Does this seem like a headgasket leak?

4W4K3 · 09-04-2016, 02:15 PM

I've flushed/bled my coolant system about a month or so ago. Since then, I've noticed the coolant in the reservoir doesn't seem to stay at the level I fill it to. It isn't completely empty, and there are no leaks of any kind on the hoses or beneath the car, but over a few days it's noticeably lower. I just kept adding to it as needed. My dipstick doesn't look entirely "milkly" either, but has more on there than I'd typically expect to see on any other type of car (I initially chalked that up to condensation).

Another interesting symptom: I changed the oil at the same time I flushed the coolant. It took about 5.7qts. I checked the oil level the day after, all seemed fine. Then I check it again about two weeks later and it was well above the "high" mark. I thought maybe I over filled it so I used a hand pump to remove about 16.9 oz of oil (a water bottle's worth). After that, dipstick was back on the upper-mid area of normal. But that's quite a bit of extra oil if I did overfill it, and I would have expected see this right away on the dipstick.

Yesterday I went for a four mile drive around town. On my way back, the car started to overheat severely, as in the red emergency light came on. The car was sputtering as I pulled it off to the side of the road. I shut it off and found there was no fluid in the coolant reservoir. I filled it with distilled water but didn't have a 12mm wrench on me to open up the bleeder. I let it cool for 15 min then took off. It started to overheat once more about a half mile from my garage, I stopped for a bit to let it cool down, then made it home. The heat wasn't working at all during this overheating spell, probably because there wasn't enough fluid for the thermostat to open.

Today, I filled it again with distilled water and bled the system. It ran fine and stayed at a normal temperature. Still no leaks on the ground from what I filled it with yesterday. I checked the oil and it had quite a bit of milkyness on the dipstick, it's also now above the "high" mark.

All that being said, does this sound like a headgasket leak, or something else? I've never replaced one before so I hoping for some insight before going down that path. Thanks for reading!

mytrplseven · mytrplseven's Garage

sounds like water is settling into the bottom of the oil pan and displacing the oil, causing the dipstick readings to be in error. In removing a quart of oil after it seems to have not taken as much as it should have tells me there's more water than oil in the crank case. Pull the oil pan and drain all of it out to verify how much oil vs water comes out. I hope there was enough oil in there to keep the bearings lubricated. On the other subject, it's possible you have a head gasket leak. Is there any indication of oil in the coolant reservoir? If so, it may be the oil cooler (heat exchanger) seals. Good luck with this. Let us know what you find after draining the oil pan.

4W4K3 · 09-05-2016, 10:06 AM

So if there is water in the oil pan, is there any other way for it to get there aside from a head gasket leak? And no, the coolant fluid is perfectly clean of any oil right now. However, when I drained it after it not being flushed for 10 years (P.O. had it in storage), there was a small amount of oil that eventually formed a film in top of the coolant drain bucket. The coolant coming out of the drain plug still looked green, it was just dirty.

I think that's the part I don't really understand, if it was a head gasket leak I'd assume there to be oil in the coolant too instead of just coolant in the oil.

For reference, the oil cooler seals and water pump were replaced 10 years ago (the coolant that was previously in there was probably from this job). I'm also having issues with high oil pressure ever since I replaced the pressure sending unit, so maybe water leaking in has something to do with that too?

4W4K3 · 09-10-2016, 02:14 PM

I drained the oil and it was the dreaded "milkshake". Definitely enough oil still in the system, I don't seem to be loosing any of that. No oil in the coolant system. It seems to lose several ounces of coolant a day, no visible leaks of any kind on the ground or hoses. Dipstick oil levels were high again before draining

I also did a compression test before draining the oil. Removed fuel relay and performed it on a cold engine:

Cylinder 2: 172 psi
Cylinder 4: 166 psi
Cylinder 3: 164 psi
Cylinder 1: 176 psi

Also notable, I always have high oil pressure levels (5 bar). Car starts up between 2 and 3 bar, then within about three seconds steadily moves up to 5 and stays there.

My theory is now that the head gasket is fine, the oil cooler seals are leaking, and the OPRV may be faulty. What do you guys think?

DannoXYZ · 09-10-2016, 04:50 PM

Pull the plugs and see if they all look sooty. No super-clean ones would confirm headgasket is OK

Then yeah, it sounds like oil-cooler housing seal. There's a couple of smaller seals around the inlet & outlet ports that may leak.

4W4K3 · 09-10-2016, 05:50 PM

Sorry, forget to mention plugs. I changed them about 100 miles ago, but the previous plugs looked about the same.

campbelljj · campbelljj's Garage

Oil cooler housing O rings and gasket.

4W4K3 · 09-11-2016, 12:38 PM

Ok, thanks. I'll order the rebuild kit for the oil cooler.

As for the OPRV, is there a way to check to see if it's functioning properly? I'd hate to get this all reassembled and then have to remove it again. I have the early 3 piece model and I see the updated OPRV is ridiculously expensive...

kevin3681 · 09-20-2016, 03:20 PM

I just experienced the same symptoms that you just described. I found that my head gasket didn't blow, but didn't seal properly on cylinder number 3. Coolant was getting into the combustion chamber, turning into steam and pressurizing the cooling system. Then the engine would overheat because the steam was displacing the coolant and pushing more coolant into cylinder number 2 now. So it was definitely the head gasket. I just pulled the head off.