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MG MGF Technical - Cam gasket weeping, could it lead to oil usage?
|Hi, I have a cam gasket weeping on my car. It's not bad as I haven't had any oil drops on the floor for last 2.5 year long ownership of my F.|
Until last year, I didn't notice much use of oil in my car, but found this year a lot thirstier. Well I topped 800ml after 4000km. Could this be due to the cam gasket weeping? The weeping only started late last year. Co-incidental?
One of my friends mentioned, oil usage could be due to
'either be valve stems (worn) or the piston oil
control ring, (dozy or broken) - this is the lowest ring on the piston. I'm not sure if the valves have seals fitted - these usually sit on top of
the valve guide.'
Should I worry this far?
My car has done 36000km todate. Had the car from 9600km.
Thanks in advance.
|Difficult one to say Hanah, if the cam cover gasket is leaking then it is either damaged or the bolts securing it are loose / not done up to the correct torque. This in itself will not lead to oil USAGE, but could be indicative of too great an oil pressure (thus causing the seepage) and if this is true then this may very well result in some oil usage.|
Looked at as a symptom, rather than the cause then it could indicate an oil use problem.
|Also, it looks like Rob has the same problem!|
>> http://www.mgf.ultimatemg.com/replace_sparkplugs.htm <<
|Thanks SF for the response. Yes, Rob's one is exactly like mine. And I also know Rob's car uses a bit of oil.|
When you said 'too great an oil pressure' what do you mean??
|I can't remember if your's is a VVC, Hanah.|
Mine leaked from one of the VVC seals - and it looked very much like gaskit... It also lost, aparantly, a fair amount of oil between services. I think it went down the front of the engine... It certainly wasn't burning it.
Maybe someone like Mike would be able to say where it comes from...
Mike Satur has seen the photo of the engine weep. He thought it was a cam gasket weeping. He said don't worry about it. If you want a copy of the photo, I can send it to you, but you don't seem to have your email address available?
Mine is a VVC as well Neil.
My car had almost had a cambolt failure, and need damaged cam gear and cam shaft late last year. The cam gear has been replaced, and cam shaft was touched up as it wasn't damaged that much. But I noticed some oil loss before that, and at first the knocking noise, I thought it was from running low on oil. I don't remember ever having to top up my car before then... Or maybe I just don't remember... :-)
That was at 27000km. Now I am sitting on 36000km. Haven't had an oil change since then yet, but will do so in a month time. Mechanic topped up a little last time I visited about 3~4 months ago, and I topped up a couple of days ago 800ml. This brought the oil level upto just a little above medium line. I was running just a 1mm below the min level.
Should I be worried at all?
More and more money I spend on my car I keep getting worried that the car might fall apart! :-(
I am also planning to get a custom exhaust manifold 4-2-1 system at the end of the year, but if the engine is going to go, I don't want to spend more money on it! Hmmm...
|Rephrase the sentence above.|
My car almost had a cambolt failure, and damaged cam gear and cam shaft at the end of the year. Also the cam belt was replaced with 5 yr service at the same time.
|If the oil pressure in the head is too great then it would be forced out passed the seals, one of which is the cam cover gasket, another is the valve stem oil seals. If oil gets passed these then it enters the combustion chamber and is burned and expelled with the exhaust gasses - oil usage.|
If the oil is over filled then there is the potential for a greater oil pressure which may cause the above seepage passed the cam cover gasket.
Therefore the seepage passed the cam cover gasket could be a symptom of a high oil pressure. The high oil pressure could cause oil usage.
|I know of no way that overfilling the crankcase could cause excess oil pressure or cause weeping of oil through a cam cover gasket. It could certainly cause excess crankcase and valve cover pressure, but this should show up as a deficiency in positive crankcase ventilation. Can someone enlighten me?|
|Thanks for the responses. |
Then, why would some cars use more oil than the other?
|A variety of reasons, from driving style to engine build tolerances.|
Mine's always used oil - from the day it was new. I just keep checking it and keeping it level. No problem.
Unless oil consumption has suddenly changed, then there is probably no real cause for worry.
|Well... I can't really remember Rob!|
When I bought the car at 9600km, well the oil was all ok because the dealer serviced the car.
At 12000km, went in for an oil change and services.
At 17000km, went in for an oil change to Full-synthetic.
At 24000km, went for oil change again.
At 27000km, kaboom cambolt goes. Camshaft damaged so touched up. Cambelt change. Cam gear replacement. Oil change
At 36000km now. Topped up probably 1.2 litre in total for last 9000km. I don't know how much it started with so I really have to check. I am on 2/3 way up to max after that 800ml.
Sorry about the late reply on your email Rob, I haven't had time... so are you getting a custom made manifold? or a.... QED system?
|What I meant on the last msg was that the gap was so small that I didn't get to check the dipstick in between....|
thus could have used oil all along, or just recently. :(
|Not a QED Hanah ;o) More news soon, hopefully :o)|
|My cam gasket wept a little bit as well after I bought my 2000 F last July, but then I found out the oil level was more than a cm. above the maximum because this moronic dealer had a moronic mechanic who thought a bit extra could'nt go amiss???|
In the garage where the car now is being serviced we took out 1,2 ltrs of oil, and afterwards the level still was an the maximum mark, and I've driven 3000 km since and the weeping has stopped!
|I quote myself... ;-)|
>> the potential for a greater oil pressure which may cause <<
Note the words 'potential' and 'may'. Just a theory thats all. It seems logical to me for an overpressurised sealed system to weep oil from the gaskets / seals.
>> It could certainly cause excess crankcase and valve cover pressure, but this should show up as a deficiency in positive crankcase ventilation. Can someone enlighten me? <<
Hmmm, i am with you up to the comma, but am not sure about the rest of the sentence. Can someone enlighten me also? ;-)
|I'll assume that your F hasn't been modified to the point that you now have a road draught tube to relieve crankcase pressure. There should be a vent that admits fresh air to the crankcase and some provision for a vacuum to be applied to the crankcase, generally into the induction system. This is known as positive crankcase ventilation. When the vacuum cannot overcome the pressure, a positive crankcase ventilation deficiency results. Then you get fumes from the former intake vent, ingestion of oil, coking and the resultant dieseling and sticking valves.|
Maybe the problem is semantics. I think the term "oil pressure" refers to to the pressure generated by the oil pump. I don't think of oil being forced out due to crankcase pressure as oil pressure, even though it is oil under pressure. The only gaskets that see oil pressure on most engines are the oil pump gasket(when used) and the head gasket. The only seals that should see it are in the oil filter.
|No not at all George,|
only modifications are the add-ons.
Last 300km no change.
But there is a problem with my suspension now.
front Lowering knuckle on the passenger's side has gone busted, and making a horrible thunk noise when I go in a deep driveway where it requires a suspension travel. I can generate the noise by putting the jack up on the front and down, and the same noise is heard. Found that the lowering knuckle was out in play. Rubber ring was detached. The white plastic part broken.
I only had it for 2 months. I emailed Satur, hope he is working at the moment. Don't like driving it around but have no choice.
This thread was discussed between 05/10/2002 and 08/10/2002
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