2017 head gasket issues - need advice

certainly worth calling them and asking for goodwill warranty help.

how many miles on her? very unusual for a gen4 to blow the head gasket.

i would try another dealer, there are tests that can be done to determine if it is the head gasket or not, sounds like they don't have a clue.

did you ever have it checked for the exhaust leak?

 

Might be, but might also be coolant leak in exhaust heat recovery system. That is common with 4th gen; head gasket is not.

 

It’s not clear to me why they’d do that: the cylinder head gasket, part number 11115-37071 (formerly 11115-37070) is a non-reusable part, and if it’s removed for any reason, you just throw it away and install a new one, list price $66.72.

If they remove the cylinder head, to get to the gasket, they should inspect the head for warpage and cracks and inspect the cylinder block for warpage. Those are tasks any mechanic should be able to do using a precision straightedge, feeler gauge, and dye penetrant, as the Repair Manual (more info) instructs; it’s hardly work that requires specialized equipment or a machine shop.

That would account for the missing coolant, but not for finding it in one of the cylinders. As @bisco suggests, has anyone done a compression test?

 

I expect the $800 is for machining the cylinder head not the head gasket. Some shops automatically do this with any head gasket repair. If you are going to tear that far into the engine you might as well make dang positive you won't have any head gasket problems in the future.

But again, make DANG sure the problem is the head gasket and not the heat exchanger. I had a shop diagnose a blown head gasket on my 2016 and it turned out to be the heat exchanger which was a DIY $10 repair by me to bypass it. Car has run perfectly since then. Here's the thread on my car: 4th Gen DIY heat exchanger bypass solution | PriusChat

 

First thing to do is to ask them for a written quote on what they recommend. Pretty sure there was miscommunication between you and the service adviser. Often the adviser has never been a mechanic and is just trying to tell you what his mechanic told him.

To be clear, no one will remove a cylinder head to check anything for $800. It is a $2,000 - $3,500 job to take it apart and put it back together again. They have to change the gasket if they tear it down that far. Timing chain and many accessories are removed and carefully reinstalled. Be sure what is being suggested.

 

^ This, this, and this…

 

Had I not intervened they would have torn apart the engine and given me an unnecessary $4,000 head gasket replacement that would not have fixed the problem. The only thing that worked in my favor was that their Prius guy was behind on the work schedule and didn't get the parts ordered on time so I caught the issue while the car was still sitting in their lot and not completely torn apart.

 

I expect the $800 was just to resurface the cylinder head by an outside machine shop. That sounds about like what an outside machine shop would charge for that job. All the other parts and labor by the shop doing the repair work would be on top of that obviously and will likely exceed $4000 all in. Tearing down a head on a modern car is an enormous task.

 

Check the heat exchanger as others have said. Very easy to bypass to test to see if the coolant usage goes away. If you were not able to do it I don’t see any shop charging anymore than an hour and five to $10 for the part. Really only takes a few minutes to do.

 

It is my understanding that the EGR and heat exchanger are different systems. So if they tested the EGR and it passed that’s great but they did not test the heat exchanger.. The way I would test the heat exchanger would be to bypass it and see if the coolant loss still occurs.

 

^^^ This! ^^^^^ Seems premature for headgasket at 100k

 

Losing coolant is not normal and you can go five years without ever adding more. So take it seriously if its more than a small amount of expansion and contraction. Half a cup a week is too much. Cold level should equal cold level. It only takes one overheat and an extra mile of driving to cause engine problems.

One thing you find out is all of the guys at a dealer are not the sharpest knives in the drawer when it comes to things they have not seen before. Including the service advisers. Often the sharpest end up in their own shop which may be small but either specializes in Toyota, hybrids or perhaps is just a clean well organized operation. It's not always great to tell a shop your diagnosis other than suggesting "I don't know but an internet guy thinks.." Being in Washington State, you should be able to find the right shop.

 

my Toyota dealership tried to tell me i had a bad head gasket in my 2016. i took it to a private shop for a second opinion and they immediately figured out that the head gasket was fine, my leak was at the exhaust heat exchanger (just like every other Gen 4 apparently). don't trust the dealership diagnosis.

 

call toyota corporate

 

Find a more competent dealer or independent shop that specializes in hybrids.

 

I think I can diagnose the problem for you. You were going to get rolled for thousands. My charge to you is peace of mind. Kindly tell them they will never see you again.

 

Oh my!! They really are clueless, aren't they! The EGR system has nothing to do with the heat exchange system back at the catalytic converter that's causing problems for you and other Gen 4 owners.