[squilliam]

I'm trying to source down what my issue is and what the solutions would be.

Background:
Sky Redline with 73K miles. Water pump failed a few months ago. I replaced the water pump and a bunch of the coolant hoses with new ones.

Issues:

• I get a slight coolant smell when the engine is up to temp and stopped at a light.
• There is an ever so small oil leak coming down the seam between the engine and the transmission.
• There looks like there may be a very small amount of oil in the coolant reservoir.

What I've tried:
- Found I hadn't tightened two hoses down as much as I should. Tightened them, cleaned up any residue, and yet I still get the coolant smell.

My thoughts so far:
I originally thought it was some loose hose I couldn't find and a rear main seal leak.
Now I'm wondering if it could be a leaky oil cooler...

Thoughts and suggestions are most welcome!

 

[SaturnSkyRedline2015]

Did you pressure test the coolant system? Put it up and look for leaks.

 

[LAC Sky]

So it has been ok for the last few months of usage after your WP repair.
Something has changed recently. If the hose was loose for all that time
you would have the coolant smell much sooner than now.
There could be coolant on the exhaust maybe.
A leaking thermostat gasket?
By finding a small amount of oil in the coolant reservoir, have you had to add any coolant?
Finding oil in the coolant is troublesome. On the dip stick? Loss of oil, have you had to add
any lately? The seam between the engine & trans. Head gasket?
Top half of the motor or bottom half of the motor? Oil pan gasket? I thought you replaced the
main seal on the motor, or was that something on trans you did I'm confused here.
Oil cooler is a new one to me. I was not aware we had one, unless this was an add on?
I have seen oil/trans coolers before similar to our IC on a smaller scale, but I'm not sure we have one.

LAC

 

[rjgramps]

Possible Oil In Coolant? That is not possible. It would be "Coolant In Oil" because the coolant operates at high pressure and the oil at no chamber pressure. When there is an internal coolant breach into the engine oil, a tan milkshake shows up on the dipstick. If your engine oil remains clean and normal looking, the two liquids are NOT mixing.

A coolant smell means it is leaking externally, most likely on something "HOT" that is evaporating it quickly creating the smell.

Your engine might also be leaking coolant into a combustion chamber and evaporated out the exhaust pipe. You can tell which cylinder is taking in coolant by comparing spark plugs. The clean one is taking on coolant. The most common cause for this is a head gasket failure that can be repaired. But sometimes a crack can occur in the head which would call for a replacement head.

I promote the BAR'S Stop Leak Pellets ( or similar dry product) as a first attack. It is cheap, effective, and long lasting. If the source of the cause does not worsen, the product will hold up until you flush out the coolant. Then simply repeat.

Treat it like a bad knee or hip. First get the injections to buy time. Then when all your those options are exhausted, get the surgery. In the case with your Sky, the easy solution may outlast the rest of the car. Keep in-mind that the end of your Sky is one significant accident away.

 

[JohnWR]

Possible Oil In Coolant? That is not possible. It would be "Coolant In Oil" because the coolant operates at high pressure and the oil at no chamber pressure. When there is an internal coolant breach into the engine oil, a tan milkshake shows up on the dipstick. If your engine oil remains clean and normal looking, the two liquids are NOT mixing.

The oil cooler (if fitted) exposes pressurized oil to the coolant.

@squilliam : The definitive test is to put UV dye into the coolant and (separately) into the oil, then use a UV light to trace the leaks.
There are different dyes for coolant and for oil-based fluids, and you can get them in different colors so you can tell which came from where.

 

[rjgramps]

The oil cooler (if fitted) exposes pressurized oil to the coolant.

But does the pressure created from the oil pump exceed the pressure created from the cooling system? Maybe the oil pressure is higher until the coolant heats up. Then the pressure is reversed.

 

[sahein]

Oil pressure is typically 25 to 65 psi depending on rpm where as coolant pressure is limited by the pressure cap at 15 psi. It is still possible that fluids can mix when there is no oil pressure when the engine is shut off but coolant is still hot. But I would expect a cross mixing both ways.

 

[JohnWR]

But does the pressure created from the oil pump exceed the pressure created from the cooling system? Maybe the oil pressure is higher until the coolant heats up. Then the pressure is reversed.

You can't really rule out anything since, as @sahein said, the pressures are all over the place as the engine heats, cools, and runs. During cool-down the coolant system can even be at low vacuum as it pulls coolant back into the engine from the expansion tank.

You can suppose, guess, and assume as much as you want, but the only way to really know about a situation like this is to use the dye.

 

[sahein]

The first thing I would do is see if the oil looked milky.

 

[squilliam]

So it has been ok for the last few months of usage after your WP repair.
Something has changed recently. If the hose was loose for all that time
you would have the coolant smell much sooner than now.
There could be coolant on the exhaust maybe.
A leaking thermostat gasket?
By finding a small amount of oil in the coolant reservoir, have you had to add any coolant?
Finding oil in the coolant is troublesome. On the dip stick? Loss of oil, have you had to add
any lately? The seam between the engine & trans. Head gasket?
Top half of the motor or bottom half of the motor? Oil pan gasket? I thought you replaced the
main seal on the motor, or was that something on trans you did I'm confused here.
Oil cooler is a new one to me. I was not aware we had one, unless this was an add on?
I have seen oil/trans coolers before similar to our IC on a smaller scale, but I'm not sure we have one.

