break23m
Rover Rookie
Getting a 3 Litre Mk II automatic back on the road
Posts: 49
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Post by break23m on Oct 23, 2023 15:51:30 GMT
I need some advice. My car is at the moment with a specialist in The Netherlands to repair the oil loss at the crankshaft seal (it is spilling a liter of 20W50 every 100 kilometer - and a bit when standing stil). My car is an MK2 automatic, so replacing the crankshaft seal is a job that requires removing the engine from the car. Now that the engine is being taken out, I am advised to have the valve seals replaced and the head gasket replaced. And of course have the head skimmed. A costly repair - and I have to miss the car for weeks.
The engine runs smoothly at 100 km/h (60 mph), no blue smoke when starting or on accelerating. So in my opinion there is no real problem with the head of valveseals.
My question: is it wise to replace the head gasket and valveseals while the engine is out? Is it so much more complicated to do that at a later time with the engine in the car?
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Post by lagain on Oct 23, 2023 17:52:38 GMT
Are you certain that the oil leak is from the crankshaft seal. I am not familiar with the 3 litre engine, but my 3.5 was loosing oil from the sump gasket. Does the head need to come off to do the seal, if it does get it done, if it does not leave it as the head can be removed with the engine in the car.
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break23m
Rover Rookie
Getting a 3 Litre Mk II automatic back on the road
Posts: 49
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Post by break23m on Oct 23, 2023 19:59:55 GMT
Thank you, lagain. I thought so, head gasket kan be done with the engine in the car. And yes, the sump gasket and the gaskets of the two valve covers will be changed to rule these out.
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Post by MK IA Norway Viking on Oct 23, 2023 21:00:20 GMT
Is the car at Berry Smink's workshop ? he is a capable mechanic on the P5, so in general it's worthwhile to follow his recommendation.
I have the MK IA engine and have to say that as a matter of PRINCIPLE do not repair something that works. When the MK II engine runs smoothly it will suggest nothing wrong.
Replacing the head gasket is not a complicated job; I have done it myself and I am not particularlly skilled.
The head needs skimming only if it is warped. If the compression in EACH cylinder is good, the head will be flat against the cylinder block and the head gasket intact - in such case there is no need to make a repair / service.
Losing a litre of oil in 100 km suggest a major leakage.
What makes you so sure the leakage is from the crankshaft ?
Note that the MK II engine is a very refined piece of mechanic and should not lose this amount of oil and not at this volume from the crankshaft seal. As it clearly does leak oil, the culprit could be a leaking banjo connection or a leaking valve rocker cover (perhaps the cork seal was not positioned right last time the valve tappet clearance was adjusted).
Since the oil only leaks when hot, and when engine running, it will be related to warm oil and high pressure. the pressure at the crankshaft seal is not particularly high. It will be high elsewhere, such as engine oil feed pipe, at the connection where the oil pressure switch sit and so on.
I should focus on stopping the oil leakage before disturbing the engine further with preventive maintenance, like the head gasket affair.
If the subframe still has not been removed from the car, I would abort that operation till you can establish more for certain WHERE the leakage occur. That oil is dripping from the bottom of the engine, or from the bell housing, does not mean the oil emanates from the crankshaft. It could come from higher up on the engine, find its way into the bell housing and exit from there.
Good luck in sorting your problem - and to get back to the natural habitat of any Rover; the open road leading to the horizon.
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break23m
Rover Rookie
Getting a 3 Litre Mk II automatic back on the road
Posts: 49
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Post by break23m on Oct 24, 2023 7:12:09 GMT
The car looses oil when driving but also when it's standing still. Of course the valve covers and other suspects will be checked, but Smink himself pointed at the crankshaft seal. I'm not sure if a new head gasket is necessary at this point.
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Post by MK IA Norway Viking on Oct 25, 2023 13:07:52 GMT
From what I can see, there is no need to do the cylinderhead job at this time.
It is easy to do this at a later stage if this area of the engine is the only area remaining to seek for the leakage if oil consumption remains high.
All work on the cylinder head can be done with the engine in the car. It is not much easier nor much quicker to do this job when the engine is out of the car.
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The 6 cyl IOE is such that when it is under load e.g. normal driving - where the engine is pulling - the lubricating oil will return from the cylinder head and gallery for exhaust valves by gravity into the engine sump. For two of the four cycles there will be vacuum in the engine, which is when the combustion chamber sucks in fuel/air mix via the carburettor. Oil can be sucked in at the same time.
Oil is pumped under pressure to the big end bearings through small holes in the crankshaft.
A usual place for oil to enter the combustion chamber is via the valve stems and the valve guides. For this reason, there is an o-ring in the valve guide to prevent engine oil from being sucked into the engine.
