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MG MGF Technical - VVC engine blowup more damaging?
|Well, finally dealer had time to open up the engine. Well, actually they removed the engine from BELOW the car, so they removed the rear train w/ axl, gearbox, clutch, etc etc. At noon I'll go visit and take as much pictures as possible of the car & parts, it seems to be worth the sight: a totally dismantled rear of my MGF.|
Now not only is the final verdict that this engine is ready to be trashed (cylinder number four is totally melted on top, no gasket can be found on that one anymore - dealer is quite fascinated by this!), the leaking oil destroyed the clutch also plus circuitry/tubes etc below engine...
can this be true?
btw, this cylinder four was the famous one which blew twice the sparking plug 20.000 km back. Then the clutch which stuttered and magically repaired itself is also closest to cylinder four. So there were enough signs to indicate something was wrong with this cylinder, though nothing was signalled, not by mems, not by dealer. Do you think this is normal?
ps: 115.000 LUF w/o VAT for new VVC engine. So 160-170K LUF for all in, w/o all the other parts needed to be replaced (quite some from what I understood). so a 200-240K LUF invoice seems to be realistic :-(
(£1 = 62 LUF)
> btw, this cylinder four was the famous one which blew twice the sparking plug 20.000 km back. Then the clutch which stuttered and magically repaired itself is also closest to
> cylinder four. So there were enough signs to indicate something was wrong with this cylinder, though nothing was signalled, not by mems, not by dealer. Do you think this
> is normal?
MEMS cannot signal everything.
Dealers can't always spot everything.
Having said that, I think I spotted your engine was going to blow up about a month ago.
I'm sure it was a lemon to start with and just got worse and worse as we all know... :-(
From previous threads I think that your engine will be quite so trashed because you chose to keep
going after hearing some really bad noises. etc.
Maybe this was a good thing as you can now start from scratch again.
Hope the new one is much better. Good luck.
|I don't normally like 'soaps' but this is an exception!!|
I am not quite sure what you mean by... <the leaking oil destroyed the clutch also plus circuitry/tubes etc below engine...>
With respect to the engine dying with no apparent warnings. MEMS is clever enough to try and keep pace with the changing engine condition, but unless it is something that is being specifically monitored then there is nothing to warn about. Dealer warnings - well - probably not, unless the car did something that they couldn't fail to notice.
Incidentlly use of the existing MEMS ECU with the replacement engine will show a period (250 miles) of perhaps rough running, whilst the unit 'adapts' to what will be quite different operating conditions for the new engine.
The clutch problem I think I mentioned before is quite probable.
|back from dealer. Saw all what's in the rear of an F (from exhaust upto engine block) on a big pile like junk.|
What I saw (sorry, my UK vocabulary is not that good regarding engine parts ;-)
piston number 4 edge broken off at two different places.
Piston number two sustained heavy wear near the centre.
Valves of cylinder 4 all burnt & worn out (were black from behind and edges showed traces of excessive wear).
valves of other cylinders were also all black behind actual little valve disc.
all 4 cylinders were partially filled with fuel!! (they couldn't answer how that came)
No more compression in ANY of the cylinders (dealer doesn't understand why, since at least 2 cylinders were still "okay" (?))
head gasket was intact (???)
clutch worn out (stripes - traces of excessive heat on both discs)
the room where the clutch resides (dunno how to call this) - oil everywhere (normally should only be dust)
diagnosis: everything ready for the junkyard, new complete VVC unit is only solution.
i got some pics of this, I'm sure the techies will be able to comment.
I'll post them on my site soon, together with the nice Mike Satur SS front pipe & full VR6 brake/EBC pads kit.
And as usual, the chip is the black goat, everything is caused by the chip. Tech supervisor said VVC is already made to the limit (he thinks most parts are too "fine" to sustain so much power), so adding a chip can only result in havoc like this.
Mentioning the hall of shame is regarded by them as "staged bullsh*t", since they don't have any problems with an F, of course the F is an excellent car with no problems whatsoever blah blah blah. Oh well, go figure!
