Best way to seal rear hatch vents?

[bavarian06]

I have a 1970 240z with the rear hatch vents. I personally think these vents were the dumbest things ever and I want to get it sealed up ASAP (water seepage and major fumes). Without completely fiberglass the vents shut, has anyone stuck something from the inside to seal it up? I was thinking of sticking a layer of neoprene to fill up the gap behind the vent and then secure it with waterproof tape.

Thanks in advance.

[ajmcforester]

How about using a series two hatch, they don't have the vents, and you don't need to modify the original. If you are going to get rid of the vents you need to get rid of them completely.

Putting something in to fill them up is asking for rust, and fiberglass would not be a good idea. If you plan to use the original hatch you need to weld them out, and it migh be easier to use a different hatch without the vents.

. . .I want to get it sealed up ASAP (water seepage and major fumes). . . .

The statement about major fumes has me concerned, yes you can get some from the vents, but not enough to call major. If that is your main reason fumes your going after the wrong thing. Let me explain how the fume problem happens with Z cars. The air flows over the top of the car and down the hatch and keeps this slope past the hatch well that creates a vacuum behind the car and we dump our exhaust in that vacuum wich pulls it under the car. So the problem is under the car. You have two problems one is your is a series 1 and the second is you have worn seals that kept most of the exhaust out. The series 2 they did a lot of work and added weight to help seal up the rear half of the car

The best thing you can do is use seam sealer and reseal the old seams in the back half of the car. Next replace the worn seals in the cab. Look at all drain seals, take the plastic covers off and check all the hoses for the covers that seal the holes including around the filler neck and rear lights (big area to have leaks) you might want to just replace these seals. If the hoses are old you might want to replace or use some silicon to help seal. You can use silicon on all the seals if you like but it might not be necessary. The other thing to do is extend the tail pipe to just past the bumper this seams to help a lot of people.

[d240zx2]

^^Ditto.

The addition of a rear spoiler and front airdam helped my fume issue. I also replaced the taillight seals... no more fumes.

[george71z]

I had similar problems on my '71 (2/71 build date). I removed the plenums and tubes, and used some black, closed-cell foam cut to fit the openings. Sealed them and secured them with clear RTV, level with the body, and put my grills back on. Also used some electrical connector dust caps to close the holes on the inside of the hatch at the bottom. Have had no problems with leaks or fumes. However, I found that the best cure for exhaust fume elimination is new T/L gaskets, agreeing with d240zx2.

[bavarian06]

I had similar problems on my '71 (2/71 build date). I removed the plenums and tubes, and used some black, closed-cell foam cut to fit the openings. Sealed them and secured them with clear RTV, level with the body, and put my grills back on. Also used some electrical connector dust caps to close the holes on the inside of the hatch at the bottom. Have had no problems with leaks or fumes. However, I found that the best cure for exhaust fume elimination is new T/L gaskets, agreeing with d240zx2.

it has been an exhausting 4days. i spent the entire long weekend stripping down the car down, removing parts so i can what needed to be replaced.

i took off my tail lights and the gaskets are solid. there are no cracks, tears, or brittle from age. i was really hoping that was the culprit. i can replace them but that would be a waste of money (i'm thinking the PO replaced them since there was silicone holding the gasket to the car).

i sealed the vents with foam/rubber and waterproof tape (what i use when i need a quick fix for my surfboard). its been raining here so i intentially left the car out in the rain and so far it works. only thing i would do differently next time is treat the inside of the hatch with some anti-rust coating and then tape it up.

on a side note:

does anyone know where i can purchase a new inner hatch lining? i contacted MSA and the aftermarket version of the rear hatch weather stripping isnt available. i noticed i am able to slip a credit card between the gap of the weatherstrip and the rear hatch. i believe this is the main reason why i have fumes leaking in. i stuck door weather stripping (like the kind you can get at home depot) on the existing one on the car and that closed out the gap. the unfortunate part is it doesnt look original and now its harder to close the hatch since there is too much padding.

thanks for all the help; members contributions and the information on the forum really helps with my restoration process.

[bavarian06]

How about using a series two hatch, they don't have the vents, and you don't need to modify the original. If you are going to get rid of the vents you need to get rid of them completely.

Putting something in to fill them up is asking for rust, and fiberglass would not be a good idea. If you plan to use the original hatch you need to weld them out, and it migh be easier to use a different hatch without the vents.

The statement about major fumes has me concerned, yes you can get some from the vents, but not enough to call major. If that is your main reason fumes your going after the wrong thing. Let me explain how the fume problem happens with Z cars. The air flows over the top of the car and down the hatch and keeps this slope past the hatch well that creates a vacuum behind the car and we dump our exhaust in that vacuum wich pulls it under the car. So the problem is under the car. You have two problems one is your is a series 1 and the second is you have worn seals that kept most of the exhaust out. The series 2 they did a lot of work and added weight to help seal up the rear half of the car

The best thing you can do is use seam sealer and reseal the old seams in the back half of the car. Next replace the worn seals in the cab. Look at all drain seals, take the plastic covers off and check all the hoses for the covers that seal the holes including around the filler neck and rear lights (big area to have leaks) you might want to just replace these seals. If the hoses are old you might want to replace or use some silicon to help seal. You can use silicon on all the seals if you like but it might not be necessary. The other thing to do is extend the tail pipe to just past the bumper this seams to help a lot of people.

thx, my next step is to slip an extension tip that bends down onto the muffler. surprisingly my car still has the original exhaust system (interesting factoid, there is a Z emblem stamped onto the pipe leading down from the header). normally the first thing i do is replace the exhaust but im going to hang onto the original one unless someone tells me for sure a new one would prevent the fumes from smelling so bad.

[gorillaFart]

I was thinking about welding in a patch but leaving the grille vents as remnants that its a series1

Or for sake of saving time and labor, just finding a series 2 hatch without the vents all together since my rear hatch appears to have a giant patch of bondo that is extra thick anyways =( looks like its been there since the early 90s.

[Z train]

How about foam in a can form Ace?And after you seal up the vents be ready to still have a fume issue.

[grantf]

Carpenter in a can has no business in a Z (any car for that matter).

[Z train]

Carpenter in a can has no business in a Z (any car for that matter).

Foam in a can is NOT "Carpenter in a can".

[Mikes Z car]

This may be one of those hair brained ideas I can come up with (my wife would agree that I can do that) but I have wondered about the idea of taping streamers all over the back of an early z including some with a different color taped to perhaps a wire wrapped around the end of the tailpipe and then drive at various speeds while another car paces it with a video camera to get an idea of where the exhaust wants to go.

Mike

[EScanlon]

But "Foam in a can" IS future RUST from the inside.

All that foam will do nothing but trap the moisture on an already non rust-protected surface (per the original PO's post, #5).

Treat the inner surface with a good rust preventative or at least a good coating of paint and maybe foam in a can won't be trouble down the road. But anywhere where you can expect moisture from condensation, that foam in a can is bad news.

2¢

E