When the engine is braking - e.g. a vacuum occurs within the combustion chamber - the lubricating oil could be sucked into the combustion chamber and exit the tailpipe as blue smoke. This will suggest the valve-system or bad piston rings sucking oil into the combustion chamber.
Even if you have blue smoke, it is unrealistic to have 0,1 litre oil disappear for every 10 km., or even 1 cl. for every km.
It follows that you have a leakage somewhere.
The crankshaft seal may very well be the source of leakage however remember that it is positioned quite high above the bottom of the engine oil sump.
If the oil level is up to the crankshaft (and above) it can leak out the crankshaft seal when the car is parked.
Since oil is not running uphill, any oil remaining in the sump at a level BELOW the crankshaft seal simply cannot escape the engine through the crankshaft.
On my engine, threads for the drain plug are weak, so oil is leaking out that way.
I think it is prudent to examine the engine carefully when hot to see if oil is pumped out anywhere.
I experienced a big leakage from the inlet rocker cover becuase the cork seal was out of position.
I believe there are vents in the bell housing, and that these can be undone, or you can see through them. You can thus gain access to see if oil comes out from behind the torque converter, which is bolted to the crankshaft.
You can elevate the car and stand under it with engine running to visually observe where the oil is dripping from. An assistant can operate the throttle to increase the engine speed from idle OR set the cold start to high RPM (at the point before enriching the fuel mixure). Increased engine speed = higher oil pressure = easier to observe a leakage.
If it is "dry" on the floor / pavement under the engine, the engine will suck the oil into the combustion chamber via the valve stems / up from the sump past worn piston rings and exit via the tailpipe as blue smoke.
If it is dry under the engine it will mean the engine does NOT have to come out of the car. All work with valve stems and valve guides can be done with the engine in situ. I believe also piston rings can be changed with the engine inside the car.
Wishing you good fortune with this project.
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Post by MK IA Norway Viking on Oct 25, 2023 13:09:49 GMT
... a head gaskets is something you replace when the pressure in the engine is leaking out of the engine. Your main concern is the disappearance of engine lubeoil and not whether any of the cylinders are losing pressure due to a bad head gasket.
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break23m
Rover Rookie
Getting a 3 Litre Mk II automatic back on the road
Posts: 49
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Post by break23m on Oct 25, 2023 14:45:51 GMT
I spoke to my specialist today. They already removed the cylinder head and it does show oil leaks. Never heard of that - a failing head gasket often means water coming in to the cylinder or compression loss. So my question is answered. Yes, a head gasket can be the source of an oil leak and yes, it can be a good idea to check after 60 years.
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Post by MK IA Norway Viking on Oct 25, 2023 15:10:30 GMT
Thank you. Is the leakage from the head gasket or is it from the valve stems / valve guides (or, perhaps, both) ?
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break23m
Rover Rookie
Getting a 3 Litre Mk II automatic back on the road
Posts: 49
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Post by break23m on Oct 25, 2023 19:28:58 GMT
The head gasket, valve covers, crankshaft seal etc. It doesn't seem to burn oil, but the valve seals will be changed just to be sure.
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Post by enigmas on Oct 25, 2023 22:25:36 GMT
Oil burning (or a blue smoke trail) on the over-run (high engine vacuum causes this issue) is generally attributed to the inlet valves and guides both being worn in concert with ineffective stem seals. The 3 litre factory O ring method from my reading of other members posts and similar situations to remedy the issue by simply replacing the O ring is prone to repeated failure. So why persist with this option?
Rather, "bite the bullet" take the head to a authentic engine reconditioning shop and have the valve guides machined to accept modern "top hat" seals. This type of repair (minor mod to the top of the inlet guide to accept modern seals) is quite routine, long lived and fully effective in ending the blue smoke trail.
The rear main seal is a definite remove and replace if the engine is out of the car. Given it's age and decades of duty, why wouldn't you replace it when it's so accessible?
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Post by MK IA Norway Viking on Oct 26, 2023 9:11:29 GMT
Can you share with us photo of the bad head gasket, so members can see where the leakage has occurred and to which extent. There lies a lot of learning in seeing the condition of a bad head gasket. Thank you.
