now!

Tonight finally got the head off

This is all on number four cylinder. The valve cap has melted off the valve stem, hit the piston and got imbedded into the head. The piston has melted right through and the liner is in a few thousand pieces.

I got a few questions. Why has this happened, what has happened? Why has my turbo seized? My thoughts are:

The turbo - due to the water escaping rather quickly the turbo has got too hot and melted/seized solid
The Engine damage - I noticed that the dump valve (yes a DV ) vac pipe was slightly loose fitting, could this have leaked air and caused this? I did notice a very slight boost loss, set at 18lb on the in car and it was down at 17.4lb when on hard accelerating

Now the question is do I fix it? I would appreciate open and honest opinions of people on this please.

http://s436.photobucket.com/albums/q...ngine%20Blown/

[Markey Mark (BD)]

Ouch!! That doesn't look good mate.

On the head on the edges of the combustion chamber is that alot of pitting on the head? Also was the metal fragments in the over pistons when you remove the head or they got there after?

To decide weather to rebuild it may be an idea to pull the whole ,ump out and see what else is damaged (cam, crank, etc). Head is scrap though.

The turbo will prob of had a load of crap go through it so that could of siezed the thing up.

[Dan O'Neill]

I would have a guess that the turbo let go and caused all the damage, Ive seen that sort of damage on a fiat engine and that was caused by turbo failure.

[Markey Mark (BD)]

I recon the valve has just dropped and then that has caused all the damage, have alook at the back of the turbo and see what the turbine wheel looks like mate?

[Chris Hebden]

Ouch!! That doesn't look good mate.

On the head on the edges of the combustion chamber is that alot of pitting on the head? Also was the metal fragments in the over pistons when you remove the head or they got there after?

Couldnt tell you buddy! I wasnt very careful when removing the head to see if the metal fragments were there before hand or not. Yea that is pitting, by the time i was taking these pics i was so f***ed off i didnt really have a good look over the head to confirm this

[Markey Mark (BD)]

With the pitting i'm wodering if its pitting from detting or pitting from pieces of metal flying round the engine, should be able to tell metal will look like its cut it to pieces

[Adam L]

The turbo's either seized because part of your engine has lodged itself inside the exhaust housing, stopping the wheel from moving... Or there was such a severe blockage in the oil feed that it starved the turbo of oil and it locked itself onto the bearings.

[Chris Hebden]

I recon the valve has just dropped and then that has caused all the damage, have alook at the back of the turbo and see what the turbine wheel looks like mate?

Its got a white residue over the inside of the housing and the wastegate. I'll get a pic tomorrow. I'm not too sure but i think both the blades have moved outwards i.e. the compressor has moved out towards the airfilter and the exhaust has been pushed out towards the bulk head

[Chris Hebden]

The turbo's either seized because part of your engine has lodged itself inside the exhaust housing, stopping the wheel from moving... Or there was such a severe blockage in the oil feed that it starved the turbo of oil and it locked itself onto the bearings.

Adam i cant say if part of the engine has been lodged or not, but the oil blockage doesnt seem right because right upto the point of the engine cutting out the oil pressure was fine. The gauge is plummed into the oil feed to the turbo

[Adam L]

But you could still get a blockage after the gauge, its unlikely though. I'd go with option 1, there's probably ali splattered inside the casing.

[Markey Mark (BD)]

What ever has happened to it mate it sounds like its totally knackered most of the engine, best thing to do now is strip it all out and see what is salvageabe.

[Adam L]

I just read your reply to Mark, that'll be why the turbo's seized. That ''white'' residue is melted engine parts...

[Chris Hebden]

I just read your reply to Mark, that'll be why the turbo's seized. That ''white'' residue is melted engine parts...

What am i looking at mate? Complete rebuild? Cost? As far as i know the turbo is a T25

[Adam L]

To be honest, it's likely the turbine wheel is damaged beyond repair. The turbo may still be repairable, just a little more expensive to do.

[Chris Hebden]

What ever has happened to it mate it sounds like its totally knackered most of the engine, best thing to do now is strip it all out and see what is salvageabe.

