Intake manifold gasket leaks...even after i replace it..
09-12-10, 10:32 PM
#1
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Intake manifold gasket leaks...even after i replace it..
I have a intake manifold gasket leak.. ive replaced it 5 times...still leaks...i have the holley setup...its at the top in the middle of the manifold...around the water ports...should i be using the o-rings with the holley carb setup...? please help?
09-12-10, 11:10 PM
#2
Is this a Vacuum intake leak or Water leak?
The O-Rings are what seal the water in. If you've got the RB Holley intake you should get the 20mm freeze plugs, and install in the water ports of the engine housing.
Do a search. I'm pretty sure they are 20mm plugs. Use Indian Shellac or Permatex #2 to seal the plugs in.
http://www.pineappleracing.com/rotor...ssageplug.aspx
STILL use the O-rings. Your Intake gasket set should include the O-Rings.
Make sure the intake is surfaced flat and you should be good to go.
The O-Rings are what seal the water in. If you've got the RB Holley intake you should get the 20mm freeze plugs, and install in the water ports of the engine housing.
Do a search. I'm pretty sure they are 20mm plugs. Use Indian Shellac or Permatex #2 to seal the plugs in.
http://www.pineappleracing.com/rotor...ssageplug.aspx
STILL use the O-rings. Your Intake gasket set should include the O-Rings.
Make sure the intake is surfaced flat and you should be good to go.
09-13-10, 02:21 AM
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its a vac leak ...i found it when i was washing my car at the car was i figured id wash the motor and engine bay(it was still running) sprayed the top of the motor it died...so when i got it started i took it home decided the only way to see if it was a vac leak was put a little water on top the intake manifold...it killed it again...so it a vac leak(i know it wasnt the best idea to find out that i had one)...(also has a high eek noise sometimes)i used the o-rings...with the new gasket...it almost seems like the o-rings push the manifold away from the motor causing it to leak...and the manifold is torqued down to spec...so idk whats up..
09-13-10, 12:20 PM
#6
I'd suspect that you used a nasty dull gasket scraper which left deep scratches in the aluminum. Or you used an air powered scuff pad which contoured the aluminum. Or maybe it's not your fault ie as the poster above me said perhaps the manifold is mildly warped so the middle at the intermediate plate is just slightly away from the engine, which will also cause the eek noise you described.
One of my Hitachi manifolds was slightly warped there and made a funny screaching noise which changed when I pushed and pulled on the gasket with a screwdriver tip. I added a small amount of RTV just around the primary ports and it fixed it. I may have the manifold surface flattened/trued/machined at some point.
One of my Hitachi manifolds was slightly warped there and made a funny screaching noise which changed when I pushed and pulled on the gasket with a screwdriver tip. I added a small amount of RTV just around the primary ports and it fixed it. I may have the manifold surface flattened/trued/machined at some point.
09-13-10, 12:37 PM
#7
Easy way to surface aluminum and some mildly warped steel... is to get some long board sand paper from the paint section of your autoparts store. about 180 grit or so. More coarse if it's heavily warped, finer to finish. Then go get yourself a granite stone about 1" thick cut to the length of the long board paper. It's usually very cheap, about $20, because you're getting a scrap piece and they just have to give it a quick few cuts.
Then sand that bugger down. 4-5 swipes one way, turn the manifold around, and go 4-5 swipes that way. Continue until flat.
It's some elbow grease, but you'll use it ALOT if you are a gearhead and it really saves on sending stuff out to be surfaced.
Then sand that bugger down. 4-5 swipes one way, turn the manifold around, and go 4-5 swipes that way. Continue until flat.
It's some elbow grease, but you'll use it ALOT if you are a gearhead and it really saves on sending stuff out to be surfaced.
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09-13-10, 01:24 PM
#8
I had access to a large belt sander and was able to do just that. I got a modded SA manifold from a forum member that had an NA FC flange welded to it. The guy said it was used to test fire 6 port engines on a stand without the need of EFI, so they could be sold more quickly as running engines. Cool idea.
When it arrived the FC flange was contoured heavily from some stupid ham fisted attempt to clean off gasket residue with an air powered scouring pad (like I mentioned earlier). It took a half hour of continuous sanding to reduce the thickness 4 or 5mm to bring the surface surounding the intermediate ports down to the same level as the damaged bridge separating front from rear runners. It only seemed like 1mm would have to be trimmed, but the warpage added up to a lot more.
How can anyone be that stupid? But you see it all the time on engines that were assembled at local rotary shops (Hayes and Mazdas & More). All gasket surfaces are damaged, especially the front cover and intake manifolds or anything else that's aluminum. But I've seen some pretty nasty contouring of the front plate (iron) where the front cover sits. It will take a lot of RTV and a good quality gasket to keep the oil in.
When it arrived the FC flange was contoured heavily from some stupid ham fisted attempt to clean off gasket residue with an air powered scouring pad (like I mentioned earlier). It took a half hour of continuous sanding to reduce the thickness 4 or 5mm to bring the surface surounding the intermediate ports down to the same level as the damaged bridge separating front from rear runners. It only seemed like 1mm would have to be trimmed, but the warpage added up to a lot more.
How can anyone be that stupid? But you see it all the time on engines that were assembled at local rotary shops (Hayes and Mazdas & More). All gasket surfaces are damaged, especially the front cover and intake manifolds or anything else that's aluminum. But I've seen some pretty nasty contouring of the front plate (iron) where the front cover sits. It will take a lot of RTV and a good quality gasket to keep the oil in.
09-13-10, 01:51 PM
#9
There's an awesome nylon wire wheel that goes in an 1/8" chuck and cleans very well without damaging the surface. I only use a certain kind of air scouring pad for steel surfaces, and nothing machined that uses gasket only.
I try to post a pic later. At work and harbor freight is blocked lol. An air pad can be used, hell I used one on my 12a when I put my modded SA intake on, but year of experiance with them allowed me to not dig with it. AND being aluminum housings, I made sure to use the least abbrasive one I could find. Coarse pads like you said are an easy way to ruin a perfectly good housing.
I try to post a pic later. At work and harbor freight is blocked lol. An air pad can be used, hell I used one on my 12a when I put my modded SA intake on, but year of experiance with them allowed me to not dig with it. AND being aluminum housings, I made sure to use the least abbrasive one I could find. Coarse pads like you said are an easy way to ruin a perfectly good housing.
09-13-10, 03:53 PM
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gosh you guys are a great source of info...i remember kinda scouring the block around the ports a little...i had a dull gasket scraper...i ordered a new gasket o-rings and those plugs for the water passages... usually takes a week to get things here which is a bummer...i wish i could get an intake gasket at the parts store...(hate having cars that u cant find anything for...I've got a flapper disc that is for a hand-grinder(320 grit)for a cleaning up gasket surfaces(on steel intakes, etc) would that work for aluminum? Ill use a straight edge when i get to take my intake off to see if its flat...should i coat the middle two ports with a thin layer of rtv silicon just in case?
09-13-10, 04:40 PM
#11
Anything made for steel will eat through aluminum. Another good trick is to take a razor blade, and hold it 100% perpendicular to the surface and run it back and forth. Scrapes the gasket but tends to leave the aluminum alone.
If you've got major imperfections now, you'll want to coat your new gasket with some CopperCoat.
If you've got major imperfections now, you'll want to coat your new gasket with some CopperCoat.
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