What sort of petrol have you been putting in?
|crossed my mind aswell...|
always been 5W40 Softec 'bazar' (Castrol?) from what I recall from invoices. Other than that I used 5W40 from Fina, a service station brand famous in Belgium.
|I remember: |
it's Marly oil, 5W40
dealer uses (Castrol?) Softec TXT 5W40
thinking positive ... as 'customer'...
- burnt valves ?
- head gasket OK ?
... I wrote it already when you repored the damadge first.
Since beginning of this year exists a MG bulletin, related to burnt valves.
Cause: Oil slam
If you have been using oil instead of petrol - this may account for some of your problems....
PS Look and Hugh's message again;-)
|Just to correct a typo by Dirk: of course Dirk has *never* put oil in the petrol tank or petrol in the oil filler tank. He answered the question regarding petrol by mistake by talking about oil...|
I am pretty curious to see the pictures of the "K-1800 massacre" (disaster tourism ;-) However, his Internet connection is currently down, so we will have to wait till tomorrow.
<Dirk, What sort of petrol have you been putting in?>
and what was the consumption?
Dieter, what does the bulletin say about 'oil slam'?
Good luck with the new engine, Dirk.
|Time for some data .. Ehy ?? Kes, Roger, |
Sorry, the most poor translation, I ever did, written offline. :(
Here it is, found anywhere, MGF related, dated Feb. 99:
Burned outlet valves
- continous ignition faults (warm or cold engine)
- non continous low revs (unregelmaeßiger Leerlauf)
- Power loss
Outlet valve dirty from oil
reasons for dirty outlet valve:
- valve seal ring has creeks (Ventildichtring gerissen)
- valve seal ring lip is hurt (Ventildichring beschaedigt)
- Valve seal ring missed (Ventildichtring fehlt)
- Piston seal ring broken (Oelabstreifring gebrochen)
- Piston worn (Kolben verschlissen)
- <g>... (Riefen in der Bohrung)
- Inlet manifold pressure should be below 45kPa, if not ... ;-(
- check the cylinder sealing an note the leakage in percent
..less then 5 percent is OK
..5 to 10 percent
.. more then 10 percent .... :(
- check engine compression:
.. difference of more then 20psi between cylinders ... :(
.. if pressure in all cylinders is less then 150psi ... :( i.e bended valve shafts)
And now something for real experts: ( I do not understand it in german)
Investigate cylinderhead seal area around the burn room.
If the burnroom boarder of the head gasket hqas caused a deap (Eindruck) on the sealarea of the head then this could be a hint on any early overheating.
If this overheating is stated in the engines repair historie, then change the cylinder head.
etc. on other hand find reason for oil dirt (probably the valve seal rings!!!) change only damdged paarts...
LGH101190 Outlet valve (K16-Engine (2 Piece))
LUB100350 Valve seal ring (K16-Engine (4 Piece))
I think a little analysis of how the engine went to the at last completely damadge should be possible for Dirk himself.
All around to late for him !! :(
But I hope our experts can 'read' some useful instructions for us out of this 'description'...
.. to teach our workshops. !!!
What wrote Tony some weeks ago.. Relation like between a doctor and his patient.
PS .. happy because of this flameless thread. Hope it will stay in this way !!! ;-
|Burnt valves? Melted pistons? Likely causes are pinking/detonation at high load/rpm OR running lean. |
Potential causes of detonation -too much ignition advance (hello ICON), wrong plugs (if the engine is running hotter and/or making more power than standard then it might need colder plugs), low octane fuel.
Potential causes of running lean - faulty fuel pressure regulator, faulty fuel pump, partially blocked fuel filter, partially blocked injector(s), MEMS and/or sensor fault.
|> Likely causes are pinking/detonation at high load/rpm OR running lean|
Yep, according to my last messages this term is vital !!! I did not include ignition adjustments, because it belongs as 'standard' to any cylinderhead works.
|okay, if you want to see my burnt valves (yes, seems like oil slam after I read Dieter's descriptions), broken pistons, oil where it shouldn't be, die-cast wear, broken clutch etc...|
surf to www.geocities.com/dirk.vael
Also Mike Satur brake kit & stainless steel frontpipe and lowering knuckles are added!
Didn't you have serious problems with cylinder #4 missing, and then the plug needed replacing? And now you say that the piston was completely 'melted'.
