236k Mile Toyota Prius C Head Gasket Failing Sign?

When Gen 3 headgaskets fail it's usually coolant getting into the engine. And good news for you is Prius C don't have the same headgasket problems as Gen3.

What's more many people with Gen3 and a minor headgasket failure can go years before engine starts running rough.

So far you're only rough running engine issues on cold start are typical of all Prius/Atkinson engines so no worries there.

Basically keep monitoring and try to get a number for amount of coolant lost per 1000 miles and try to do your road trips at night when its not as hot out. But in general your coolant leak is so minor that you don't need to do anything until it gets worse.

The hard limit on this problem is when engine runs rough on startup consistently and rattles so much that you risk damaging the dampener in the transmisison. But again these are Gen 3 problems, not Prius C problems.

 

I think it's much more likely to be an external leak than a head gasket. Pinhole in the radiator or something.

Don't panic and don't spend big bucks yet. Even if this is a head gasket failure it's early.

 

It's hard to see in the photos but the very tiny coolant leak is indeed weeping out from the seam where headgasket is...

But more to the point, fairly certain I've never read of a Prius C headgasket failure on here? Wondering if you have?

 

Could be a leak in the radiator. I don' think your Prius C has a head gasket issue, does not looks like it. Take a look at all the coolant hoses and the radiator coolant thing [forgot the name] used to drain the coolant from the radiator and make sure is screwed all the way in.

 

Hello!
Based on the description it looks like I have the same exact problem. The same spot, driver side, where the block connects with the head. I don't notice any visible coolant level drop in the tank yet. The car is Prius C One 2014 with about 118,000 miles.

Cilbit, is it how it looks on your car (see the picture attached)?

I used a mirror to check if there is any traces of coolant above the head gasket area. But unfortunately right above the gasket line the head and all connections are clean. So the only place I can imagine it can come out of is through the head gasket.

Doesn't look like a radiator leak to me though How would coolant get so far from the radiator?

 

The fat hose connected to the 90° steel elbow is your main engine coolant line. If you're seeing a residue in that area, it's much more likely to be the result of a weep at the hose/elbow union or where the steel elbow was pressed into the aluminum casting.

 

Yeah I agree with leadfoot... Do some deep cleaning of that area and tighten up the clamp if possible and see if it comes back... I've yet to see a Prius C have legit headgasket problems, just people worried about it who've been unable to confirm.

 

Hello!

Thank you for the opinions! And I appreciate the advice as well! Following the hypothesis I've double checked the areas you've mentioned today again.

I've put a small mirror on the transmission and took a few pictures of the radiator hose elbow from under near. Please see the pictures below. I've also inspected what I believe are a heater hose elbow and a temperature sensor the same way. I cannot find pink crystals in those areas.

Am I wrong assuming that if it was an elbow/hose connection, pink crust would be found on the bottom of the elbow itself and below the elbow? And if it was elbow/head connection, the crust would reside on the head itself between the elbow and the head gasket area?

I'd appreciate any hints on how to localize the problem! Thank you in advance!

 

I think those are both fair intuitions, but neither would be conclusive. Sometimes a coolant leak is in the vapor state, and where you find the crust is just the first thing in its escape path cool enough to condense the steam.

What's the coolant loss rate? Have you found any wet leaks or just dry crusts? Have you looked at the exhaust heat recovery underneath?

 

Thank you for the hints! Here are the answers to the questions below.

I've noticed this crust not so long ago. So I don't know yet what the loss rate is. Level is still near MAX. And today is the day 3 since I've noticed the crust formation.

It is crust what I see. If there is any coolant in liquid form I'm not 100% sure. I don't see or feel any with my finger tips. Even if there is any liquid squeezed out shouldn't it quickly dry out on the surface of the hot engine?

I've checked the exhaust heat recovery and the two hoses under the car. Just in case I also have checked the exhaust pipe end (might it be an internal leak). I was unable to find any coolant signs in those areas. Honestly, I must confess, I'm not sure I understand how exhaust heat recovery can make pink crust to form on the driver's side of the engine. Would you please provide some details?

I'll double check it. But I'm almost certain I didn't hear any hissing sounds under the hood. I'm not sure though if there should be any.

Thank you again for the advices!

 

The coolant loss rate is the most important thing.

A pink crust can form with the loss of just a few ml of coolant. It really doesn't take a lot.

So establishing the loss rate is a very important factor in deciding if you've got a gasket leak. You can use a grease pencil to put a witness mark on the reservoir and check it a week or month later to see if it has dropped. (other markers work too, don't feel constrained)

I asked about the exhaust heat recovery because it is the weirdest part of the Prius coolant plumbing. Poorly understood, out of view and often forgotten, it can also be a leak point. I don't think it could have contributed to the deposits found on your engine.

In another thread recently, somebody raised the possibility that someone had paid for a head gasket replacement yet still saw coolant loss, when it may have just been a leak at the exhaust heat exchanger the whole time.

Are you getting any other symptoms of a breached head gasket?

 

Ah, got it! Thank you! Another important thing to keep an eye on.

No. Really nothing what would indicate an internal leak; no misfires; no water in the motor oil; no smoke out of the tail pipe.

It is only the location of the crust makes me believe that it might be the gasket leaking externally instead of into a cylinder and/or into an oil channel.

 

I'd say don't worry about it. Not a significant marker of an active problem. It's not uncommon for any car to develop appearances like that, and yours has apparently had ~8 years of a head start.

If you want to be constructively paranoid about your car, clean the battery cooling fan and attached ductwork, and set a reminder in your phone to repeat that at least annually.

Get a good sunshade for parking. Consider tinting the windows if they aren't already. The MPG in the c is very sensitive to air conditioner usage, and a good tint job can cut the heat load paid once instead of every fill-up.

 

Hello!

I've measured the loss rate. A week ago I've topped the coolant level to exactly the max mark. Today (1 week/60 miles/8 trips later) it is ~1 inch below max level. I'll re-check again in a week to see if it is consistent.

Is 1 inch per 60 miles a considerable rate?

Thank you!

 

Assuming you made both measurements cold like first thing in the morning, then that's a significant loss rate. Are you finding any drips in your parking spaces? Deposits on the back of the car or under?

 

Hello!

No, unfortunately I don't see any other traces of coolant like you've mentioned.

 

At this point I'd suggest taking it to a pro (not necessarily a Toyota dealer) and asking them to diagnose the coolant loss.

I'm a bit suspicious of the hose/pipe union next to the head. Not saying it couldn't be a head gasket failure, but those are just darn rare in the 1NZ-FXE engine. Besides, you'd want it to be a hose. Much cheaper.

 

The original author of this thread, Cilbit; their pictures look almost identical to what I observe on my car. I'd be very interested to know the progress with the issue.

Yes, a hose would be quick to replace.

Head gasket would be at least 3 full days. And I already imagine lots of wrestling with the harmonic balancer bolt...