Engine Questions regarding a 93 Cobra Vacuum Leak/Intake Manifold

Baron164

Member
Jul 16, 2014
36
5
18
Upstate NY
I have a 93 Cobra and I've been trying to sort out what I believe is a vacuum leak. The car has been idling very rough and always sounds/feels like it is about to stall. I've been poking around and after doing the carb spray test I believe I found the issue. It looks like the PCV hose running from the lower intake manifold to the upper intake manifold came loose. My guess is that the hose clamp rusted through and fell off. If I'm reading the manual right, this hose for the venting crankcase vapors back into the intake. I was able to pull the hose up and take a picture of it. However, between the AC line/manifold and a strut tower brace I'm unable to get my hand back there to re-attach it.
IMG_20200525_131031.jpg

The only thing I can think of is to remove the upper intake manifold so I can re-attach the hoses. At the very least I think if I unbolt it, maybe I can move the intake to make room for my giant hands. But I'm fairly confident I'll need to replace the upper intake manifold gasket seeing as I don't think it's been taken apart since it came out of the factory. I'm also of the mind that if I'm taking the intake manifold off I might as well replace all of the PCV hosing behind it since it's all 27 years old.

So at this point I'm wondering what my best course of action is. Should I unbolt the upper intake and try to move it around enough to re-attach the existing hoses and install a new gasket? Or should I just remove the upper intake entirely, replace all of the hoses and the gasket and put it back together?

IMG_20200525_163910.jpg IMG_20200525_163554.jpg

Also, the strut tower brace was put in by a previous owner, and I'm not against taking it out. I think I can get the intake manifold out with it still in there but it's certainly a tight fit.
 
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91GTstroked

Active Member
Jun 14, 2007
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Yup, do exactly what is mentioned above. My 90 has a strut tower brace. I've kept it off for the last few weeks while I iron a few things out.

I'm actually doing this same thing today, and also replacing my upper intake vacuum hose. I replaced it not long ago, and come to realize it might be collapsing under vacuum.
 

Baron164

Member
Jul 16, 2014
36
5
18
Upstate NY
Thanks, I'll pull it completely apart. Quick question, since this is my first time pulling apart an intake manifold. How concerned should I be with dirt/pieces of gasket etc falling into the intake ports? Once I get it apart I'm assuming the old gasket is going to fall apart and I'll need to scrap and clean the old one off. Will vacuuming out the ports with the shop vac be sufficient or should I take more precautions?
 

91GTstroked

Active Member
Jun 14, 2007
227
64
38
Thanks, I'll pull it completely apart. Quick question, since this is my first time pulling apart an intake manifold. How concerned should I be with dirt/pieces of gasket etc falling into the intake ports? Once I get it apart I'm assuming the old gasket is going to fall apart and I'll need to scrap and clean the old one off. Will vacuuming out the ports with the shop vac be sufficient or should I take more precautions?
I just took mine off today, without any gasket trouble. But mine has been off multiple times and not original.

I would suggest stuffing some clean rags in the lower intake ports while scraping off the old gasket. Be careful and don't scar the intake while scraping.
 
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90sickfox

I didn't really have an issue with the stink...
SN Certified Technician
Mar 2, 2015
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You can stuff plastic grocery bags in the ports to keep debris out. Carefully vacuum any loose bits.
 
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