What are these Spots on Engine Surface

[Bill W]

Tried tar remover, goof off and others to no avail. What are these spots and what can I use to remove them?

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[Desert Venom Racer]

Have you tried aluminum cleaner/polish?
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[Bill W]

No but I will now. Thanks.

[DirtyD]

The intake manifold is aluminum and what you are seeing there is minor pitting corrosion. I've cleaned/polished my IM ribs a couple times by wetsanding with a home-made sanding block. One rib at a time, stroking along the length with light pressure. First time: 1000, 1500, 2000. Next time only need 1500/2000 or just 2000. It can get messy. Make sure to tuck an absorbent towel between the IM & valve covers and tape off a towel between the snaking intake runners to catch excess water.

Can also do the same with the VIPER & SneakyPete logo on the magnesium valve covers, just be sure to mask off as much as possible as the logos are only slightly raised and you dont want to accidentally scuff the paint.

The Mag/Aluminum liquid/paste polish will shine them up but i dont think it'd be enough to get past the pitting defects. I personally wouldnt use it because there is also some pretty aggressive chemicals in there that i wouldnt want effecting the paints adhersion to the metal. Ive seen a lot of viper motors where the red podwercoat is bubbling & or missing in areas and the reality is that the thing is 20years old and goes through alot of heat cycles so you can only expect so much but i definitely would not want to do anything to expedite the aging/deterioration. If you do use it be quick and follow up with a towel and cleaner to remove all the residue.

Good Luck!

[daveg]

So I have sanded my valve covers in the past with great success but I was always wondering if you take one of those old type pen eraser's and rubbed it on top of the letters and Pete if it would clean them up nice... Haven't had the chance as of yet to try it..
Hmmmmm....

[Bill W]

The intake manifold is aluminum and what you are seeing there is minor pitting corrosion. I've cleaned/polished my IM ribs a couple times by wetsanding with a home-made sanding block. One rib at a time, stroking along the length with light pressure. First time: 1000, 1500, 2000. Next time only need 1500/2000 or just 2000. It can get messy. Make sure to tuck an absorbent towel between the IM & valve covers and tape off a towel between the snaking intake runners to catch excess water.

Can also do the same with the VIPER & SneakyPete logo on the magnesium valve covers, just be sure to mask off as much as possible as the logos are only slightly raised and you dont want to accidentally scuff the paint.

The Mag/Aluminum liquid/paste polish will shine them up but i dont think it'd be enough to get past the pitting defects. I personally wouldnt use it because there is also some pretty aggressive chemicals in there that i wouldnt want effecting the paints adhersion to the metal. Ive seen a lot of viper motors where the red podwercoat is bubbling & or missing in areas and the reality is that the thing is 20years old and goes through alot of heat cycles so you can only expect so much but i definitely would not want to do anything to expedite the aging/deterioration. If you do use it be quick and follow up with a towel and cleaner to remove all the residue.

Good Luck!

Sounds like a plan. Thank you!

[Desert Venom Racer]

Yes, I would only try the polish on the unpainted aluminum.

[99RT10]

So I have sanded my valve covers in the past with great success but I was always wondering if you take one of those old type pen eraser's and rubbed it on top of the letters and Pete if it would clean them up nice... Haven't had the chance as of yet to try it..
Hmmmmm....

Although the intake is aluminum, the valve covers are Magnesium.

[Bill Pemberton]

Lots of good info here , and it is very common , unfortunately. Trying to remember what we did to try and correct it , but never tried what Dirty D suggested and that sounds quite promising?!

[DirtyD]

Almost forgot to mention: It is totally worth touching up the Intake Manifold ribs every-other year or so. Fans love it when you pop the hood and that beast of a powerplant has a little bling.

However, the magnesium valve covers are a diff story. I remember when i took my valve covers off 8years ago to give them & the gasket a thorough cleaning. It took a lot of time taping off and delicately polishing(sanding) the raised lettering&logo. I patted myself on the back at how brilliant they looked and at how they were seemingly restored to new condition.

6 months later they were back to being that old dull grey finish.

Turns out Magnesium tarnishes very quickly. Tarnish is different from corrosion Its actually a natural process that protects the metal from further corrosion, Other metals like copper do a similar thing. So, my opinion is to leave them valve covers be unless you are preparing your car for some high end show.