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MG MGF Technical - Camshaft oil seal

Apologies in advance for what may be a long post.Suffered the dreaded head gasket failure,fitted a secondhand head using my old cams(the second hand head was a manual tensioner,original head was an auto tensioner) and went for a test run yesterday and all seemed well.No mayo,water level steady etc...Ran it again this morning and left it to warm up,5 mins later had a check around and there is a steady trickle of oil from the engine.A quick check reveals its coming from the oil seal behind the distributer,the seal has been pushed out of its housing...Tought i'd better check the other three so timing belt and pulleys off and sure enough they have almost popped out as well! DOH!! So what did i do wrong,have i simply fitted them incorrectly(i just pushed them on once the head was built up) or is there a knack or trick to it? Thanks in advace Kev.
bubblehead

there really shouldn't be any pressure behind them to push them out, pull the cam cover off to check you didn't leave anything in the head which might have blocked the drain down ports around the bolts, and check that the pipework between the head and the manifold and betwen the manifold and throttle is in place and not kinked, buckled or blocked.
Did you clean the brillopad type air cleaners in the cover?

The crankcase should be running at -ve pressure so I would start by finding out why it's not.
Will Munns

Hi Will,i cleaned out the two brillo pad filters as they were full of mayo,had the cam cover off again and it looks fine,the cam ladder on the recon head does not have drain ports for the cam oil seals like my newer one does so i was surmising that this might be the problem."The crankcase should be -ve pressure",can i check this by removing the oil filler when its running,thanks for the help.Kev
bubblehead

yup run the engine and place you hand on the open filler (the one on the engine), it will beat, but overall you should feel it start to suck (it may take a couple of seconds to build up enough -ve pressure to notice over the beating.
Will Munns

Cheers Will,Going to put it back together tonight/tomorrow will let you know how i get on.Just been and checked the hoses and drain holes and they are all clear any other ideas before i put that bloody timing belt back on,i just know i'm gonna have to take it off again ! Kev.
bubblehead

Update on my oil seal problem. Put it all back together but without the brillo pad air cleaner elements,had to refit the old oil seals as the new ones will not be here till tomorrow and ran the engine....As soon as i got round the car to check the exhaust rear seal, blanking plate left off, the seal had been spat out.Had a check of the filler cap as you said Will and it was definitely pulling a small vacuum, diconnected the breather hoses as well and the induction manifold is definitely drawing from the cam cover.Going to do it all again tomorrow when the new seals arrive but i can't help thinking i've missed something so if you have any ideas before i do it all again i'd be very grateful.Thanks Kev.
bubblehead

there type of seals are usually a really tight fit (although I have not done the ones in the head) and require tapping into place with a suitable tool. If they are easy to fit then either the seals are too small, or the hole is too large (is it stepped internally perhaps?).

I can't visualize the inside of the head so I don't know if the drain ports are important in reducing the oil pressure here.

More bad news, you should junk the cambelt if it gets oil on it :-(
Will Munns

Hi again Will,the seals were not that tight to fit,the only one that required real pressure to push in being the exhaust cam rear seal and that still popped out.The reason i suspected the oil pressure was pushing the seal out was because of the difference in the cam ladder design between the two heads,my newer head has a oil return path machined into all four seal recesses whereas the older recon ladder has none. Rover must have changed the design for a reason although i don't think it has anything to do with blowing out oil seals but my head is now a mix and match of new cams, old cam cover etc and i'm wondering if this is having a bearing on events.My presumption is that as there is no drain from the seal recess on this design then the seal will see oil pump discharge pressure and hence the popping out........But the part numbers and dimensions for the different designs are identical and i'm sure early k series engines did not have oil seal problems did they? I've tried fitting the modified cam ladder to the recon head to test my theory but the inlet cam bound up when assembled.. so if tomorrows test fails short of maching my own drain ports in the cam ladder i'm at a loss.....
One bit of good news is that the belt,pulleys etc are oil free,every cloud eh...plus i can change an mgf timing belt with my eyes shut now !
Thanks again Kev.
bubblehead

