924Board.org

[zwoodward]

Looks like I've blown my headgasket. I have all the symptoms, coffee like mix on the oil filler cap, oil very thin and running all the way up the dipstick, smoking exhaust, hard as hell to have the car start and stay running, magically disappearing coolant (no leaks), quick to overheat, etc. I have not done a compression test yet but is this a sure way to diagnose the headgasket? Any other way? I did a search and Khal or someone else had a blown headgasket and noticed some rusted spark plugs, would this be a normal sign to look for? How hard of a job is this for someone who is moderately decent at turning wrenches but no expert? If I'm going in there are there any other small (read:cheap) items I should look into replacing while I'm at it? I have read that the 931 headgasket will bump the compression 1/2 a point, is this worth it? I was thinking I should definitly have the head decked .010 inches to make sure the mating surface is flat, is this sound advice? I have noticed on other posts that peole have mentioned warped and cracked cylinder heads, is this very common on a 924na or primarily a problem with 931s? And finally, sorry for all the questions, Performance product lists a head gasket set for $90, what would be included in the set?
Thanks,
Zac
1979 924 n/a

[Joes924Racer]

its easy all youll get for the ninety bucks is a head gasket.
you might want to get exhaust manifold gaskets that go between the head and manifold..just depends on where your disconnect point is.
down pipe or manifold..you might get ready to replace some bolts
on the exhaust they might break from all the heat and corrosion theve been exposed to. youll need a torque wrench and a haynes manual.
maybe replace some hose clamps.
_________________
1979 porsche 924 Na
1980 porsche Turbo 931GT Replica
Have u ever driven a turbo.

[gohim]

Replacing the headgasket on a 924 NA is a fairly simple exercise. Even if you haven't done one before, removing the head should take less than four hours, and replacing it, less than two hours if you don;t get die tracked along the way.

Make sure that you locate a competent machine shop before you you start. You will need a good, accurate 1/2" torque wrench, a set of hex sockets, 3/8' rachet with extensions and metric sockets, a tool to remove the fuel injectors, and a tool/socket to fit the head bolts (12 point or hex).

What you will do is disconnect the battery, remove the fuel injectors, remove the intake manifold intact, disconnect the exhaust manifold from the collector (remove it with the cylinder head), remove the distributor with spark plug wires, remove the drive belt/s, the timing cover and the timing belt. Last, remove the valve cover, and loosen the head bolts in the correct pattern, going down 5-10lbs at a time until they are loose and remove the head.

You will need a head gasket set, fuel injector seals, possibly fuel injector inserts, teflon based, non-hardening sealer if you need to replace the fuel injector inserts, and probably some new coolant hoses. Don;t forget to get a new plastic elbow for the camshaft oil supply tube, and make sure that it gets installed (you could put it on yourself when the cylinder head returns from the machine shop).

If you don't hand the head gasket set to the machine shop when you drop the head off to be inspected and serviced, they are going to charge you for a set of valve stem seals (which are included in the head gasket set). The machine shop will probably want to replace some valves and valve guides. Make sure that they use phosphor bronze guides as replacements. Even if all of the guides do not need replacement, you may want to go ahead and have them all replaced to get guides made from the better material. The original valve guides were made of straight bronze that proved to be too soft, and wore rapidly.

Don't have the head shaved, unless it is badly warped. Shaving the head changes the relationship between the crankshaft, the camshaft, and the valve timing (BAD).

[zwoodward]

I was wondering, what exactly will the machine shop do to my head after I drop it off, is there anything specific I should tell them. So the head gasket set does indeed include the valve stem seals? Looking in the performance products catalogue I see they only list magnesium bronze valve guides for the 924, is there much of a difference between this and phosphor bronze? I already have the fuel injector seals (i bought a lot of new rubber parts when I bought the car and have been waiting for school to end to get to work on it) will it be hard to tell whether or not the teflon injector inserts need replacing?
Thanks for your replies.
Zac
1979 924 n/a

[augidog]

Yea, I'm getting the coffee oil in my expansion tank.I get a fouled sounding plug at startup that clears after a few min.Could it be just the valve stems?
My vacuum gauge is reading steady . But I feel the worst is yet to come.
Is the collector pipe the best removal point? are the bolts easily replaced if broken?
Napa has a full head gasket kit for $100.00
I feel your pain yet I'm a liitle excited to do it.
_________________
1978 924 95 mile daily driver.
Audi TB/POR174M/High Flow Cat/2.25" exhaust
I knew that positive thinking thing wouldn't work.

[gohim]

You should not have to tell the machine shop what to do. They are going to charge you a fee to inspect it, and tell you what the head needs (how many valves, valve guides, machine work, cut head, etc...).

It is easier to leave the exhaust manifold on the cylinder head because some of the nuts that hold the exhaust manifold to the head will be seized. the exhaust manifold to collector bolts are much easier to reach and there is plenty of room to pull the head and exhaust manifold together.

I have never heard of magnesium bronze valve guides (could that possibly be manganese bronze?). I know that phosphor bronze is suppose to have very good wear characteristics. That does not mean that magnesium bronze will not make a good material for valve guides.

[Paul]

No issue here, but not all machine shops know that 924 turbo exhaust valves are not to be ground.
_________________
White 87 924S "Ghost"
Silver 98 986 3.6l 320 HP "Frank N Stein"
White 01 986 "Christine"
Polar Silver 02 996TT. "Turbo"
Owned and repaired 924s since 1977
Porsche: It's not driving, it's therapy.

[gohim]

I think the no grinding on the valve stems rule would apply to all sodium filled valves, not just those of the 931 (924S, 944, 914 2.0, 928, etc). I would expect EVERY COMPETENT MACHINE SHOP to check the specs on a head BEFORE doing any sort of work, including inspections. This should tell them that the original exhaust valves are sodium filled.

But zwoodward's car is a 924 NA, so that should not be a consideration.

The German made head gasket sets that I have purchased for my Porsches have always included the valve stem seals.

[augidog]

Zwoodward I found this set
http://catalog.drivewire.com/drivewire/baseline/wizard.jsp?partner=drivewire&year=1978&make=PO&model=924--001&category=A&part=Cylinder+Head+Gasket+Set
by Goetze
should I go for it or price up to reinz?
Are there any upgrades that should be looked at while the machine shop has the head?better springs etc.?
_________________
1978 924 95 mile daily driver.
Audi TB/POR174M/High Flow Cat/2.25" exhaust
I knew that positive thinking thing wouldn't work.

[Joes924Racer]

You can pay about 90 bucks for the german reinz head gasket and it will not come with valve stem seals just a plastic wrapped head gasket.
_________________
1979 porsche 924 Na
1980 porsche Turbo 931GT Replica
Have u ever driven a turbo.

[gohim]

I would contact the Seller and confirm that the part that is being advertised is in fact a complete head gasket set, and not just the head gasket by itself.

Some companies sell the head gasket by itself, and a complete head gasket set. You want to make sure that you are getting the complete set.