How to remove sound absorber from the bonnet / hood of a Porsche 944


The benefits of removing and replacing the sound absorbing material from the hood is that it prevents the engine heat from damaging the exterior hood paintwork, it absorbs some of the noise from the engine and also stops the old material depositing itself all over engine bay.


This is one of those jobs that there's no easy or quick way of doing, it purely comes down to sweat and elbow grease. Saying that anyone can tackle it, you just need patience and determination. Allow about 8 hours to remove all the sound absorbing material.

You'll need the following:

Plastic edged scraper (I used a white body filler spatular)
A large plastic or disposable sheet - to cover the engine bay
Cellulose Paint Thinners (I used 4 bottles of this!)
White Spirit
A mini roller and tray (use the cotton roller, not the sponge type)
Something to scrape the gunk into - I used a dustpan
Some latex gloves to keep the gunk off your hands


(Amateur mechanic Job time : Approx 3 hours per side)

Firstly cover the entire engine bay with a sheet otherwise it'll be a nightmare to clean all the old gunk off afterwards. Now unlike mine yours might still have all, some or bits of the original sound absorbing material clinging to it, so remove as much of this as you can until you're left with about 1mm of the combined glue and foam layer.

Now the fun begins. You need to soften up the dried glue and foam layer by rollering on the cellulose thinners in 30cm sections several times over and then quickly scraping this off with the plastic scraper until you are left with just the glue. Repeat as necessary. If you look at the image below the right hand section is after the cellulose thinners has been used and the left hand section is still to do.

Now, once you're left with just the glue on both sections we switch to the white spirit and use the same method of rollering it on. You can afford to do larger sections with the white spirit as it doesn't evaporate as quickly as the cellulose thinners. The picture below shows the glue completely removed from the left panel using the the white spirit.

And now the finished article....

Now, see my post on how to install new sound absorbing material here