Best way to fix a deep scratch in engine bay?

eujiji · 06-30-2013, 09:18 AM

Hi guys, I've had my Z4MR for almost two years now, but have only recently come across this forum.

I took my car in for a wheel alignment, and it came back with a scratch along the lip of the front strut tower. It looks like it went through the primer (pic attached) and I'm concerned it could start rusting. Any advice on the best way to fix this to protect the metal from corrosion over the long term? Do they sell primer touch up so I can just paint over the scratch with a brush?

Gladius · 06-30-2013, 09:32 AM

Get a strut tower brace and you'll never see it again or worry about it

Why not just get some regular old primer and touch it up? I imagine you can find a can of automotive primer, and use that. And if you care about the aesthetics afterward, use the touch-up paint in your car's color. Is the strut top covered in a flimsy plastic hat with the BMW logo on it ? (If I recall my E46's was).

Nate4641 · 06-30-2013, 09:36 AM

Most BMW dealerships I've been to usually have a selection of touch up paint bottles around the parts department.

eujiji · 06-30-2013, 01:49 PM

Does BMW sell the flat black primer used for the inside panels? Is there a paint code for it, I haven't found one... I have a bottle of Black Sapphire Metallic touch up paint for the exterior, but it's not the same color even without the clear coat. I'm not too concerned with the aesthetics, but I'd rather match the color if I can.

There's no plastic tops for the strut towers, or at least my car doesn't have them.

tabpo · 07-05-2013, 08:12 PM

I can't even see a scratch

just get a few touch up pens and fix it. You'll probably want to get one in primer, one in color matched paint and one in clearcoat

Caddyshk · 07-05-2013, 08:15 PM

This is a joke thread right?

chickdr · 07-05-2013, 09:36 PM

You said you have the black sapphire touch up kit with separate clear coat? This should be exactly what the engine bay is painted- at least they are in my imola red - the inside of the trunk and engine bay are imola red, but without the clear coat. Even if it isn't perfect will you really notice such a small area on the strut tower? As others said- get the M strut tower covers used on the M3. That is what I did as it is a lot cleaner looking.

Part #31312229458

Here is a pic of what they look like:

StickMon · 07-06-2013, 12:30 AM

Not a joke thread anymore. I didn't know there were strut tower covers available!
Adding to my Tischer sale list.

XMetal · 07-06-2013, 12:42 AM

I'm assuming that the strut tower covers will only work if you don't have a strut brace?

StickMon · 07-06-2013, 12:56 AM

Would depend on the brand of brace.
You might be able to notch them out. They look like soft plastic that you could easily Exacto.
You would have to want to cover your brace. Some of them look pretty sharp as-is.

I don't have a brace, so I have big ugly holes.

XMetal · 07-06-2013, 01:34 AM

Just wanted to cover the hole on the strut. As you can see, the brace still exposes those holes. Tried some ebay covers, but those didn't fit well at all

Z4inAZ · 07-06-2013, 12:10 PM

Touch up paint is what you need. Contrary to popular belief, touch up paint is NOT designed to hide the scratch or the defect, touch up paint is designed to fill the scratch and provide anti-corrosion resistance to protect the bare steel.

All you need is touchup paint, nothing else...

Ebay covers or using a strut to cover it will not actually protect it or provide any anti-corrosion capabilities. All that will happen if you put a cap over it is water will drip past it so it wont get wet from above, but then condensation will come in from below and bead under the cap then drip onto the scratch.

You need touchup paint. A cap or cover is just a bandaid not a real fix. Touchup paint is all-in-one there is no primer to touch-up paint (though some come with a second stage clear which is strictly cosmetic)

eujiji · 07-06-2013, 03:59 PM

Thanks guys. I've ended up filling the chip with some regular touch up paint. I guess my original question was whether I would need to apply some primer instead of regular paint to fully protect against rust.

I am probably going to install a strut bar. Roads are pretty bad here, so I'm thinking it will help protect the strut towers over the long run.

