Found vacuum leak
12-18-07, 07:06 PM
#1
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Found vacuum leak
Well it ended up being the intake manifold gasket after all. So I replaced it and its still steaming like a biotch, and yes I cleaned it really well. I was hoping with rotaries that you let the enging warm up the gasket and let it cool and that would stop the leak. Coolant is going into my intake runners I believe.
12-18-07, 07:15 PM
#2
I don't know if there was an original thread that I missed but...
There are two parts - the intake manifold gasket and the rubber o-rings which go around the coolant holes between the intake manifold and the engine.
Personally, I hate the rubber O-rings, so I replace them with 20mm Frost Plugs (you can get these from any place that rebuilds engines, or some parts stores can order them. I got a box of 10 for like $4). Those can be used to carefully plug the holes in the block, so that you only have to worry about the gasket and not the coolant. Plus it makes your gasket last longer.
If you want to use the stock o-rings, use high-temp silicon to hold them in place. If they were to get pinched on reassembly that would cause a leak.
Another thing that can cause a leak is old gasket material. The first time I removed my intake manifold my gasket was on there so tough that after I went over it with a wire wheel, it *looked* like metal. I actually reassembled my intake half a dozen times before I realized that parts of the mating area were flat and parts were raised. It took a lot of time, patience, "gasket remover" (a spray can of stuff that eats through gasket) and lots of wire wheel, but it all came off and then there were no leaks (vacuum or coolant).
Jon
There are two parts - the intake manifold gasket and the rubber o-rings which go around the coolant holes between the intake manifold and the engine.
Personally, I hate the rubber O-rings, so I replace them with 20mm Frost Plugs (you can get these from any place that rebuilds engines, or some parts stores can order them. I got a box of 10 for like $4). Those can be used to carefully plug the holes in the block, so that you only have to worry about the gasket and not the coolant. Plus it makes your gasket last longer.
If you want to use the stock o-rings, use high-temp silicon to hold them in place. If they were to get pinched on reassembly that would cause a leak.
Another thing that can cause a leak is old gasket material. The first time I removed my intake manifold my gasket was on there so tough that after I went over it with a wire wheel, it *looked* like metal. I actually reassembled my intake half a dozen times before I realized that parts of the mating area were flat and parts were raised. It took a lot of time, patience, "gasket remover" (a spray can of stuff that eats through gasket) and lots of wire wheel, but it all came off and then there were no leaks (vacuum or coolant).
Jon
12-18-07, 07:22 PM
#3
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I assume the steel is where the intake ports are going in? I couldn't tell if it was rubber or the steel, it was slightly raised but I couldn't remove it for anything. Really irritating but I really want this PITA to run. I'll try what you said. Thank you. I've taken the damn thing apart so many times the rat's nest doesn't confuse me.
12-23-07, 09:02 PM
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Alright I did the 20 mm freeze plugs, but I still had steam coming out. I am hoping its just what poured onto the exhaust. We will see in a few days. Thanks.
12-23-07, 10:03 PM
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Thats the hard part to figure out, since the fan is blowing. It seems to be above the exhaust manifold, from where I can't figure out. Could it be the Tstat isn't functioning and the pressure is building too much?
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12-24-07, 02:00 PM
#9
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The darkside is twisted.
The smell is a bit sweet, yet when it hit my tongue it was kinda bitter; probably death knocking on my door. :P
I really hope you are kidding about the vacuum leak. I haven't run it long enough to find out since I'm afraid of over heating the engine.
The smell is a bit sweet, yet when it hit my tongue it was kinda bitter; probably death knocking on my door. :P
I really hope you are kidding about the vacuum leak. I haven't run it long enough to find out since I'm afraid of over heating the engine.
12-24-07, 10:06 PM
#10
I made a pretty good post here about tracking down vac leaks:
https://www.rx7club.com/1st-generation-specific-1979-1985-18/nikki-idle-problems-714426/
So if you really want to troubleshoot your intake to its fullest extent, read that and run with it.
But yeah, as for overheating, start it, run it and WATCH the gauge. If it moves enough that the needle covers the C, turn it off and you'll have caught it before it heated up to do any damage. If it just covers the little degree sign before the C you're fine, that's proper running range.
Jon
Edit : I just realized that my gauge cluster might look different from yours.
Here's mine. Note the "C" and the degree sign I was talking about on the temp gauge.
https://www.rx7club.com/1st-generation-specific-1979-1985-18/nikki-idle-problems-714426/
So if you really want to troubleshoot your intake to its fullest extent, read that and run with it.
But yeah, as for overheating, start it, run it and WATCH the gauge. If it moves enough that the needle covers the C, turn it off and you'll have caught it before it heated up to do any damage. If it just covers the little degree sign before the C you're fine, that's proper running range.
Jon
Edit : I just realized that my gauge cluster might look different from yours.
Here's mine. Note the "C" and the degree sign I was talking about on the temp gauge.
Last edited by vipernicus42; 12-24-07 at 10:14 PM.
12-24-07, 10:45 PM
#11
Found a better pic
Here's where my temp gauge stays at operating temp. I took this partway through a 5hr drive to Toronto I believe, when I clicked over a cool-looking number on the highway I pulled off, topped up the gas and snapped a pic.
Remember: Happiness is a full tank!
Jon
Remember: Happiness is a full tank!
Jon
12-25-07, 05:05 PM
#12
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Well I went back out there and started it up. It smelled of coolant, but it wasn't steaming. Rather it also smelled like burning rubber. (?)
Must be the new gasket. Anyways, thanks for the write up, I'll have to try that out.
Must be the new gasket. Anyways, thanks for the write up, I'll have to try that out.
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