924Board.org

[ourkid]

I thought at first this was from the cam/valve train area but a few of the lads at work are convinced that my ex manifold is blowing (expansion when hot calms it down).
I've removed the heat shield and cannot actually feel a blow from anywhere,although a couple of the nuts were quite loose.So,if i decide to fit a new gasket,what is the best way to plan removal as it looks like one hell of a job to get at the nuts.Do i need to access these from down below?

Thanks,
Ade.
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1983 924 N/A

[vexed73]

Is yours N/A or Turbo? I have not tackled this job either but have the same problem according to my mechanic (brother). I am conflicted from doing a head job or a full rebuild. Seeing as how much of a pain the exhuast manifold is might as well do more and make it worth my while. I have the turbo model though.
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1982 PORSCHE 931

[Rich H]

Its it a nightmare to move in situ, I would be inclined to tighten the nuts up and see if it fixes it.

Easyest way of finding exhaust leaks is to get it running and then get a willing volunteer to bung a ball of rags up the exhaust, any leak will then make a loud hiss (Then the ball of rags pops out or the engine stalls, don't do it for too long)
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1994 Lotus Esprit S4 - Work in progress...
1980 Porsche 924 S2 DITC Turbo - Original spec
1978 Homo-Sapiens - Tired spec
1953 Landrover S1 - Pensioner Spec

[Rob the plumber]

Or use a length of tubing as a stethascope.
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1981 931

[Slam]

On a regular NA you can change the exhaust manifold gaskets with the engine and head in the car. You can actually get to all the manifold nuts by reaching around under the manifold from above. Then pry the manifold away from the head, slip the new gaskets in and pop the nuts back on. I've done it. Chances are you'll find a couple of broken studs, in which case you've got a different problem and you will have to take the head off.

HTH
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'84 944 - kid blew motor
'83 944 - resting comfortably. For 12 years
'87 944 - sideswiped by trucker
'80 924 - gone
'78 924 - gone
'77 924 - rusting comfortably

[gohim]

Crawl under the car and check the bottom of the exhaust manifold for cracks.

Your 83 should have gotten the upgraded (reinforced with ribs cast on the bottom to help repvent cracks), but overheating the exhaust (excessive lean condition or too much timing advance) could have caused the exhaust to crack anyway.

The heat shield on the top of the exhaust manifold also has a tendency to crack and buzzz.

[ourkid]

Cool - I have the heatshield off now (it was cracked).

I'll have to get it over a pit.Looking at it now,if the bottom bolts are like the top ones,it just needs tightening up

Thanks.
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1983 924 N/A