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break23m
Rover Rookie
Getting a 3 Litre Mk II automatic back on the road
Posts: 49
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Post by break23m on Oct 26, 2023 17:48:30 GMT
Oil burning (or a blue smoke trail) on the over-run (high engine vacuum causes this issue) is generally attributed to the inlet valves and guides both being worn in concert with ineffective stem seals. The 3 litre factory O ring method from my reading of other members posts and similar situations to remedy the issue by simply replacing the O ring is prone to repeated failure. So why persist with this option? Rather, "bite the bullet" take the head to a authentic engine reconditioning shop and have the valve guides machined to accept modern "top hat" seals. This type of repair (minor mod to the top of the inlet guide to accept modern seals) is quite routine, long lived and fully effective in ending the blue smoke trail. The rear main seal is a definite remove and replace if the engine is out of the car. Given it's age and decades of duty, why wouldn't you replace it when it's so accessible? As I stated earlier, the engine doesn't burn oil, it never gives blue smoke, not on power nor on the overrun. The engine looses oil. That is the problem I need to have solved. But now with the head detached, my specialist thinks it's a good idea to change the valve seals. I agree.
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Post by MK IA Norway Viking on Oct 26, 2023 18:31:08 GMT
Oil burning (or a blue smoke trail) on the over-run (high engine vacuum causes this issue) is generally attributed to the inlet valves and guides both being worn in concert with ineffective stem seals. The 3 litre factory O ring method from my reading of other members posts and similar situations to remedy the issue by simply replacing the O ring is prone to repeated failure. So why persist with this option? Rather, "bite the bullet" take the head to a authentic engine reconditioning shop and have the valve guides machined to accept modern "top hat" seals. This type of repair (minor mod to the top of the inlet guide to accept modern seals) is quite routine, long lived and fully effective in ending the blue smoke trail. The rear main seal is a definite remove and replace if the engine is out of the car. Given it's age and decades of duty, why wouldn't you replace it when it's so accessible? As I stated earlier, the engine doesn't burn oil, it never gives blue smoke, not on power nor on the overrun. The engine looses oil. That is the problem I need to have solved. But now with the head detached, my specialist thinks it's a good idea to change the valve seals. I agree.
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Post by MK IA Norway Viking on Oct 26, 2023 18:34:18 GMT
I will greatly appreciate hearing from you the findings your specialist establish, for many club members will benefit from what you learn from this particular job. Fingers crossed, and best wishes for this engine job.
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Post by enigmas on Oct 26, 2023 21:52:12 GMT
As I stated earlier, the engine doesn't burn oil, it never gives blue smoke, not on power nor on the overrun. The engine looses oil. That is the problem I need to have solved. But now with the head detached, my specialist thinks it's a good idea to change the valve seals. I agree. What colour is the end of the exhaust pipe on your car? The colour as well as any exhaust residue coating is an accurate indicator of what is occurring with the engine's combustion cycle. Blue smoke occurs on the over-run, for example descending a steep gradient on a closed throttle. This scenario causes high engine vacuum that pulls oil mist past worn inlet valve guides and seals. It is very unlikely given the age of your MK2 that it would have sound and viable valve guide seals. Your mechanic is being diligent and proactive in correcting these issues whilst the engine is out and easily accessible. His repairs will only add value and reliability to the car.
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break23m
Rover Rookie
Getting a 3 Litre Mk II automatic back on the road
Posts: 49
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Post by break23m on Oct 27, 2023 7:30:13 GMT
Can you share with us photo of the bad head gasket, so members can see where the leakage has occurred and to which extent. There lies a lot of learning in seeing the condition of a bad head gasket. Thank you. I don't have a picture of the gasket itself, but here are pictures of the engine and head. I don't see damage on either of them, so I hope a new gasket on a skimmed head will cure this part of the oil leakage.
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break23m
Rover Rookie
Getting a 3 Litre Mk II automatic back on the road
Posts: 49
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Post by break23m on Oct 27, 2023 7:40:56 GMT
The crankshaft is slightly worn in. So it's fingers crossed a new seal will do the job. Now the gearbox is out it will recieve a new-old-stock set of gaskets. It's a small job to do now everything is in reach - better safe than sorry. Also the desintegrating rubbers of the subframe will be changed for good set of used rubbers. Now is the time to do it.
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Post by MK IA Norway Viking on Oct 30, 2023 9:40:17 GMT
Thank you for sharing these pictures with us. I should think a slightly worn in crankshaft is not going to cause a big leakage. Shall be very interesting to see how this project develops, as I too have an MK II engine.
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Post by MK IA Norway Viking on Oct 31, 2023 13:18:11 GMT
The case you have on your MK II engine intrigues me, so I've been pondering over this case. I hope to learn from it.
Maybe review following with your specialist:
Careful inspection of the used head gasket will reveal many of the defects on this engine.
It looks like the rear cylinder has had a vacuum leak, probably from the manifold gasket or from the vacuum outlet on the manifold being used for other purposes.
Consequences of such a leak are "lean burn", which automatically means high combustion temperature. We know that the brake servo is powered by the vacuum in the inlet manifold, in the area around cyl. no. 5.