LAC

The coolant smell has been present the whole time.
It's just been me puttering around looking for the source.
Both semi "loose" hoses were the same one (the block to radiator return hose).
I was stupidly too cautious with tightening it (was worried about the clamp eating into the expensive new hose).

No coolant on the oil dipstick (I think).

For the first time in 2-3 months I had to add a tiny bit of coolant, bringing it from a 1/4 inch below the reservoir median fill point.

The thermostat and gasket are brand new (done same time as the WP).

I replaced the transmission filter, gasket, and fluid. The transmission is doing great!

The reason I think the RMS needs to be replaced is the same as it was 2 or so months ago (I just haven't done anything about it).

Here's an example of our oil cooler:

https://www.autozone.com/external-engine/engine-oil-cooler/dorman-engine-oil-cooler-918-438/1055403_0_0

 

[squilliam]

Did you pressure test the coolant system? Put it up and look for leaks.

I do not know how to pressure test the system.

Possible Oil In Coolant? That is not possible. It would be "Coolant In Oil" because the coolant operates at high pressure and the oil at no chamber pressure. When there is an internal coolant breach into the engine oil, a tan milkshake shows up on the dipstick. If your engine oil remains clean and normal looking, the two liquids are NOT mixing.

A coolant smell means it is leaking externally, most likely on something "HOT" that is evaporating it quickly creating the smell.

Your engine might also be leaking coolant into a combustion chamber and evaporated out the exhaust pipe. You can tell which cylinder is taking in coolant by comparing spark plugs. The clean one is taking on coolant. The most common cause for this is a head gasket failure that can be repaired. But sometimes a crack can occur in the head which would call for a replacement head.

I promote the BAR'S Stop Leak Pellets ( or similar dry product) as a first attack. It is cheap, effective, and long lasting. If the source of the cause does not worsen, the product will hold up until you flush out the coolant. Then simply repeat.

Treat it like a bad knee or hip. First get the injections to buy time. Then when all your those options are exhausted, get the surgery. In the case with your Sky, the easy solution may outlast the rest of the car. Keep in-mind that the end of your Sky is one significant accident away.

You are one kick ass dude. The oil looks clean, smells clean, etc. Just checked. When I say oil in coolant, I mean there is no discoloration, just those weird slick lines you get in water or what have you with a tiny bit of oil.

I should note: I'm a dumbass and used tap water to cut my coolant. We have really hard water in Arizona. I recently heard you're supposed to use distilled water. That might be a thing?

See this pic:

I will check the spark plugs tonight. That will be one easy test I know how to do right now.

I put in liquid stop leak (I think it was CRC) last weekend. No changes have occurred.

 

[squilliam]

The oil cooler (if fitted) exposes pressurized oil to the coolant.

@squilliam : The definitive test is to put UV dye into the coolant and (separately) into the oil, then use a UV light to trace the leaks.
There are different dyes for coolant and for oil-based fluids, and you can get them in different colors so you can tell which came from where.

That sounds expensive. I'm going to try @rjgramps things first, since those sound cheap.

Oil pressure is typically 25 to 65 psi depending on rpm where as coolant pressure is limited by the pressure cap at 15 psi. It is still possible that fluids can mix when there is no oil pressure when the engine is shut off but coolant is still hot. But I would expect a cross mixing both ways.

Super interesting! Are you saying they would mix if there is an issue with the oil cooler?

 

[sahein]

Blown head gasket would be the most common problem. From observing the above photo I would ignore that little bit of contamination in the coolant for a little while. But would keep observing the engine oil for coolant intrusion. A little oil in the coolant system is not a severe problem like catastrophic coolant in the engine oil.

 

[squilliam]

Just did the plug check. It looks like 1 of them is much dirtier than the others (the one I'm calling #3). Note: I put in new plugs in 4 months ago.

Starting with the one closest to the firewall, and moving towards the front bumper.

1

2

3

4

 

[sahein]

Depending on how much driving you did in 4 months. If a lot, I would think that the plugs are too white and think they are too hot a value or running too lean. What plugs are you using? 2.0 or 2.4? Mods?

 

[squilliam]

Depending on how much driving you did in 4 months. If a lot, I would think that the plugs are too white and think they are too hot a value or running too lean. What plugs are you using?

That is after about 1,200 miles.

They are NGK Iridium plugs

 

[sahein]

That is after about 1,200 miles.

They are NGK Iridium plugs

LNF, LE5, Modified? Be more specific. There are probably hundreds of different NGK plugs. Oem plugs are AC Delco 41-103 LE5. ACDelco 41-108 LNF.

 

[squilliam]

LNF, LE5, Modified? Be more specific. There are probably hundreds of different NGK plugs. Oem plugs are AC Delco 41-103 LE5. ACDelco 41-108 LNF.

LNF engine.
NGK IX Iridium 4344

https://www.autozone.com/external-engine/spark-plug/ngk-ix-iridium-spark-plug-4344/940700_0_0

 

[sahein]

Use the 41-108 I would use a camera in the plug holes to look for damage. The above 4344 plugs are listed the same for LE5 and LNF. Too hot for LNF.

. Yours:.

 

[squilliam]

Use the 41-108 I would use a camera in the plug holes to look for damage. The above 4344 plugs are listed the same for LE5 and LNF. Too hot for LNF. View attachment 114486 . Yours:. View attachment 114487

You think there is damage inside the cylinder head??

I did the CRC GDI treatment about 2 months ago, which may explain debris.