removing old hood insulation

Hi, my bonnet/hood insulation need replacing. Should I just brush off the old stuff (like recommended here). I was thinking of some kind of chemical cleaning, so that the new stuff is sticking directly to the hood, not the remaining layer of old insulation?

Thanks.

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nomis3613
Hi, my bonnet/hood insulation need replacing. Should I just brush off the old stuff (like recommended here). I was thinking of some kind of chemical cleaning, so that the new stuff is sticking directly to the hood, not the remaining layer of old insulation?

Thanks.

I thought all our cars have clips that hold the hood insulation in place, maybe cars in Australia had a different set-up.

If yours is glued on just scrape it off whats left, don't worry about the glue residue, clean it and glue right over it; contact cement is the easiest, just cover the motor.

Rick

Thanks Rick,
Yeah only the 325e cars in Aus have the clips. The new insulation is self-adhesive, so that makes it easy.

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nomis3613
Thanks Rick,
Yeah only the 325e cars in Aus have the clips. The new insulation is self-adhesive, so that makes it easy.

It's been my experience that the self adhesive stuff needs a bit of contact cement on the mating surface so it will really stick. Relying on just the self stickiness on the insulation is risky.

Cool, I'll add some cement. Better safe than sorry. B)

But realize with contact cement, you get one shot at it.

alan

Simon,

I accidentally found the fastest and most efficient way to remove the insulation(for those hoods that have it glued on)...use a pressure washer!

When my throttle body heater recently sprung a leak and disgorged have the coolant around the engine bay, I used my pressure washer to clean things up. Even with the widest spray broadcast I could use, I accidentally made a few ratty looking holes in the insulation. Given how easy it was to do this small bit of damage; I'm sure that the entire hood(bonnet) could be cleared of insulation in a matter of minutes with this method!

With a pressure washer you clear the insulation, not the glue...

Digging up an old thread but I did this job recently. Prepsolve is the stuff you want to get the gunk off. Put some on a rag and rub it in a bit. Leave it for a minute and then attack with razor blade scraper.

Cool, thanks for the tip, Tim.

If one does not care about the paint on their hood, is there any other damage or negative impact to not having insulation on the hood?

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1989 - E30 - M20 - Manual. Approximately 270,000 miles
2000 - E46 - M52TUB28 - Manual. Approximately 110,000 miles

Engine sound attenuation?

alan

It also protects the hood from becoming as hot as the exhaust manifold. Not good for the paint or the hand that rests on it

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Archeo-peteriX
It also protects the hood from becoming as hot as the exhaust manifold. Not good for the paint or the hand that rests on it

But my cats like it in in the winter.

When I come home from work the two cats are waiting at the house door anxious to be let out. Except if I look out the window two minutes later, there they are both keeping their feet warm sitting on the hood of my car. @#%& cats!!!

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Archeo-peteriX
It also protects the hood from becoming as hot as the exhaust manifold. Not good for the paint or the hand that rests on it

Doh. I had not really thought it would do that. My insulation is just to the point where touching it causes it to crumble into dust. Literally, dust. You couldn't remove a piece larger than the tip of a pen if you wanted to. This also means that my engine gets a slow and steady rain of this insulation during driving. I've contemplated more than once driving down to the car wash, removing the hood, and pressure washing off anything that will go. But, if burning my hand and my cats paws are the only thing at stake, perhaps I'll do it and keep an eye on it as the summer comes. If the temp gets too hot, I'll do something about it. It's no longer a daily driver, so I'm less concerned about silly things like 2nd degree burns

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1989 - E30 - M20 - Manual. Approximately 270,000 miles
2000 - E46 - M52TUB28 - Manual. Approximately 110,000 miles

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Earendil
so I'm less concerned about silly things like 2nd degree burns

Haha! Also, you'll be creating a great Cat Repellent...

Earendil, get rid of it, it doesn't get that hot, mine has been gone for years, and I must say the look of a nice clean painted hood underneath is quite pleasing.
Mine was removed so long ago that I can not remember how much difference it makes to the noise levels inside the car, but my car is very quiet inside.



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E30'S AREN'T BUILT, THEY'RE CAUGHT IN THE WILD!!!



When in doubt, use full throttle,
it may not improve the situation, but it will end the suspence.

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Flyboy
Earendil, get rid of it, it doesn't get that hot, mine has been gone for years, and I must say the look of a nice clean painted hood underneath is quite pleasing.
Mine was removed so long ago that I can not remember how much difference it makes to the noise levels inside the car, but my car is very quiet inside.

I may just do it. I won't mind a little more noise. The car is going to be weekend fun and for track use. One of my favorite things about the E30 compared to the E46 (now that I have it) is that you CAN hear the engine. When I get tired of hearing an engine I can drive my daily driver.

A clean underside to my hood would go well with all the work I put into making the engine look good last spring

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1989 - E30 - M20 - Manual. Approximately 270,000 miles
2000 - E46 - M52TUB28 - Manual. Approximately 110,000 miles

That motor looks seriously good, nice job, well done.

----------------------------------------------------------------------------------------------------------------------------------
E30'S AREN'T BUILT, THEY'RE CAUGHT IN THE WILD!!!



When in doubt, use full throttle,
it may not improve the situation, but it will end the suspence.

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TimH
Digging up an old thread but I did this job recently. Prepsolve is the stuff you want to get the gunk off. Put some on a rag and rub it in a bit. Leave it for a minute and then attack with razor blade scraper.

Are you sure it's "prepsolve" (a general purpose solvent) and not "prepsol" (specifically for automotive, link)?

Thanks,
Simon