Author Topic: Manifolds and blanking plates  (Read 308 times)

Fergus

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Manifolds and blanking plates
« on: 24 June 2020, 11:32 AM »
Hello Colleagues I took the car to have the manifolds changed and to sort out a minor oil leak.

The replacement manifolds appear to have fitted in well (pic 1 and 2 ) but the mechanic told me that the oil leaks appeared to be coming from the blanking plates on the side of the block. Is this a common occurrence and would replacing the plates address the problem? I appreciate there might be issues behind the plates.

Cheers

Fergus

UTn_boy

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Re: Manifolds and blanking plates
« Reply #1 on: 24 June 2020, 02:22 PM »
I'm seriously questioning your mechanics knowledge and abilities at the moment, as well as his ethics.   There is no oil behind these plates.  These plates cover up cooling passages for the engine cooling system of the engine block.  So if they were leaking they'd be leaking antifreeze, not oil.  Where you're leaking oil is likely from the mating surface of the top of the cylinder head and the bottom of the camshaft housing.  If not, then it could also be the head gasket leaking oil via the return or supply ports to the valve train.  It could also be leaking oil from the front of the engine (crankshaft seal) and blowing back along side the engine block as the car is driven....and then dripping down after the car is parked. 

Have the engine steam cleaned and then look for where the oil is coming from. 
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Randys01

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Re: Manifolds and blanking plates
« Reply #2 on: 24 June 2020, 05:00 PM »
I'm thinking the same as UTN.

floyd111

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Re: Manifolds and blanking plates
« Reply #3 on: 24 June 2020, 05:25 PM »
Is your mechanic from Taiwan? ;D If not, send him here and the average skills in both our countries will go up immediately.

Lance

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Re: Manifolds and blanking plates
« Reply #4 on: 24 June 2020, 08:08 PM »
Look down to the left of the spark plugs, you will see a drain hole for the oil that collects in there from cam cover leaks. These drain out to the side of the block, near the mating surface with the head under the exhaust manifold. Put a new rocker cover gasket on and clean out your PCV valve, it is likely clogged. Or just don't worry about it and top up the oil every now and then.

Fergus

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Re: Manifolds and blanking plates
« Reply #5 on: 24 June 2020, 10:34 PM »
Many thanks Lance, Floyd, Randy and UTN for your very constructive comments. Most helpful. The engine apparently had been steam cleaned to check for leaks.

Every day a learn a little more

Cheers

Fergus

Fergus

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Re: Manifolds and blanking plates update
« Reply #6 on: 08 October 2020, 03:41 AM »
Hello Colleagues
Brief update on coolant and oil / liquid leaks but no oil major oil leaks any more or oil in spark plug wells.

Moved to a new garage

Had the head gasket job done and new blanking plates.

Just got the car back yesterday and I gave it a good run and noticed today that there are minor leaks and weeps from the two plates behind the black hose in the pic the one with with the two hose clips.

Garage said monitor the leaks and take back if problem continues.... I have booked it in for next week. Before I got it back the garage had steam cleaned the engine and cleaned away any residue oil.

Any wise words observations gratefully received as I tend to pass redacted versions to garage. They said they would take the HG  apart again if needs be.

Cheers

Fergus

rumb

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Re: Manifolds and blanking plates
« Reply #7 on: 08 October 2020, 12:16 PM »
The bolts may need snugging up a bit on the covers. If the leak is very small they may stop on their own after some driving.

I had a small leak on my water pump after installation and used some radiator stop leak. Worked fine.
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Fergus

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Re: Manifolds and blanking plates
« Reply #8 on: 09 October 2020, 02:22 AM »
Thanks Rumb

I will try that

cheers

raueda1

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Re: Manifolds and blanking plates
« Reply #9 on: 09 October 2020, 09:43 AM »
The bolts may need snugging up a bit on the covers. If the leak is very small they may stop on their own after some driving.

I had a small leak on my water pump after installation and used some radiator stop leak. Worked fine.
Sorry for a slight thread hijack . . . 
If you used stop leak there and it was fine, is there any reason I can't do the same on my heater core?  The leak seems to be very small and it would be nice to have a heater again.  I posted about this once before and the idea was soundly thrashed as I recall.
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Before that:  1966 230S, 1964 220SE coupe, 1977 Carrera 3.0

rumb

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Re: Manifolds and blanking plates
« Reply #10 on: 09 October 2020, 10:40 AM »
Even though I say it could work on this situation I would still rather not be using it. As you know the water pump on a 6.9 is a monster to remove.  I felt in that case stop leak would be a possibility.  I used about 1/3 of the regular dose and it worked. A small leak like that is a bit different that a heater core leak. 

You could try it, it either will work or not, or just push off a job that should probably be done right anyway.
'68 250S, '77 6.9 euro, '91 300SE, '98 SL500 '14 CLS550