2013 PiP, overheated, the adventure begins

We bought a 2013 Prius Plug-in from a craigslist seller in known broken condition. Previous owner disconnected a coolant hose to replace a headlight, didn't reconnect it, and ... well, the long and short of it is that the car overheated while being driven by someone else, who didn't fully understand the significance of what was going on.

He tried refilling it with coolant after it cooled down, but now there's oodles of smoke from the tailpipe. He had it towed to a dealer, which pulled the ECU snapshot data and said it hit 275F. Dealer said he'll definitely need to replace the engine, quoting a pretty ambitious price for the job, at which he sold us the car instead.

It runs, if not very well, and had enough oomph to load itself on the u-haul tow dolly. (Incidentally, that part worked fine - I'd seen discussions about that on here. Nothing scraped, either while loading it or while on the 25 mile drive from the dealer to our house.)

Car itself is very clean, appears well maintained, just had its state inspection about 200 miles before all of this happened. (Ouch!)

So we had bought it budgeting for a used engine (I've changed engines before, done timing belts, etc and have a good set of tools) but in reading PriusChat, it sounds like there's a pretty decent chance that what I actually need to do is this:

- pull the cylinder head
- check head and block for warping (guessing this is going to show a flat block and a warped head?)
- send the head for rebuild if need be
- reassemble with fresh head gasket
- clean all the junk out of the EGR system and intake manifold while I have it all apart
- and, eh, make sure that whatever the previous owner disconnected in the cooling system finds its original home again

Anything I'm missing here?

 

Thanks. At first I was going to ask why I need the other gaskets, but in looking through those links I see that you do use several others. Will I need others beyond those? The overall kit is around $150 shipped from part souq, and the head gasket was IIRC something like $80 shipped.

Leakdown test: given the clouds of white smoke in the exhaust, we already know that coolant is getting into the cylinders and being burned. Is there a realistic way for that to happen that wouldn't involve needing to take the cylinder head off? IOW I don't mind doing the test, but I don't really see what extra info I'll get from it.

Car has 104k miles on it, well worth fixing.

From reading the HG info in your signature it sounds a lot like the old timing belt jobs. Taking off the crank pulley was usually my least favorite part - I'm not a huge guy and there's never enough room to use an impact wrench. Can you use the "set the wrench strongly against something and bump the starter for a moment" technique to break it loose? And what are you using in place of the sst's it mentions?

Thanks again!

 

... And the maiden voyage was today! Praise God, it works well and I'm very happy with it.

The overheating event destroyed the head gasket (visible damage between cylinders #1 and #2) and left some material on the cylinder head. We took the head to a machine shop to have it resurfaced, but the machinist reported that 11 of the 16 valves also weren't sealing well, likely because of the overheating. We thus had the shop rebuild the cylinder head.

While the engine was apart, we also cleaned the EGR system thoroughly. It was not as badly clogged as some pictures posted here, but was certainly very due for a cleaning. If the theory that clogged EGRs lead to head gasket failure is correct, then this engine was going to need a head gasket soon, regardless.

The project taught me several things that I would like to share, since this repair seems to be a frequent topic here. As background, I'm not a professional tech, but I had dreamed of becoming one awhile back and built up a pretty good set of tools. I was surprised by how many of them, including a few obscure ones, came in handy. I also had the privilege of practicing by taking apart a Gen4 at pick-n-pull. I had wanted to buy the cylinder head on "all you can get to the counter for $40" day, but had to work that morning and ran out of time. However, I had to buy other parts that day anyhow and brought along the Prius parts I'd removed. That bag of hardware saved a few headaches, as did the parts I'd moused up on the junkyard car while learning how to take it apart. (The fuel rail does not like to be manhandled!)

But some thoughts, in no particular order, in case they might be helpful to others.

1. The thing I always tell friends starting their first project on a car: Take more pictures than you think you will need. Even keeping this in mind, I wished at several points during reassembly that I had taken far more pictures. You can often get an idea of what goes where by looking at Toyota's parts schematics (i.e., on Partsouq), but a picture of your own car is much higher-resolution and has more context. Keep in mind that especially if you need to rebuild the head, or wait for parts, that a fair bit of time may pass between disassembly and reassembly.

2. Related to #1, organize bolts you take off. When I get something that comes in a clean ziploc bag -- which is an awful lot of things -- I set it aside for projects. So I had (for example) one baggie for the right wiper's hardware, one for the left wiper's hardware, one for the wiper motor's mounts, one for the tray underneath the wiper motor ... and so on.

3. Overseas discounters take their time, and anecdotally they seem not to have the inventory they once did: orders are sometimes incomplete, and this sometimes without warning. It isn't a scam -- you only pay for what they actually send you -- but it does take up time if you have to hunt down parts you thought you'd already located.

