Rust on cams/top of heads

[phil a]

Strange….pulled off the passenger side cam cover and there’s rust on some of the caps, intake camshaft and a few spots of rust on the faces of the lobes on the IC. Didn’t expect to find anything like this. Car has only been sitting for ~1mo, had overheating issues prior to being taken apart.

Compression test, leakdown test were fine. Cooling system held pressure/didn’t leak. Only thing out of the ordinary - had otherwise been running and driving fine.

Has anyone else seen this before when taking off the covers? Wondering what it could be….

Phil

 

[phil a]

Well, that was quick. I just called Shaun at AED and talked for a while - he felt strongly that it was caused by E85…and not taking long enough drives to heat up the oil/evaporate the water from the ethanol. So, looks like the occasional longer drive is in my future. Heads up for anyone else who might come across this running ethanol!

Phil

 

[DSG2003Mach1]

good to know, guess it's good Ive stayed on pump gas because I dont usually end up going all that far

 

[CobraBob]

That's an interesting find. A good number of folks here run E85. Is this something that is generally well known?

 

[MG0h3]

Does this car not have a PCV system? Catch cans?

Pretty sure your car would have driveability issues if there was a water issue present that isn’t present in normal gas.

The not getting up to temp on short drives can def play into this E85 or not.


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[phil a]

Does this car not have a PCV system? Catch cans?

Pretty sure your car would have driveability issues if there was a water issue present that isn’t present in normal gas.

The not getting up to temp on short drives can def play into this E85 or not.


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Brought back stuff from chemistry as an undergrad lol. It’s because ethanol is hydrophilic while gasoline is hydrophobic. It’s why e85 separates out if you check ethanol content at the pump. It attracts water while gasoline doesn’t. The car has an evac system to the exhaust from the cam covers instead of typical PCV.

 

[Stangra]

Brought back stuff from chemistry as an undergrad lol. It’s because ethanol is hydrophilic while gasoline is hydrophobic. It’s why e85 separates out if you check ethanol content at the pump. It attracts water while gasoline doesn’t. The car has an evac system to the exhaust from the cam covers instead of typical PCV.

Sounds plausible as to the cause of corrosion but what was going on with the overheating issue?

 

[CobraBob]

Brought back stuff from chemistry as an undergrad lol. It’s because ethanol is hydrophilic while gasoline is hydrophobic. It’s why e85 separates out if you check ethanol content at the pump. It attracts water while gasoline doesn’t. The car has an evac system to the exhaust from the cam covers instead of typical PCV.

That is interesting, and something that I definitely did not know. Thanks!

 

[Stangra]

These days it's hard to find gasoline that doesn't have up to 10% ethanol in it. While some of us are aware of e85's affinity for water and the associated complications, fewer realize that even e10 can present some problems:

Can E10 Gas Couse Moisture In Your Engine? – McNally Institute

www.mcnallyinstitute.com

Also want to clarify a technicality here. While ethanol is hydrophilic it is more accurately defined as hygroscopic (as is brake fluid too):

Definitions of Hygroscopic, Hydrophilic and Hydrophobic

The term hygroscopic refers to the ability of a material to absorb humidity from the air. A hygroscope indicates changes in humidity. Hydrophilic refers to substances that absorb water. Hydrophobic materials hate water and repel it.

furtech.typepad.com

 

[MG0h3]

I’m aware that E85 is hydrophilic.

So is human decomposition fluid.

Is there water present in DCF just because.

NO!

I test my E85 regularly. I bet I could test the E85 that’s been in a gas can in my back yard for a year and find the same content of water as the 91.




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[Dave.O]

Why is there fuel in your oil/ lubrication system?
Enough to cause that…


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[Black02GT]

I'll go with yeah e85 absorbing water but when you think how much and how much fuel should getting by the ring in general. I have a set of stock cams just laying in a cardboard box in a storage unit (not exactly climate controlled dont why I keep em) and they don't look like that. You sure it's rust and not just burnt build up from being hot and over heating the lube? Also the caps are aluminum so they wouldn't "rust".

 

[phil a]

I’m aware that E85 is hydrophilic.

So is human decomposition fluid.

Is there water present in DCF just because.

NO!

I test my E85 regularly. I bet I could test the E85 that’s been in a gas can in my back yard for a year and find the same content of water as the 91.




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Sounds good. Test your gas.

I'll go with yeah e85 absorbing water but when you think how much and how much fuel should getting by the ring in general. I have a set of stock cams just laying in a cardboard box in a storage unit (not exactly climate controlled dont why I keep em) and they don't look like that. You sure it's rust and not just burnt build up from being hot and over heating the lube? Also the caps are aluminum so they wouldn't "rust".

Totally agree about the caps. Collecting there likely from the heads of the bolts. I bought the car three or so years ago, and it’d been on E for years before then. With a good compression and leakdown test I gotta assume it’s just from a small amount of blow by over years of exposure to ethanol.

Yes, good call on hygroscopic. Better descriptor than hydrophilic.

 

[c6zhombre]

I’ve not seen anything like that from E85 use.

Has the car used torco for the pump gas tune? Torco has been known to leave rusty looking deposits.….and the more wild the pump gas setup/tune, people will use insane amounts of it. Especially cars in 91 octane states trying to make chicken salad out of chicken poop

 

[01yellercobra]

That would have to be a lot of E85 getting passed the rings to leave deposits like that. Enough that I think you'd be questioning how well the engine is running.

What did you find from the overheating? I'm thinking more like you ended up with some water/coolant in your oil and that's what's there.

 

[Stangra]

That would have to be a lot of E85 getting passed the rings to leave deposits like that. Enough that I think you'd be questioning how well the engine is running.

What did you find from the overheating? I'm thinking more like you ended up with some water/coolant in your oil and that's what's there.

My first thought too, but Shaun at AED know his stuff when it comes to e85, so... maybe?
And I'm still interested in what the cause of the overheating issue was too.

 

[Black02GT]

Sounds good. Test your gas.



Totally agree about the caps. Collecting there likely from the heads of the bolts. I bought the car three or so years ago, and it’d been on E for years before then. With a good compression and leakdown test I gotta assume it’s just from a small amount of blow by over years of exposure to ethanol.

Yes, good call on hygroscopic. Better descriptor than hydrophilic.

I blown a few of these up all Teksid. AL on AL. Who built, decked it? Great engine but lil picky about you know being put together correctly.

 

[CobraBob]

Sounds good. Test your gas.



Totally agree about the caps. Collecting there likely from the heads of the bolts. I bought the car three or so years ago, and it’d been on E for years before then. With a good compression and leakdown test I gotta assume it’s just from a small amount of blow by over years of exposure to ethanol.

Yes, good call on hygroscopic. Better descriptor than hydrophilic.

I would love to see the results of that test.