06-30-2013, 09:18 AM	#1
eujiji New Member 2 Rep 17 Posts Drives: Z4 M Join Date: Jul 2011 Location: Cambridge, MA iTrader: (0)	Best way to fix a deep scratch in engine bay? Hi guys, I've had my Z4MR for almost two years now, but have only recently come across this forum. I took my car in for a wheel alignment, and it came back with a scratch along the lip of the front strut tower. It looks like it went through the primer (pic attached) and I'm concerned it could start rusting. Any advice on the best way to fix this to protect the metal from corrosion over the long term? Do they sell primer touch up so I can just paint over the scratch with a brush?
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06-30-2013, 09:32 AM	#2
Gladius Two Wheels or Four? 93 Rep 655 Posts Drives: '18 Perf Edition m240i Join Date: Mar 2007 Location: Colorado iTrader: (1)	Get a strut tower brace and you'll never see it again or worry about it Why not just get some regular old primer and touch it up? I imagine you can find a can of automotive primer, and use that. And if you care about the aesthetics afterward, use the touch-up paint in your car's color. Is the strut top covered in a flimsy plastic hat with the BMW logo on it ? (If I recall my E46's was). __________________ Current: '18 AW Performance Edition m240i Gone: '15 Mineral Grey m235i \|\| '07 Silver Grey M Coupe \|\| '11 Space Grey 328i XDrive \|\| '08 SparkG M3 \|\| '01 LSB M3 \|\| '01 TiAg 330ci
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06-30-2013, 09:36 AM	#3
Nate4641 Major 151 Rep 1,134 Posts Drives: '07 M Roadster Join Date: Dec 2011 Location: Warner Robins, GA iTrader: (0) Garage List 2007 BMW Z4 M Roadster [0.00]	Most BMW dealerships I've been to usually have a selection of touch up paint bottles around the parts department. __________________ My build/adventure thread
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06-30-2013, 01:49 PM	#4
eujiji New Member 2 Rep 17 Posts Drives: Z4 M Join Date: Jul 2011 Location: Cambridge, MA iTrader: (0)	Does BMW sell the flat black primer used for the inside panels? Is there a paint code for it, I haven't found one... I have a bottle of Black Sapphire Metallic touch up paint for the exterior, but it's not the same color even without the clear coat. I'm not too concerned with the aesthetics, but I'd rather match the color if I can. There's no plastic tops for the strut towers, or at least my car doesn't have them.
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07-05-2013, 08:12 PM	#5
tabpo Registered 0 Rep 4 Posts Drives: Z4 Join Date: Jul 2013 Location: NJ iTrader: (0)	I can't even see a scratch just get a few touch up pens and fix it. You'll probably want to get one in primer, one in color matched paint and one in clearcoat
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07-05-2013, 08:15 PM	#6
Caddyshk M = Midlife Crisis 65 Rep 2,006 Posts Drives: 2006 Z4MC Interlagos Join Date: May 2007 Location: Fort Erie, Ontario, Canada iTrader: (0)	This is a joke thread right? __________________ 2006 Z4MC - #LL93158 SS Race Cans, RE X Pipe, DKF Sec 1, Fabspeed Headers, OE STB, AS Shifter, Dave Z CDV, GC Coil Overs, Stoptech lines, Hawk DTC Pads, RE Clutch Stop, RE Transmission Mounts, Vibra-Technics Engine Mounts, Poly FCAB & RTAB, LeatherZ M Shift Boot, Tekarbon Rear Spoiler, CF Grills, Advan RS DGM
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07-05-2013, 09:36 PM	#7
chickdr Lieutenant Colonel 140 Rep 1,989 Posts Drives: 2006 M Roadster Join Date: May 2009 Location: Buford, GA iTrader: (0)	You said you have the black sapphire touch up kit with separate clear coat? This should be exactly what the engine bay is painted- at least they are in my imola red - the inside of the trunk and engine bay are imola red, but without the clear coat. Even if it isn't perfect will you really notice such a small area on the strut tower? As others said- get the M strut tower covers used on the M3. That is what I did as it is a lot cleaner looking. Part #31312229458 Here is a pic of what they look like: Attached Images
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07-06-2013, 12:30 AM	#8
StickMon My other car is on Mars 636 Rep 3,124 Posts Drives: 2006 MR Join Date: Feb 2011 Location: Lo-Cal iTrader: (1)	Not a joke thread anymore. I didn't know there were strut tower covers available! Adding to my Tischer sale list.
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07-06-2013, 12:42 AM	#9
XMetal Colonel 1128 Rep 2,863 Posts Drives: Anything Join Date: Apr 2010 Location: SoCal iTrader: (0) Garage List 2008 Z4M Coupe [10.00] 2018 Audi S3 [0.00] 2004 X5 [8.50]	I'm assuming that the strut tower covers will only work if you don't have a strut brace?
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07-06-2013, 12:56 AM	#10
StickMon My other car is on Mars 636 Rep 3,124 Posts Drives: 2006 MR Join Date: Feb 2011 Location: Lo-Cal iTrader: (1)	Would depend on the brand of brace. You might be able to notch them out. They look like soft plastic that you could easily Exacto. You would have to want to cover your brace. Some of them look pretty sharp as-is. I don't have a brace, so I have big ugly holes.
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07-06-2013, 01:34 AM	#11
XMetal Colonel 1128 Rep 2,863 Posts Drives: Anything Join Date: Apr 2010 Location: SoCal iTrader: (0) Garage List 2008 Z4M Coupe [10.00] 2018 Audi S3 [0.00] 2004 X5 [8.50]	Just wanted to cover the hole on the strut. As you can see, the brace still exposes those holes. Tried some ebay covers, but those didn't fit well at all Attached Images
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07-06-2013, 12:10 PM	#12
Z4inAZ Second Lieutenant 4 Rep 224 Posts Drives: Z4 2.5 03 Join Date: May 2013 Location: United States iTrader: (0)	Touch up paint is what you need. Contrary to popular belief, touch up paint is NOT designed to hide the scratch or the defect, touch up paint is designed to fill the scratch and provide anti-corrosion resistance to protect the bare steel. All you need is touchup paint, nothing else... Ebay covers or using a strut to cover it will not actually protect it or provide any anti-corrosion capabilities. All that will happen if you put a cap over it is water will drip past it so it wont get wet from above, but then condensation will come in from below and bead under the cap then drip onto the scratch. You need touchup paint. A cap or cover is just a bandaid not a real fix. Touchup paint is all-in-one there is no primer to touch-up paint (though some come with a second stage clear which is strictly cosmetic)
	Appreciate 0 Quote

07-06-2013, 03:59 PM	#13
eujiji New Member 2 Rep 17 Posts Drives: Z4 M Join Date: Jul 2011 Location: Cambridge, MA iTrader: (0)	Thanks guys. I've ended up filling the chip with some regular touch up paint. I guess my original question was whether I would need to apply some primer instead of regular paint to fully protect against rust. I am probably going to install a strut bar. Roads are pretty bad here, so I'm thinking it will help protect the strut towers over the long run.
	Appreciate 0 Quote