'18 Tacoma in the shop for a week!

I've seen multiple people pull a 1GR head just fine with the engine in place; can't imagine this is that much access/size difference. Might just be a miscommunication between service and the OP. If anything, maybe they'd have to pull the engine to get to the rear on a Sienna?

 

re: service vs OP: I have found that many service writers don't have an inkling of mechanical knowledge and just convey info "as they interpret it". That is why I will wait until the job is done, or have word from the mechanic, before I press him for more detail.

I do get some comfort that no one seems to have experienced, or heard of a similar problem.

 

@AZ Pete

It's been a while. Any resolution?

 

not yet. Monday, possibly Tuesday. I did stop by Friday and was told the same story by the service writer. New head, engine has to be removed to install. He says that the timing cover must be removed to remove the head, and the engine has to be removed to get that off, due to the radiator. Seems odd to me, hopefully I can talk to the mechanic when I pick it up.

I asked what failed and why. He shrugged and said "a valve retracted into the head". He could not say why but said it must have been a manufacturing defect. All pretty vague to me, so far.

 

I feel your pain. Had the exact same issue on a 2018 Jeep that only made it 200 miles before the CEL. Valve would stick open when it got to 3500 RPM. According to the tech it was a manufacturing issue with the valve channel being slightly out of tolerance so when that valve expanded it would stick. They replaced the head also. Was down for 3 weeks but never an issue after that...well, with the engine anyway

 

Why pull the engine for a head swap on a FE powered Fairlane/Cyclone/ponycar? I used to do that all the time in the car. Get used to doing the header bolts after awhile. LOL

 

Sounds like my truck will be ready tomorrow PM. The service manager said that he has had four Tacomas in his shop with the same issue. He described it as a valve that stops seating properly. I will look at the old head when I pick up the truck, though he stated that the only visible damage is some discoloration of the valve.

 

always good to do preliminary work b4 going to shop

a cold compression check compromises nothing

easily would have identified a valve issue & which cylinder

UNnecessary work tho done under warranty can produce future liabilty

 

a valve not seating properly could need as little as a correct adjustment

adjustment done

cold compression / leak down

then proceed to head removal IF necessary

 

Picked up the truck this afternoon. Repair sheet says "replaced two exhaust valves cylinder 3, lapped valves and seats. Other than that they removed the engine twice, because they did not mate it to the torque converter the first time, recharged the A/C, replaced the engine oil, and coolant, etc. Truck runs as expected. There is a conflict between what I was told and what shows on the work sheet. I was told the head was replaced, and shown a head with the #3 cylinder with one exhaust valve still in place. I didn't stick around to see why the paperwork is different than what I was told.

The service writer said this valve leakage is becoming a frequent problem and they do not know why. They feel it is an assembly issue, not a problem with the valve train.

 

A little update on engine performance. I drove over 700 miles in the two days after picking the truck up, the first 150 on mountain, two lane roads, the balance on I-40 with a speed limit of 75 mph, which is not widely observed. The engine performs as it should.

I was initially a little concerned, because the first hundred miles was registering only 15.5 mpg. I have driven the same route many times and got closer to 19, historically. Then like magic the fuel economy improver to 22 mpg. On I-40 the truck averaged 19.6 with cruise speeds in the 75-80 mph range. I am a happy camper, if this continues.

 

OK, final clarification related to the actual repair work. I re-read the repair receipt. They did in fact replace the head. But they got a bare head assembly and two new exhaust valves that were lapped into the seats on cyl. 3. No mention of lapping in the OE valves into the other 22 seats, but maybe they were conserving paper and just didn't want to document all work.

I did another 850 miles to complete my trip and fuel economy continued to be very good. I averaged 25.5 from Globe AZ to Apache Junction for the final leg, but got over 21 mpg total for the trip.

The only issue that remains is that the coolant over flow tank slowly emptied into the engine over the 1,550 miles. Don't know if this is just because of air trapped in the block after reassembly, but have topped it off with distilled water and will know in the next few driving days. I would have used Toyota coolant, but no Toyota dealerships were open on Sunday when I discovered my need.

 

You can get coolant at auto parts store. I don’t know much about coolant, but I’d be concerned about using distilled water. Early this year our 4Runner was going through coolant, and I bought some premixed stuff at Napa. Look around the water pump, and the bottom of the radiator. Look for some crusty build up.

 

Actually distilled water is what you’re supposed to use to top off small amounts in your radiator overflow and what you’re supposed to use to cut coolant when adding it straight from the bulk jug.

 

My son's 18 Tacoma had a similar code. It is a 4 cylinder. The code was P0171, it was something like "lean in bank 1". It was a strange problem. The truck would die after backing up or after filling the tank. The dealership pulled his gas tank claiming water in the tank, charged him a fortune and continued to change parts, charging him all along and never fixed the problem. They just told him that they were sorry, they couldn't fix it. He and I narrowed it down to the valve that clears the charcoal canister. Part number 25805-0C010. We ordered it online and replaced it, problem solved. I think that they stole nearly a grand from him.

Long story short, I doubt seriously that you had a stuck valve but they will never admit it. It just seems strange that their mechanic has diagnosed several of these stuck valve issues, yet this is the first report that I have heard of this being an issue.

 

But isn’t there a certain percentage mix? Again, I don’t know much, but it was clear that I had to get the correct premixed jug when I bought some.

 

The mix is 50/50. In northern states and Canada, I think that 60/40 is normally recommended.

 

just so you know. Coolant was originally called antifreeze, then it became multifunctional, according to the manufacturers. Anyway, it came in jugs and required mixing with water. There was a chart on the gallon mug that stated the ratio to use for freeze protection to a specified temperature. Then some manufacturers started mixing their product for best performance, others still sold coolant that required mixing. Topping off with distilled water is recommended, when the correct coolant cannot be found. Today there are a number of coolants, and each manufacturer specifies which they require. In my youth all of the antifreezes were ethylene glycol. Not so today. BTW, I have been taking care of my own maintenance since 1964, so coolant is not a new term to me.

 

I remember needing to mix in the past, and You maintenance experience has 10 years on my age.
But again, if you just add distilled water, won’t you reduce the 50/50 mix?

 

OK, yes it will. Do the math: if the coolant capacity is 9.2 quarts, how much is it diluted by 1 pint of distilled water? What I avoided by using distilled water rather than some coolant that is not specifically formulated by Toyota, for this engine, is not contaminating the coolant in the engine with a product that someone else says is OK. As I said, had a dealership, on my travel route been open, I would have bought the pre mixed Toyota coolant. The dilution I created is insignificant. Keeping the radiator full is not, and there is little chance of freezing this time of year in the Upper Sonoran Desert.

My final point is this: I want to know if I am loosing coolant, rather than simply observing the elimination of any air pocket trapped in the block/coolant system during the engine removal/reinstallation process. I was happy to do nothing, but observe so long as some pink stuff was still in the over flow tank. When there no longer was, I wanted to add coolant to the tank to see if the level continued to fall, over time and miles. It appears that it is, but I want to be certain before I return to the dealer. So I will keep tabs on the level in the coolant tank for another day of driving and see.