Under airgrill rust

[240znz]

Pulling my Zed to bits and finding hidden places where the rust monster is hiding. Impossible to spot when I first looked at the car as you will read.

Took off the airgrill panel and found some surface rust in only two spots. While there are lavish amounts of Fisholine used, it appears that it is not enough....or is the rust caused by a PO additon.

Did the factory install some white (off white now) foam cushioning to the underside of the airgrill, directly in front of the drivers wiper pivot? (Sorry, but my digital camera is out again.*&^"£$^%!)

I have killed it but just wondering if this foam is standard.

BTW, I have cleaned all the fisholine off and wow....as good as new, I'll be re-applying that good old fish oil again...unless someone can suggest a better solution.

Cheers

[LanceM]

I have mine apart there currently and no foam, nothing but steel in the whole compartment besides the wiper motor.

My whole area there was a nightmare, found that the mice had been using it for a bathroom for the 15 years the car was stored!!! Pulled out 5 pounds of $hit and after hours of cleaning, scraping, sanding got the mess and rust cleaned up. I am using a rust converter made by Permatex, Don't know if it is available in NZ but in my limited testing seems to work well at stoping rust.

[Z Kid]

If you are talking about the panel just in front of the windscreen, mine was mounted with foam, and had two large areas of rust exactly where the foamy stuff was. I think that might have been one of those good idea (at the time) bad idea many years later things.

[mdbrandy]

The cowl cover on mine has two rectangular pieces of white foam underneath. Don't know if I'll replace them or not once I refinish the panel and POR-15 that underside...

[EScanlon]

When Nissan was first making the Z, the cowl panel was fitted to the car with a pair of foam padding insulators to avoid the high speed vibration rattle that would / could rattle the cowl bad enough to rattle against the sub metal.

Although at the time and for the first few years, the foam padding was water repellant enough to avoid getting filled up with water, over time the foam tends to break down and what was once CLOSED cell foam becomes somewhat OPEN Celled. For the most part, OPEN cell is another word for SPONGE. Closed cell foam has thicker walls between the bubbles and as a result don't completely compress unless CRUSHED. When they get crushed, as in the case of long term pressure and vibration, they will absorb water to a small degree.

Add to this mix the fact that the galvanizing done on the sheet metal of the Z is not the thickest nor top coated afterwards and you have a perfect scenario for later rust problems.

If you can access a different cowl in better condition, then go for it. If you haven't a choice, you can still repair the panel.

Personally, I would recommend the POR and Power Mesh route. It's quick, will protect the rest of the metal, provide a good enough backing for most bodywork, and a breeze compared to brazing or welding a patch in. While you're at it, clean out the whole cowl area, POR it and check both drains and the vent hole.

Enrique