If my diagnosis isn't completely off I would suggest that perhaps the cylinder wasn't getting enough fuel, causing localised hotspots. This firstly ruptured the HG, then took out the plug and finally the piston. I don't know if the icon had anything to do with this....but advancing the timing probably wouldn't have helped... Also don't use supermarket petrol....
There are a number of other quack diagnosis waiting in the wings too.......9408 SD 76
|>Dirk, What sort of petrol have you been|
>and what was the consumption?
at the end it consumed almost nothing! (well, I mean 8-8.5 litres/100km, which is very good for my driving style, normally 9.5-10 l/100km)
What exactly is included with a new engine? If it was running lean because of bloody fuel pump or faulty fuel pressure regulator, I might get back in the same alley with this new engine...
ps: Steven Palmer himself will call me on Thursday, let's see what he has to say on this havoc. SP told me Icon has been informed on this blowup/meltdown/whatever...
|Dirk, sorry to deviate but with this new BBS, enter web addresses as follows:|
surf to http://www.geocities.com/dirk.vael
Just saves lazy bums like me from having to cut and paste :-)
|Seen the pictures of the killed K-1800 engine of Dirk.|
Well uh, what can I say, except that it looks like the engine must have sustained *extreme* high temperatures lately... Things got a bit out of hand, isn't it ?
So I'm calling out to all you techheads (hello Rog, Dieter, Mike B., Carl, Kes, e.a.): take a look at the pictures and tell us about your assessment as regards possible cause ? Toughest question: just on the basis of the pictures, are you able to assess already whether it is not unlikely that ICON is to be blamed (wholly [sole cause] ? partially [speeding up the detonation process]? not at all ?) ?
|OK have had viewed them over the last few minutes and one technical decription comes to mind ... FRIED!!|
I suggest the progression to this unhappy state is something as follows.
1, Problems experienced over a period of time relating to head gasket failures requiring remedial work.
2, Included in this period was one where the cat was 'cooked' and correct me if my memory is wrong, but wasn't there some extensive heat damage to the exhaust manifold that required it to be changed? Assuming that is correct then there would have been considerable thermal shock to the engine as well.
3, The heat soak through the engine would have not done seals and gaskets any good, probably inducing a degree of hardening that would more often be associated with very high mileage engines.
4, Once back on the road the engine would have not been able to run as efficiently as before. This often leads to the driver working the engine harder to achieve what he was able to before the problems. In turn this extra load on a weakened engine leads to more deterioration of certain parts, very much the start on a downward spiral.
5, Over a period of time different parts start to fail and show in small but significant ways. For example misfire on one cylinder. Incidentlaly I can't remember when you first posted this problem whether the offending plugs were oiled up or just coked up with deposits. Whatever this was the result of the increasing failure of the valve stem oil seals to control oil passing between the stem and guide into the combustion chamber.
6, There may also have been a degree of wear between rings and bore that would have increased 'blow by' that would in turn increase crankcase pressures, which in turn would pressurise oil into passing all oil seals. This would increase amounts of oil being forced into the cylinders, but would have started the passage of oil into the clutch housing.
7, Oil and crankcase fumes will very significantly reduce the octane rating of fuel. This would on a standard engine lead to an increased risk of detonation in the cylinders. Clearly number 4 with the early signs of contamination would be the first to be affected.
8, The retention of the ICON, which provides greater ignition advance, would now have a very significant effect on increasing detonation and would most certainly now be hastening the final demise of the engine.
9, The continued use of the engine would confirm the engine into a rapidly deepening spiral towards total failure. The detonation finally causing the break up on number 4 piston. This then would see the detached pieces of alloy bounce around the cylinder causing damage.
10, General engine running would by now be at a critical stage with all cylinders becoming affected. The engine management would have tried to alter it's control based on the sensor inputs but these would now be weay out of phase with normal engine operation and the final nail would be hammered into the coffin.
11, Like many patients with terminal ilnesses they seem to have a short period of improvment before expiring. I have seen the same with engines where for a short period things work quite well then something breaks which causes a chain reaction disaster in the engine.
12, R.I.P. At least as far as this engine is concerned.
This is how I view the chain of events - anyone else care to pass on their thoughts?
This thread was discussed between 19/10/1999 and 23/10/1999
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