4. Don't assume. When I took the cylinder head to the machinist, I brought the relevant gaskets from the set, since I figured a rebuild was pretty likely after the overheating. When I gave them to him, I assumed he either knew or would check which oil seals go on the intake valves and which go on the exhaust. (Toyota does not label them in the kit.) When I went to pick up the cylinder head, I checked to make sure the gray ones were on the intake and the black ones were on the exhaust. Murphy's Law strikes again: they were reversed. The machinist agreed to reimburse me for new Toyota seals and to change them out for free, but I could have saved both him and myself some heartburn by not assuming. Related to #3, I tried to save him money by ordering from an overseas discounter, but received only the intake seals. By the time I had bought the exhaust seals locally, I was most of the way to what an entire second gasket set would have cost -- which would have given me spare EGR gaskets to clean up the EGR on my buddy's Prius, and plenty of other spares besides.

5. Do order the gasket set. You will replace a large number of gaskets on this project. Off the top of my head we replaced:

- the head gasket (of course!)
- the intake manifold gasket
- the exhaust manifold gasket
- the throttle-body-to-intake gasket
- the 3 O-rings between the timing chain cover and the block and head
- the 2 seals between the cam carrier and the valve cover
- the 4 seals at the top of the spark plug tubes
- the oil seal for the crankshaft at the timing chain cover
- various EGR hardware
- the 4 fuel injector seals
- the timing chain tensioner gasket

6. The tutorials by flat-rate mechanics who do the job quickly offer some advice that I am not sure I would recommend. I can't say for sure that they are wrong, but I can say that this is a long, complicated job that I would not care to repeat very soon, and I can also say that the cost to do it Toyota's way is not very much more. For example, Toyota has a very specific way to seal the timing chain cover. It's not as simple as applying RTV around the edge, extra RTV in a few places around the edge, and smoothing it down. Toyota specifies applying FIPG (Toyota RTV) to 6 places on the block and head, also applying extra FIPG to those places around the edge of the timing chain cover, applying a bead of FIPG around the perimeter of the timing chain cover, and applying a circle of FIPG, as if it were an O-ring, to one place near the middle. Wait, we are not done sealing the timing chain cover yet! Toyota also uses a second kind of sealant, which is not plain FIPG, in one particular place -- which is the coolant passage from the block to the water pump. This second kind of sealant is called 1282b and is meant to resist SLLC (super long life coolant, "Toyota pink" -- replacing long life coolant, "Toyota red,".) A tube of 1282b cost $35 on ebay, and that was the lowest price I'd seen. But with that said, it's cheap peace of mind compared to redoing the job: the gasket set, even from the overseas discounters, is $130+ shipped.

Another example: I would not suggest using a metal razor blade, even held perpendicular to the surface, on an aluminum cylinder head or engine. Use the plastic ones.

7. We added an oil catch can while the car was apart. Once we saw how to do it, the job was relatively straightforward, but I struggled with the hose routing. I had bought a length of 3/4 hose and a length of 5/8 hose, but I struggled to fit everything into the space without having hose get closer than I liked to hot parts, or coolant lines. I also did not really like having an end of a worm-gear clamp rubbing against a coolant line. So we ended up modifying Toyota's U-shaped PCV hose, cutting it in half near the middle, using a 3/8-to-3/8 barb fitting from Home Depot, and connecting it to 3/8 fuel hose. Now the entire hose run is 3/8, and the Toyota hose points down towards the ground, making for a nice easy hose run, away from the most crowded parts of the engine compartment.

8. It is possible -- barely! -- to sneak the exhaust manifold gasket into place if you didn't start with it there. That was not easy, and I don't recommend it.

9. It is much, much easier to put the engine mount back in place if you have already jacked the engine up somewhat. I spent too long trying to force it, but only earned myself more work repairing the threads on the bolt and the unibody.

10. When reassembling the EGR system, get everything loosely mounted before tightening anything. I spent too much time loosening fasteners so that other fasteners would line up correctly.

11. Mount the fuel rail before the EGR! Otherwise you get to mount the EGR a second time. (at least I was quicker the second time!)

12. There is a tool to separate electrical connectors, like this:



It is called Merry HS175c. The price has gone up considerably since we bought ours 10+ years ago, and they now seem to go for more like $60. (I think I paid perhaps half that?) All the same, if you work on cars regularly, it might save enough headaches to be worth it. It is a brilliant idea.

Someone here had posted that he had never done significant repair jobs before, started with this one, and did it successfully. Props if you managed to pull it off, but this was a pretty challenging repair even after having done major jobs in the past. All the same, I am glad I did it -- I love my little car!