In the photo, it looks like the spark plug is also exposed to abnormally high temperatures.
As we know, aluminum cylinder heads are not as resistant to abnormally high temperatures compared with cast iron.
Consequences of excessively high temperatures could be that the flat part of the cylinder head against the top gasket will slightly twist, the torque pressure against the gasket weakens and leaks occur.
We see soot deposits on cyl. 1 and 6, which could suggest that pressure from combustion leak out in these places.
All this said and done, should not have significant impact on oil consumption or oil leakages.
It highlights however the need to measure precisely the shape of the cylinder head and determine if grinding is needed to ensure a fully flat/plane surface when the 'head is mated to the engine block.
As we know, the design of the MK II engine (as well as the MK III) was given a thorough overhaul by Harry Weslake, to fine tune and trim the engine to deliver higher output.
The power rose from the MK I to the MK II version by 16,5% (115 BHP at 4000 RPM to 134 BHP at 4500 RPM = 19 BHP) in manual gearbox edition. The auto edition (which you have) had a slightly lower (3 BHP ) power increase.
The modifications made were to improve breathing, gas flow etc. by slightly changed cylinder head, indent to give room for the exhaust valve, and a different porting of the fuel/air mix by a modified inlet manifold.
Point with all this is how important a good fit of the cylinder head is to ensure optimal operation of the engine.
Good luck with your project.
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break23m
Rover Rookie
Getting a 3 Litre Mk II automatic back on the road
Posts: 49
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Post by break23m on Nov 1, 2023 18:19:12 GMT
You are right that this engine has more problems than just loosing oil. I have a feeling this car had a harsh life. One valve was bent 😳 and burnt. Some valves didn't close properly in the valve seat. That has now been taken care of. The head is back from the machine shop and gives now a perfect fit. The engine is now ready to back in the car. I have good hopes the engine will run well after this. Attachments:
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Post by MK IA Norway Viking on Nov 2, 2023 10:03:49 GMT
Thanks for sharing, this is really quite useful information.
Most likely the valve guides in the cylinder head have been examined for a proper fit to the valves.
You may want to inspect the condition of exhaust valves too, now that the engine is out and you have easy access.
Common failure is excessive wear on the bush of each valve lifter and, sometimes, also excessive wear on the shafts holding the valve lifters.
I notice more pittings than normal around all of the cooling water ducts in the cylinder head, which will suggest corrosion induced by lack of antifreeze in the coolant.
Antifreeze is biodegradable so if antifreeze is not replenished the efficiency in resisting corrosion is gradually reduced. Especially if the cooling system is topped up with water only = diluting the antifreeze.
Point is that since there is corrosion in the waterways of the cylinder head, there is likely to be corrosion elsewhere too. The weakest point will be the radiator so that the engine overheats. Check also amount of corrosion and gunk inside the engine block (take off the waterpump).
On the two 6 cyl IOE engines I have opened, both had considerable amounts of gunk in the engine block and waterpump. There is a copper/brass duct spraying "cool" water onto the outside of each cylinder liner. The holes in this duct can get blocked so that the cylinder walls do not receive adequate cooling.
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break23m
Rover Rookie
Getting a 3 Litre Mk II automatic back on the road
Posts: 49
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Post by break23m on Nov 2, 2023 12:22:02 GMT
Thank you for a bit of your knowledge. The outletvalves do get attention too.
Since I bought this car, there is cooling fluid in the system, not just water with antifreeze. I have not experienced overheating, not even on trips on the motorway with hot weather. Coolant level didn't need filling up after long and warm drives. So the cooling system is left as it is for now.
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Post by djm16 on Nov 7, 2023 0:51:46 GMT
I am not disagreeing with Vince about machining the inlet valve guides to take top hat seals, since I have had the usual trouble too with O-rings.
However, being stubborn, I persisted this last time and fitted (from memory) 1.6mm Viton O-rings from TransSeals - an OTC product. I believe you can get other fractional sizes like 1.7 and 1.8.
Having said that, the great advantage of top hat seals is that you can replace them on the 3-litre without taking the head off. Simply putting the piston at TDC and removing the rocker shaft allows you to remove the springs without dropping the valve.
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break23m
Rover Rookie
Getting a 3 Litre Mk II automatic back on the road
Posts: 49
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Post by break23m on Nov 12, 2023 14:09:43 GMT
I have got the car back from the workshop. Totally clean engine, so the oil leaks are taken care for. It's running very nice, a low idle and less noise from the engine. Bit of a pity that one of the seals of the outlet manifold gave way after an half our on the motorway. Sounds like it is failing on one cilinder only. Don't know if I can just tighten the bolts or that a new seal is the best solution. Back to the workshop I'm afraid.
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