LOL not much on first inspection mate. Possible 3pistons, liners and the block!

[Markey Mark (BD)]

LOL not much on first inspection mate. Possible 3pistons, liners and the block!

Maybe the crank and cam would be ok, could use them again. I'd be tempted to replace all the pistons though mate or use 4 decent ones out of another engine.

[Mart]

Could be detonation induced, as has been hinted at. 17psi map + a leaking vacuum pipe, giving no/reduced igniton retardation when on boost, is potential det' material for sure.

The whiteness in the turbine could also indicate the overall fuelling has been running v lean for a while.

With that much metal doing the rounds, I'd be more inclined to start with a fresh motor & go from there. If you decide to retain the block you've got though, it's gonna need some ultrasonic cleaning of the internals for sure, new bearings throughout on the bottom-end, possibly new cam followers, and that's before you even start worrying about getting the head fully checked over, the cam (journals), replacing the turbo, and flushing the radiator (oil section), oil lines, sump, etc of any potential swarf that may be lurking.

[Chris Hebden]

Maybe the crank and cam would be ok, could use them again. I'd be tempted to replace all the pistons though mate or use 4 decent ones out of another engine.

Well i still need to rip the bottom end apart, i am praying to everything that is holy that my cam and crank are fine! I agree with you on the piston front and would also like to replace all the liners as well, with the amount of water thats gone through those i've more than likely done some sort of damage too the other pistons

[Ashy]

sh!t the bed, what a mess!!!

Looks like the engine failure will of killed the blower, as thats a missing exhaust valve I guess a bit of piston, head or liner has made its way through the hole and shook hands with the exhaust wheel!!

The question is whats caused the failure in the first place?

[Chris Hebden]

Could be detonation induced, as has been hinted at. 17psi map + a leaking vacuum pipe, giving no/reduced igniton retardation when on boost, is potential det' material for sure.

The whiteness in the turbine could also indicate the overall fuelling has been running v lean for a while.

With that much metal doing the rounds, I'd be more inclined to start with a fresh motor & go from there. If you decide to retain the block you've got though, it's gonna need some ultrasonic cleaning of the internals for sure, new bearings throughout on the bottom-end, possibly new cam followers, and that's before you even start worrying about getting the head fully checked over, the cam (journals), replacing the turbo, and flushing the radiator (oil section), oil lines, sump, etc of any potential swarf that may be lurking.

Mart at the last RR day which was a few months ago, the engine was running quite rich, down in the 9's in places. Granted this was at 16psi and i was running 18 at this point, the fuelling of the carb has been set too 22psi from the start. Boost leak from the DV vack pipe, could this cause enough of a lean to cause this much damage?

I see what your saying about the metal parts and how quickly they travel, but a full strip and rebuild would irradicate this problem, surey (if done properly, granted)

[Chris Hebden]

sh!t the bed, what a mess!!!

Looks like the engine failure will of killed the blower, as thats a missing exhaust valve I guess a bit of piston, head or liner has made its way through the hole and shook hands with the exhaust wheel!!

The question is whats caused the failure in the first place?

stumped me buddy!? Not hard granted

[Mart]

Chris, the afr's may have been ok (albeit mega rich) back at the RR day, but how d'you know that's been the case since? Doesn't take much to go wrong with the fuelling supply and/or carb to cause lean fuelling conditions.

Even if the afr's were fine though, with no pressure reference at the aei (vacuum capsule), it'll be constantly running a v.advanced ignition map, with, and to mention again, no retard of the map when positive pressure/boost is seen. That, coupled with 17psi boost, and you're defo into detonation territory.

Yep, a boost leak from a dump valve pipe (or any other pipe on the aei line) would be enough to limit, or remove altogether, the amount of vacuum & boosted air getting to the vacuum capsule - It's possible the vacuum capsule could've constantly just been reading atmospheric pressure.

A full stripdown might be ok, but either way you cut it, it's exactly that - A full stripdown, followed by a thorough clean of everything which is in contact with oil. Likewise, if the turbo has been spitting out metal, the intercooler will require a good internal clean up too.

