Engine deck lid coming loose on bumpy roads

[jwakil]

My engine deck lid keeps opening when I go on rough roads. I tried adjusting the spring loaded pin that engages the the locking mechanism in the car body, but I don't know whether to make it shorter or longer, or if the spring is weak or what. It closes fine and if I try to shake it or press on it holds fine, but somehow the vibrations from going over bumps make it let go. Has anyone had similar issues and know of what part I should adjust/replace?
PS. I have the stock 80s 930 whale tail deck lid.

[rwest]

I had the same issue many years ago, so my memory could be a bit foggy. I believe that the lid would come unlatched if the cable broke, so to increase the grab on the lid pin, you put more tension on the cable- might want to unbolt the pin from the lid during your adjustment tests just in case you adjust it too far and it won't release.

[ivanuf]

Subscribed, keep us posted. Same thing happens to one of my cars. I close it and pull on it and is shut close, but when you hit a bumpy road it will sometimes the lid opens up. It is very anoying is like playing jack in a box every time you take a drive.

[Liam O]

Same thing happens to me as well, I think only the weight of the tail holds it from going right up.

[ericbash]

I had the same problem and spent many hours trying to adjust the top pin and the bottom receiver. Eventually I replaced just the bottom receiver. Same problem. Replaced the top pin and problem solved. Never popped again.

Both top and bottom pieces came from an ebay seller in Germany, claimed to be a repro. The part number is 90151205200. About $135 including shipping. Got it in a week. Quality was just like oem as far as I can tell.

Lock Bonnet yellow Porsche 911 65-89 93051205200 90151205200 NEW | eBay

Lots of posts here about how to replace the bottom part of the latch. Do yourself a big favor, take off your deck lid grill while you are fitting and adjusting the latch and for the first few test drives. This way if the engine deck lid won't open you can reach in and get it open. Otherwise you have to remove the muffler to get access.

[911T70]

Same happens occasionally to my 1970 T. Hit a bump a certain way and it unlatches, pushed all the way up by the struts. I was told by a local expert that this is how the ducktail spoiler was discovered. Porsche had a 911 in a wind tunnel and they noticed the downforce at the rear increase. The decklid had accidentally come up! Don't know if it's true or an urban legend.

[sugarwood]

Originally Posted by sugarwood

Look down into the hole, and then behind it. When handle is pulled out, the little inside lip should be pulled to the left, out of the center, so the prong released. When you let it go, the inner lip should protrude into the circle a little bit, so it grabs the male prong to keep the lid closed. Push and pull on the lever under the hole (like revving with a throttle cable), and observe the inside latch, and you will see how it works.

The end of the latch wire may have slipped a few mm's under the adjustment screw behind the female latch. This slippage resulted in the deck lid staying open since the inner catching latch was now in default open position. If it's slipping open, that inside lip might need to be adjusted towards the middle more, since it's not catching. It's a simple 60 second adjustment to unscrew, and push the latch arm back a little bit on the wire, and re-tighten. You might need to use vice grips to keep the door sill release handle pulled out, but I can't remember.

How to realign sticking/stuck engine lid latch?

[RSBob]

Very important! when performing adjustments, first remove the rear grill just in case your adjustment is too much and it won't open using the door pull. doing this will allow you to reach inside and release the latch. When you are confident you have the adjustment right, then replace the grill.

[JSV798]

It is a good idea to remove the grille BEFORE you attempt adjustment. When adjusting bear in mind that the cable must be pre-tensioned. First make sure that the handle is fully screwed onto the cable at the door end. At the lock end loosen the cable clamp screw; the lock will then be open; it opens automatically if the cable breaks. Move the lever with the clamp screw to a point where you can see most of the "blade" and tighten the clamp screw. Test. If it fails to open you can reach in through the grille opening and release the lock lever by hand.

It is important to realize that the lock has two open positions: one when the cables has no tension and two when you pull on the handle. This clever design means that if the cable breaks the lock opens, otherwise as you have found there is a problem.

The front hood lock was the same on the early models but has been changed. Presumably it was thought not to be such a good idea to have the hood unlock at speed.
__________________

[sugarwood]

Good point on the release handle sometimes unscrewing itself. Over time, Each time you grab it, you sometimes undo it a half turn.

[jwakil]

I tried the cable wire adjustment posted by Sugarwood and it's working beautifully now. Took all of five minutes. The screw holding the cable seemed like it had loosened over time. As far as ensuring you don't lock yourself out, all I did was pull on the handle and make sure the sliding plate cleared the hole for the rod before I closed the lid. It's easy to have a friend pull and you look, or you can pull the handle and use a vice grip on the cable at the door to keep it in place while you look. No need to mess with trying to take the grill off (not a simple thing when you have the AC condensor attached).