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Coolant in spark plug all 4 cylinders


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Hey everyone I have a 2005 subaru forester with 188000 miles on it and it's an auto. I was tracing a misfire on cylinder 4 which I noticed was break in the plug wire. So I decided to replace the wires with NGKs. But when I pulled each wire they were covered in coolant and oil. I was planning on replacing the valve cover gaskets and spark plug seals anyway but I was wondering if anyone has seen coolant in the spark plug wells before. The car runs great and only loses a little coolant.

 

Thanks,

HAS

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You’re a real person and not an 11 year old making stuff up right?

 

Cracked head is the only possibility.

 

If these symptoms are accurately described my wild butt guess is this car saw a winter with less than necessary coolant concentration, froze internally, and cracked the heads.

 

And you it recently saw some major circumstance like You just bought it, it had major work, etc....

 

When did you buy this car?

Has it ever had major work?

Is there any chance the coolant concentration was wrong or never monitored?

 

There’s no way for coolant to otherwise get to all the spark plug tubes. And it would be impossible for both to do it, and at the exact same time.

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I hope I am not some 11 year old lol! I bought the car back in September the previous owner passed away and I bought the car from his daughter who said the car sat from April 2017 til I bought it in September before that she drove until she bought a new car. I have stacks of papers on the work done to the car I would have to look through but I know the radiator was replaced shortly before it sat as well as the entire steering system. The head gaskets leak but not too bad it burns and leaks about 2.5 quarts in 5000 miles. It runs great except when it rained and it would misfire. With new wires that doesn't seem to be an issue anymore. I also replaced the coolant back in October when I had to replace the oil cooler lines that were rusted. The control arms and axles were replaced a few months ago.

Edited by HASx11
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haha. The 11 year old joke had the most favorable outcome. Shoot.

 

Id test for cracked heads first.

 

Having never seen or heard of this before here’s my suggestion:

 

Remove the plugs and wires and then pressure test the cooling system and watch the spark plug tubes to see if they take in coolant.

 

Review the paperwork on the radiator.

 

Radiator replaced in April - which means something was leaking or overheating before that and they tried to replace the radiator to fix it. the radiator was replaced and then the car wasn’t driven again until sold. They ditched the car after the radiator didn’t fix it.

 

Anyway - at some point there was too much water in the system and it froze and cracked the heads. Which isn’t surprising someone got stuck or desperate and filled with water to get home or drive to work and left it without checking it. Then it froze. Or worse it was leaking coolant - as it currently is - and the previous owner let it get so low that it overheated significantly and blew the heads. This seems unlikely for a few reasons so I’m betting on freezing.

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The simple answer is that coolant leaked in from above. Radiator was replaced, possible that the old radiator split open and sprayed antifreeze everywhere under the hood.

 

No other way for there to be a noticeable amount of coolant in the plug tubes without there being huge amounts of it in the rest of the engine oil as well.

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Fairtax beat me to it. Old radiator, or possibly a hose, etc. let go, and there was residual coolant everywhere, that probably coated the underside of the hood and engine, and whatever didn't wash away is what you are finding. If it was an inline engine, might be a different story.

 

To be safe though, watch everything like a hawk for awhile. Everything from oil level, coolant level, engine temps, etc. and pay attention if it starts loosing power, making odd sounds, etc. and go from there?

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  • 2 weeks later...

So since cleaning it all up I haven't seen any more signs of coolant in the spark plug holes. The only issues now are if I turn my vents on outside air I get an overwhelming coolant smell that doesn't happen if I have it on recirculation. Also I have some check engine codes p0171, p0457, and p1443 these came up shortly after I replaced the plug wires. And every once in awhile I have to hold the gas pedal down to start the car after full up.

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Ther is a leak somewhere. Probably very small now, and it evaporates on the hot block, or exhaust. There are a bunch of coolant hoses that should be replaced if they are old, not just the 4 most people think of.

 

Running over normal temperature while low on coolant is very bad for headgaskets.

 

Check for air in the cooling system by squeezing the upper radiator hose. Listen for gurgles and the jiggle pin. Ideally there should be no air. A small amount that doesn't change might be ok. If the air increases, and the overflow keeps going down, you have to find the problem before it gets worse.

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Thanks bushwick for the video I'll take a look at my evap canister and go through my vaccum hoses for leaks.It does leak coolant out of the passenger head gasket right onto the exhaust. I check coolant level and all fluid level once a week or more depending on how often I drive the car. The forester is my back up car so it only is driven once or twice a week at the moment. It only drains the reservoir in about 5000 miles of driving I do check the actual radiator and hasn't been low yet.

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Have you checked compression on that side of the motor? You can also measure engine vacuum ( https://www.hemmings.com/magazine/hsx/2012/02/Testing-Engine-Vacuum/3709071.html ) with an inexpensive gauge. That can tell you if a HG is actually faulty as well.

 

Not sure what you've done/not done, but if it were me, I'd spray everything off with gentle setting garden hose water (minimize electronic connectors, or anywhere water really shouldn't be) like block, head, hoses, etc., let it dry fully, then idle it until full temp. If no coolant leaks, go for a 30 minute drive, stopping every 5-10 minutes (leave it running) roughly and quickly pop hood and look for signs of misting, spraying, etc. from a heater/coolant hose. Also look under front of car at same time to see if any misting, drips, etc. are showing. As others mentioned already, a pinhole, etc. might be opening under enough pressure, misting/spraying, then closing back up once pressure drops. They can be tricky to find, as the hole might be the size of a threading needle poke, and only under full pressure will it be enough to open it. Once it seals, it looks like it came from nowhere, or wherever the largest amount of spray landed. Then again, it could actually be a HG.

Edited by Bushwick
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