Cylinder head gasket sugestions
03-23-2011, 04:10 PM
#1
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Cylinder head gasket sugestions
Well this is really turning into quite the project. Early '85 FYI
Looks like I need a head gasket.
Car is losing coolant, no leaks, but some dried up green gunk on the bottom of the cat.
Compression check was good? thats the weird part of it, thinking I'll do a leak down test and see what I find.
Anything special I should know before diving into this?
What's the best head gasket to use?
Should I change anything else while I'm in there.
all belts and WP are done already,
Thanks
Looks like I need a head gasket.
Car is losing coolant, no leaks, but some dried up green gunk on the bottom of the cat.
Compression check was good? thats the weird part of it, thinking I'll do a leak down test and see what I find.
Anything special I should know before diving into this?
What's the best head gasket to use?
Should I change anything else while I'm in there.
all belts and WP are done already,
Thanks
03-23-2011, 04:35 PM
#2
Race Director
Get a standard heatgasket set from a place like paragon products.
The only issue wil be that once you remove the head you should get it decked. Most of the time there are corrosion holes in the head surface and the head can use a few thousands removed get back to a nice clean, flat, and smooth surface.
You could have a valve job done while you are at it. Beyond that it maybe good to realize you may find other stuff that you need to repair while you are in there. It is easy for little stuff to come up. New spark plugs are good, new plug wires. vacuum lines etc.
BTW.... I just did a head on my 944 spec car after missing a shfit and banging 4 valves so I was just in there.
The only issue wil be that once you remove the head you should get it decked. Most of the time there are corrosion holes in the head surface and the head can use a few thousands removed get back to a nice clean, flat, and smooth surface.
You could have a valve job done while you are at it. Beyond that it maybe good to realize you may find other stuff that you need to repair while you are in there. It is easy for little stuff to come up. New spark plugs are good, new plug wires. vacuum lines etc.
BTW.... I just did a head on my 944 spec car after missing a shfit and banging 4 valves so I was just in there.
03-23-2011, 09:00 PM
#3
Proprietoristicly Refined
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If the coolant did get into the oil, Porsche says to replace the rod bearings. Coolant eats rod bearings.
Get the head machine work done. About $200 for grinding valves, machine the flat surface and maybe replacing the valve guides if needed. Call around for best price. The shop will tell you if you need a "thick" head gasket. The WSM has the specs as well.
Pelican still has the "standard" head gasket set for $100, you still need exhaust manifold flange gaskets, new injector seals (send the injectors to be tested and cleaned), new cam gear bolt, maybe a couple of lifters if they are soft.
Read all about it on Clarks.
Wake up the cam bolts.
Keep the lifters in the same holes--catch the lifters when you lift the cam housing by sliding a steel plate under the cam housing first---if not they will bounce on the floor when they drop out.
Clean --clean ---clean 5 to 8 hours to get all the old gasket off and clean up. Suck the crud in the rear chamber between the cly and block on the bottom. It settles there.
It is an easy job to do slowly. Engine at TDC!
Gl
John
Get the head machine work done. About $200 for grinding valves, machine the flat surface and maybe replacing the valve guides if needed. Call around for best price. The shop will tell you if you need a "thick" head gasket. The WSM has the specs as well.
Pelican still has the "standard" head gasket set for $100, you still need exhaust manifold flange gaskets, new injector seals (send the injectors to be tested and cleaned), new cam gear bolt, maybe a couple of lifters if they are soft.
Read all about it on Clarks.
Wake up the cam bolts.
Keep the lifters in the same holes--catch the lifters when you lift the cam housing by sliding a steel plate under the cam housing first---if not they will bounce on the floor when they drop out.
Clean --clean ---clean 5 to 8 hours to get all the old gasket off and clean up. Suck the crud in the rear chamber between the cly and block on the bottom. It settles there.
It is an easy job to do slowly. Engine at TDC!
Gl
John
03-23-2011, 10:03 PM
#4
Burning Brakes
I would definatly spend some time trying to find out where the coolent is going...into the oil, combustion chamber our leaking externally somewhere...It would suck to change the head gasket only to find the problem is somewhere else
03-23-2011, 11:47 PM
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No coolant in the oil, no oil in the coolant.
Just looses coolant, and llike I said the cat has some green sludge build up on the bottom of it, looks like the coolant is going thru the combustion camber and the gylcol (spelling) part of it is reforming after combustion.
I will do the lead down and see whats up, like I said though perfect compression check numbers?
Car drives fine, you would never know there is an issue.
John you should try the Permatex gasket remover, it makes life alot easier.