Well Will i built it all up again this afternoon using new seals,these were of a slightly different design to the previous set and were really tough to fit,i really struggled to get them in to the housing....so i think this time its going to work.....start the car and in less than 20secs the exhaust cam rear seal has been spat out. Check the others and sure enough there popping out as well.Have decided that i'm going to modify the cam ladder as per the one with the drain ports to see if that helps otherwise it's looking like i'll need a new head.Regards Kev.
bubblehead

Hi Kev
Wow is all I have to say !! how many spanners did you throw ?
I dont think I could have gone through all that without loosing it at least once :-)
I hope you get it sorted soon, so you can get back out in the car and enjoy it again.
I am about to do a cambelt change maybe I should wait incase you are passing my neck of the woods :-)

regards Markj
MA Jenkins

Mark in my job you never know i may be in your neck of the woods some time soon...Mate i've had far worse snags than this which eventually we have solved and i'm sure i can resolve this one "eventually" after all as my old boss always said "Son it's just a ring of bolts",but as you say yes doing the timing belt again and again is now doing my head.I will get to the bottom of it and when i find out what i have done wrong i will let you all know so no one else has to go thru this SH*T.As i said previously i can change a cambelt now with my eyes shut so if anyone needs some advice on how its done or anyone local needs help i'll give you a hand.

Will if your about as one last test i want to run the engine with the cam cover removed to eliminate any pressurisation of the crankcase as the cause of the seal problem,after this test i cannot think what else to try,but as always i'm open to suggestions......

I really don't want to machine the cam ladder............But i will if i have to......
Apologies for the spelling,grammar etc just back from the pub,all the talk was of engines and my bloody oil seals in particular.............
Regards Kev.
bubblehead

Just in case you may have the seals mixes up they are coded.Red seals are for the rear and the black seals for the front.The design of the seals are directional and if fitted incorrectly could cause the oil to be 'pumped' out. that said the seals themselves shouldn't be forced out and should be a firm fit but not overtight that you have to force them in. They should be lubricated before fitting and they should go in easily with finger pressure.Check the bore diameters of the seal housings as if the wrong cam carrier has been fitted this could cause the problem. Each carrier is mated to the head and cannot be swapped as you found out but maybe the 'new' head wasn't supplied with the correct carrier for it.
m j satur

Hi Mike,
don't know if you remember,it was a some time ago, but i was the the guy whose head gasket went two days before i was "deployed abroad" for four months, you gave me all the advice regards what i should do prior to leaving as i did not have time to remove the head and fix it before i left.Thanks all the parts were there for my return and all went well untill my incident.As you say my first thought was i'd put fwd seals in aft etc but no it was correct and you obviously know the rest.....One thing i will say is that the "pattern" seals i got from my local motor factors(gaco) were not directional and not colour coded and also a damn site harder to fit! Mic'd up the journals on the different cams i've got and they are all the same, but i haven't checked the housings,thats what i should have done first thinking about it,cheers for that...the obvious eludes me yet again....Thanks for the advice,the head came from flea bay.......will dim check it tomorrow....but i've got a feeling where this is going now,always one for a bargain me.....
Cheers Kev
bubblehead

Good luck,you know my number if you get stuck.
m j satur

A quick update on my continuing saga.Had a look at the housings as you sugested Mike but due to the fact the head is fitted i found it difficult to get any worthwile measurements, however what i did notice is that there appears to be a lip (mis-alignment) between the head and cam carrier itself....Thought about my options and decided that as the head is fitted i'd try one last idea before i removed it and beat it to death with a sledge hammer... So i machined four drain paths as per my original into the cam ladder's seal recess's, refitted it all again,ran it and............well so far so good,the seals are all still where they should be and i've had it running for about 2 hours now.All the timing covers and engine cover are still off so i can eyeball it , i'll have to do the timing belt again at least one more time but i'm not convinced enough to put them all back on yet.....
Cheers Kev.
bubblehead

This thread was discussed between 27/09/2006 and 02/10/2006

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