[J$£5GTT]

you be fine mate,shame its happend but at least you can get a
good strong build together that will last you an also learn a bit
along the way like,i was very lucky when i melted my piston etc....

there ya go.!!

[Chris Hebden]

Chris, the afr's may have been ok (albeit mega rich) back at the RR day, but how d'you know that's been the case since? Doesn't take much to go wrong with the fuelling supply and/or carb to cause lean fuelling conditions.

Even if the afr's were fine though, with no pressure reference at the aei (vacuum capsule), it'll be constantly running a v.advanced ignition map, with, and to mention again, no retard of the map when positive pressure/boost is seen. That, coupled with 17psi boost, and you're defo into detonation territory.

Yep, a boost leak from a dump valve pipe (or any other pipe on the aei line) would be enough to limit, or remove altogether, the amount of vacuum & boosted air getting to the vacuum capsule - It's possible the vacuum capsule could've constantly just been reading atmospheric pressure.

A full stripdown might be ok, but either way you cut it, it's exactly that - A full stripdown, followed by a thorough clean of everything which is in contact with oil. Likewise, if the turbo has been spitting out metal, the intercooler will require a good internal clean up too.

Thanks for the info Mart. I take your point about the AFR change, i cant say that there wasnt a change granted and i personnally blame a lean off causing this problem

I am really confused about this paragraph though Even if the afr's were fine though, with no pressure reference at the aei (vacuum capsule), it'll be constantly running a v.advanced ignition map, with, and to mention again, no retard of the map when positive pressure/boost is seen. That, coupled with 17psi boost, and you're defo into detonation territory. The AEI is getting fed by the carb base (i think) pipe, which has the dv plumbed into it also? Is this not what you meant by the AEI receiving a pressure reference?

On this note, i have W/I would this be the reason that i may not have felt/heard the det occuring?

It would be a full strip, clean and rebuild with this amount of damage spread.

Thank you to you all for your very quick and helpful responses , much appreciated

[Mart]

Aii mate, exactly that. Even though you're feeding the aei from the inlet manifold throat connection (which is correct), if that pipe, or a pipe 'T' off of it, is split, you're then gonna reduce or completely eliminate any of the pressure (reference) from the inlet manifold reaching the aei vacuum capsule, hence it's effectively only then reading an atmospheric/ambient pressure, hence no ignition retard when on boost.

w/i - water injection? Have you checked to see that it's actually working? ie, the pump is operating & water is being squirted out of the jet, when the system is activated.

On a side note, was the w/i fitted & running when you were at that RR day? If so, there's something not right big time if your afr's were in the 9's @ wot with the w/i running!

[Sparkie]

i'd agree with Mart on this.

leaky vac pipe or leaky d/v, ignition unit doesnt see what the engine is doing with the vac/boost, so it doesnt retard the ignition. bango bango, detonation on the squish areas as shown on all the pix of the head.

i would pull the block, and before attempting to clean it, take the cam out and check the journals for wear.

if the journals (where the cam runs in the block) are deeply scored, then just chuck the block, as it will never be right again.

[Chris Hebden]

Aii mate, exactly that. Even though you're feeding the aei from the inlet manifold throat connection (which is correct), if that pipe, or a pipe 'T' off of it, is split, you're then gonna reduce or completely eliminate any of the pressure (reference) from the inlet manifold reaching the aei vacuum capsule, hence it's effectively only then reading an atmospheric/ambient pressure, hence no ignition retard when on boost.

w/i - water injection? Have you checked to see that it's actually working? ie, the pump is operating & water is being squirted out of the jet, when the system is activated.

On a side note, was the w/i fitted & running when you were at that RR day? If so, there's something not right big time if your afr's were in the 9's @ wot with the w/i running!

I got you now, the lickly hood is the reference pipe had reduce vac also due to the possible leak!

Yes water injection, it never crossed my mind to check it was working or not. I just presumed so because my fluid was dropping in the screenwash tub quicker than i was ever putting it on my windscreen!