Is it worth using one of the "wide fire" head gaskets?
Just looses coolant, and llike I said the cat has some green sludge build up on the bottom of it, looks like the coolant is going thru the combustion camber and the gylcol (spelling) part of it is reforming after combustion.
I will do the lead down and see whats up, like I said though perfect compression check numbers?
Car drives fine, you would never know there is an issue.
clean --clean ---clean 5 to 8 hours to get all the old gasket off and clean up. Suck the crud in the rear chamber between the cly and block on the bottom. It settles there
Is it worth using one of the "wide fire" head gaskets?
03-24-2011, 01:36 AM
#6
Proprietoristicly Refined
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The "wide fire" head gaskets I am familiar with are for the 951 turbos.
Paragon/Pelican has it.
If you get your head machined properly, you will have better success with the stock HG.
Have you noticed any white smoke coming from the tail pipe just after you start the car for a short time? This is usually the first indication that the HG has deterioated. The leak down test will tell a lot as well. Watch for bubbles in the coolant reservoir and noise at the tail pipe and the oil fill tube.
I use acetone and the soft scrub pad with carefully applied scrapers. The cleaning time is for all parts.
If you want to keep the dirt out of the cyl walls, put grease around the piston tops. When finished carefully lower the piston and wipe it away. This will work good IF you remove the carbon on top of each piston as well.
Do not remove the top carbon ring on each cylinder wall. It helps compression.
GL
John
Paragon/Pelican has it.
If you get your head machined properly, you will have better success with the stock HG.
Have you noticed any white smoke coming from the tail pipe just after you start the car for a short time? This is usually the first indication that the HG has deterioated. The leak down test will tell a lot as well. Watch for bubbles in the coolant reservoir and noise at the tail pipe and the oil fill tube.
I use acetone and the soft scrub pad with carefully applied scrapers. The cleaning time is for all parts.
If you want to keep the dirt out of the cyl walls, put grease around the piston tops. When finished carefully lower the piston and wipe it away. This will work good IF you remove the carbon on top of each piston as well.
Do not remove the top carbon ring on each cylinder wall. It helps compression.
GL
John
03-24-2011, 01:52 AM
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Do you have a bit of white smoke produced for a few seconds after the car starts and a struggling idle during that time?
How long does the car rest between drives?
I had a similair issue with my headgasket going. The car was losing coolant, and it became apparent that it was leaking into the cylinder(s) after the car was shut off while the cooling system was still pressurized. Subsequently, every time I would start it, it had a low, struggling idle and would burn off the coolant in the form of white smoke.
At first, it was just a low idle at starting and slowly worked up dying on me unless I held the throttle open and producing some sizable, if short lived, white smoke clouds.
The car ran great after it burned off the coolant. I never got any (detectable level of) coolant into the oil and vice versa. I still did a water with a few drops of detergent flush of the cooling system and a Seafoam clean of the oil system after the job.
The headgasket replacement seems pretty scary, but it's quite straight forward following Clark's guide.
What was a real pain was doing the Oil cooler seals while I was in there. I have no idea how anyone manages that one with the head still on. Might as well replace them while you are at it.
I don't think the wide fire gasket will help you out, they are used for lowering the compression ratio on Turbo'd cars. In the case of N/A we would get an ever-so slightly higher compression ratio from the shaving of the head and a normal thickness headgasket.
Speaking of which, the normal headgasket kit as mentioned before will ses' you up just fine.
How long does the car rest between drives?
I had a similair issue with my headgasket going. The car was losing coolant, and it became apparent that it was leaking into the cylinder(s) after the car was shut off while the cooling system was still pressurized. Subsequently, every time I would start it, it had a low, struggling idle and would burn off the coolant in the form of white smoke.
At first, it was just a low idle at starting and slowly worked up dying on me unless I held the throttle open and producing some sizable, if short lived, white smoke clouds.
The car ran great after it burned off the coolant. I never got any (detectable level of) coolant into the oil and vice versa. I still did a water with a few drops of detergent flush of the cooling system and a Seafoam clean of the oil system after the job.
The headgasket replacement seems pretty scary, but it's quite straight forward following Clark's guide.
What was a real pain was doing the Oil cooler seals while I was in there. I have no idea how anyone manages that one with the head still on. Might as well replace them while you are at it.
I don't think the wide fire gasket will help you out, they are used for lowering the compression ratio on Turbo'd cars. In the case of N/A we would get an ever-so slightly higher compression ratio from the shaving of the head and a normal thickness headgasket.
Speaking of which, the normal headgasket kit as mentioned before will ses' you up just fine.
