Coolant Loss, maybe Head Gasket?

[mlibanio]

Hello, everyone I have a sudden loss of coolant in both resevoirs. I have checked everywhere under the hood, and I have found no leakages whatsoever. I have checked all hoses and all is well. Recently I have been getting some inexplicably poor fuel economy, as well, I noticed on my last oil change some strange beige looking peanut butter looking stuff under my oil cap, but I think that may be related to something I do not want to even think about. At the time I did not suspect anything, but cleaned it. However does anyone out there think that this might be a head gasket issue? If it is, I am selling the car as I cannot hope to afford replacing that at Toyota, and I will not trust any backyard mechanics touching the internals of the Prius. Anyone have this issue or can offer any help. I am so worried right now. Help! Oh and in case you were wondering it is a 2002 Prius.

[statultra]

thats odd, unless you recently changed inverter coolant and engine coolant.

both of the coolant reservoirs your pointing out are separate, both have separate lines.

I have no idea what would cause this other than if you changed your fluid recently and they didnt purge the air from the system.

forgot to mention the head gasket would not effect the reservoir next to the inverter, since that coolant doesnt go through the engine.

[Patrick Wong]

Originally Posted by mlibanio

...I noticed on my last oil change some strange beige looking peanut butter looking stuff under my oil cap, but I think that may be related to something I do not want to even think about... However does anyone out there think that this might be a head gasket issue?

It appears that engine coolant is leaking into your engine's crankcase due to a faulty head gasket. An engine cylinder compression check at your Toyota dealer would confirm this.

The inverter coolant loss is a separate issue.

What is your odometer reading, and have you had any problems with engine overheating in the past?

[jayman]

The peanut-butter like stuff buildup under the oil filler cap is usually a good indicator of a coolant leak. A used oil analysis will postively confirm this

Don't wait too long before doing something about it. The coolant is just leaking right now, the gasket hasn't entirely failed - yet. You risk a lot of damage to bearings, as the glycol will ruin the oil's lubricating properties.

Once the head gasket does blow, it's a catastrophic failure. You will need a tow, at the very least. If the engine is starting to overheat, it doesn't take much for an aluminum motor to be ruined by partial overheating

[mlibanio]

Well I found out what it was. Apparently my Toyota Technician told me that the recent trip to Florida was the root cause. From what was explained, the Prius when transitioning from the very cold state of Kentucky between my next fill up at Jacksonville Florida, the temperature variation caused the computer to get crazy readings. This caused the rad fluid to pressurize and thus caused fluid to spill out while I was driving on the highway. I now remember commenting to my wife that I thought the "Stupid GMC Suburban" was reeking of burning coolant, in the end it was my car. But the kicker is when the Prius is restarted it senses the temperature variation and reacts accordingly. The tech knows this as he has a 2004 and says he drives to Florida regularly and experiences the same issue each and everytime.

Interestingly, he says that 2004 ato 2006 Prius' are prone to this happening when transitioning from Extreme Cold to Extreme Heat without stopping. 2007-2009 do not have this issue as Toyota has recalibrated the software to compensate for this, and the Prius now checks for these conditions.

Of even more interesting news, my father who is a proud owner of a 2006 Toyota Highlander Hybrid, suddenly became curious and checked his fluid level.... wouldn't you believe it... SAME PROBLEM!!! Not as low as mine, but both the inverter coolant and the Engine Coolant were both very low.

Well I hope this helps other people out there. Any thoughts?

[mlibanio]

I should mention that my father came with us to Florida as well, that is how it happened to his Highlander.

Oh and for all us Classic owners out there, I was told to use Toyota Long Life Coolant, mixed to 60% Coolant/40% Water, not 50/50. This works for both the inverter coolant and the engine coolant as they are the same. The tech did not charge me for diagnostic and only charged me for the bottle and told me that I could do it myself. Really great guy!

For you 2nd Gen Prius owners its Toyota Super Long Life Coolant. Mix is already pre-mixed for you at 50/50.

[patsparks]

I'm really sorry but the explanation above makes no sense at all.
I suspect the tech didn't want to do a head gasket today.

[Patrick Wong]

Originally Posted by patsparks

I'm really sorry but the explanation above makes no sense at all...

I agree.

1. Radiator pressure is maintained by the low-tech radiator cap, which operates under the same principle as any other car. If the radiator cap is faced with excess pressure, coolant will vent into the overflow container. Then when the engine is turned off and cools down, the resulting partial vacuum encourages coolant in the overflow container to reenter the radiator, so the "engine cold" fluid level in the overflow container should remain relatively constant.
2. This explanation does not address why your inverter coolant level was low, nor does it cover the unusual substance that you found on your oil filler cap.
3. I have a HiHy 4WD-i and have driven that vehicle to Lake Tahoe, NV each winter for the last three years, coming from southern CA where temps are moderate. Wintertime ambient low temps at Lake Tahoe are well below freezing. At no time does the radiator or inverter coolant drop down significantly below normal levels.

Perhaps your father's car was low on coolant for a long time. If his car really experienced a sudden drop, then this should be investigated.

[mlibanio]

Well assuming both of you are correct (which I am not saying you aren't!!! I don't really trust Toyota Tech's at all after my nav system experience), but if its a head gasket, then this means I will sell this car. He told me that in replacing a head gasket on a prius would cost in excess of $2200 + tax. I am not interested in forking over that kind of money. It seems that my past two Toyota's have been so unreliable its rediculous. My 1999 Corolla spent more time in the shop with a failed Engine ECU, then tranny ECU, then Right front suspension went, the wheel bearings. All of this in only 36,000 kms. Now this Prius with a potential head gasket issue is complete garbage.
I have a 2002 Chrysler Neon that I have had nothing but oil changes and gas for 7 years. Its been absolutely bullet proof. Nothing replaced... ever. My Prius has been a pain like no other. The Inverter has been replaced (covered under warranty), the O2 sensor failed, the Hyrbid ECU under the hood went too (warranty!), then the rear defroster failed, then Daytime Running Lights relay mysteriously burned out... I am getting really tired of this car. It only has 62,000 miles. My 2002 Neon same year, has 119,000 miles with no problems. I will have to watch carefully but if it is, I will never buy a Toyota ever again. Plus cost of parts is insane! I mean 120 for a head gasket... are you kidding me? 275 + tax for a new 12V battery? No way... Prius may have saved me money on fuel, but it more than sucks it back in replacement parts.

[patsparks]

Sorry to hear you haven't had a good run. Your story is in stark contrast to most who do nothing but oil changes on their Toyotas and still achieve 300,000 miles with little drama.

I wouldn't have a Toyota shop do the work, the Prius head is no different to a Yaris. Find a non Toyota dealer to do the work. Personally I'd still use genuine parts.
I've never had occasion to complain about the price of Toyota parts, having only driven Toyotas for almost 25 years I haven't bought too many.