On a side note, was the w/i fitted & running when you were at that RR day? If so, there's something not right big time if your afr's were in the 9's @ wot with the w/i running! Yes it was fitted mate. Sorry should have been more spacific, the 9's werent at WOT they where mid range (from memory 2500-3500rpm) at WOT the AFR was 10.1 i think. Why what are your thoughts? edit to say the W/I was set too come in at 5psi, i have never checked this either

[Chris Hebden]

i'd agree with Mart on this.

leaky vac pipe or leaky d/v, ignition unit doesnt see what the engine is doing with the vac/boost, so it doesnt retard the ignition. bango bango, detonation on the squish areas as shown on all the pix of the head.

i would pull the block, and before attempting to clean it, take the cam out and check the journals for wear.

if the journals (where the cam runs in the block) are deeply scored, then just chuck the block, as it will never be right again.

will do Sparkie, thanks!

[Mart]

I got you now, the lickly hood is the reference pipe had reduce vac also due to the possible leak!

Yes water injection, it never crossed my mind to check it was working or not. I just presumed so because my fluid was dropping in the screenwash tub quicker than i was ever putting it on my windscreen!

On a side note, was the w/i fitted & running when you were at that RR day? If so, there's something not right big time if your afr's were in the 9's @ wot with the w/i running! Yes it was fitted mate. Sorry should have been more spacific, the 9's werent at WOT they where mid range (from memory 2500-3500rpm) at WOT the AFR was 10.1 i think. Why what are your thoughts? edit to say the W/I was set too come in at 5psi, i have never checked this either

Exactly mate. Reduced vacuum readings, and also a reduction in how much positive pressure/boost it's also seeing, if any at all.

w/i goes through water like a hot knife through butter. When I used to run it on my Raider back in the day, I was topping up the windscreen washer bottle at least twice a week.

10.1afr @ wot isn't that much better (read healthy) either to be honest. That's far too rich even if you were running silly high boost levels, which you weren't - 17psi is mediocre imho.

5psi boost is also far too low to be injecting the water in at. 1bar boost, if not even a bit more than that, is usually the minimum threshold point for activating the pump.

Maybe a combination of cr8p (no offence meant) fuelling & the w/i coming in far too early is where the problem may begin to lie with your engine failure...

[5teve L]

Last time i dropped a valve (a few years back now) it was due to det, i was running a fair whack of advance & 20 psi boost ... didn't do my engine any good either..
But i have to say yours is alot worse !!
Hope you sort it soon.. FWIW i'd drop a whole new engine in i think..

[Chris Hebden]

Exactly mate. Reduced vacuum readings, and also a reduction in how much positive pressure/boost it's also seeing, if any at all.

w/i goes through water like a hot knife through butter. When I used to run it on my Raider back in the day, I was topping up the windscreen washer bottle at least twice a week.

10.1afr @ wot isn't that much better (read healthy) either to be honest. That's far too rich even if you were running silly high boost levels, which you weren't - 17psi is mediocre imho.

5psi boost is also far too low to be injecting the water in at. 1bar boost, if not even a bit more than that, is usually the minimum threshold point for activating the pump.

Maybe a combination of cr8p (no offence meant) fuelling & the w/i coming in far too early is where the problem may begin to lie with your engine failure...

Have to be honest Mart i have thought that from day 1 "Maybe a combination of cr8p (no offence meant) fuelling & the w/i coming in far too early is where the problem may begin to lie with your engine failure"!

Unfortunately though i had the view if it wasnt broke dont fix it. Since the RR day i have only started looking into AFR's and what not and beggun to look at what i realistically needed to do to get my car "reliable " and removing the W/I, removing the in car boost knob and sorting the fueling to one boost were supposed to be happening soon not soon enough i guess

[Chris Hebden]

Last time i dropped a valve (a few years back now) it was due to det, i was running a fair whack of advance & 20 psi boost ... didn't do my engine any good either..
But i have to say yours is alot worse !!
Hope you sort it soon.. FWIW i'd drop a whole new engine in i think..

Cheers budski ! I'd rather salvage as much safely as possible so should know more once the bottom end stripping occurs!

