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MG MGF Technical - MGF 1.8 Sounds like a diesel
Further to my previous thread regarding replacment of the gearbox in my 2000W Steptronic MGF, I have now moved on to the engine which sounds like a diesel at all engine speeds and temperatures.
I now know what is wrong with the car but thought it might amuse some of you, if you had an award for the most unusual problem I think this would be a contender!
When I bought the car two weeks ago I was told that it had just had a head gasket replaced before the gearbox failed(this appears to be confimed as the head is very clean inside and out and the gasket looks new, more on this later). The car sounded noisy and I was a bit concerned but it had been stood for 4 months and has only done 500 miles in the last 11months.
At first I thought it was the hydraulic tappets, I changed the oil and added some valve lifter concentrate. No improvement.
I removed the cam cover and checked the cam lobes, a little bit of marking was evident however what was really noticeable was that the hydraulic lifters could be pushed into the head against their springs with no hydraulic resistance.
I then surmised that if the engine had got hot when the head gasket had failed this may have damaged the seals in the hydraulic lifters. At this point I had been using the car and had covered some 80-90miles.
I bought a good second hand set and fitted them to the car along with a new cambelt and tensioner. I noticed a little bit of scoring on the cam carrier but nothing which caused me too much concern.
I took the car out for a test run, after 5 miles there was a loud screeching noise,
I immediatly switched the engine off. I tried to restart the car but it just made a terrible noise. I assumed that the cambelt had broken. At this point I surmised that one of the cams had locked for some reason and caused the belt to break.
This morning I recovered the car from where I had left it. Upon stripping the car down the cambelt was still intact. I tried to turn the engine over using a socket on the bottom pully, the crank turned but the cams did not. The belt was slipping around the bottom pully.
I removed the cam cover and it was plainly evident that the end of one cam had run dry and siezed in the head.
I removed the cams and inspected the damage. Both cams, the head and the cam carrier are scrap. The oil ways were clear in the cam carrier however no oil was getting through.
In hindsight I should have noticed when I first removed the cams that there was not much oil in the head.
I checked the oil feed to the head by pushing a piece of wire down the hole. When I pulled it out, oil was only halfway up the hole (to about the level of the top of the block). I was now thinking that the head may still have plastic dowels and these had broken up causing the oil to be pumped straight back into the sump instead of the head.
I removed the head but the dowels were steel and the gasket showed no signs of any oil passing.
A friend of mine who came round to look at the car suggested that the oil feed to head should have drained back down by now and so no oil should be present in the feed to head.
We removed the oil pump which was full of oil as you would expect. The oil feed to the head was completely blocked solid with a large quanity of something that looks like paper or a fibre of some kind or maybe a cigarette end!
I have now cleaned the oilway out and have obtained a secondhand head complete with cams and cam carrier which I will have skimmed and fit to the engine.
I can't see where this stuff that has blocked the oilway has come from and can only assume that it was put in their when the head was removed as there is no way that it was dragged though the oil filter. There is far to much of it and it was too deeply imbeded for it to have been accidently left in the engine. I am wondering why it has been put there (Maybe the garage had a grevience with the cars owner!)
On another note, what are he best headgasket and stretch bolts that I should buy? Any idea how much?
Thanks for reading all of this!
|A D Smith|
|Thanks Andrew, an informative and interesting read; that is certainly an unusual problem. Do you feel it was deliberately sabotaged or maybe some bystander flicked away a cigarette butt and failed to spot it's landing in some work-in-progress while the head was off?|
I cannot help wondering how many other Fs have been passed on in such condition to the detriment of an already wretched reputation!
To a generation accustomed to not even checking oil air and water occasionally, this would have been a devastating and 'unfair' catastrophe entirely the 'fault' of the F. I don't suppose you are that pleased either - even though clearly able to cope!
Good luck with the restoration.
Thanks for your post, given the small size of the oil way, theamount of material in the oilway and the depth of it, it can only have been put there deliberatly. I can see no other explanation.
Does anyone know how I can post a picture of the debris?
|A D Smith|
|Shot in the dark. Contents of a disintegrating oil filter maybe???|
|Does sound like it, and would explain why it was post pickup. |
Not sure where the filter sits in the oil flow though
|I've never heard of an oil filter disintegrating. I would think that if it had the other hole from the oil pump to the crank would be similary blocked, but it's not.|
Interesting theory though.
|A D Smith|
|have you checked the mains or the big ends?|
|I haven't remmoved the sump however the engine now runs fine and the oil light goes straight off, no rumbling or tapping that would be associated with mains or big ends.|
I am now in the process of fitting a new hood from BAS which is really really easy! Unlike everything else on the bloody car!!
|A D Smith|
This thread was discussed between 26/08/2006 and 30/08/2006
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