Changed oil, coolant in reservoir dropped?

Hi all,

This is my first post. This community has been amazing in saving me money on my truck with tips and great DIY guides on basic repairs/maintenance that I would have paid out the eyeballs for over the ownership of my truck (10 years). So thank you a ton.

I am posting because I am in need of some help/advice. Yesterday, I changed my oil with SuperTech High-Mileage Full Synthetic. No issues, no leaks, level looks good. However, I noticed the coolant in my reservoir dropped by a good 1.5-2 inches when I check this morning.

Important back story: Fall, 2017 had my coolant flushed and the shop failed to put my radiator cap on correctly and it popped off on the highway. Engine overheated, but eventually made it home after putting in distilled water and coolant. Later, started having rough start issues and cpu showed 2 cylinders misfires. Had milky oil in cap and some white smoke from time to time. Chalked it up to cracked head gasket. Used the blue devil pour-n-go, reset the cpu, and the issue has not popped up since, except every 3 weeks or so of hard driving, the coolant will decrease a little, but not drastically.

However, this morning after my fresh oil change, it dropped quite significantly in a small time window, which gives me pause. No signs of coolant anywhere on the engine or on the ground (and there never has been), so I'm thinking it is in my oil system. But I am surprised it dropped so much so quickly.

Is this to be expected? Could the fresh oil have somehow undone some of the blue devil fix? As I mentioned, the blue devil fix has actually been pretty effective, so I am pretty surprised at the new drop. Anyone have any ideas why, or what this means or implies?

2008 Tacoma 4.0 V6, 4x4 TRD.

Thanks!!

 

dunno.......weird......

 

You can use all the solutions and stop leaks you want, nothing will ever prevent a damaged head gasket from rearing it's ugly head or manifesting itself one way or another.

It is highly likely it is consuming coolant through the combustion chamber still in small amounts the 3 week time period is indicative of that.

The shop which did your coolant service is on the hook, and they should be, bring it back and inform them of the issue and let them track it so they can see it for themselves.

I'm sorry you are having this issue, but you should ultimately not be the one to pay for this, whatsoever.

 

OP, at first glance I was originally going to post something to ease you fear a bit by saying that Toy indicates flux between the full an low lines marked on the overflow tank is to be expected. Mine does it all the time and ranges from the full line to the bottom line and everything in between.

But the overheating is critical. I have personally had nothing but bad outcomes from overheated engines...usually the head gaskets or worse. Sorry but I think you have a major repair in your future.

 

Appreciate the replies. And I agree...I've been kinda putting my head in the sand hoping for the best after the Blue Devil fix, but I think a head-gasket repair is knocking at the door Only place I can think the coolant is going is into the oil. Gonna replace the water pump and radiator cap to OEM in the next few weeks to see if that helps any (probably due for it anyways at 161,000 miles).

For now, I guess I will add a little coolant and see how it acts over the next few weeks. All bc someone hastily put on my radiator cap poorly.

 

Have you looked for that missing coolant in the crankcase?

 

Back in the day when I drove my 92 Yota 22RE had my head gasket blow twice. The first time it went in the oil and was easy to see because of milky oil. Two years later it blew and went in the exhaust which you can tell from a white cloud of smoke coming out your tail pipe. Drove it like that for a while till it got worse. The water was getting into one of my cylinders and not letting it even turn over. I pulled off the spark plugs and turned it over and water shot out. I could then put the plugs back in and crank it up. Soon after that I got me a manual and learned how to fix it myself. Very rewording feeling and since then have done several 4 bangers and a 3.0 v6. Don't wait to long because a head job is a lot cheaper than a new motor if a piston locks up on ya. First verify you have a leak first of course. Milky oil or white smoke that smells like antifreeze.

 

Are you by chance comparing the coolant level from hot engine to cold engine? The coolant level could be a little higher when the engine is hot.

 

When you changed your oil did you notice any coolant in it?

 

I agree but since he didn't confront the shop about it back in 2017, I would bet money they'll tell him to go pound sand if he brings it to them now, 2 years after the incident.

Gotta get that head gasket fixed OP, like @12TRDTacoma says that stop-leak stuff is a band-aid at best...and it can actually do more harm than good long term to your cooling system. I would only use that stuff if I needed it to get me home or to a shop safely. Get that head gasket fixed

 

How high did you jack it up to change the oil? Could have released an air bubble that formed when your cap blew off and coolant spilled out.

Other symptoms, missfires, may be a blown head gasket. Coolant won't always show up in the oil in any meaningful way without an oil test.