Firewall Insulation Delete? (1 Viewer)

[SaturnAscends]

Earlier this year I ripped out my hood insulation since it was disintegrating and helping cause a burning smell as the material came in contact with hot engine surfaces. The smell improved after removal, but it seems to have returned lately. As @BillyGoatMTB pointed oit in another thread it may still be some of the insulation material falling out of the interior of the hood.

Lately however I've noticed the firewall insulation appears to made of the same material, and is also very brittle and falling apart: maybe another cause of the burning smell?

Furthermore, I (stupidly) sprayed some WD-40 on the firewall when installing a brake booster, thinking that would ease the process. Now I get a WD-40 smell while driving. I'm thinking some of it may have saturated into the insulation. Is there any reason not to tear it out as I did with the good insulation? I don't mind straight 6 noises in the cabin.

Also, any advice on getting red of the WD-40 smell? I sprayed a lot on between the brake booster/booster bracket and the firewall; is there any hope of getting rid of it?

Thanks

 

[bigredmachine]

Also, any advice on getting red of the WD-40 smell? I sprayed a lot on between the brake booster/booster bracket and the firewall; is there any hope of getting rid of it?

loads of degreaser. wash rinse repeat

 

[Kernal]

You'll end up destroying the insulation if you try to clean it. The odor should go away some with time.

 

[BILT4ME]

Earlier this year I ripped out my hood insulation since it was disintegrating and helping cause a burning smell as the material came in contact with hot engine surfaces. The smell improved after removal, but it seems to have returned lately. As @BillyGoatMTB pointed oit in another thread it may still be some of the insulation material falling out of the interior of the hood.

Lately however I've noticed the firewall insulation appears to made of the same material, and is also very brittle and falling apart: maybe another cause of the burning smell?

Furthermore, I (stupidly) sprayed some WD-40 on the firewall when installing a brake booster, thinking that would ease the process. Now I get a WD-40 smell while driving. I'm thinking some of it may have saturated into the insulation. Is there any reason not to tear it out as I did with the good insulation? I don't mind straight 6 noises in the cabin.

Also, any advice on getting red of the WD-40 smell? I sprayed a lot on between the brake booster/booster bracket and the firewall; is there any hope of getting rid of it?

Thanks

Wash with soap and water. Dawn dish soap.

Also, change your steering shaft seal on the firewall so you don't get the airflow from the engine bay to the cabin.

(Look up "hot feet" for the thread on the seal.)

 

[SaturnAscends]

You'll end up destroying the insulation if you try to clean it. The odor should go away some with time.

That’s why I was wondering if I couldn’t just take it out. The material crumbles when o touch it anyway, and I wasn’t sure if it’s just for noise insulation or it has some fire retardant properties. It can’t be insulating much in its current state.

 

[SaturnAscends]

Wash with soap and water. Dawn dish soap.

Also, change your steering shaft seal on the firewall so you don't get the airflow from the engine bay to the cabin.

(Look up "hot feet" for the thread on the seal.)

I haven’t had any issues with hot feet, and in fact I notice the smell more with the sunroof open than with all the windows closed.

Now that you mention it though I was able to see daylight through my footwell area when I was working under there through the hole below, can’t remember if that was the steering column though. Is there supposed to be a seal in this location?

 

[Kernal]

The insulation on the engine side of the firewall appears to be mostly for heat protection, like the hood liner but wthout the aluminum layer, but may absorb some engine noise. The main sound absorbing/blocking is likely done by the grey vinyl and rag cloth pad located on the inside of the firewall/cabin IMHO.

There are products that can be installed in place of the factory insulation but it would be a bear to get it in all the same locations as the original with the engine, heater pipes, AC pipes, etc on the firewall. That's a project to do when the engine is removed for something else.

 

[Njck22]

You need a new steering shaft seal.
And unless you're planning on replacing it, no good reason to pull all that insulation off. It may be crumbly but it's still fulfilling its role.

 

[BILT4ME]

I haven’t had any issues with hot feet, and in fact I notice the smell more with the sunroof open than with all the windows closed.

Now that you mention it though I was able to see daylight through my footwell area when I was working under there through the hole below, can’t remember if that was the steering column though. Is there supposed to be a seal in this location?

View attachment 3000980View attachment 3000982

Yes. That's your steering shaft and the seal is on the firewall on the INSIDE.

When you have the sunroof open, it draws air from the cabin and since that seal is shot, it draws air from the engine compartment and you will get the WD 40 smell.

That's why I suggested to replace it.

To find what I'm talking about, look up "hot feet". I didn't say you HAD hot feet.

Hot drivers feet? This may be your fix.

The most overlooked reason for hot drivers feet is the steering shaft seal. Chances are if your seal has never been replaced then its bad. The FSM replacement procedure is crazy. Here is another option that takes ~20 minute and a ~$10 part. The seal is located on the inside of the floor board...

forum.ih8mud.com

 

[SaturnAscends]

You need a new steering shaft seal.
And unless you're planning on replacing it, no good reason to pull all that insulation off. It may be crumbly but it's still fulfilling its role.

I was wondering if the material breaking off could be contributing to the burning plastic/rubber smell from the engine bay. There is a lot of built up oil residue and power steering fluid, but I don’t really notice that distinctive burning oil smell.

 

[SaturnAscends]

Yes. That's your steering shaft and the seal is on the firewall on the INSIDE.

When you have the sunroof open, it draws air from the cabin and since that seal is shot, it draws air from the engine compartment and you will get the WD 40 smell.

That's why I suggested to replace it.