[Sparkie]

if the block is ok, then id soak the whole block in a large plastic container full of water. - and add 1 or 2 bottles of concentrated drain cleaner from B&Q (concentrated sodium hydroxide) - works wonders on blocks and grease and your skin....
then wash it out thoroughly with a jet wash and dry it.

[ROB C2GTT]

If ya get really stuck mate and ya block is scrap im sure i have a bare block sat in the shed? not far from you anyway. Also willing to lend a hand if need be just shout.

[Chris Hebden]

if the block is ok, then id soak the whole block in a large plastic container full of water. - and add 1 or 2 bottles of concentrated drain cleaner from B&Q (concentrated sodium hydroxide) - works wonders on blocks and grease and your skin....
then wash it out thoroughly with a jet wash and dry it.

I'm going to be checking the block tonight sparkie. What do i need to check to confirm that its ok? Cam journals.... anything else?

I've been looking over the pics this morning and damage to the crank hasnt really been commented on, whats the chances of this being FUBAR?

[Chris Hebden]

If ya get really stuck mate and ya block is scrap im sure i have a bare block sat in the shed? not far from you anyway. Also willing to lend a hand if need be just shout.

Really appreciate this matey! Sounds like a BBQ round mine might be needed

[Markey Mark (BD)]

Really appreciate this matey! Sounds like a BBQ round mine might be needed

I'll give a you a hand too mate, more hands the better.

[Sparkie]

ill give you a hand too.....


here have three...

[Chris Hebden]

ill give you a hand too.....


here have three...

Appreciated Sparkie !

[Chris Hebden]

I'll give a you a hand too mate, more hands the better.

Your more than welcome Mark! I think i've sourced a complete engine, just need to confirm this!

Next is the turbo, i'm waiting to hear from Adam L about a possible rebuild, if it can be done. Out of interst what cars run a suitable T25? I know of the Saab 9000 and the 200sx. Do these fit without modification? Looking at pics on Ebay and groogle some have very different exhaust housings and some look like the inlet housing needs to be spun 180degrees, what other options have i got if this one is on the way to the bin!?!!?

[R5GTTRaider]

nice..

i dont wanna get shot down here, but maybe a diffrent engine in order?

there ould be metal fragments every were,

did it damage the block or just the liner?

well good luck with it shame for something like that to happen

[Andrew Cooke]

looking at the combustion chambers that survived; they look to have been detonating badly, adding credence to the to the previous AEI leak / det failure comments.

[J$£5GTT]

Your more than welcome Mark! I think i've sourced a complete engine, just need to confirm this!

Next is the turbo, i'm waiting to hear from Adam L about a possible rebuild, if it can be done. Out of interst what cars run a suitable T25? I know of the Saab 9000 and the 200sx. Do these fit without modification? Looking at pics on Ebay and groogle some have very different exhaust housings and some look like the inlet housing needs to be spun 180degrees, what other options have i got if this one is on the way to the bin!?!!?

rover tomcat

[Sparkie]

ive got a brand new (as in never been fitted) rover tomcat turbo - with the housings off, just aching to be converted....

[Sy5GTT]

ive got a brand new (as in never been fitted) rover tomcat turbo - with the housings off, just aching to be converted....

I run one of these. Easy job to convert. Cheap as chips on the Bay.

[Chris Hebden]

ive got a brand new (as in never been fitted) rover tomcat turbo - with the housings off, just aching to be converted....

Coverted? What needs to be changed Spakie?

[James5]

Rotation of housings, water feeds to be replaced using unions of your old turbo, oil feed may need an adaptor for the core, oil drain but you may be able to use the one of your turbo dependant on type, drill and tap rear of compressor housing for actuator relocaton, blank of the d/v on the compressor housing I think that's about it

[Chris Hebden]

LOL that doesnt sound easy! I am not too good with taps!

[Chris Hebden]

Well just spent the morning cleaning and stripping the old head. While i was at it i thought i would take the exhaust housing off the turbo and as soon as i did the turbine was free! Took some pics while i was at it

[Adam L]

That wheel has a funny profile, not sure what size it is. Its also a diesel shaft.