To find what I'm talking about, look up "hot feet". I didn't say you HAD hot feet.

Hot drivers feet? This may be your fix.

The most overlooked reason for hot drivers feet is the steering shaft seal. Chances are if your seal has never been replaced then its bad. The FSM replacement procedure is crazy. Here is another option that takes ~20 minute and a ~$10 part. The seal is located on the inside of the floor board...

forum.ih8mud.com

Thanks, I read through it and it doesn’t seem too hard to take care of that, so I’ll order that part. I didn’t realise a little seal like that could play such a big role in preventing fumes from entering the cabin.

I was also wondering if it’d be worth removing the booster to clean that area up in between the firewall and BB.

 

[BILT4ME]

Thanks, I read through it and it doesn’t seem too hard to take care of that, so I’ll order that part. I didn’t realise a little seal like that could play such a big role in preventing fumes from entering the cabin.

I was also wondering if it’d be worth removing the booster to clean that area up in between the firewall and BB.

The booster has a paper seal between it and the firewall, so no issue there unless you've torn it apart.

 

[SaturnAscends]

The booster has a paper seal between it and the firewall, so no issue there unless you've torn it apart.

Thanks. Would you say it's safe to drive in the meantime? I also still get the burning rubber/plastic/grease smell discussed on the thread below, mostly when I open the windows or turn off the truck and stay in the cabin. Air from the vents seems to dissipate most of the smells. I did get it checked out for exhaust leaks and the muffler shop couldn't find any.

Burning rubber smell

I tracked my burnt rubber smell down. The hood is a skin that is glued to the frame of the hood. The old black material used to glue the hood and frame together becomes brittle. As you drive down the road it vibrates chunks of that rubber adhesive off which then roll down the hood insulator and...

forum.ih8mud.com

 

[SaturnAscends]

You need a new steering shaft seal.
And unless you're planning on replacing it, no good reason to pull all that insulation off. It may be crumbly but it's still fulfilling its role.

I only ask since I already pulled off the hood liner and it seemed to improve the burning rubber smell, if not totally get rid of it.

 

[SaturnAscends]

The insulation on the engine side of the firewall appears to be mostly for heat protection, like the hood liner but wthout the aluminum layer, but may absorb some engine noise. The main sound absorbing/blocking is likely done by the grey vinyl and rag cloth pad located on the inside of the firewall/cabin IMHO.

There are products that can be installed in place of the factory insulation but it would be a bear to get it in all the same locations as the original with the engine, heater pipes, AC pipes, etc on the firewall. That's a project to do when the engine is removed for something else.

I wouldn't try to replace it if I took it off. Just wondering if it'd be a safety issue not to have it there. I don't think the older 60s and 40s had anything there, but I could be wrong.

 

[Njck22]

Many people remove the firewall insulation, beyond just land cruiser people. It won’t hurt anything. But the firewall will likely be hotter and the interior noisier. So give it a shot cleaning it and see if it’s burning where the downpipe runs. It shouldn’t get hot enough to start burning under normal conditions (or else firewalls would regularly be flaking paint or rubber grommets burning) so I suspect your burning smell is something else, and not a little bit of leftover mineral oil on the insulation.

 

[BILT4ME]

Thanks. Would you say it's safe to drive in the meantime? I also still get the burning rubber/plastic/grease smell discussed on the thread below, mostly when I open the windows or turn off the truck and stay in the cabin. Air from the vents seems to dissipate most of the smells. I did get it checked out for exhaust leaks and the muffler shop couldn't find any.

Burning rubber smell

I tracked my burnt rubber smell down. The hood is a skin that is glued to the frame of the hood. The old black material used to glue the hood and frame together becomes brittle. As you drive down the road it vibrates chunks of that rubber adhesive off which then roll down the hood insulator and...

forum.ih8mud.com

I'm not there to physically see what is causing the burnt rubber smell.

Do you have a hose or a wire laying on the exhaust? Check your O2 sensors.

Odds are it's not the firewall insulation blanket, as that is there to shield from heat and to help prevent or control.....fires.

I would not randomly start ripping stuff off the truck just because I think it's something. These things are installed on your vehicle for a reason. I mean, you can do what you want, but the firewall insulation is brittle even when it's new. It's not designed to be installed and removed regularly or abraded by rubbing on it.

Personally I would leave it on.

Having driven lots of old cars without the insulation on the firewall, your feet can get hot in the summer and it can be kinda miserable to deal with. Especially if a female will be in the vehicle for any reason. It also makes the interior louder to hear all the engine and road noise.

 

[SaturnAscends]

I'm not there to physically see what is causing the burnt rubber smell.

Do you have a hose or a wire laying on the exhaust? Check your O2 sensors.

Odds are it's not the firewall insulation blanket, as that is there to shield from heat and to help prevent or control.....fires.

I would not randomly start ripping stuff off the truck just because I think it's something. These things are installed on your vehicle for a reason. I mean, you can do what you want, but the firewall insulation is brittle even when it's new. It's not designed to be installed and removed regularly or abraded by rubbing on it.

Personally I would leave it on.

Having driven lots of old cars without the insulation on the firewall, your feet can get hot in the summer and it can be kinda miserable to deal with. Especially if a female will be in the vehicle for any reason. It also makes the interior louder to hear all the engine and road noise.

I haven;'t noticed any brining rubber or wires. I guess it might just be all the oil and fluid residue burning off the engine, so I might try degreasing it by hand this weekend, maybe a pressure wash too if I can manage to tape off the dizzy alternator and connections.

I was also gonna drain and fill the trans, so maybe that'd help as well.